MAX6379XR33-T中文资料 - 360文档中心

MAX6379XR34-T中文资料

General DescriptionThe MAX6375–MAX6380 are ultra-low-power circuits used for monitoring battery, power-supply, and regulat-ed system voltages. Each detector contains a precision bandgap reference, comparator, and internally trimmed resistors that set specified trip threshold voltages.These devices provide excellent circuit reliability and low cost by eliminating external components and adjustments when monitoring nominal system voltages from 2.5V to 5V.These circuits perform a single function: they assert an output signal whenever the V CC supply voltage falls below a preset threshold. The devices are differentiated by their output logic configurations and preset thresh-old voltages. The MAX6375/MAX6378 (push-pull) and MAX6377/MAX6380 (open-drain) have an active-low output (OUT is logic low when V CC is below V TH ). The MAX6376/MAX6379 have an active-high push-pull out-put (OUT is logic high when V CC is below V TH ). All parts are guaranteed to be in the correct output logic state for V CC down to 1V. The detector is designed to ignore fast transients on V CC . The MAX6375/MAX6376/MAX6377 have voltage thresholds between 2.20V and 3.08V in approximately 100mV increments. The MAX6378/MAX6379/MAX6380 have voltage thresholds between 3.30V and 4.63V in approximately 100mV increments.Ultra-low supply current of 500nA (MAX6375/MAX6376/MAX6377) makes these parts ideal for use in portable equipment. All six devices are available in a space-sav-ing SC70 package or in a tiny SOT23 package.ApplicationsPrecision Battery Monitoring Load Switching/Power SequencingPower-Supply Monitoring in Digital/Analog Systems Portable/Battery-Powered EquipmentFeatureso Ultra-Low 500nA Supply Current (MAX6375/MAX6376/MAX6377)o Thresholds Available from 2.20V to 4.63V in Approximately 100mV Incrementso ±2.5% Threshold Accuracy Over Temperature o Low Costo Available in Three Versions: Push-Pull OUT ,Push-Pull OUT, and Open-Drain OUT o Power-Supply Transient Immunity o No External Components o Available in Either a 3-Pin SC70 or 3-Pin SOT23 PackageMAX6375–MAX63803-Pin, Ultra-Low-Power SC70/SOT23Voltage Detectors________________________________________________________________Maxim Integrated Products 1Pin Configuration19-1721; Rev 2; 2/03*The MAX6375/MAX6376/MAX6377 are available in factory-pre-set thresholds from 2.20V to 3.08V, in approximately 0.1V incre-ments. The MAX6378/MAX6379/MAX6380 are available infactory-preset thresholds from 3.30V to 4.63V, in approximately 0.1V increments. Choose the desired threshold suffix fromTable 1 and insert it in the blank spaces following R.There are 21 standard versions, with a required order increment of 2500pieces. Sample stock is generally held on the standard versions only (see the Selector Guide). The required order increment is 10,000 pieces for nonstandard versions (Table 2). Contact facto-ry for availability. All devices available in tape-and-reel only.Selector Guide appears at end of data sheet.For pricing, delivery, and ordering information,please contact Maxim/Dallas Direct!at 1-888-629-4642, or visit Maxim’s website at .Ordering information continued at end of data sheetM A X 6375–M A X 63803-Pin, Ultra-Low-Power SC70/SOT23Voltage Detectors 2_______________________________________________________________________________________ABSOLUTE MAXIMUM RATINGSELECTRICAL CHARACTERISTICS(V CC = full range, T A = -40°C to +85°C, unless otherwise noted. Typical values are at T A = +25°C and V CC = 3V.) (Note 1)Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.Terminal Voltage (with respect to GND)V CC ...........................................................................-0.3V to +6V OUT, OUT (push-pull)................................-0.3V to (V CC + 0.3V)OUT (open-drain).....................................................-0.3V to +6V Input Current (V CC ).............................................................20mA Output Current (OUT, OUT )................................................20mAContinuous Power Dissipation (T A = +70°C)3-Pin SC70 (derate 2.17mW/°C above +70°C)...........174mW 3-Pin SOT23 (derate 4mW/°C above +70°C)..............320mW Operating Temperature Range ...........................-40°C to +85°C Storage Temperature Range.............................-65°C to +150°C Junction Temperature......................................................+150°C Lead Temperature (soldering, 10s).................................+300°CNote 1:Production tested at +25°C only. Overtemperature limits are guaranteed by design, not production tested.MAX6375–MAX63803-Pin, Ultra-Low-Power SC70/SOT23Voltage Detectors__________________________________________Typical Operating Characteristics(V CC = 5V, T A = +25°C, unless otherwise noted.)00.30.20.10.40.50.60.70.80.91.0-40-2020406080SUPPLY CURRENT vs. TEMPERATURETEMPERATURE (°C)S U P P L Y C U R R E N T (µA )050100150200-40-2020406080PROPAGATION DELAY (FALLING)vs. TEMPERATURETEMPERATURE (°C)P R O P A G A T I O N D E L A Y (µs )040208060120100140-4020-20406080PROPAGATION DELAY (RISING)vs. TEMPERATURETEMPERATURE (°C)P R O P A G A T I O N D E L A Y (µs )50011001000MAXIMUM TRANSIENT DURATION vs. THRESHOLD OVERDRIVE100300400200THRESHOLD OVERDRIVEV TH - V CC (mV)M A X I M U M T R A N S I E N T D U R A T I O N (µs )10Pin DescriptionM A X 6375–M A X 63803-Pin, Ultra-Low-Power SC70/SOT23Voltage Detectors____________Applications InformationInterfacing to Different Logic Voltage ComponentsThe MAX6377/MAX6380 have an active-low, open-drain output. This output structure sinks current when OUT is asserted. Connect a pullup resistor from OUT to any supply voltage up to 5.50V (Figure 1). Select a resistor value large enough to allow a valid logic low (see Electrical Characteristics ), and small enough to register a logic high while supplying all input current and leakage paths connected to the OUT line.Negative-Going V CC TransientsThese devices are relatively immune to short-duration,negative-going V CC transients (glitches). The Typical Operating Characteristics show the Maximum Transient Duration vs. Threshold Overdrive graph, for which out-put pulses are not generated. The graph shows the maximum pulse width that a negative-going V CC tran-sient may typically have before the devices issue out-put signals. As the amplitude of the transient increases,the maximum-allowable pulse width decreases.Figure 1. Interfacing to Different Logic Voltage ComponentsTable 1. Factory-Trimmed Reset Thresholds ‡3-Pin, Ultra-Low-Power SC70/SOT23Voltage Detectors_______________________________________________________________________________________5Table 2. Device Marking Codes and Minimum Order IncrementsMAX6375–MAX6380M A X 6375–M A X 63803-Pin, Ultra-Low-Power SC70/SOT23Voltage Detectors 6___________________Chip InformationTRANSISTOR COUNT: 419Selector Guide**S ample stock is generally held on all standard versions.Contact factory for availability of nonstandard versions.Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600_____________________7©2003 Maxim Integrated ProductsPrinted USAis a registered trademark of Maxim Integrated Products.3-Pin, Ultra-Low-Power SC70/SOT23Voltage DetectorsMAX6375–MAX6380Package Information(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,go to /packages .)。

MAX1722EZK-T中文资料

GND 2
MAX1722
FB 3
4
OUT
THIN SOT23-5
Pin Configurations are continued at end of data sheet.
________________________________________________________________ Maxim Integrated Products
元器件交易网
19-1735; Rev 0; 7/01
1.5µA IQ, Step-Up DC-DC Converters in Thin SOT23-5
General Description
The MAX1722/MAX1723/MAX1724 compact, high-efficiency, step-up DC-DC converters are available in tiny, 5pin thin SOT23 packages. They feature an extremely low 1.5µA quiescent supply current to ensure the highest possible light-load efficiency. Optimized for operation from one to two alkaline or nickel-metal-hydride (NiMH) cells, or a single Li+ cell, these devices are ideal for applications where extremely low quiescent current and ultra-small size are critical. Built-in synchronous rectification significantly improves efficiency and reduces size and cost by eliminating the need for an external Schottky diode. All three devices feature a 0.5Ω N-channel power switch. The MAX1722/ MAX1724 also feature proprietary noise-reduction circuitry, which suppresses electromagnetic interference (EMI) caused by the inductor in many step-up applications. The family offers different combinations of fixed or adjustable outputs, shutdown, and EMI reduction (see Selector Guide). o o o o o o o o o o o

AD637JQ中文资料

元器件交易网
AD637–SPECIFICATIONS (@ +25؇C, and ؎15 V dc unless otherwise noted)
Model TRANSFER FUNCTION CONVERSION ACCURACY Total Error, Internal Trim1 (Fig. 2) T MIN to TMAX vs. Supply, + VIN = +300 mV vs. Supply, – VIN = –300 mV DC Reversal Error at 2 V Nonlinearity 2 V Full Scale2 Nonlinearity 7 V Full Scale Total Error, External Trim ERROR VS. CREST FACTOR3 Crest Factor 1 to 2 Crest Factor = 3 Crest Factor = 10 AVERAGING TIME CONSTANT INPUT CHARACTERISTICS Signal Range, ± 15 V Supply Continuous RMS Level Peak Transient Input Signal Range, ± 5 V Supply Continuous rms Level Peak Transient Input Maximum Continuous Nondestructive Input Level (All Supply Voltages) Input Resistance Input Offset Voltage Min AD637J/A Typ
The AD637 is available in two accuracy grades (J, K) for commercial (0° C to +70°C) temperature range applications; two accuracy grades (A, B) for industrial (–40°C to +85°C) applications; and one (S) rated over the –55°C to +125°C temperature range. All versions are available in hermetically-sealed, 14-lead side-brazed ceramic DIPs as well as low cost cerdip packages. A 16-lead SOIC package is also available.

RT-XX0909中文资料

August 2002
EC 37
EC 36
August 2002

元器件交易网
ECONOLINE - DC/DC-Converter
RT Series, 1 Watt, DIP14, Isolated Outputs (Dual Output) Package Style and Pinning (mm)
14 PIN DIP Package
3rd angle projection
1
7
Bottom View
14 11 10 9 8
Pin Connections Pin # 1 7 8 Dual –Vin NC –Vout 2 +Vout 2 –Vout 1 +Vout 1 +Vin
19.90
RT-051212 RECOM ****
Output Power (Watts) 2.0 1.5 1.0 Safe Operating Area 0.5 0 -40 0 50 100 125 150 85 Operating Temperature ˚C
100mVp-p max. 70% min. 1.000VDC min. 10 GΩ min. 20pF min./94pF max. 1 Second 100kHz typ. –40°C to +85°C (see Graph) -55°C to +125°C 2.7g
元器件交易网
ECONOLINE - DC/DC-Converter
RT Series, 1 Watt, DIP14, Isolated Outputs (Dual Output) Features
● ● ● ● ●
Twin Independent Outputs Output/Output Isolation 1kVDC Power Sharing on Outputs Input/Output Isolation 1kVDC No Heatsink Required

RT9193-33

Pin Configurations
(TOP VIEW)
VOUT
5
BP
4
2
3
EN GND VIN
1 2 3 7
6 5 4
BP NC VOUT
NC VIN NC VOUT
8 2 3 4 7 6 5
NC EN BP GND
VIN GND EN
WDFN-6L 2x2
MSOP-8
SC-70-5/SOT-23-5/TSOT-23-5
Functional Pin Description
Pin Name EN BP GND VOUT VIN Pin Function Chip Enable (Active High). Note that this pin is high impedance. There should be a pull low 100kΩ resistor connected to GND when the control signal is floating. Reference Noise Bypass. Ground . Output Voltage. Power Input Voltage.
Ordering Information
RT9193Package Type U5 : SC-70-5 B : SOT-23-5 J5 : TSOT-23-5 QW : WDFN-6L 2x2 (W-Type) F : MSOP-8
Marking Information
Operating Temperature Range P : Pb Free with Commercial Standard For marking information, contact our sales representative G : Green (Halogen Free with Commer- directly or through a Richtek distributor located in your cial Standard) area, otherwise visit our website for detail. Output Voltage 15 : 1.5V 16 : 1.6V : 49 : 4.9V 50 : 5.0V 1H : 1.85V 2H : 2.85V 4G : 4.75V

MAX793T中文资料

o Guaranteed Reset Assertion to VCC = 1V o Backup-Battery Power Switching—Battery
Voltage Can Exceed VCC o On-Board Gating of Chip-Enable Signals—7ns
Max Propagation Delay
元器件交易网
19-0366; Rev 1; 1/96
MAX793/MAX794/MAX795
3.0V/3.3V Adjustable Microprocessor Supervisory Circuits
_______________General Description
MAX793
WDO
CE IN
MR
WDI
PFO
LOWLINE
ADDRESS DECODER
VCC
VCC A0-A15
I/O NMI
µP
PFI
RESET
BATT OK
GND
RESET
________________________________________________________________ Maxim Integrated Products 1
Output Current VOUT................................................................................200mA All Other Outputs ..............................................................20mA
Pin Configurations appear at end of data sheet.

TOREX XC6371 XC6372 XC6373Series 说明书

XC6371/XC6372/XC6373 SeriesPWM Controlled Step - Up DC/DC Contorollers/Convereters■GENERAL DESCRIPTIONThe XC6371/6372/6373 series are a group of PWM controlled and PWM/PFM controlled step-up DC/DC converters. The built-in 1.4Ω switching transistor type enables a step-up circuit to be configured using only three components, a coil, a diode, and a capacitor. Output voltage can be selectable in the range from 2.0V to 7.0V in increments of 100mV (accuracy:±2.5%). Oscillation frequency is also selectable from 50kHz, 100kHz, and 180kHz (accuracy:±15%) for the XC6371 and the XC6372 series. Soft-start time is internally set and offers protection against in-rush currents when the power is switched on and prevents voltage overshoot. 5 pin packages, which are provided with either a CE (chip enable) function that reduces power consumption during shut-down mode, or a V DD pin (separated power and voltage detect pins) are available.The XC6371 series is the standard PWM controlled products. The control of the XC6372 series switches from PWM to PFM control during light loads when automatically switching is selected and the series is highly efficient from light loads to large output currents. Since the XC6373 series is a low noise, it is suitable for a wireless circuit. Also the series is particularly suited for use with pager applications because oscillation frequency is set at 30kHz (±20%) so as to attain the lowest consumption current possible.■APPLICATIONS●Cellular phones, Pagers ●Palmtops●Cameras, Video recorders ●Portable products■TYPICAL APPLICATION CIRCUIT■TYPICAL PERFORMANCECHARACTERISTICS■FEATURESOperation Start Voltage Range : 0.9V~10V Output Voltage Range : 2.0V~7.0V in 100mV increments Highly Accurate : Setting voltage accuracy ±2.5%Oscillation Frequency :50kHz, 100kHz, 180kHz (±15%) selectable (XC6371/72) 30kHz (XC6373) Maximum Output Currents (Tr. built-in):100mA(TYP.) @ V IN =3.0V, V OUT =5.0V * Highly Efficient (Tr. built-in): 85%(TYP.) @ V IN =3.0V, V OUT =5.0V * Built-in switching transistor type.Five-lead packaged units offer either chip enable or independent V OUT pin option.Phase compensation and soft start-up circuits built-in. CMOS Low Power Consumption Small Packages : SOT-89, SOT-89-5,USP-6B *: Performance depends on external components and PCB layout.☆GO-Compatible ETR0402_002PIN NUMBERSOT-89USP-6BPIN NAMEFUNCTION1 6 V SS Ground2 1 V OUT Output Voltage Monitor/IC Internal Power Supply34 Lx Switch － 2, 3,5 NC No Connection PIN NUMBERSOT-89-5USP-6BPIN NAMEFUNCTION5 6 V SS Ground 2 1 V OUT Output Voltage Monitor/IC Internal Power Supply 4 4 Lx Switch 3 3 CE Chip Enable 12, 5 NC No ConnectionPIN NUMBERSOT-89-5USP-6BPIN NAME FUNCTION5 6 V SS Ground 2 1 V DD IC Internal Power Supply 4 4 Lx Switch 3 3 V OUT Output Voltage Monitor 12, 5 NC No Connection■PIN CONFIGURATION■PIN ASSIGNMENTXC6371/72/73AXC6371/72/73CXC6371/72/73E*The dissipation pad for the USP-6B package should be solder-plated in recommended mount pattern and metal masking so as to enhance mounting strength and heat release. If the pad needs to be connected to other pins, it should be connected to the pin No.1.XC6371/XC6372/XC6373SeriesDESIGNATORDESCRIPTION SYMBOLDESCRIPTIONA : 3-pin DC/DC converter with built-in switching transistor C : Stand-by capability with built-in switching transistor①Type of DC/DC Converter E : Separated V DD and V OUT with built-in switching transistor ② ③Output VoltageInteger: e.g. V OUT =3.5V →②=3, ③=50 : 50kHz 1 : 100kHz ④ Oscillation Frequency2 : 180kHz: SOT-89 (XC6371/72 A type)P: SOT-89-5 (XC6371/72 C/D type) ⑤ PackageD : USP-6B R : Embossed tape, standard feed ⑥ Device OrientationL: Embossed tape, reverse feedDESIGNATORDESCRIPTION SYMBOLDESCRIPTIONA : 3-pin DC/DC converter with built-in switching transistor C : Stand-by capability with built-in switching transistor① Type of DC/DC Converter E : Separated V DD and V OUT with built-in switching transistor ②③ Output Voltage Integer : e.g. V OUT =3.5V →②=3, ③=5 ④ Oscillation Frequency0 : 30kHz: SOT-89 (XC6373 A type) P : SOT-89-5 (XC6373 C/D type) ⑤PackageD : USP-6BR : Embossed tape, standard feed ⑥ Device OrientationL: Embossed tape, reverse feed■PRODUCT CLASSIFICATION●Selection Guide●Ordering InformationXC6371 SeriesXC6371/73A XC6371/73C XC6371/73EXC6372A XC6372C XC6372EXC6371①②③④⑤⑥ : PWM controlledXC6372①②③④⑤⑥ : PWM/PFM switching controlXC6373①②③④⑤⑥ : PWM controlledPARAMETER SYMBOL RATINGS UNITSV OUT Input Voltage V OUT 12 V L X pin Voltage V LX 12 VL X pin Current I LX 400 mACE Input VoltageV CE 12 VSOT-89, 89-5500Power DissipationUSP-6BP d 100mW V DD Input VoltageV DD 12 VOperating Temperature RangeTopr -30~＋80 ℃Storage Temperature RangeTstg -40~＋125 ℃Ta=25℃■BLOCK DIAGRAMS (p XC6371/72/73A, C(The V OUT pin serves also as V DD )XC6371/XC6372/XC6373SeriesPARAMETER SYMBOL CONDITIONS MIN. TYP. MAX.UNITSOutput Voltage V OUT 4.875 5.000 5.125VMaximum Input Voltage V IN10--V Operation Start Voltage V ST1External Components Connected, I OUT=1mA - - 0.90 VOscillation Start Voltage V ST2No external components. Apply voltage to V OUTLx : 10kΩpull-up to 5V- - 0.80 VNo Load Input Current I IN V IN=V OUT×0.8, I OUT=0mA (*1) - 12.8 25.7 μASupply Current 1 I DD1Same as V ST2,Apply output voltage×0.95 to V OUT- 80.2133.8μASupply Current 2 I DD2Same as V ST2,Apply output voltage×1.1 to V OUT- 8.2 16.5 μALx Switch-On Resistance R SWON Same as I DD1, V LX=0.4V -1.42.4ΩLx Leak Current I LXL No external components. V OUT=V LX=10V - - 1.0μA Oscillation Frequency FOSC Same as I DD1. Measuring of Lx waveform 85 100 115 kHz Maximum Duty Ratio MAXDTY Same as I DD1. Measuring of Lx waveform 80 87 92 % PFM Duty Ratio (*4) PFMDTY Same as I DD1. Measuring of Lx waveform 10 17 25 %Lx Limit Voltage V LXLMT Same as I DD1. Apply output voltage to Lx,Voltage required to produce FOSC×20.7 - 1.3 VEfficiency EFFI - 85 - % Slow-Start Time T SS 4.010.020.0mS ■ELECTRICAL CHARACTERISTICSNOTE: Unless otherwise stated, V IN=V OUT×0.6, I OUT=50mA. See Typical Application Circuits, Circuit1*1: The Schottky diode (SD) must be type MA735, with reverse current (I R)<1.0μA at reverse voltage (V R)=10.0V.(XC6372A)*2: "Supply Current 1" is the supply current while the oscillator is continuously oscillating. In actual operation the oscillator periodically operates which results in less average power consumption. The current actually provided by an external V IN source is represented by"No Load Input Current (I IN)".*3: When PWM operates at PWM Mode.*4: When PFM operates at PFM Mode.(XC6372A)XC6371/72A501PR V OUT=5.0V, FOSC=100kHZ Ta=25℃PARAMETER SYMBOL CONDITIONS MIN. TYP. MAX.UNITSOutput Voltage V OUT 4.875 5.000 5.125VMaximum Input Voltage V IN10--V Operation Start Voltage V ST1External Components Connected, I OUT=1mA - - 0.90 VOperation Start Voltage V ST2No external components. Apply voltage to V OUT,Lx : 10kΩpull-up to 5V- - 0.80 VNo Load Input Current I IN V IN=V OUT×0.8, I OUT=0mA (*1) - 12.8 25.7 μASupply Current 1 I DD1Same as V ST2,Apply output voltage×0.95 to V OUT- 80.2133.8μASupply Current 2 I DD2Same as V ST2,Apply output voltage×1.1 to V OUT- 8.2 16.5 μALx Switch-On Resistance R SWON Same as I DD1, V Lx=0.4V -1.42.4ΩLx Leak Current I LXL No external components, V OUT =V LX=10V - - 1.0μA Oscillation Frequency FOSC Same as I DD1, Measuring of Lx waveform 85 100 115 kHZMaximum Duty Ratio MAXDTY Same as I DD1, Measuring of Lx waveform 80 87 92 %PFM Duty Ratio (*4) PFMDTY Same as I DD1, Measuring of Lx waveform 10 17 25 %Stand-by Current I STB Same as I DD1 --0.5μACE "High" Voltage V CEH Same as I DD1, Lx Oscillation start 0.75 - - VCE "Low" Voltage V CEL Same as I DD1, Lx Oscillation stop - - 0.20 VCE "High" Current I CEH Same as I DD1, V CE=V OUT×0.95 - - 0.25μACE "Low" Current I CEL Same as I DD1, V CE=0V ---0.25μALx Limit Voltage V LxLMT Same as I DD1, Apply output voltage to Lx,Voltage required to produce FOSC×20.7 - 1.3 VEfficiency EFFI - 85 - % Slow-Start Time T SS 4.010.020.0ms XC6371/72C501PR V OUT=5.0V, FOSC=100kHz Ta=25℃NOTE: Unless otherwise stated, connect CE to V OUT, V IN=V OUT×0.6, I OUT=50mA. See Typical Application Circuits, Circuit 2.*1: The Schottky diode (SD) must be type MA735, with reverse current (I R)<1.0μA at reverse voltage (V R)=10.0V.(XC6372C)*2: "Supply Current 1" is the supply current while the oscillator is continuously oscillating. In actual operation the oscillator periodically operates which results in less average power consumption. The current actually provided by an external VIN source is represented by"No Load Input Current (I IN)".*3: When PWM operates at PWM Mode.*4: When PFM operates at PFM Mode.(XC6372C)■ELECTRICAL CHARACTERISTICS (Continued)XC6371/XC6372/XC6373SeriesPARAMETER SYMBOL CONDITIONS MIN. TYP. MAX.UNITSOutput Voltage V OUT 4.875 5.000 5.125VMaximum Input Voltage V IN10--V Operation Start Voltage V ST1External Components Connected, I OUT=1mA - - 0.90 VOscillation Start Voltage V ST2No external components,Apply voltage to V OUT, Lx:10kΩpull-up to 5V- - 0.80 VNo Load Input Voltage I IN V IN=V OUT×0.8, I OUT=0mA(*1) - 12.8 25.7 μASupply Current 1 I DD1Same as V ST2,Apply output voltage×0.95 to V OUT- 80.2133.8μASupply Current 2 I DD2Same as V ST2,Apply output voltage×1.1 to V OUT- 8.2 16.5 μALx Switch-On Resistance R SWON Same as I DD1, V LX=0.4V -1.42.4ΩLx Leak Current I LXL No external components, V OUT =V LX=10V - - 1.0 μA Oscillation Frequency FOSC Same as I DD1, Measuring of Lx waveform 85 100 115 kHZ Maximum Duty Ratio MAXDTY Same as I DD1, Measuring of Lx waveform 80 87 92 % PFM Duty Ratio (*4) PFMDTY Same as I DD1, Measuring of Lx waveform 10 17 25 %Lx Limit Voltage V LxLMT Same as I DD1, Apply output voltage to Lx,Voltage required to produce FOSC×20.7 - 1.3 VEfficiency EFFI - 85 - % Slow-Start Time T SS 4.010.020.0ms XC6371/72E501PR V OUT=5.0V, FOSC=100kHz Ta=25℃NOTE: Unless otherwise stated, connect V DD to V OUT, V IN=V OUT×0.6, I OUT=50mA. See Typical Application Circuits, Circuit 3.*1: The Schottky diode (SD) must be type MA2Q735, with reverse current (I R)<1.0μA at reverse voltage (V R)=10.0V.(XC6372E)*2: "Supply current 1" is the supply current while the oscillator is continuously oscillating. In actual operation the oscillator periodically operates which results in less average power consumption. The current actually provided by external V IN source is represented by "NoLoad Input Current (I IN)".*3: When PWM operates at PWM Mode.*4: When PFM operates at PFM Mode.(XC6372E)*5: When the V DD and V OUT pins are independently used, the voltage range at the V DD pin should be 2.2V to 10V. The IC operates from V DD=0.8V. However, output voltage and oscillation frequency are properly stabilized when V DD=2.2V or higher.■ELECTRICAL CHARACTERISTICS (Continued)PARAMETERSYMBOL CONDITIONS MIN. TYP . MAX.UNITS Output Voltage V OUT 2.925 3.000 3.075V Maximum Input Voltage V IN 10 - - VOperation Start Voltage V ST1 External Components Connected,I OUT =1mA- - 0.90VOscillation Start VoltageV ST2 No external components,Apply voltage to V OUT , LX :10k Ωpull-up to 5V- - 0.80VSupply Current 1 I DD1 Same as V ST2.Apply output voltage ×0.95 to V OUT- 13.1 21.9μASupply Current 2 I DD2 Same as V ST2,Apply output voltage ×1.1 to V OUT- 3.9 7.9 μALx Switch-On ResistanceR SWON Same as I DD1, V LX =0.4V - 3.4 5.7 ΩLx Leak Current I LXL No external components,V OUT =V LX =10V- - 1.0 μAOscillation Frequency FOSC Same as I DD1, Measuring of Lx waveform 24 30 36 kHZ Maximum Duty RatioMAXDTY Same as I DD1, Measuring of Lx waveform 80 87 92 % Efficiency EFFI - 77 - % Slow-Start TimeT SS 4.0 10.0 20.0mSPARAMETER SYMBOL CONDITIONS MIN. TYP . MAX.UNITS Output Voltage V OUT 3.128 3.300 3.383V Maximum Input Voltage V IN 10 - - V Operation Start Voltage V ST1 External Components Connected, I OUT =1mA - - 0.90VOscillation Start VoltageV ST2 No external components,Apply voltage to V OUT , LX :10k Ωpull-up to 5V- - 0.80VSupply Current 1 I DD1 Same as V ST2,Apply output voltage ×0.95 to V OUT- 14.1 23.5μASupply Current 2 I DD2 Same as V ST2,Apply output voltage ×1.1 to V OUT - 4.0 8.1 μALx Switch-On Resistance R SWON Same as I DD1. V LX =0.4V - 3.4 5.7 ΩLx Leak Current I LXLNo external components,V OUT =V LX =10V - - 1.0 μAOscillation Frequency FOSC Same as I DD1,Measuring of Lx waveform24 30 36 kHZMaximum Duty Ratio MAXDTY Same as I DD1,Measuring of Lx waveform80 87 92 %Efficiency EFFI - 77 - % Slow-Start TimeT SS 4.0 10.0 20.0mS■ELECTRICAL CHARACTERISTICS (Continued) XC6373A300PR V OUT =3.0V, FOSC=30kHzTa=25℃NOTE: Unless otherwise stated, V IN =V OUT ×0.6, I OUT =15mA. See Typical Application Circuits, Circuit 1. XC6373A330PRV OUT =3.3V, FOSC=30kHzTa=25℃NOTE: Unless otherwise stated, V IN =VOUT ×0.6, IOUT=16.5mA. See Typical Application Circuits, Circuit 1.XC6371/XC6372/XC6373Series■TYPICAL APPRICATION CIRCUITSCircuit 1: XC6372A seriesCircuit 3: XC6372E seriesCircuit 2: XC6372C seriesL : 100μH (CR54, SUMIDA)L : 100H (CR54, SUMIDA) L : 100μH (CR54, SUMIDA)L : 100μH (CR54, SUMIDA)SD : MA2Q735 (Schottky Diode; MATUSHITA)C L : 16V47μF (Tantalum Capacitor, NICHICHEMI MCE)SD : MA2Q735 (Schottky Diode; MATUSHITA)C L : 16V 47μF (Tantalum Capacitor, NICHICHEMI MCE)SD : MA2Q735 (Schottky Diode; MATUSHITA)C L : 16V 47μF (Tantalum Capacitor; NICHICHEMI MCE)■TYPICAL PERFORMANCE CHARACTERISTICS(1) Output Voltage vs. Output Current 0.11101001000L ＝100μH （CR54），C L ＝47μF（Tantalum ）Output Current:I OUT （mA ）XC6371A301P R3.103.053.002.952.90O u t p u t V o l t a g e :V O U T （V ）4.84.95.05.15.20.11101001000XC6372A501PRO u t p u t V o l t a g e :V O U T （V ）Output Current:I OUT (mA)2.902.953.003.053.100.11101001000XC6372A301PRO u t p u t V o l t a g e :V O U T （V ）Output Current:I OUT (mA)2.902.953.003.053.10XC6373A300PROutput Current: I OUT (mA)O u t p u t V o l t a g e : V O U T (V )0.11101001000L ＝100μH (CR54),C L ＝47μF (Tantalum )Output Current:I OUT （mA ）XC6371A501PR5.25.15.04.94.8O u t p u t V o l t a g e :V O U T （V ）1000(2) Efficiency vs. Output Current ■TYPICAL PERFORMANCE CHARACTERISTICS (Continued)204060801000.11101001000XC6373A300PROutput Current: I OUT (mA)E f f i c i e n c y : EF F I (%)0.11101001000L ＝100μH (CR54),C L ＝47μF (Tantalum )Output Current:I OUT （mA ）XC6371A301PR100806040200E f f i c i e n c y :EF F I (%)0.11101001000L Output Current:I OUT （mA ）XC6371A501PR100806040200E f f i c i e n c y :EF F I (%)1000 1000 1000(3) Ripple Voltage vs. Output Current■TYPICAL PERFORMANCE CHARACTERISTICS (Continued)204060801000.11101001000XC6373A300PROutput Current:I OUT (mA)R i p p l e V o l t a g e : V r (m V p -p )0204060800.11101001000XC6371A301PRR i p p l e V o l t a g e :V r （m V p -p ）Output Current:I OUT (mA)1000 1000 10(4) No Load Input Current vs. Input Voltage ■TYPICAL PERFORMANCE CHARACTERISTICS (Continued) 01002003004005001XC6371A301PRI n p u t C u r r e n t :I I N (μA )Input Voltage:V IN (V)23050100150200012345XC6372A501PRInput Voltage:V IN (V)I n p u t C u r r e n t :I I N (μA )(5) Operation Start Voltage / Hold Voltage vs. Output Current (6) Load Transient Response■TYPICAL PERFORMANCE CHARACTERISTICS (Continued)■PACKAGING INFORMATION ●SOT-89●SOT-89-5●USP-6BOSCILLATION FREQUENCYOUTPUT VOLTAGE (V)50kHz 100kHz 180kHz1.x B 1 12.x C 2 23.x F 3 34.x E 4 45.x F 5 56.x H 6 67.x K 7 7OSCILLATION FREQUENCYOUTPUT VOLTAGE (V)50kHz 100kHz 180kHzx.0 0 0 A x.1 1 1 B x.2 2 2 C x.3 3 3 D x.4 4 4 E x.5 5 5 F x.6 6 6 H x.7 7 7 K x.8 8 8 L x.9 9 9 M■MARKING RULE[XC6371/72] ① Represents product series② Represents integer of output voltage and oscillation frequency ③ Represents decimal number of output voltage and oscillation frequency ●SOT-89, SOT-89-5SOT-89 (TOP VIEW)④③②①123SOT-89-5(TOP VIEW)■PACKAGING INFORMATION (Continued)●USP-6B Recommended Pattern Layout●USP-6B Recommended Metal Mask DesignMARK PRODUCT SERIES5 XC6371xxxxDx2 XC6372xxxxDxMARK PRODUCT SERIESA XC6371A C XC6371CE XC6371EMARK③④OUTPUT VOLTAGE (V)3 3 3.3 5 05.0MARK OSCILLATION FREQUENCY (kHz)0 501 1002 180■MARKING RULE (Continued)●USP-6B① Represents product series② Represents product classification③④ Represents output voltage (ex.)⑤ Represents oscillation frequency⑥ Represents production lot number0 to 9, A to Z repeated (G, I, J, O, Q, W excepted) Note: No character inversion used.USP-6B (TOP VIEW)[XC6371/72] (Continued)MARK FUNCTION PRODUCT SERIESA - Built-in Transistor XC6372AxxxPx A CE Built-in Transistor XC6372CxxxPx S Separated V DD and V OUT Built-in Transistor XC6372ExxxPxOSCILLATION FREQUENCY (PRODUCT SERIES)OUTPUT VOLTAGE (V)30kHz (XC6373xxx0Px)1.x B2.x C3.x F4.x E5.x F6.x H7.x KOSCILLATION FREQUENCY (PRODUCT SERIES)OUTPUT VOLTAGE (V)30kHz (XC6373xxx0Px)x.0 0 x.1 1 x.2 2 x.3 3x.4 4 x.5 5 x.6 6 x.7 7 x.8 8 x.9 9① Represents product series② Represents integer of output voltage and oscillation frequency ③ Represents decimal number of output voltage and oscillation frequency ④ Represents production lot number0 to 9, A to Z repeated (G, I, J, O, Q, W excepted).■MARKING RULE (Continued)●SOT-89,SOT-89-5④③②①123SOT-89(TOP VIEW)SOT-89-5 (TOP VIEW)〔XC6373〕。

MAX6369-MAX6374

General DescriptionThe MAX6369–MAX6374 are pin-selectable watchdog timers that supervise microprocessor (µP) activity and signal when a system is operating improperly. During normal operation, the microprocessor should repeated-ly toggle the watchdog input (WDI) before the selected watchdog timeout period elapses to demonstrate that the system is processing code properly. If the µP does not provide a valid watchdog input transition before the timeout period expires, the supervisor asserts a watch-dog (WDO ) output to signal that the system is not exe-cuting the desired instructions within the expected time frame. The watchdog output pulse can be used to reset the µP or interrupt the system to warn of processing errors.The MAX6369–MAX6374 are flexible watchdog timer supervisors that can increase system reliability through notification of code execution errors. The family offers several pin-selectable watchdog timing options to match a wide range of system timing applications:•Watchdog startup delay: provides an initial delay before the watchdog timer is started.•Watchdog timeout period: normal operating watch-dog timeout period after the initial startup delay.•Watchdog output/timing options: open drain (100ms)or push-pull (1ms).The MAX6369–MAX6374 operate over a +2.5V to +5.5V supply range and are available in miniature 8-pin SOT23 packages.________________________ApplicationsEmbedded Control Systems Industrial ControllersCritical µP and Microcontroller (µC) Monitoring AutomotiveTelecommunications NetworkingFeatures♦Precision Watchdog Timer for Critical µP Applications ♦Pin-Selectable Watchdog Timeout Periods ♦Pin-Selectable Watchdog Startup Delay Periods ♦Ability to Change Watchdog Timing Characteristics Without Power Cycling ♦Open-Drain or Push-Pull Pulsed Active-Low Watchdog Output ♦Watchdog Timer Disable Feature ♦+2.5V to +5.5V Operating Voltage ♦8µA Low Supply Current♦No External Components Required ♦Miniature 8-Pin SOT23 PackageMAX6369–MAX6374Pin-Selectable Watchdog Timers19-1676; Rev 3; 11/05Ordering InformationPin Configuration appears at end of data sheet.Note:All devices are available in tape-and-reel only. Required order increment is 2,500 pieces.Devices are available in both leaded and lead-free packaging.Specify lead-free by replacing “-T” with “+T” when ordering.Selector GuideFor pricing, delivery, and ordering information,please contact Maxim/Dallas Direct!at1-888-629-4642, or visit Maxim’s website at .M A X 6369–M A X 6374Pin-Selectable Watchdog Timers 2_______________________________________________________________________________________ABSOLUTE MAXIMUM RATINGSELECTRICAL CHARACTERISTICS(V CC = +2.5V to +5.5V, SET_ = V CC or GND, T A = -40°C to +85°C, unless otherwise noted. Typical values are at T A = +25°C andStresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.Terminal Voltage (with respect to GND)V CC .....................................................................-0.3V to +6V WDI.....................................................................-0.3V to +6V WDO (Open Drain: MAX6369/71/73).................-0.3V to +6V WDO (Push-Pull: MAX6370/72/74 .......-0.3V to (V CC + 0.3V)SET0, SET1, SET2................................-0.3V to (V CC + 0.3V)Maximum Current, Any Pin (input/output)...........................20mAContinuous Power Dissipation (T A = +70°C)SOT23-8 (derate 8.75mW/°C above +70°C)...............700mW Operating Temperature Range ...........................-40°C to +85°C Storage Temperature Range.............................-65°C to +150°C Junction Temperature......................................................+150°C Lead Temperature (soldering, 10s).................................+300°C V CC Rise or Fall Rate......................................................0.05V/µsMAX6369–MAX6374Pin-Selectable Watchdog Timers_______________________________________________________________________________________3ELECTRICAL CHARACTERISTICS (continued)M A X 6369–M A X 6374Pin-Selectable Watchdog Timers 4_______________________________________________________________________________________461081214-4010-15356085SUPPLY CURRENT vs. TEMPERATURETEMPERATURE (°C)S U P P L Y C U R R E N T (µA )Typical Operating Characteristics(Circuit of Figure 1, T A = +25°C, unless otherwise noted .)0.9970.9990.9981.0011.0001.0021.003-4010-15356085WATCHDOG TIMEOUT PERIODvs. TEMPERATUREM A X 6369/74-02TEMPERATURE (°C)N O R M A L I Z E D W A T C H D O G T I M E O U T P E R I O DELECTRICAL CHARACTERISTICS (continued)Note 2:Guaranteed by design.Note 3:In this setting the watchdog timer is inactive and startup delay ends when WDI sees its first level transition. See SelectingDevice Timing for more information.Note 4:After power-up, or a setting change, there is an internal setup time during which WDI is ignored.MAX6369–MAX6374Pin-Selectable Watchdog Timers_______________________________________________________________________________________5Pin DescriptionDetailed DescriptionThe MAX6369–MAX6374 are flexible watchdog circuits for monitoring µP activity. During normal operation, the internal timer is cleared each time the µP toggles the WDI with a valid logic transition (low to high or high to low) within the selected timeout period (t WD ). The WDO remains high as long as the input is strobed within the selected timeout period. If the input is not strobed before the timeout period expires, the watchdog output is asserted low for the watchdog output pulse width (t WDO ). The device type and the state of the three logic control pins (SET0, SET1, and SET2) determine watch-dog timing characteristics. The three basic timing varia-tions for the watchdog startup delay and the normalTable 1 for the timeout characteristics for all devices in the family):•Watchdog Startup Delay:Provides an initial delay before the watchdog timer is started.Allows time for the µP system to power up and initial-ize before assuming responsibility for normal watch-dog timer updates.Includes several fixed or pin-selectable startup delay options from 200µs to 60s, and an option to wait for the first watchdog input transition before starting the watchdog timer.M A X 6369–M A X 6374Pin-Selectable Watchdog Timers 6_______________________________________________________________________________________•Watchdog Timeout Period:Normal operating watchdog timeout period after the initial startup delay.A watchdog output pulse is asserted if a valid watch-dog input transition is not received before the timeout period elapses.Eight pin-selectable timeout period options for each device, from 30µs to 60s.Pin-selectable watchdog timer disable feature.•Watchdog Output/Timing Options:Open drain, active low with 100ms minimum watch-dog output pulse (MAX6369/MAX6371/MAX6373).Push-pull, active low with 1ms minimum watchdog output pulse (MAX6370/MAX6372/MAX6374).Each device has a watchdog startup delay that is initi-ated when the supervisor is first powered or after the user modifies any of the logic control set inputs. The watchdog timer does not begin to count down until theFigure 1. Functional Diagramcompletion of the startup delay period, and no watch-dog output pulses are asserted during the startup delay. When the startup delay expires, the watchdog begins counting its normal watchdog timeout period and waiting for WDI transitions. The startup delay allows time for the µP system to power up and fully ini-tialize before assuming responsibility for the normal watchdog timer updates. Startup delay periods vary between the different devices and may be altered by the logic control set pins. To ensure that the system generates no undesired watchdog outputs, the routine watchdog input transitions should begin before the selected minimum startup delay period has expired. The normal watchdog timeout period countdown is initi-ated when the startup delay is complete. If a valid logic transition is not recognized at WDI before the watchdog timeout period has expired, the supervisor asserts a watchdog output. Watchdog timeout periods vary between the different devices and may be altered by the logic control set pins. To ensure that the system generates no undesired watchdog outputs, the watch-dog input transitions should occur before the selected minimum watchdog timeout period has expired.The startup delay and the watchdog timeout period are determined by the states of the SET0, SET1, and SET2 pins, and by the particular device within the family. For the MAX6369 and MAX6370, the startup delay is equal to the watchdog timeout period. The startup and watchdog timeout periods are pin selectable from 1ms to 60s (minimum).For the MAX6371 and MAX6372, the startup delay is fixed at 60s and the watchdog timeout period is pin selectable from 1ms to 60s (minimum).The MAX6373/MAX6374 provide two timing variations for the startup delay and normal watchdog timeout. Five of the pin-selectable modes provide startup delays from 200µs to 60s minimum, and watchdog timeout delays from 3ms to 10s minimum. Two of the selectable modes do not initiate the watchdog timer until the device receives its first valid watchdog input transition (there is no fixed period by which the first input must be received). These two extended startup delay modesare useful for applications requiring more than 60s for system initialization.All the MAX6369–MAX6374 devices may be disabledwith the proper logic control pin setting (Table 1).Applications InformationInput Signal Considerations Watchdog timing is measured from the last WDI risingor falling edge associated with a pulse of at least 100nsin width. WDI transitions are ignored when WDO is asserted, and during the startup delay period (Figure2). Watchdog input transitions are also ignored for asetup period, t SETUP, of up to 300µs after power-up ora setting change (Figure 3).Selecting Device TimingSET2, SET1, and SET0 program the startup delay and watchdog timeout periods (Table 1). Timeout settingscan be hard wired, or they can be controlled with logicgates and modified during operation. To ensure smooth transitions, the system should strobe WDI immediately before the timing settings are changed. This minimizesthe risk of initializing a setting change too late in thetimer countdown period and generating undesired watchdog outputs. After changing the timing settings,two outcomes are possible based on WDO. If the change is made while WDO is asserted, the previous setting is allowed to finish, the characteristics of thenew setting are assumed, and the new startup phase is entered after a 300µs setup time (t SETUP) elapses. Ifthe change is made while WDO is not asserted, thenew setting is initiated immediately, and the new start-up phase is entered after the 300µs setup time elapses.MAX6369–MAX6374Pin-Selectable Watchdog Timers_______________________________________________________________________________________7 Figure 3. Setting Change TimingM A X 6369–M A X 6374Pin-Selectable Watchdog TimersSelecting 011 (SET2 = 0, SET1 = 1, SET0 = 1) disables the watchdog timer function on all devices in the family.Operation can be reenabled without powering down by changing the set inputs to the new desired setting. The device assumes the new selected timing characteris-tics and enter the startup phase after the 300µs setup time elapses (Figure 3).The MAX6373/MAX6374 offer a first-edge feature. In first-edge mode (settings 101 or 110, Table 1), the internal timer does not control the startup delay period.Instead, startup terminates when WDI sees a transition.If changing to first-edge mode while the device is oper-ating, disable mode must be entered first. It is then safe to select first-edge mode. Entering disable mode first ensures the output is unasserted when selecting first-edge mode and removes the danger of WDI being masked out.OutputThe MAX6369/MAX6371/MAX6373 have an active-low,open-drain output that provides a watchdog output pulse of 100ms. This output structure sinks current when WDO is asserted. Connect a pullup resistor from WDO to any supply voltage up to +5.5V.Select a resistor value large enough to register a logic low (see Ele ctrical Characte ristics ), and small enoughto register a logic high while supplying all input current and leakage paths connected to the WDO line. A 10k Ωpullup is sufficient in most applications. The MAX6370/MAX6372/MAX6374 have push-pull outputs that pro-vide an active-low watchdog output pulse of 1ms.When WDO deasserts, timing begins again at the beginning of the watchdog timeout period (Figure 2).Usage in Noisy EnvironmentsIf using the watchdog timer in an electrically noisy envi-ronment, a bypass capacitor of 0.1µF should be con-nected between V CC and GND as close to the device as possible, and no further away than 0.2 inches.________________Watchdog SoftwareConsiderationsTo help the watchdog timer monitor software execution more closely, set and reset the watchdog input at differ-ent points in the program, rather than pulsing the watch-dog input high-low-high or low-high-low. This technique avoids a stuck loop, in which the watchdog timer would continue to be reset inside the loop, keeping the watch-dog from timing out. Figure 4 shows an example of a flow diagram where the I/O driving the watchdog input is set high at the beginning of the program, set low at the end of every subroutine or loop, then set high again when the program returns to the beginning. If the pro-gram should hang in any subroutine, the problem would be quickly corrected, since the I/O is continually set low and the watchdog timer is allowed to time out, causing WDO to pulse.Figure 4. Watchdog Flow DiagramChip InformationTRANSISTOR COUNT: 1500PROCESS: BiCMOSPin ConfigurationMaxim cannot assume re sponsibility for use of any circuitry othe r than circuitry e ntire ly e mbodie d in a Maxim product. No circuit pate nt lice nse s are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.8_____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600©2005 Maxim Integrated ProductsPrinted USAis a registered trademark of Maxim Integrated Products, Inc.。

MAX6309UK44D3-T中文资料

General DescriptionThe MAX6305–MAX6313 CMOS microprocessor (µP)supervisory circuits are designed to monitor more than one power supply. Ideal for monitoring both 5V and 3.3V in personal computer systems, these devices assert a system reset if any of the monitored supplies falls outside the programmed threshold. Low supply current (15µA) and a small package suit them for portable applications. The MAX6305–MAX6313 are specifically designed to ignore fast transients on any monitored supply.These devices are available in a SOT23-5 package,have factory-programmed reset thresholds from 2.5V to 5.0V (in 100mV increments), and feature four power-on reset timeout periods. Ten standard versions are avail-able. Contact the factory for availability of non standard versions.ApplicationsPortable Computers Computers ControllersIntelligent InstrumentsPortable/Battery-Powered Equipment Multivoltage Systems: 3V/5V, 5V/12V, 5V/24V Embedded Control SystemsFeatureso Small 5-Pin SOT23 Packageo Precision Factory-Set V CC Reset Thresholds;Available in 0.1V Increments from 2.5V to 5V o Immune to Short V CC Transientso Guaranteed RESET Valid to V CC = 1V o Guaranteed Over Temperature o 8µA Supply Currento Factory-Set Reset Timeout Delay from 1ms (min) to 1120ms (min)o No External Components o Manual Reset Inputo Under/Overvoltage Supply MonitoringMAX6305–MAX63135-Pin, Multiple-Input,Programmable Reset ICs________________________________________________________________Maxim Integrated Products119-1145; Rev 5; 4/08†The MAX6306/MAX6307/MAX6309/MAX6310/MAX6312/MAX6313 are available with factory-set V CC reset thresholds from 2.5V to 5V, in 0.1V increments. Insert the desired nominal reset threshold (from Table 1) into the blanks following the letters UK.All parts also offer factory-programmed reset timeout periods.Insert the number corresponding to the desired nominal timeout period index following the “D” in the part number (D1 = 1ms min,D2 = 20ms min, D3 = 140ms min, and D4 = 1120ms min). There are 10 standard versions with a required order increment of 2,500pieces. Sample stock is generally held on the standard versions only (see Standard Versions table). Required order increment is 10,000 pieces for non-standard versions. Contact factory for availability of non-standard versions. All devices available in tape-and-reel only.Devices are available in both leaded and lead-free packaging.Specify lead-free by replacing “-T” with “+T” when ordering.Pin Configurations and Typical Operating Circuit appear atend of data sheet.Ordering Information continued at end of data sheet.Standard Versions Table appears at end of data sheet._______________________________________________________________Selector TableFor pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,or visit Maxim’s website at .M A X 6305–M A X 63135-Pin, Multiple-Input, Programmable Reset ICsABSOLUTE MAXIMUM RATINGSELECTRICAL CHARACTERISTICSV CC = +2.5V to +5.5V for the MAX6305/MAX6308/MAX6311, V CC = (V TH + 2.5%) to +5.5V for the MAX6306/MAX6307/MAX6309/Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.V CC ...........................................................................-0.3V to +6V All Other Pins..............................................-0.3V to (V CC + 0.3V)Input/Output Current, All Pins.............................................20mA Rate of Rise, V CC ............................................................100V/µs Continuous Power Dissipation (T A = +70°C)SOT23-5 (derate 7.1mW/°C above +70°C).................571mWOperating Temperature RangeMAX63_ _UK _ _D_-T.........................................0°C to +70°C MAX63_ _EUK _ _D_-T...................................-40°C to +85°C Storage Temperature Range.............................-65°C to +160°C Lead Temperature (soldering, 10sec).............................+300°CMAX6305–MAX63135-Pin, Multiple-Input, Programmable Reset ICs_______________________________________________________________________________________3ELECTRICAL CHARACTERISTICS (continued)V CC = +2.5V to +5.5V for the MAX6305/MAX6308/MAX6311, V CC = (V TH + 2.5%) to +5.5V for the MAX6306/MAX6307/MAX6309/Note 2: The MAX6305/MAX6308/MAX6311 switch from undervoltage reset to normal operation between 1.5V < V CC < 2.5V.Note 3: The MAX6306/MAX6307/MAX6309/MAX6310/MAX6312/MAX6313 monitor V CC through an internal factory-trimmed voltagedivider, which programs the nominal reset threshold. Factory-trimmed reset thresholds are available in approximately 100mV increments from 2.5V to 5V (Table 1).Note 4:Guaranteed by design.M A X 6305–M A X 63135-Pin, Multiple-Input, Programmable Reset ICs 4_________________________________________________________________________________________________________________________________Typical Operating Characteristics(V CC = +5V, T A = +25°C, unless otherwise noted.)5.05.56.06.57.07.58.08.59.09.5-60-40-2020406080100SUPPLY CURRENT vs. TEMPERATURETEMPERATURE (°C)S U P P L Y C U R R E N T (μA )01020304050607080-60-40-2020406080100V CC FALLING PROPAGATION DELAYvs. TEMPERATURETEMPERATURE (°C)P R O P A G A T I O N D E L A Y (n s )010203040506070-60-40-20020406080100OVRST IN RISING PROPAGATION DELAY vs. TEMPERATURE (OVERVOLTAGE RESET INPUT)TEMPERATURE (°C)P R O P A G A T I O N D E L A Y (n s )020406080100120-60-40-2020406080100RST IN_ FALLING PROPAGATION DELAY vs. TEMPERATURETEMPERATURE (°C)R S T I N _ P R O P A G A T I O N D E L A Y (n s )104001200800MAXIMUM TRANSIENT DURATION vs.VCC RESET THRESHOLD OVERDRIVE10OVERDRIVE, V TH - V CC (mV)T R A N S I E N T D U R A T I O N (μs )100100010,0000.900.920.940.960.981.001.021.041.061.081.10-60-40-20020406080100RESET TIMEOUT vs. TEMPERATURE6305 T O C 05TEMPERATURE (°C)N O R M A L I Z E D R E S E T T I M E O U T0.9900.9920.9940.9960.9981.0001.0021.0041.0061.0081.010-60-40-2020406080100RESET THRESHOLD vs. TEMPERATURE6305 T O C 06TEMPERATURE (°C)N O R M A L I Z E D R E S E T T H R E S H O L D (V /V )104001200800MAXIMUM TRANSIENT DURATION vs.OVRST IN THRESHOLD OVERDRIVE10OVERDRIVE, V OVRST IN - V REF (mV)T R A N S I E N T D U R A T I O N (μs )100100010,000104001200800MAXIMUM TRANSIENT DURATION vs.RST IN_ THRESHOLD OVERDRIVE10OVERDRIVE, V REF - V RST IN (mV)T R A N S I E N T D U R A T I O N (μs )100100010,000_______________Detailed DescriptionThe MAX6305–MAX6313 CMOS microprocessor (µP)supervisory circuits are designed to monitor more than one power supply and issue a system reset when any monitored supply falls out of regulation. The MAX6305/MAX6308/MAX6311 have two adjustable undervoltage reset inputs (RST IN1 and RST IN2). The MAX6306/MAX6307/MAX6309/MAX6310/MAX6312/MAX6313 mon-itor V CC through an internal, factory-trimmed voltage divider. The MAX6306/MAX6309/MAX6312 have, in addition, an adjustable undervoltage reset input and a manual-reset input. The internal voltage divider sets the reset threshold as specified in the device part number (Table 1). The MAX6307/MAX6310/ MAX6313 feature an adjustable undervoltage reset input (RST IN) and an adjustable overvoltage reset input (OVRST IN) in addition to the factory-trimmed reset threshold on the V CC moni-tor. Program the adjustable reset inputs with an external resistor divider (see Adjustable Reset Inputs section).Reset OutputsA µP’s reset input starts the µP in a known state. These µP supervisory circuits assert reset to prevent code-execution errors during power-up, power-down, or brownout conditions.RESET (MAX6305–MAX6310) and RESET (MAX6311/MAX6312/MAX6313) are guaranteed to be asserted at a valid logic level for V CC > 1V (see Electrical Characteristics ). Once all monitored voltages exceed their programmed reset thresholds, an internal timer keeps reset asserted for the reset timeout period (t RP );after this interval, reset deasserts.If a brownout condition occurs (any or all monitored volt-ages dip outside their programmed reset threshold),reset asserts (RESET goes high; RESET goes low). Any time any of the monitored voltages dip below their reset threshold, the internal timer resets to zero and reset asserts. The internal timer starts when all of the moni-tored voltages return above their reset thresholds, and reset remains asserted for a reset timeout period. The MAX6305/MAX6306/MAX6307 feature an active-low,MAX6305–MAX63135-Pin, Multiple-Input, Programmable Reset ICs_______________________________________________________________________________________5______________________________________________________________Pin DescriptionM A X 6305–M A X 6313open-drain, N-channel output. The MAX6308/MAX6309/MAX6310 feature an active-low, complementary output structure that both sinks and sources current, and the MAX6311/MAX6312/MAX6313 have an active-high com-plementary reset output.The MAX6305/MAX6308/MAX6311 switch from under-voltage lockout operation to normal operation between 1.5V < V CC < 2.5V. Below 1.5V, V CC undervoltage-lockout mode asserts RESET . Above 2.5V, V CC normal-operation mode asserts reset if RST IN_ falls below the RST IN_ threshold.Manual-Reset Input(MAX6306/MAX6309/MAX6312)Many µP-based products require manual-reset capability,allowing an operator or external logic circuitry to initiate a reset. A logic low on MR asserts reset. Reset remains asserted while MR is low, and for a reset active timeout period (t RP ) after MR returns high. This input has an inter-nal 63.5k Ωpull-up resistor, so it can be left open if it is not used. MR can be driven with TTL-logic levels in 5V sys-tems, with CMOS-logic levels in 3V systems, or with open-drain/collector output devices. Connect a normally open momentary switch from MR to GND to create a manual-reset function; external debounce circuitry is not required.If MR is driven from long cables or if the device is used in a noisy environment, connecting a 0.1µF capacitor from MR to ground provides additional noise immunity.The MR pin has internal ESD-protection circuitry that may be forward biased under certain conditions, drawing excessive current. For example, assume the circuitry driv-ing MR uses a +5V supply other than V CC . If V CC drops or browns out lower than +4.7V, MR ’s absolute maximum rat-ing is violated (-0.3V to (V CC + 0.3V)), and undesirable current flows through the ESD structure from MR to V CC .To avoid this, it is recommended that the supply for the MR pin be the same as the supply monitored by V CC . In this way, the voltage at MR will not exceed V CC .Adjustable Reset InputsThe MAX6305–MAX6313 each have one or more reset inputs (RST IN_ /OVRST IN). These inputs are com-pared to the internal reference voltage (F igure 1).Connect a resistor voltage divider to RST IN_ such that V RST IN_falls below V RSTH (1.23V) when the monitored voltage (V IN ) falls below the desired reset threshold (V TH ) (F igure 2). Calculate the desired reset voltage with the following formula:R1 + R2V TH = ________x VRSTHR25-Pin, Multiple-Input, Programmable Reset ICs 6_______________________________________________________________________________________Figure 1. Functional DiagramMAX6305–MAX63135-Pin, Multiple-Input, Programmable Reset ICs_______________________________________________________________________________________7The ±25nA max input leakage current allows resistors on the order of megohms. Choose the pull-up resistor in the divider to minimize the error due to the input leakage cur-rent. The error term in the calculated threshold is simply:±25nA x R1If you choose R1 to be 1M Ω, the resulting error is ±25 x 10-9x 1 x 106= ±25mV.Like the V CC voltage monitors on the MAX6306/MAX6307/MAX6309/MAX6310/MAX6312/MAX6313, the RST IN_inputs (when used with a voltage divider) are designed to ignore fast voltage transients. Increase the noise immunity by connecting a capacitor on the order of 0.1µF between RST IN and GND (Figure 2). This creates a single-pole lowpass filter with a corner frequency given by:f = (1/2π) / (R1 + R2)(R1 x R2 x C)For example, if R1 = 1M Ωand R2 = 1.6M Ω, adding a 0.1µF capacitor from RST IN_ to ground results in a lowpass corner frequency of f = 2.59Hz. Note that adding capacitance to RST IN slows the circuit’s overall response time.__________Applications InformationInterfacing to µPs with Bidirectional Reset PinsSince the RESET output on the MAX6305/MAX6306/MAX6307 is open drain, these devices interface easily with µPs that have bidirectional reset pins, such as the Motorola 68HC11. Connecting the µP supervisor’s RESET output directly to the microcontroller’s RESET pin with a single pull-up resistor allows either device to assert reset (Figure 3).Negative-Going V CC TransientsIn addition to issuing a reset to the µP during power-up,power-down, and brownout conditions, these devices are relatively immune to short-duration, negative-going V CC transients (glitches).The Typical Operating Characteristics show the Maximum Transient Duration vs. V CC Reset Threshold Overdrive, for which reset pulses are not generated.The graph was produced using negative-going pulses,starting at V TH max, and ending below the pro-grammed reset threshold by the magnitude indicated (reset threshold overdrive). The graph shows the maxi-mum pulse width that a negative-going V CC transient may typically have without causing a reset pulse to be issued. As the amplitude of the transient increases (i.e.,goes farther below the reset threshold), the maximum allowable pulse width decreases.RST IN_/OVRST IN are also immune to negative/positive-going transients (see Typical Operating Characteristics ).A 0.1µF bypass capacitor mounted close to the RST IN_,OVRST IN, and/or the V CC pin provides additional tran-sient immunity.Ensuring a Valid RESET /RESETOutput Down to V CC = 0VWhen V CC falls below 1V, push/pull structured RESET /RESET current sinking (or sourcing) capabilities decrease drastically. High-impedance CMOS-logic inputs connected to RESET can drift to undetermined voltages. This presents no problem in most applica-tions, since most µPs and other circuitry do not operate with V CC below 1V. In those applications where RESET must be valid down to 0V, adding a pull-down resistor between RESET and ground sinks any stray leakageFigure 2. Increasing Noise ImmunityFigure 3. Interfacing to µPs with Bidirectional Reset I/Ocurrents, holding RESET low (Figure 4). The pull-down resistor’s value is not critical; 100k Ωis large enough not to load RESET and small enough to pull RESET to ground. For applications where RESET must be valid to V CC , a 100k Ωpull-up resistor between RESET and V CC will hold RESET high when V CC falls below 1V (Figure 5).Since the MAX6305/MAX6306/MAX6307 have open-drain, active-low outputs, they typically use a pull-up resistor. With these devices and under these conditions (V CC < 1V), RESET will most likely not maintain an active condition, but will drift toward a nonactive level due to the pull-up resistor and the RESET output’s reduction in sinking capability. These devices are not recommended for applications that require a valid RESET output below 1V.* Factory-trimmed reset thresholds are available in approximately 100mV increments with a ±1.5% room-temperature variance.M A X 6305–M A X 63135-Pin, Multiple-Input, Programmable Reset ICs 8_______________________________________________________________________________________Figure 4. Ensuring RESET Valid to V CC = 0VFigure 5. Ensuring RESET Valid to V CC = 0VTable 1. Factory-Trimmed Reset Thresholds*MAX6305–MAX63135-Pin, Multiple-Input, Programmable Reset ICs_______________________________________________________________________________________9Chip InformationTRANSISTOR COUNT: 800Typical Operating Circuit†The MAX6306/MAX6307/MAX6309/MAX6310/MAX6312/MAX6313 are available with factory-set V CC reset thresholds from 2.5V to 5V, in 0.1V increments. Insert the desired nominal reset threshold (from Table 1) into the blanks following the letters UK.All parts also offer factory-programmed reset timeout periods.Insert the number corresponding to the desired nominal timeout period index following the “D” in the part number (D1 = 1ms min,D2 = 20ms min, D3 = 140ms min, and D4 = 1120ms min). There are 10 standard versions with a required order increment of 2,500pieces. Sample stock is generally held on the standard versions only (see Standard Versions table). Required order increment is 10,000 pieces for non-standard versions. Contact factory for avail-ability of non-standard versions. All devices available in tape-and-reel only.Devices are available in both leaded and lead-free packaging.Specify lead-free by replacing “-T” with “+T” when ordering.M A X 6305–M A X 63135-Pin, Multiple-Input, Programmable Reset ICs 10______________________________________________________________________________________Pin ConfigurationsPackage InformationFor the latest package outline information, go to /packages .Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________11©2008 Maxim Integrated Productsis a registered trademark of Maxim Integrated Products, Inc.MAX6305–MAX6313 5-Pin, Multiple-Input, Programmable Reset ICs元器件交易网。

MAX6675中文数据手册

图 1a 是串行接口协议图，图 1b 是串行接口时序图。图 2 为 SO 输出数据格式。
热电偶开路检测
位 D2 一般情况下为 0，在热电偶开路时跳变为 1。为了使热电偶开路检测器能够正常运行，T-必须接地，且接地点需尽可能靠近 GND 引脚。
温升的考虑
在某些应用中器件自身发热会降低 MAX6675 的精度。温度误差的大小取决于 MAX6675 封装的热传导性、安装技术、和气流的影响。使用一个大的地平面可以提高 MAX6675 的温度测量精度。
100
ns
100 ns
100 ns
100 ns
Note 1: 所有参数都是在 TA=25℃下 100%测试。温度超过极限 (TA = TMIN to TMAX) 的参数只从设计和特性上保证，没有产品测试。 Note 2: 从设计上保证，没有产品测试。
（没有特别指出，VCC=+3.3V，TA=+25℃）输出码误差和环境温度
使用适当的保护套保护热电偶
仅仅在低温、温度波动小的区域使用补偿导线
保存事件日志和热电偶阻抗的记录
噪声方面的考虑
MAX6675 的精确度易受电源耦合噪声的影响。电源噪声的影响可以通过放置 1 个 0.1μ F 的陶瓷电容消弱，电容应靠近器件的电源引脚。
减小拾取噪声的影响
输入放大器（A1）是一个低噪声的放大器，它被设计为能够放大高精度的传感器输入信号。确保热电偶和与其想接的导线远离电子噪声源。
可以用以下措施改善热电偶系统的测量精度：
使用尽可能粗的导线，这样的导线不至于从测量区域分流来大量的热
如果要求使用比较细的导线在，则仅仅在测量区使用这种线，在没有温升的地方使用补偿导线

MAX6364PUT31-T中文资料

For free samples and the latest literature, visit or phone 1-800-998-8800.For small orders, phone 1-800-835-8769.General DescriptionThe MAX6361–MAX6364 supervisory circuits reduce the complexity and number of components required for power-supply monitoring and battery control functions in microprocessor (µP) systems. The circuits significantly improve system reliability and accuracy compared to that obtainable with separate ICs or discrete components.Their functions include µP reset, backup battery switchover, and power failure warning.The MAX6361–MAX6364 operate from supply voltages as low as +1.2V. The factory-preset reset threshold voltage ranges from 2.32V to 4.63V (see Ordering Information ).These devices provide a manual reset input (MAX6361),watchdog timer input (MAX6362), battery-on output (MAX6363), and an auxiliary adjustable reset input (MAX6364). In addition, each part type is offered in three reset output versions: an active-low open-drain reset, an active-low open-drain reset, and an active-high open-drain reset (see Selector Guide at end of data sheet).ApplicationsFeatures♦Low +1.2V Operating Supply Voltage (V CC or V BATT )♦Precision Monitoring of +5.0V, +3.3V, +3.0V, and +2.5V Power-Supply Voltages♦Debounced Manual Reset Input (MAX6361)♦Watchdog Timer with 1.6s Timeout Period (MAX6362)♦Battery-On Output Indicator (MAX6363)♦Auxiliary User-Adjustable RESET IN (MAX6364)♦Three Available Output StructuresPush-Pull RESET , Open-Drain RESET , Open-Drain RESET♦RESET/RESET Valid Down to 1.2V Guaranteed (V CC or V BATT )♦Power-Supply Transient Immunity ♦150ms (min) Reset Timeout Period ♦Small 6-Pin SOT23 PackageMAX6361–MAX6364SOT23, Low-Power µP Supervisory Circuitswith Battery Backup________________________________________________________________Maxim Integrated Products119-1615; Rev 3; 11/05Ordering InformationPin ConfigurationsFrom the table below, select the suffix corresponding to the desired threshold voltage and insert it into the part number to complete it. When ordering from the factory, there is a 2500-piece minimum on the SOT package (tape-and-reel only).Devices are available in both leaded and lead-free packaging.Specify lead-free by replacing "-T" with "+T" when ordering.Computers ControllersIntelligent Instruments Critical µP/µC Power MonitoringFax Machines Industrial Control POS EquipmentPortable/Battery-Powered EquipmentSelector Guide appears at end of data sheet.Typical Operating Circuit appears at end of data sheet.M A X 6361–M A X 6364SOT23, Low-Power µP Supervisory Circuits with Battery BackupABSOLUTE MAXIMUM RATINGSELECTRICAL CHARACTERISTICS(V CC = +2.4V to +5.5V, V BATT = 3V, T A = -40°C to +85°C, reset not asserted. Typical values are at T A = +25°C, unless otherwise noted.) (Note 1)Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.Terminal Voltages (with respect to GND)V CC , BATT, OUT.......................................................-0.3V to +6V RESET (open drain), RESET (open drain)................-0.3V to +6V BATT ON, RESET (push-pull), RESET IN,WDI.......................................................-0.3V to (V OUT + 0.3V)MR .............................................................-0.3V to (V CC + 0.3V)Input CurrentV CC Peak ............................................................................1A V CC Continuous............................................................250mA BATT Peak....................................................................250mA BATT Continuous............................................................40mAGND................................................................................75mA Output CurrentOUT................................Short-Circuit Protection for up to 10s RESET, RESET , BATT ON ..............................................20mA Continuous Power Dissipation (T A = +70°C)6-Pin SOT23 (derate 8.70mW/°C above +70°C) .........696mW Operating Temperature Range ...........................-40°C to +85°C Junction Temperature......................................................+150°C Storage Temperature Range.............................-65°C to +150°C Lead Temperature (soldering, 10s).................................+300°CMAX6361–MAX6364SOT23, Low-Power µP Supervisory Circuitswith Battery Backup_______________________________________________________________________________________3ELECTRICAL CHARACTERISTICS (continued)(V CC = +2.4V to +5.5V, V BATT = 3V, T A = -40°C to +85°C, reset not asserted. Typical values are at T A = +25°C, unless otherwise noted.) (Note 1)Note 1:All devices are 100% production tested at T A = +25°C. Limits over temperature are guaranteed by design.Note 2:V BATT can be 0 anytime or V CC can go down to 0 if V BATT is active (except at startup).M A X 6361–M A X 6364SOT23, Low-Power µP Supervisory Circuits with Battery Backup 4_______________________________________________________________________________________Typical Operating Characteristics(T A = +25°C, unless otherwise noted.)1214161820SUPPLY CURRENT vs. TEMPERATURE(NO LOAD)TEMPERATURE (°C)S U P P L Y C U R R E N T (µA )-402040-2060800.20.60.40.81.01.2BATTERY SUPPLY CURRENT (BACKUP MODE) vs. TEMPERATURETEMPERATURE (°C)B A T T E R Y S U P P L Y C U R R E N T (µA )-402040-20060801432567BATTERY TO OUT ON-RESISTANCEvs. TEMPERATURETEMPERATURE (°C)B A T T T O O U T O N -R E S I S T A NC E (Ω)-402040-20608000.30.90.61.2V CC TO OUT ON-RESISTANCEvs. TEMPERATURETEMPERATURE (°C)V O U T T O O U T O N -R E S I S T A N C E (Ω)-402040-206080190195205200210RESET TIMEOUT PERIOD vs. TEMPERATUREM A X 6361 t o c 05TEMPERATURE (°C)R E S E T T I M E O U T P E R I O D (m s )-402040-206080301575604513512010590V CC TO RESET PROPAGATION DELAYvs. TEMPERATURETEMPERATURE (°C)P R O P A G A T I O N D E LA Y (µs )-402040-2060802.03.02.55.04.54.03.5RESET THRESHOLD vs. TEMPERATURETEMPERATURE (°C)T H R E S H O L D (V )-402040-2060801.21.41.31.61.51.91.81.72.0-40-2020406080MAX6362WATCHDOG TIMEOUT PERIODvs. TEMPERATUREM A X 6361t o c 06aTEMPERATURE (°C)W A T C H D O G T I M E O U T P E R I O D (s )1100101k10kMAXIMUM TRANSIENT DURATION vs. RESET THRESHOLD OVERDRIVERESET THRESHOLD OVERDRIVE V TH - V CC (mV)M A X I M U M T R A N S I E N T D U R A T I O N (µs )400300350250200050150100MAX6361–MAX6364SOT23, Low-Power µP Supervisory Circuitswith Battery Backup1.2341.2351.236MAX6364RESET IN THRESHOLD vs. TEMPERATUREM A X 6361 t o c 10TEMPERATURE (°C)T H R E S H O L D (V )-402040-206080Typical Operating Characteristics (continued)(T A = +25°C, unless otherwise noted.)1.01.91.61.32.82.52.2MAX6364RESET IN TO RESET PROPAGATION DELAYvs. TEMPERATURETEMPERATURE (°C)P R O P A G A T I O N D E L A Y (µs )-402040-206080Pin Description0321456789101234BATTERY SUPPLY CURRENT vs. SUPPLY VOLTAGEV CC (V)B A T T E R Y S U P P L YC U R R E N T (µA )M A X 6361–M A X 6364Detailed DescriptionThe Typical Operating Circuit shows a typical connection for the MAX6361–MAX6364 family. OUT powers the stat-ic random-access memory (SRAM). OUT is internally connected to V CC if V CC is greater than the reset thresh-old, or to the greater of V CC or V BATT when V CC is less than the reset threshold. OUT can supply up to 150mA from V CC . When V CC is higher than V BATT , the BATT ON (MAX6363) output is low. When V CC is lower than V BATT ,an internal MOSF ET connects the backup battery to OUT. The on-resistance of the MOSFET is a function of backup-battery voltage and is shown in the Battery to Out On-Resistance vs. Temperature graph in the Typical Operating Characteristics section.Backup-Battery SwitchoverIn a brownout or power failure, it may be necessary to preserve the contents of the RAM. With a backup bat-tery installed at BATT, the MAX6361–MAX6364 auto-matically switch the RAM to backup power when V CC falls. The MAX6363 has a BATT ON output that goes high when in battery-backup mode. These devices require two conditions before switching to battery-backup mode:1)V CC must be below the reset threshold.2)V CC must be below V BATT .Table 1 lists the status of the inputs and outputs in bat-tery-backup mode. The device will not power up if the only voltage source is on BATT. OUT will only power up from V CC at startup.Manual Reset Input (MAX6361 Only)Many µP-based products require manual reset capabili-ty, allowing the operator, a test technician, or external logic circuitry to initiate a reset. For the MAX6361, a logic low on MR asserts reset. Reset remains asserted while MR is low, and for a minimum of 150ms (t RP ) after it returns high. MR has an internal 20k Ωpull-up resistor to V CC . This input can be driven with TTL/CMOS logic lev-els or with open-drain/collector outputs. Connect a nor-mally open momentary switch from MR to GND to create a manual reset function; external debounce circuitry is not required. If MR is driven from long cables or the device is used in a noisy environment, connect a 0.1µF capacitor from MR to GND to provide additional noise immunity.Watchdog Input (MAX6362 Only)The watchdog monitors µP activity through the input WDI. If the µP becomes inactive, the reset output is asserted in pulses. To use the watchdog function, con-nect WDI to a bus line or µP I/O line. A change of state(high to low or low to high) within the watchdog timeout period (t WD ) with a 100ns minimum pulse width clears the watchdog timer. If WDI remains high or low for longer than the watchdog timeout period, the internal watchdog timer runs out and a reset pulse is triggered for the reset timeout period (t RP ). The internal watchdog timer clears whenever reset asserts or the WDI sees a rising or falling edge within the watchdog timeout period. If WDI remains in a high or low state for an extended period of time, a reset pulse asserts after every watchdog timeout period (t WD ) (Figure 1).Reset In (MAX6364 Only)RESET IN is compared to an internal 1.235V reference.If the voltage at RESET IN is less than 1.235V, reset is asserted. The RESET IN comparator may be used as an undervoltage detector to signal a failing power sup-ply. It can also be used as a secondary power-supply reset monitor.To program the reset threshold (V RTH ) of the secondary power supply, use the following equation (see Typical Operating Circuit ):where V REF = 1.235V. To simplify the resistor selection,choose a value for R2 and calculate R1:Since the input current at RESET IN is 25nA (max), large values (up to 1M Ω) can be used for R2 with no signifi-cant loss in accuracy. F or example, in the TypicalSOT23, Low-Power µP Supervisory Circuits with Battery Backup 6_______________________________________________________________________________________R R V V RTH REF 121 /=()−[]MAX6361–MAX6364SOT23, Low-Power µP Supervisory Circuitswith Battery Backup_______________________________________________________________________________________7Operating Circuit,the MAX6362 monitors two supply voltages. To monitor the secondary 5V logic or analog supply with a 4.60V nominal programmed reset thresh-old, choose R2 = 100k Ω, and calculate R1 = 273k Ω.Reset OutputA µP’s reset input starts the µP in a known state. The MAX6361–MAX6364 µP supervisory circuits assert a reset to prevent code-execution errors during power-up, power-down, and brownout conditions. RESET is guaranteed to be a logic low or high depending on the device chosen (see Ordering Information ). RESET or RESET asserts when V CC is below the reset threshold and for at least 150ms (t RP ) after V CC rises above the reset threshold. RESET or RESET also asserts when MR is low (MAX6361) and when RESET IN is less than 1.235V (MAX6364). The MAX6362 watchdog function will cause RESET (or RESET ) to assert in pulses follow-ing a watchdog timeout (Figure 1).Applications InformationOperation Without a BackupPower SourceThe MAX6361–MAX6364 were designed for battery-backed applications. If a backup battery is not used,connect V CC to OUT and connect BATT to GND.Replacing the Backup BatteryIf BATT is decoupled with a 0.1µF capacitor to ground,the backup power source can be removed while V CC remains valid without danger of triggering a reset pulse.The device does not enter battery-backup mode when V CC stays above the reset threshold voltage.Negative-Going V CC TransientsThese supervisors are relatively immune to short-dura-tion, negative-going V CC transients. Resetting the µPwhen V CC experiences only small glitches is usually not desirable.The Typical Operating Characteristics section shows a graph of Maximum Transient Duration vs. Reset Threshold Overdrive for which reset is not asserted.The graph was produced using negative-going V CC pulses, starting at V CC and ending below the reset threshold by the magnitude indicated (reset threshold overdrive). The graph shows the maximum pulse width that a negative-going V CC transient can typically have without triggering a reset pulse. As the amplitude of the transient increases (i.e., goes further below the reset threshold), the maximum allowable pulse width decreases. Typically, a V CC transient that goes 100mV below the reset threshold and lasts for 30µs will not trigger a reset pulse.A 0.1µF bypass capacitor mounted close to the V CC pin provides additional transient immunity.Figure 1. MAX6362 Watchdog Timeout Period and Reset Active TimeM A X 6361–M A X 6364Watchdog Software Considerations(MAX6362 Only)To help the watchdog timer monitor software execution more closely, set and reset the watchdog input at dif-ferent points in the program, rather than “pulsing” the watchdog input low-high-low. This technique avoids a “stuck” loop, in which the watchdog timer would contin-ue to be reset within the loop, keeping the watchdog from timing out. F igure 2 shows an example of a flow diagram where the I/O driving the WDI is set low at the beginning of the program, set high at the beginning of every subroutine or loop, then set low again when the program returns to the beginning. If the program should “hang” in any subroutine, the problem would quickly be corrected, since the I/O is continually set low and the watchdog timer is allowed to time out, trigger-ing a reset.SOT23, Low-Power µP Supervisory Circuits with Battery Backup 8_______________________________________________________________________________________Figure 2. Watchdog Flow DiagramMAX6361–MAX6364SOT23, Low-Power µP Supervisory Circuitswith Battery Backup_______________________________________________________________________________________9*Sample stock generally held on standard versions only. Contact factory for availability of nonstandard versions.Device Marking CodesSelector GuideM A X 6361–M A X 6364SOT23, Low-Power µP Supervisory Circuits with Battery Backup 10______________________________________________________________________________________Pin Configurations (continued)Typical Operating CircuitChip InformationTRANSISTOR COUNT: 720MAX6361–MAX6364SOT23, Low-Power µP Supervisory Circuits with Battery Backup______________________________________________________________________________________11Package InformationM A X 6361–M A X 6364SOT23, Low-Power µP Supervisory Circuits with Battery BackupMaxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.12____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600©2005 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc.NOTES。

MAX1978中文数据手册

用于Peltier模块的集成温度控制器概论MAX1978 / MAX1979是用于Peltier热电冷却器（TEC）模块的最小, 最安全, 最精确完整的单芯片温度控制器。

片上功率FET和热控制环路电路可最大限度地减少外部元件, 同时保持高效率。

可选择的500kHz / 1MHz开关频率和独特的纹波消除方案可优化元件尺寸和效率, 同时降低噪声。

内部MOSFET的开关速度经过优化, 可降低噪声和EMI。

超低漂移斩波放大器可保持±0.001°C的温度稳定性。

直接控制输出电流而不是电压, 以消除电流浪涌。

独立的加热和冷却电流和电压限制提供最高水平的TEC保护。

MAX1978采用单电源供电, 通过在两个同步降压调节器的输出之间偏置TEC, 提供双极性±3A输出。

真正的双极性操作控制温度, 在低负载电流下没有“死区”或其他非线性。

当设定点非常接近自然操作点时, 控制系统不会捕获, 其中仅需要少量的加热或冷却。

模拟控制信号精确设置TEC 电流。

MAX1979提供高达6A的单极性输出。

提供斩波稳定的仪表放大器和高精度积分放大器, 以创建比例积分（PI）或比例积分微分（PID）控制器。

仪表放大器可以连接外部NTC或PTC热敏电阻, 热电偶或半导体温度传感器。

提供模拟输出以监控TEC温度和电流。

此外, 单独的过热和欠温输出表明当TEC温度超出范围时。

片上电压基准为热敏电阻桥提供偏置。

MAX1978 / MAX1979采用薄型48引脚薄型QFN-EP 封装, 工作在-40°C至+ 85°C温度范围。

采用外露金属焊盘的耐热增强型QFN-EP封装可最大限度地降低工作结温。

评估套件可用于加速设计。

应用光纤激光模块典型工作电路出现在数据手册的最后。

WDM, DWDM激光二极管温度控制光纤网络设备EDFA光放大器电信光纤接口ATE特征♦尺寸最小, 最安全, 最精确完整的单芯片控制器♦片上功率MOSFET-无外部FET♦电路占用面积<0.93in2♦回路高度<3mm♦温度稳定性为0.001°C♦集成精密积分器和斩波稳定运算放大器♦精确, 独立的加热和冷却电流限制♦通过直接控制TEC电流消除浪涌♦可调节差分TEC电压限制♦低纹波和低噪声设计♦TEC电流监视器♦温度监控器♦过温和欠温警报♦双极性±3A输出电流（MAX1978）♦单极性+ 6A输出电流（MAX1979）订购信息* EP =裸焊盘。

MAX6033规格书,MAX6033AAUT50技术资料,MAX6033AAUT25,datasheet,PDF

General DescriptionThe MAX6033 ultra-high-precision series voltage refer-ence features a low 7ppm/°C (max) temperature coeffi-cient and a low dropout voltage (200mV, max). Low temperature drift and low noise make the MAX6033ideal for use with high-resolution ADCs or DACs.This device uses bandgap technology for low-noise per-formance and excellent accuracy. Laser-trimmed, high-stability, thin-film resistors, and postpackage trimming guarantee excellent initial accuracy (±0.04%, max). The MAX6033 consumes only 40µA of supply current and sources up to 15mA. Series mode references save sys-tem power and use minimal external components com-pared to two-terminal shunt references.The MAX6033 is available in the miniature 6-pin SOT23package and is offered over the automotive tempera-ture range (-40°C to +125°C).ApplicationsPrecision Regulators A/D and D/A Converters Power Supplies Hard-Disk DrivesHigh-Accuracy Industrial and Process Control Hand-Held InstrumentsFeatureso Tiny 6-Pin SOT23 Packageo Ultra-Low Temperature Drift: 7ppm/°C (max)o ±0.04% Initial Accuracy o Stable with Capacitive Loadso Low 16µV P-P Noise (0.1Hz to 10Hz) (2.5V Output)o 15mA Output Source Current o Low 200mV Dropout Voltage o Low 40µA Quiescent Current o Wide 2.7V to 12.6V Supply Voltage o Excellent Load Regulation: 0.001mV/mAMAX6033Ultra-High-Precision SOT23 SeriesVoltage Reference________________________________________________________________Maxim Integrated Products 1Selector GuidePin ConfigurationOrdering InformationTypical Operating Circuit19-2300; Rev 2; 6/03For pricing, delivery, and ordering information,please contact Maxim/Dallas Direct!at 1-888-629-4642, or visit Maxim’s website at .Note:Two-number part suffix indicates output voltage option.SOT23 Package Top Marks appear at end of data sheet.M A X 6033Ultra-High-Precision SOT23 Series Voltage ReferenceABSOLUTE MAXIMUM RATINGSELECTRICAL CHARACTERISTICS —V OUT = 2.500V(V IN = 5V, C OUT = 0.1µF, I OUT = 0, T A = T MIN to T MAX , unless otherwise specified. Typical values are at T A = +25°C.) (Note 1)Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.IN to GND...............................................................-0.3V to +13V OUTF, OUTS to GND................................................-0.3V to +6V Continuous Power Dissipation (T A = +70°C)6-Pin SOT23 (derate 9.1mW/°C above +70°C)............727mWOperating Temperature Range .........................-40°C to +125°C Storage Temperature Range.............................-65°C to +150°C Maximum Junction Temperature.....................................+150°C Lead Temperature (soldering, 10s).................................+300°CMAX6033Ultra-High-Precision SOT23 SeriesVoltage Reference_______________________________________________________________________________________3ELECTRICAL CHARACTERISTICS —V OUT = 3.000V(V IN = 5V, C OUT = 0.1µF, I OUT = 0, T A = T MIN to T MAX , unless otherwise specified. Typical values are at T A = +25°C.) (Note 1)ELECTRICAL CHARACTERISTICS —V OUT = 4.096VM A X 6033Ultra-High-Precision SOT23 Series Voltage ReferenceELECTRICAL CHARACTERISTICS —V OUT = 4.096V (continued)(V IN = 5V, C OUT = 0.1µF, I OUT = 0, T A = T MIN to T MAX , unless otherwise specified. Typical values are at T A = +25°C.) (Note 1)ELECTRICAL CHARACTERISTICS —V OUT = 5.000V(V = 5.5V, C = 0.1µF, I = 0, T = T to T , unless otherwise specified. Typical values are at T = +25°C.) (Note 1)MAX6033Ultra-High-Precision SOT23 SeriesVoltage Reference_______________________________________________________________________________________5ELECTRICAL CHARACTERISTICS —V OUT = 5.000V (continued)Typical Operating Characteristics(V IN = 5V, C OUT = 0.1µF, I OUT = 0, T A = +25°C, unless otherwise specified.) (Note 4)Note 2:Dropout Voltage is the minimum input voltage at which V OUT changes ≤0.1% from V OUT at V IN = 5V (V IN = 5.5V forV OUT = 5V).Note 3:Temperature Hysteresis is defined as the change in +25°C output voltage before and after cycling the devicefrom T MAX to T MIN .OUTPUT VOLTAGE vs.TEMPERATURE (V OUT = 2.5V)TEMPERATURE (°C)O U T P U T V OL T A G E (V )110956580-105203550-252.49822.49842.49862.49882.49902.49922.49942.49962.49982.50002.50022.50042.50062.50082.50102.4980-40125OUTPUT VOLTAGE vs.TEMPERATURE (V OUT = 5V)TEMPERATURE (°C)O U T P U T V O L T A G E (V )110956580-105203550-254.99824.99844.99864.99884.99904.99924.99944.99964.99985.00005.00025.00045.00065.00085.00104.9980-40125LOAD REGULATION (V OUT = 2.5V)OUTPUT CURRENT (mA)O U T P U T V O L T A G E (V )1816121424681002.49952.50002.50052.50102.50152.50202.50252.50302.50352.50402.4990-220M A X 6033Ultra-High-Precision SOT23 Series Voltage Reference 6_______________________________________________________________________________________Typical Operating Characteristics (continued)(V IN = 5V, C OUT = 0.1µF, I OUT = 0, T A = +25°C, unless otherwise specified.) (Note 4)LOAD REGULATION (V OUT = 5V)OUTPUT CURRENT (mA)O U T P U T V O L T A G E (V )1816024810126144.9995.0005.0015.0025.0035.0045.0055.0064.998-220DROPOUT VOLTAGE vs. OUTPUT CURRENT(V OUT = 2.5V)OUTPUT CURRENT (mA)D R O P O U T V O L T A GE (m V )181********6421002003004005006007000020DROPOUT VOLTAGE vs. OUTPUT CURRENT(V OUT = 5V)OUTPUT CURRENT (mA)D R O P O U T V O L T A GE (m V )18161214468102501001502002503003504004505005506000020POWER-SUPPLY REJECTION RATIO vs. FREQUENCY (V OUT = 2.5V)FREQUENCY (kHz)0.0011101000.010.11000P S R R (d B )0-100-90-80-70-60-50-40-10-20-30-100-70-80-90-60-50-40-30-20-1000.0010.10.011101001000POWER-SUPPLY REJECTION RATIO vs. FREQUENCY (V OUT = 5V)M A X 6033 t o c 08FREQUENCY (kHz)P S R R (d B )SUPPLY CURRENT vs. INPUT VOLTAGE(V OUT = 2.5V)INPUT VOLTAGE (V)S U P P L Y C U R R E N T (µA )121191034567812153045607590105120135150013SUPPLY CURRENT vs. INPUT VOLTAGE(V OUT = 5V)INPUT VOLTAGE (V)S U P P L Y C U R R E N T (µA )121191034567812204060801001201401601802002200130.1Hz TO 10Hz OUTPUT NOISE(V OUT = 2.5V)MAX6033 toc11V OUT 4µV/div 1s/div 0.1Hz TO 10Hz OUTPUT NOISE(V OUT = 5V)MAX6033 toc12V OUT 10µV/div1s/divMAX6033Ultra-High-Precision SOT23 SeriesVoltage Reference_______________________________________________________________________________________7LOAD TRANSIENT (V OUT = 2.5V)2.5V10mAI OUT10mA/divV OUT 50mV/div AC-COUPLED400µs/divV IN = 5V C OUT = 0.1µFLOAD TRANSIENT (V OUT = 2.5V)2.5V-100µA1mA 1ms/divI OUT 1mA/divV OUT 50mV/div AC-COUPLEDV IN = 5V C OUT = 0.1µFLOAD TRANSIENT (V OUT = 2.5V)MAX6033 toc152.5V10mAI OUT10mA/divV OUT 50mV/div AC-COUPLED400µs/divV IN = 5V C OUT = 10µFLOAD TRANSIENT (V OUT = 2.5V)MAX6033 toc162.5V-100µA1mAI OUT 1mA/divV OUT 20mV/div AC-COUPLED1ms/divV IN = 5V C OUT = 10µFLINE TRANSIENT (V OUT = 2.5V)MAX6033 toc175.5V2.5V4.5V VOUT 10mV/div AC-COUPLEDV IN500mV/div AC-COUPLED400µs/div C OUT = 0.1µFLINE TRANSIENT (VOUT = 5V)6.5V5V5.5VV OUT 10mV/div AC-COUPLEDV IN500mV/div AC-COUPLED1ms/divTypical Operating Characteristics (continued)(V IN = 5V, C OUT = 0.1µF, I OUT = 0, T A = +25°C, unless otherwise specified.) (Note 4)M A X 6033Ultra-High-Precision SOT23 Series Voltage Reference 8_______________________________________________________________________________________Typical Operating Characteristics (continued)(V IN = 5V, C OUT = 0.1µF, I OUT = 0, T A = +25°C, unless otherwise specified.) (Note 4)TURN-ON TRANSIENT (V OUT = 2.5V)5V2.5VV OUT 1V/divV IN 2V/div100µs/div0C OUT = 0.1µFTURN-ON TRANSIENT(V OUT = 5V)MAX6033 toc205.5V5VV OUT 2V/divV IN 2V/div400µs/divC OUT = 0.1µFTURN-ON TRANSIENT (V OUT = 2.5V)5V2.5VV OUT 1V/divV IN 2V/div2ms/divC OUT = 10µFTURN-ON TRANSIENT(V OUT = 5V)5.5V5VV OUT 2V/divV IN 2V/div2ms/divC OUT = 10µFNote 4:Many of the MAX6033 Typical Operating Characteristics are similar. The extremes of these characteristics are found in theMAX6033 (2.5V output) and the MAX6033 (5V output). The Typical Operating Characteristics of the remainder of the MAX6033 family typically lie between these two extremes and can be estimated based on their output voltages.LONG-TERM STABILITY vs. TIME(V OUT = 2.5V)TIME (HOURS)V O U T (V )9008006007002003004005001002.499952.500002.500052.500102.500152.500202.500252.500302.500352.500402.4999001000LONG-TERM STABILITY vs. TIME(V OUT= 5V)TIME (HOURS)V O U T (V )9008006007002003004005001005.00005.00015.00025.00035.00045.00055.00065.00075.00085.00094.999901000Applications InformationBypassing/Load CapacitanceFor the best line-transient performance, decouple the input with a 0.1µF ceramic capacitor as shown in the Typical Operating Circuit . Place the capacitor as close to I N as possible. When transient performance is less important, no capacitor is necessary.The MAX6033 family requires a minimum output capac-itance of 0.1µF for stability and is stable with capacitive loads (including the bypass capacitance) of up to 100µF. In applications where the load or the supply can experience step changes, a larger output capacitor reduces the amount of overshoot (undershoot) and improves the circuit ’s transient response. Place output capacitors as close to the device as possible.Supply CurrentThe quiescent supply current of the MAX6033 series reference is typically 40µA and is virtually independent of the supply voltage. In the MAX6033 family, the load current is drawn from the input only when required, so supply current is not wasted and efficiency is maxi-mized at all input voltages. This improved efficiency reduces power dissipation and extends battery life.When the supply voltage is below the minimum-speci-fied input voltage (as during turn-on), the devices can draw up to 150µA beyond the nominal supply current.The input voltage source must be capable of providing this current to ensure reliable turn-on.Output-Voltage HysteresisOutput voltage hysteresis is the change in the output voltage at T A = +25°C before and after the device is cycled over its entire operating temperature range.Hysteresis is caused by differential package stress appearing across the bandgap core transistors. The typical temperature hysteresis value is 150ppm.Turn-On TimeThese devices typically turn on and settle to within0.01% of their final value in >1µs. The turn-on time can increase up to 2ms with the device operating at the minimum dropout voltage and the maximum load.Precision Current SourceFigure 1 shows a typical circuit providing a precision current source. The OUTF output provides the bias cur-rent for the bipolar transistor. OUTS senses the voltage across the resistor and adjusts the current sourced by OUTF accordingly.High-Resolution DAC and Reference from Single SupplyFigure 2 shows a typical circuit providing both the power supply and reference for a high-resolution DAC.A MAX6033 with 2.5V output provides the reference voltage for the DAC.MAX6033Ultra-High-Precision SOT23 SeriesVoltage Reference_______________________________________________________________________________________9Figure 1. Precision Current SourceM A X 6033Ultra-High-Precision SOT23 Series Voltage Reference 10______________________________________________________________________________________Chip InformationTRANSISTOR COUNT: 656PROCESS: BiCMOSSOT23 Package Top MarksMAX6033Ultra-High-Precision SOT23 Series Voltage ReferenceMaxim cannot assume responsibility for use of any circuitry other than circuitry entirely embod ied in a Maxim prod uct. No circuit patent licenses areimplied. Maxim reserves the right to change the circuitry and specifications without notice at any time.Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________11©2003 Maxim Integrated Products Printed USAis a registered trademark of Maxim Integrated Products.Package Information(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline informationgo to /packages .)美信代理商,MAXIM 代理,深圳市万瑞尔科技有限公司 +86-755-28269789 。

MAX6368LKA29-T中文资料

General DescriptionThe MAX6365–MAX6368 supervisory circuits simplify power-supply monitoring, battery-backup control func-tions, and memory write protection in microprocessor (µP) systems. The circuits significantly improve the size,accuracy, and reliability of modern systems with an ultra-small integrated solution.These devices perform four basic system functions:1) Provide a µP reset output during V CC supply power-up, power-down, and brownout conditions.2) Internally control V CC to backup-battery switching tomaintain data or low-power operation for CMOS RAM, CMOS µPs, real-time clocks, and other digital logic when the main supply fails.3) Provide memory write protection through internalchip-enable gating during supply or processor faults.4) Include one of the following options: a manual resetinput (MAX6365), a watchdog timer function (MAX6366), a battery-on output (MAX6367), or an auxiliary user-adjustable reset input (MAX6368).The MAX6365–MAX6368 operate from V CC supply volt-ages as low as 1.2V. The factory preset reset threshold voltages range from 2.32V to 4.63V (see Ordering Information ). In addition, each part is offered in three reset output versions: push-pull active low, open-drain active low, or open-drain active high (see Selector Guide ). The MAX6365–MAX6368 are available in minia-ture 8-pin SOT23 packages.ApplicationsCritical µP/µC Power Portable/Battery-Monitoring Powered Equipment Fax Machines Set-Top Boxes Industrial Control POS EquipmentComputers/ControllersFeatureso Low +1.2V Operating Supply Voltage (V CC or V BATT )o Precision Monitoring of +5.0V, +3.3V, +3.0V, and +2.5V Power-Supply Voltageso On-Board Gating of Chip-Enable Signals, 1.5ns Propagation Delayo Debounced Manual Reset Input (MAX6365)o Watchdog Timer, 1.6s Timeout (MAX6366)o Battery-On Output Indicator (MAX6367)o Auxiliary User-Adjustable RESET IN (MAX6368)o Low 10µA Quiescent Supply Current o Three Available Output StructuresPush-Pull RESET Open-Drain RESET Open-Drain RESETo RESET/RESET Valid Down to 1.2V Guaranteed (V CC or V BATT )o Power-Supply Transient Immunity o 150ms min Reset Timeout Period o Miniature 8-Pin SOT23 PackageMAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating________________________________________________________________Maxim Integrated Products1Pin Configurations19-1658; Rev 1; 6/01For pricing, delivery, and ordering information,please contact Maxim/Dallas Direct!at 1-888-629-4642, or visit Maxim’s website at .Ordering Information*These parts offer a choice of reset threshold voltages. From the Reset Threshold Ranges table, insert the desired threshold volt-age code in the blank to complete the part number. SOT parts come in tape-and-reel only and must be ordered in 2500-piece increments. See Device Marking Codes for a complete parts list,including SOT top marks and standard threshold versions. See Selector Guide for a listing of device features.Typical Operating Circuit appears at end of data sheet.M A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable GatingABSOLUTE MAXIMUM RATINGSELECTRICAL CHARACTERISTICS(V = +2.4V to +5.5V, V = +3.0V, CE IN = V , reset not asserted, T = -40°C to +85°C. Typical values are at T = +25°C,Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.Terminal Voltages (with respect to GND)V CC , BATT, OUT.......................................................-0.3V to +6V RESET (open drain), RESET (open drain)................-0.3V to +6V BATT ON, RESET (push-pull), RESET IN,WDI, CE IN, CE OUT...........................-0.3V to (V OUT + 0.3V)MR ..............................................................-0.3V to (V CC + 0.3V)Input CurrentV CC Peak ..............................................................................1A V CC Continuous.............................................................250mA BATT Peak.....................................................................250mA BATT Continuous.............................................................40mAGND...............................................................................75mA Output CurrentOUT...............................Short-Circuit Protected for up to 10s RESET, RESET , BATT ON, CE OUT...............................20mA Continuous Power Dissipation (T A = +70°C)8-Pin SOT23 (derate 8.75mW/°C above +70°C)........700mW Operating Temperature Range ...........................-40°C to +85°C Storage Temperature Range.............................-65°C to +150°C Junction Temperature .....................................................+150°C Lead Temperature (soldering, 10s).................................+300°CMAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating_______________________________________________________________________________________3ELECTRICAL CHARACTERISTICS (continued)(V CC = +2.4V to +5.5V, V BATT = +3.0V, CE IN = V CC , reset not asserted, T A = -40°C to +85°C. Typical values are at T A = +25°C,M A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating 4_______________________________________________________________________________________Typical Operating Characteristics(T A = +25°C, unless otherwise noted.)8109121115141316-400-2020406080SUPPLY CURRENTvs. TEMPERATURE (NO LOAD)TEMPERATURE (°C)S U P P L Y C U R R E N T (µA )0.20.60.40.81.01.2BATTERY SUPPLY CURRENT (BACKUP MODE) vs. TEMPERATURETEMPERATURE (°C)B A T T E R Y S U P P L YC U R R E N T (µA )-402040-200608021437658-40-2020406080BATT-TO-OUT ON-RESISTANCEvs. TEMPERATURETEMPERATURE (°C)B A T T -T O -O U T O N -R E S I S T A NC E (Ω)ELECTRICAL CHARACTERISTICS (continued)(V= +2.4V to +5.5V, V = +3.0V, CE IN = V , reset not asserted, T = -40°C to +85°C. Typical values are at T = +25°C,Note 2:V BATT can be 0 anytime, or V CC can go down to 0 if V BATT is active (except at startup).Note 3:RESET is pulled up to OUT. Specifications apply for OUT = V CC or OUT = BATT.Note 4:The chip-enable resistance is tested with V CC = V TH(MAX)and CE IN = V CC /2.MAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating_______________________________________________________________________________________5Typical Operating Characteristics (continued)(T A = +25°C, unless otherwise noted.)00.40.20.80.61.21.01.4-4020-20406080V CC TO OUT ON-RESISTANCEvs. TEMPERATURETEMPERATURE (°C)V C C T O O U T O N -R E S I S T A N C E (Ω)190195205200210RESET TIMEOUT PERIOD vs. TEMPERATUREM A X 6365/8-05TEMPERATURE (°C)R E S E T T I M E O U T P E R I O D (m s )-402040-206080301575604513512010590TEMPERATURE (°C)P R O P A G A T I O N D E L A Y (µs )-402040-206080V CC vs. TEMPERATURE2.03.02.55.04.54.03.5RESET THRESHOLD vs. TEMPERATURETEMPERATURE (°C)T H R E S H O L D (V )-402040-206080110010100010,000MAXIMUM TRANSIENT DURATION vs. RESET THRESHOLD OVERDRIVERESET THRESHOLD OVERDRIVE V TH - V CC (mV)M A X I M U M T R A N S I E N T D U R A T I O N (µs )40030035025020005015010003215498761000.5 1.0 1.5 2.0 2.5 3.0 3.5BATTERY SUPPLY CURRENT vs. SUPPLY VOLTAGEV CC (V)B A T T E R Y S U P P L YC U R R E N T (µA )M A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating 6_______________________________________________________________________________________1.2341.2351.236MAX6368RESET IN THRESHOLD vs. TEMPERATUREM A X 6365/8 -10TEMPERATURE (°C)V R T H (V )-402040-2060801.01.91.61.32.82.52.2MAX6368RESET IN TO RESET PROPAGATION DELAYvs. TEMPERATURETEMPERATURE (°C)P R O P A G A T I O N D E L A Y (µs )-402040-206080013245C LOAD (pF)P R O P A G A T I O N D E L A Y (n s )10050150200CHIP-ENABLE PROPAGATION DELAY vs. CE OUT LOAD CAPACITANCE515102025-40-2020406080TEMPERATURE (°C)C E I N T O C E O U T O N -R E S I S T A N C E (Ω)CE IN TO CE OUT ON-RESISTANCEvs. TEMPERATURE1.01.31.21.11.51.41.91.81.71.62.0-40-2020406080TEMPERATURE (°C)W A T C H D O G T I M E O U T P E R I O D (s )MAX6366WATCHDOG TIMEOUT PERIODvs. TEMPERATURETypical Operating Characteristics (continued)(T A = +25°C, unless otherwise noted.)MAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating_______________________________________________________________________________________7M A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating 8_______________________________________________________________________________________Detailed DescriptionThe Typical Operating Circuit shows a typical connec-tion for the MAX6365–MAX6368. OUT powers the static random-access memory (SRAM). If V CC is greater than the reset threshold (V TH ), or if V CC is lower than V TH but higher than V BATT , V CC is connected to OUT. If V CC is lower than V TH and V CC is less than V BATT ,BATT is connected to OUT. OUT supplies up to 150mA from V CC . In battery-backup mode, an internal MOSFET connects the backup battery to OUT. The on-resistance of the MOSFET is a function of backup-battery voltage and is shown in the BATT-to-OUT On-Resistance vs.Temperature graph in the T ypical Operating Char-acteristics .Chip-Enable Signal GatingThe MAX6365–MAX6368 provide internal gating of CE signals to prevent erroneous data from being written toCMOS RAM in the event of a power failure. During nor-mal operation, the CE gate is enabled and passes all CE transitions. When reset asserts, this path becomes disabled, preventing erroneous data from corrupting the CMOS RAM. All of these devices use a series trans-mission gate from CE IN to CE OUT. The 2ns propaga-tion delay from CE IN to CE OUT allows the devices to be used with most µPs and high-speed DSPs.During normal operation, CE IN is connected to CE OUT through a low on-resistance transmission gate.This is valid when reset is not asserted. If CE IN is high when reset is asserted, CE OUT remains high regard-less of any subsequent transitions on CE IN during the reset event.If CE IN is low when reset is asserted, CE OUT is held low for 12µs to allow completion of the read/write oper-ation (F igure 1). After the 12µs delay expires, the CEFunctional DiagramMAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating_______________________________________________________________________________________9OUT goes high and stays high regardless of any sub-sequent transitions on CE IN during the reset event.When CE OUT is disconnected from CE IN, CE OUT is actively pulled up to OUT.The propagation delay through the chip-enable circuit-ry depends on both the source impedance of the drive to CE IN and the capacitive loading at CE OUT. The chip-enable propagation delay is production tested from the 50% point of CE IN to the 50% point of CE OUT, using a 50Ωdriver and 50pF load capacitance.Minimize the capacitive load at CE OUT to minimize propagation delay, and use a low-output-impedance driver.Backup-Battery SwitchoverIn a brownout or power failure, it may be necessary to preserve the contents of the RAM. With a backup bat-tery installed at BATT, the MAX6365–MAX6368 auto-matically switch the RAM to backup power when V CC falls. The MAX6367 has a BATT ON output that goes high in battery-backup mode. These devices require two conditions before switching to battery-backup mode:1) V CC must be below the reset threshold.2) V CC must be below V BATT .Table 1 lists the status of the inputs and outputs in bat-tery-backup mode. The devices do not power up if theonly voltage source is on BATT. OUT only powers up from V CC at startup.Many µP-based products require manual reset capabili-ty, allowing the user or external logic circuitry to initiate a reset. For the MAX6365, a logic low on MR asserts reset.Reset remains asserted while MR is low and for a mini-mum of 150ms (t RP ) after it returns high. MR has an inter-nal 20k Ωpullup resistor to V CC . This input can be driven with TTL/CMOS logic levels or with open-drain/collector outputs. Connect a normally open momentary switch from MR to GND to create a manual reset function; exter-nal debounce circuitry is not required. If MR is driven from long cables or the device is used in a noisy environ-ment, connect a 0.1µF capacitor from MR to GND to pro-vide additional noise immunity.Figure 1. Reset and Chip-Enable TimingM A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating 10______________________________________________________________________________________Watchdog Input (MAX6366 Only)The watchdog monitors µP activity through the watch-dog input (WDI). If the µP becomes inactive, reset asserts. To use the watchdog function, connect WDI to a bus line or µP I/O line. A change of state (high to low,low to high, or a minimum 100ns pulse) resets the watchdog timer. If WDI remains high or low for longer than the watchdog timeout period (t WD ), the internal watchdog timer runs out and a reset pulse is triggered for the reset timeout period (t RP ). The internal watchdog timer clears whenever reset asserts or whenever WDI sees a rising or falling edge. If WDI remains in either a high or low state, a reset pulse asserts periodically after every t WD (F igure 2). Leave WDI unconnected to dis-able the watchdog function.BATT ON Indicator (MAX6367 Only)BATT ON is a push-pull output that drives high when in battery-backup mode. BATT ON typically sinks 3.2mA at 0.1V saturation voltage. In battery-backup mode, this terminal sources approximately 10µA from OUT. Use BATT ON to indicate battery-switchover status or to supply base drive to an external pass transistor for higher current applications (Figure 3).RESET IN Comparator (MAX6368 Only)RESET IN is compared to an internal 1.235V reference.If the voltage at RESET IN is less than 1.235V, reset asserts. Use the RESET IN comparator as an undervolt-age detector to signal a failing power supply or as a secondary power-supply reset monitor.To program the reset threshold (V RTH ) of the secondary power supply, use the following (see Typical Operating Circuit ):V RTH = V REF (R1 / R2 + 1)where V REF = 1.235V. To simplify the resistor selection,choose a value for R2 and calculate R1:R1 = R2 [(V RTH / V REF ) - 1]Since the input current at RESET IN is 25nA (max),large values (up to 1M Ω) can be used for R2 with no significant loss in accuracy. For example, in the Typical Operating Circuit , the MAX6368 monitors two supply voltages. To monitor the secondary 5V logic or analog supply with a 4.60V nominal programmed reset thresh-old, choose R2 = 100k Ω, and calculate R1 = 273k Ω.Reset OutputA µP ’s reset input starts the µP in a known state. The MAX6365–MAX6368 µP supervisory circuits assert a reset to prevent code-execution errors during power-up, power-down, and brownout conditions. RESET is guaranteed to be a logic low or logic high, depending on the device chosen (see Ordering Information ).RESET or RESET asserts when V CC is below the reset threshold and for at least 150ms (t RP ) after V CC rises above the reset threshold. RESET or RESET also asserts when MR is low (MAX6365) and when RESET IN is less than 1.235V (MAX6368). The MAX6366 watch-dog function will cause RESET (or RESET ) to assert in pulses following a watchdog timeout (Figure 2).Applications InformationOperation Withouta Backup Power SourceThe MAX6365–MAX6368 provide battery-backup func-tions. If a backup power source is not used, connect BATT to GND and OUT to V CC .Watchdog Software ConsiderationsOne way to help the watchdog timer monitor the soft-ware execution more closely is to set and reset the watchdog at different points in the program rather than pulsing the watchdog input periodically. F igure 4shows a flow diagram in which the I/O driving theFigure 2. MAX6366 Watchdog Timeout Period and Reset Active TimeMAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating______________________________________________________________________________________11watchdog is set low in the beginning of the program,set high at the beginning of every subroutine or loop,and set low again when the program returns to the beginning. If the program should hang in any subrou-tine, the problem would be quickly corrected.Replacing the Backup BatteryWhen V CC is above V TH , the backup power source can be removed without danger of triggering a reset pulse.The device does not enter battery-backup mode when V CC stays above the reset threshold voltage.Negative-Going V CC TransientsThese supervisors are relatively immune to short-dura-tion, negative-going V CC transients. Resetting the µP when V CC experiences only small glitches is usually not desirable.The T ypical Operating Characteristics section has a Maximum Transient Duration vs. Reset Threshold Overdrive graph for which reset is not asserted. The graph was produced using negative-going V CC pulses,starting at V CC and ending below the reset threshold by the magnitude indicated (reset threshold overdrive).The graph shows the maximum pulse width that a neg-ative-going V CC transient can typically have without triggering a reset pulse. As the amplitude of the tran-sient increases (i.e., goes further below the reset threshold), the maximum allowable pulse width decreases. Typically, a V CC transient that goes 100mV below the reset threshold and lasts for 30µs will not trig-ger a reset pulse.A 0.1µF bypass capacitor mounted close to the V CC pin provides additional transient immunity.M A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating 12______________________________________________________________________________________standard versions only. Contact factory for availability of nonstandard versions.MAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating______________________________________________________________________________________13Pin Configurations (continued)M A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating 14______________________________________________________________________________________Typical Operating CircuitChip InformationTRANSISTOR COUNT: 729PROCESS: CMOSSOT23, Low-Power µP Supervisory Circuitswith Battery Backup and Chip-Enable GatingMAX6365–MAX6368Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________15©2001 Maxim Integrated Products Printed USAis a registered trademark of Maxim Integrated Products.Package Information。

MAX6369KA+T中文资料

General DescriptionThe MAX6369–MAX6374 are pin-selectable watchdog timers that supervise microprocessor (µP) activity and signal when a system is operating improperly. During normal operation, the microprocessor should repeated-ly toggle the watchdog input (WDI) before the selected watchdog timeout period elapses to demonstrate that the system is processing code properly. If the µP does not provide a valid watchdog input transition before the timeout period expires, the supervisor asserts a watch-dog (WDO ) output to signal that the system is not exe-cuting the desired instructions within the expected time frame. The watchdog output pulse can be used to reset the µP or interrupt the system to warn of processing errors.The MAX6369–MAX6374 are flexible watchdog timer supervisors that can increase system reliability through notification of code execution errors. The family offers several pin-selectable watchdog timing options to match a wide range of system timing applications:•Watchdog startup delay: provides an initial delay before the watchdog timer is started.•Watchdog timeout period: normal operating watch-dog timeout period after the initial startup delay.•Watchdog output/timing options: open drain (100ms)or push-pull (1ms).The MAX6369–MAX6374 operate over a +2.5V to +5.5V supply range and are available in miniature 8-pin SOT23 packages.________________________ApplicationsEmbedded Control Systems Industrial ControllersCritical µP and Microcontroller (µC) Monitoring AutomotiveTelecommunications NetworkingFeatures♦Precision Watchdog Timer for Critical µP Applications ♦Pin-Selectable Watchdog Timeout Periods ♦Pin-Selectable Watchdog Startup Delay Periods ♦Ability to Change Watchdog Timing Characteristics Without Power Cycling ♦Open-Drain or Push-Pull Pulsed Active-Low Watchdog Output ♦Watchdog Timer Disable Feature ♦+2.5V to +5.5V Operating Voltage ♦8µA Low Supply Current♦No External Components Required ♦Miniature 8-Pin SOT23 PackageMAX6369–MAX6374Pin-Selectable Watchdog Timers19-1676; Rev 3; 11/05Ordering InformationPin Configuration appears at end of data sheet.Note:All devices are available in tape-and-reel only. Required order increment is 2,500 pieces.Devices are available in both leaded and lead-free packaging.Specify lead-free by replacing “-T” with “+T” when ordering.Selector GuideFor pricing, delivery, and ordering information,please contact Maxim/Dallas Direct!at1-888-629-4642, or visit Maxim’s website at .M A X 6369–M A X 6374Pin-Selectable Watchdog Timers 2_______________________________________________________________________________________ABSOLUTE MAXIMUM RATINGSELECTRICAL CHARACTERISTICS(V CC = +2.5V to +5.5V, SET_ = V CC or GND, T A = -40°C to +85°C, unless otherwise noted. Typical values are at T A = +25°C andStresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.Terminal Voltage (with respect to GND)V CC .....................................................................-0.3V to +6V WDI.....................................................................-0.3V to +6V WDO (Open Drain: MAX6369/71/73).................-0.3V to +6V WDO (Push-Pull: MAX6370/72/74 .......-0.3V to (V CC + 0.3V)SET0, SET1, SET2................................-0.3V to (V CC + 0.3V)Maximum Current, Any Pin (input/output)...........................20mAContinuous Power Dissipation (T A = +70°C)SOT23-8 (derate 8.75mW/°C above +70°C)...............700mW Operating Temperature Range ...........................-40°C to +85°C Storage Temperature Range.............................-65°C to +150°C Junction Temperature......................................................+150°C Lead Temperature (soldering, 10s).................................+300°C V CC Rise or Fall Rate......................................................0.05V/µsMAX6369–MAX6374Pin-Selectable Watchdog Timers_______________________________________________________________________________________3ELECTRICAL CHARACTERISTICS (continued)M A X 6369–M A X 6374Pin-Selectable Watchdog Timers 4_______________________________________________________________________________________461081214-4010-15356085SUPPLY CURRENT vs. TEMPERATURETEMPERATURE (°C)S U P P L Y C U R R E N T (µA )Typical Operating Characteristics(Circuit of Figure 1, T A = +25°C, unless otherwise noted .)0.9970.9990.9981.0011.0001.0021.003-4010-15356085WATCHDOG TIMEOUT PERIODvs. TEMPERATUREM A X 6369/74-02TEMPERATURE (°C)N O R M A L I Z E D W A T C H D O G T I M E O U T P E R I O DELECTRICAL CHARACTERISTICS (continued)Note 2:Guaranteed by design.Note 3:In this setting the watchdog timer is inactive and startup delay ends when WDI sees its first level transition. See SelectingDevice Timing for more information.Note 4:After power-up, or a setting change, there is an internal setup time during which WDI is ignored.MAX6369–MAX6374Pin-Selectable Watchdog Timers_______________________________________________________________________________________5Pin DescriptionDetailed DescriptionThe MAX6369–MAX6374 are flexible watchdog circuits for monitoring µP activity. During normal operation, the internal timer is cleared each time the µP toggles the WDI with a valid logic transition (low to high or high to low) within the selected timeout period (t WD ). The WDO remains high as long as the input is strobed within the selected timeout period. If the input is not strobed before the timeout period expires, the watchdog output is asserted low for the watchdog output pulse width (t WDO ). The device type and the state of the three logic control pins (SET0, SET1, and SET2) determine watch-dog timing characteristics. The three basic timing varia-tions for the watchdog startup delay and the normalTable 1 for the timeout characteristics for all devices in the family):•Watchdog Startup Delay:Provides an initial delay before the watchdog timer is started.Allows time for the µP system to power up and initial-ize before assuming responsibility for normal watch-dog timer updates.Includes several fixed or pin-selectable startup delay options from 200µs to 60s, and an option to wait for the first watchdog input transition before starting the watchdog timer.M A X 6369–M A X 6374Pin-Selectable Watchdog Timers 6_______________________________________________________________________________________•Watchdog Timeout Period:Normal operating watchdog timeout period after the initial startup delay.A watchdog output pulse is asserted if a valid watch-dog input transition is not received before the timeout period elapses.Eight pin-selectable timeout period options for each device, from 30µs to 60s.Pin-selectable watchdog timer disable feature.•Watchdog Output/Timing Options:Open drain, active low with 100ms minimum watch-dog output pulse (MAX6369/MAX6371/MAX6373).Push-pull, active low with 1ms minimum watchdog output pulse (MAX6370/MAX6372/MAX6374).Each device has a watchdog startup delay that is initi-ated when the supervisor is first powered or after the user modifies any of the logic control set inputs. The watchdog timer does not begin to count down until theFigure 1. Functional Diagramcompletion of the startup delay period, and no watch-dog output pulses are asserted during the startup delay. When the startup delay expires, the watchdog begins counting its normal watchdog timeout period and waiting for WDI transitions. The startup delay allows time for the µP system to power up and fully ini-tialize before assuming responsibility for the normal watchdog timer updates. Startup delay periods vary between the different devices and may be altered by the logic control set pins. To ensure that the system generates no undesired watchdog outputs, the routine watchdog input transitions should begin before the selected minimum startup delay period has expired. The normal watchdog timeout period countdown is initi-ated when the startup delay is complete. If a valid logic transition is not recognized at WDI before the watchdog timeout period has expired, the supervisor asserts a watchdog output. Watchdog timeout periods vary between the different devices and may be altered by the logic control set pins. To ensure that the system generates no undesired watchdog outputs, the watch-dog input transitions should occur before the selected minimum watchdog timeout period has expired.The startup delay and the watchdog timeout period are determined by the states of the SET0, SET1, and SET2 pins, and by the particular device within the family. For the MAX6369 and MAX6370, the startup delay is equal to the watchdog timeout period. The startup and watchdog timeout periods are pin selectable from 1ms to 60s (minimum).For the MAX6371 and MAX6372, the startup delay is fixed at 60s and the watchdog timeout period is pin selectable from 1ms to 60s (minimum).The MAX6373/MAX6374 provide two timing variations for the startup delay and normal watchdog timeout. Five of the pin-selectable modes provide startup delays from 200µs to 60s minimum, and watchdog timeout delays from 3ms to 10s minimum. Two of the selectable modes do not initiate the watchdog timer until the device receives its first valid watchdog input transition (there is no fixed period by which the first input must be received). These two extended startup delay modesare useful for applications requiring more than 60s for system initialization.All the MAX6369–MAX6374 devices may be disabledwith the proper logic control pin setting (Table 1).Applications InformationInput Signal Considerations Watchdog timing is measured from the last WDI risingor falling edge associated with a pulse of at least 100nsin width. WDI transitions are ignored when WDO is asserted, and during the startup delay period (Figure2). Watchdog input transitions are also ignored for asetup period, t SETUP, of up to 300µs after power-up ora setting change (Figure 3).Selecting Device TimingSET2, SET1, and SET0 program the startup delay and watchdog timeout periods (Table 1). Timeout settingscan be hard wired, or they can be controlled with logicgates and modified during operation. To ensure smooth transitions, the system should strobe WDI immediately before the timing settings are changed. This minimizesthe risk of initializing a setting change too late in thetimer countdown period and generating undesired watchdog outputs. After changing the timing settings,two outcomes are possible based on WDO. If the change is made while WDO is asserted, the previous setting is allowed to finish, the characteristics of thenew setting are assumed, and the new startup phase is entered after a 300µs setup time (t SETUP) elapses. Ifthe change is made while WDO is not asserted, thenew setting is initiated immediately, and the new start-up phase is entered after the 300µs setup time elapses.MAX6369–MAX6374Pin-Selectable Watchdog Timers_______________________________________________________________________________________7 Figure 3. Setting Change TimingM A X 6369–M A X 6374Pin-Selectable Watchdog TimersSelecting 011 (SET2 = 0, SET1 = 1, SET0 = 1) disables the watchdog timer function on all devices in the family.Operation can be reenabled without powering down by changing the set inputs to the new desired setting. The device assumes the new selected timing characteris-tics and enter the startup phase after the 300µs setup time elapses (Figure 3).The MAX6373/MAX6374 offer a first-edge feature. In first-edge mode (settings 101 or 110, Table 1), the internal timer does not control the startup delay period.Instead, startup terminates when WDI sees a transition.If changing to first-edge mode while the device is oper-ating, disable mode must be entered first. It is then safe to select first-edge mode. Entering disable mode first ensures the output is unasserted when selecting first-edge mode and removes the danger of WDI being masked out.OutputThe MAX6369/MAX6371/MAX6373 have an active-low,open-drain output that provides a watchdog output pulse of 100ms. This output structure sinks current when WDO is asserted. Connect a pullup resistor from WDO to any supply voltage up to +5.5V.Select a resistor value large enough to register a logic low (see Ele ctrical Characte ristics ), and small enoughto register a logic high while supplying all input current and leakage paths connected to the WDO line. A 10k Ωpullup is sufficient in most applications. The MAX6370/MAX6372/MAX6374 have push-pull outputs that pro-vide an active-low watchdog output pulse of 1ms.When WDO deasserts, timing begins again at the beginning of the watchdog timeout period (Figure 2).Usage in Noisy EnvironmentsIf using the watchdog timer in an electrically noisy envi-ronment, a bypass capacitor of 0.1µF should be con-nected between V CC and GND as close to the device as possible, and no further away than 0.2 inches.________________Watchdog SoftwareConsiderationsTo help the watchdog timer monitor software execution more closely, set and reset the watchdog input at differ-ent points in the program, rather than pulsing the watch-dog input high-low-high or low-high-low. This technique avoids a stuck loop, in which the watchdog timer would continue to be reset inside the loop, keeping the watch-dog from timing out. Figure 4 shows an example of a flow diagram where the I/O driving the watchdog input is set high at the beginning of the program, set low at the end of every subroutine or loop, then set high again when the program returns to the beginning. If the pro-gram should hang in any subroutine, the problem would be quickly corrected, since the I/O is continually set low and the watchdog timer is allowed to time out, causing WDO to pulse.Figure 4. Watchdog Flow DiagramChip InformationTRANSISTOR COUNT: 1500PROCESS: BiCMOSPin ConfigurationMaxim cannot assume re sponsibility for use of any circuitry othe r than circuitry e ntire ly e mbodie d in a Maxim product. No circuit pate nt lice nse s are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.8_____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600©2005 Maxim Integrated ProductsPrinted USAis a registered trademark of Maxim Integrated Products, Inc.。

Kenwood TK-941 Conversion 33-centimeter Programmin

Ray Montagne - W7CIAThe frequency must be converted to a Kenwood Channel Number prior to programming. The following table, obtained from the KW900EZP program documentation by K2MCI, is used to obtain the channel number for the target frequencies:927 902919907920908921909926903 801602403200.00001811612413210.0125 2821622423220.0250 3831632433230.0375 4841642443240.0500 5851652453250.0625 6861662463260.0750 7871672473270.0875 8881682483280.1000 9891692493290.1125 10901702503300.1250 11911712513310.1375 12921722523320.1500 13931732533330.1625 14941742543340.1750 15951752553350.1875 16961762563360.2000 17971772573370.2125 18981782583380.2250 19991792593390.2375 201001802603400.2500 211011812613410.2625 221021822623420.2750 231031832633430.2875 241041842643440.3000 251051852653450.3125 261061862563460.3250 271071872573470.3375 281081882583480.3500 291091892593490.3625 301101902603500.3750 311111912613510.3875 321121922623520.4000 331131932633530.4125 341141942643540.4250 351151952653550.4375 361161962663560.4500 371171972673570.4625 381181982683580.4750 391191992693590.4875 401202002703600.5000 411212012713610.5125 421222022723620.5250 431232032733630.5375 441242042743640.5500 451252052753650.5625 461262062763660.5750 471272072773670.5875 481282082783680.6000 491292092793690.6125927 902919907920908921909926903501302102803700.6250511312112813710.6375521322122823720.6500531332132833730.6625541342142843740.6750551352152853750.6875561362162863760.7000571372172873770.7125581382182883780.7250591392192893790.7375601402202903800.7500611412212913810.7625621422222923820.7750631432232933830.7875641442242943840.8000651452252953850.8125661462262963860.8250671472272973870.8375681482282983880.8500691492292993890.8675701502303003900.8750711512313013910.8875721522323023920.9000731532333033930.9125741542343043940.9250751552353053050.9375761562363063960.9500771572373073970.9625781582383083980.9750791592393093990.9875The target frequency pairs of 927.2125 / 902.2125 and 927.2250 / 902.2250 use FCC channels 17 and 18 respectively.Programming ProcedureI. Launch KPG-25D.exe and start with an empty template by selecting New from the File menu.II. Set the Model to TK-941.III. Select Feature Option from the Edit menu.IV. Set the T.O.T. (Dispatch) parameter to 600. This is the transmission time limit, in dispatch mode, expressed in 15 seconds per step with a range of from 15 seconds to 600 seconds. The default is 60 seconds. These are set to 10 minutes (600 seconds) so that the timers in the repeater controller can be used.V. Set the T.O.T. (Tel)parameter to 600. This is the transmission time limit, in telephone mode, expressed in 15 seconds per step with a range of from 15 seconds to 600 seconds. The default is 180 seconds. These are set to 10 minutes (600 seconds) so that the timers in the repeater controller can be used.VI. Set the Drop out delay time parameter to 1. This sets the time between carrier detect drop out and the resumption of scanning. This parameter can be set from 0 to 254 seconds at 1 second per count. The default is 3 seconds.VII. Set the dwell time parameter to 1. This sets the time between the end of transmission and the resumption of scanning. This parameter can be set from 0 to 254 seconds at 1 second per count. The default is 15 seconds.VIII. Set the Transpond delay time parameter to 3. This sets the delay from the decode of a transpond enabled ID to the beginning of a transpond transmission. This parameter can be set from 0 to 254 seconds at 1 second per count. The default is 3 seconds. If this parameter is set to a value greater than the Drop out delay time then the Drop out delay time will be used as the Transpond delay time.IX. Set the TX inhibit time parameter to 5.0. This parameter sets the period of time that the transmitter is inhibited after an inhibited ID is detected. The value can be set from 0.5 seconds to 8.0 seconds in 0.5 second steps.X. Set the Aux switch parameter to N/A. This parameter toggles the following functions off:A. N/A: No functionB. Option Sig: Option signaling board reset switch.C. Manual Relay: Auxiliary output signal ON/OFF.D. Horn Alert: Horn Alert ON/OFFE. Telephone Search: Automatically searches for a vacant telephone channel (trunked system).F. ALP/Sys.Grp.: Toggle display between alphanumeric or the system & group number.G. Fixed Call: Reset radio to a pre-programmed system & group.H. Del/Add: Provides the user system Delete / Add button.XI. Set the Scan switch parameter to List scan. This parameter sets the scan type selection as follows:A. N/A:Disables the scan switch function and sounds an alert tone (if programmed) when the scan key ispressed.B. List Scan: Automatic roaming scan.C. Fix System Scan: Operator selectable system scan.XII. Set the Revert sys type parameter to Last Use. This parameter sets the programmable transmit destination system & group during scanning. Options include:A. Last Used: Last transmitted system & group.B. Last Called: Last received system & group.XIII. Set the Free System ring back parameter to No. This feature is only active during telephone use (trunked system). The radio will beep when the telephone interconnect line is not busy.XIV. Set the Clear to talk beep parameter to Yes. Upon successful access of a trunked system, this beep tone sounds to alert the user they can begin speaking.XV. Set the System search parameter to None. While a selected system is busy (the radio sounds an intercept tone) then release the PTT key, the radio will start to search for an available system automatically or manually. Options include:A. None: Disable system search.B. Auto: During the intercept tone, keep the PTT key held down and press the SCAN key. Upon release of theSCAN key, system search begins.C. Manual: During the intercept tone, releasing the PTT will initiate auto system search.XVI. Set the Display Character parameter to Grp Name. This parameter selects the display character Group name (Alphanumeric) or System & Group number. If you select the AUX switch as the display character, this selection will be just as default. Options include:A. Sys Grp: Set the display character as System & Group number.B. Grp Name: Set the display character as alphanumeric (pre-programing necessary).XVII. Set the Minimum volume parameter to 0. The minimum volume is the level which will be set automatically every time you turn on the radio. If the volume is adjusted below this level prior to turning the radio off, the volume will be set to this level the next time the radio is turned on. In order to ensure that the speaker is quiet at the repeater site, this value is set to zero. The default value is 8.XVIII. Set the Off hook scan parameter to Disable. The radio is able to scan, even with the mic off hook. Options include:A. Enable: Scan start & stop is independent of the mic hook switch.B. Disable: Mic must be on hook for scanning to start.XIX. Set the Off hook horn alt parameter to Disable. Horn alert is auto disabled when the microphone goes off hook Options include:A. Enable: Off hook auto disable.B. Disable: Manual disable only.XX. Set the Off hook decode parameter to Enable. The radio is still tone squelched, even though the mic is in the off hook condition (valid for QT, DQT and Option Signaling board decode). Options include:A. Enable: Decode signaling active even in the off hook condition.B. Disable: Decode signaling is disabled during off hook.Setting this parameter to Enable allows the radio to operate in decode without having to wire the off-hook signal to the on-hook position.XXI. Set the Access logic sig parameter to Sngl. Pulse. This logic signal is useful for external radio control unit (i.e. Mobile Data Terminal, Computer Aided Dispatch or Over The Air Re-Programming etc) that require a signal at the time of successful trunked repeater access. Options include:A. Continuous: Logic Level high during length of access.B. Sng. Pulse: Logic level high pulse at the time of a successful handshake.XXII. Set the Horn alt logic sig parameter to Pulse. The Horn Alert logic can be used to drive a vehicle horn relay, light or other device. The logic level signal can be set for a continuous (EX: light) or momentary pulse output (EX: vehicle horn relay). Options include:A. Continuous: Continuous logic level low output until reset.B. Pulse: Momentary logic level low output.XXIII.The options should now appear as:XXIV. Layout all of the repeater input frequencies in the first group. Setup each repeater output frequency in a separate system. Using the Kenwood3.exe program, the hexadecimal representation of each frequency can be determined (as seen in the table below).Group & System ConfigurationGroup 1Group 2Group 3Group 4Group 5Group 6Group 7Group 81KC7MCCTX A927.2125CarrierCH. 170xD197KC7MCCTX A927.2125EncodeCH. 170xD197KC7MCCRX A902.2125CarrierCH. 170x0190KC7MCCRX A902.2125EncodeCH. 170x0190KC7MCCTX B927.2250CarrierCH. 180xD297KC7MCCTX B927.2250EncodeCH. 180xD297KC7MCCRX B902.2250CarrierCH. 180x0290KC7MCCRX B902.2250EncodeCH. 180x0290The carrier access groups are not intended for active use but support test configurations, such as performing a -12 dB SINAD measurement on a receiver.XXV. Set the system configuration to Conventional.XXVI. Hit Enter to edit the system configuration.XXVII. Program each group as follows:A. Set the FCC field to 200.B. Set the transmit Encode field as appropriate.C. Set the receive Decode field as appropriate.D. Set the Grp-Name field as appropriate. Use unique text that will help you identify the group name whenusing the HxD program at a later step.E. Set the TlkArnd field to Yes.F. Leave all other fields at their default values.XXVIII. Save the KPG25D configuration file.XXIX. Exit the KPG25D.exe program.XXX. The KPG25D.exe program will have inserted a value of 0x089B, corresponding to channel 200 or 937.5000 MHz, into each of the frequency slots. The channel numbers are stored as a 16-bit word in little endian format. Endian swapping the default channel value results in a value of 0x9B08, which converts to a decimal value of 39688. The decimal channel value can be determined by subtracting the target frequency from 937.5000 MHz and then dividing by the channel frequency step size of 0.0125 MHz. The resulting value is then subtracted from a value of 38923, converted back to hexadecimal and then endian swapped into little endian format before storing the frequency. This is apparently what the Kenwood3.exe program does (except that the conversion to decimal and endian swapping is not required in programming since little endian is the native format for x86 processors).XXXI. Launch the HxD.exe program.XXXII. Open the KPG25D data file with the HxD program.XXXIII. Locate each frequency entry with a value of 0x089B and edit the value to the appropriate value obtained from the Kenwood3.exe program. The Grp-Name field data will be visible in the window and will help to locate the 0x089B value associated with a specific group name..XXXIV. Save the file and exit the Kenwood3.exe program.XXXV. Launch the KPG25D.exe program.XXXVI. Load the KPG25D data file.XXXVII. A view of the Feature option window will show the new channel data.XXXVIII. Program the radio.Filter InstallationTwo TK-941 radios are used to implement the full-duplex link back-bone, with one radio acting as the transmitter and the other radio acting as the receiver. The front-end filter on the receive radio must be swapped out with a filter that has the bandpass frequency having the receive frequency fall within the bandpass.A hot air SMD station was used to remove the pair of filters from the TK-941 receive radio front-end. 915 MHz filters were then installed using a standard soldering station. Note that the filter terminals did not align with the solder pads on the printed circuit board. The terminals had to be bent in to contact the pads prior to soldering. A check was made, using an Ohm meter, to verify that the terminals did not short to the ground traces surrounding the filter terminal pads.Upon completion of the filter installation, the VCO was adjusted to obtain VCO lock.Repeater Controller Interface - Receive RadioThe repeater controller interface requires access to the COS signal and de-emphasized audio. The signal driving the BASE of Q20 presents an Active LOW COS. Further, the COS signal carries only the COS when programmed for COS access or the logical NAND of COS and Tone Decode when programmed for tone or DCS access. The observed logic level on the COS signal shows 3.6 volts when HIGH.Squelch gated de-emphasized audio is available at the junction of C75 and IC6-13. The signal level of the audio, using a 1KHz tone with 3KHz deviation (as used for a -12 dB SINAD measurement), was observed to be 1.2 Vpp.The following annotated PCB view shows where to connect the COS and Gated Audio signals to interface to the repeater controller.The following image shows the repeater controller interface wires attached to the receive radio. The COS wire is blue. The squelch gated de-emphasized audio is orange. A black ground connection is made at emitter of Q20. A Dremel tool was used to grind a small slot to route the cable out of the RF shielded area where the interface signals are available. A Hot Glue gun was used to fasten down the wires, providing strain relief for the PCB pad connections.The power cable chassis strain relief can be lifted, exposing a small but removable plug. Removing this plug allows for routing of the repeater controller interface wires out of the radio chassis.Repeater Controller Interface - Transmit RadioThe transmit radio requires access to the PTT and Microphone input signals. The front panel was removed in preparation to route wires from under the power cable and on to through the chassis to the front panel PCB.The attachment points on the back of the front panel PCB are well marked as follows:1. PTT: Push-to-talk (Green Wire)2. ME: Microphone Return (audio-signal-ground - Black Wire)3. MI: Microphone Input (Red Wire)。

MAX6389XS19D7+T中文资料

General Description The MAX6381–MAX6390 microprocessor (µP) supervisory circuits monitor power-supply voltages from +1.8V to +5.0V while consuming only 3µA of supply current at +1.8V. Whenever V CC falls below the factory-set reset thresholds, the reset output asserts and remains assert-ed for a minimum reset timeout period after V CC rises above the reset threshold. Reset thresholds are available from +1.58V to +4.63V, in approximately 100mV incre-ments. Seven minimum reset timeout delays ranging from 1ms to 1200ms are available.The MAX6381/MAX6384/MAX6387 have a push-pull active-low reset output. The MAX6382/MAX6385/ MAX6388 have a push-pull active-high reset output, and the MAX6383/MAX6386/MAX6389/MAX6390 have an open-drain active-low reset output. The MAX6384/MAX6385/MAX6386 also feature a debounced manual reset input (with internal pullup resistor). The MAX6387/MAX6388/MAX6389 have an auxiliary input for monitoring a second voltage. The MAX6390 offers a manual reset input with a longer V CC reset timeout period (1120ms or 1200ms) and a shorter manual reset timeout (140ms or 150ms).The MAX6381/MAX6382/MAX6383 are available in 3-pin SC70 and6-pinµDFN packages and the MAX6384–MAX6390 are available in 4-pin SC70 andFeatures♦Factory-Set Reset Threshold Voltages Rangingfrom +1.58V to +4.63V in Approximately 100mVIncrements♦±2.5% Reset Threshold Accuracy OverTemperature (-40°C to +125°C)♦Seven Reset Timeout Periods Available: 1ms,20ms, 140ms, 280ms, 560ms, 1120ms,1200ms (min)♦3 Reset Output OptionsActive-Low Push-PullActive-High Push-PullActive-Low Open-Drain♦Reset Output State Guaranteed ValidDown to V CC= 1V♦Manual Reset Input (MAX6384/MAX6385/MAX6386)♦Auxiliary RESET IN(MAX6387/MAX6388/MAX6389)♦V CC Reset Timeout (1120ms or 1200ms)/ManualReset Timeout (140ms or 150ms) (MAX6390)♦Negative-Going V CC Transient Immunity♦Low Power Consumption of 6µA at +3.6Vand 3µA at +1.8V♦Pin Compatible withMAX809/MAX810/MAX803/MAX6326/MAX6327/MAX6328/MAX6346/MAX6347/MAX6348,and MAX6711/MAX6712/MAX6713♦Tiny 3-Pin/4-Pin SC70 and 6-Pin µDFN PackagesMAX6381–MAX6390 SC70/µDFN, Single/Dual Low-Voltage,Low-Power µP Reset Circuits ________________________________________________________________Maxim Integrated Products1Pin Configurations19-1839; Rev 4; 4/07Ordering InformationOrdering Information continued at end of data sheet.Typi cal Operati ng Ci rcui t appears at end of data sheet.Selector Guide appears at end of data sheet.after "XR", "XS", or "LT." Insert reset timeout delay (see ResetTimeout Delay table) after "D" to complete the part number.Sample stock is generally held on standard versions only (seeStandard Versions table). Standard versions have an orderincrement requirement of 2500 pieces. Nonstandard versionshave an order increment requirement of 10,000 pieces.Contact factory for availability of nonstandard versions.+Denotes a lead-free package.For pricing, delivery, and ordering information,please contact Maxim Direct at 1-888-629-4642,or visit Maxim’s website at .ComputersControllersIntelligent InstrumentsCritical µP and µCPower MonitoringPortable/Battery-Powered EquipmentDual Voltage SystemsM A X 6381–M A X 6390SC70/µDFN, Single/Dual Low-Voltage, Low-Power µP Reset CircuitsABSOLUTE MAXIMUM RATINGSELECTRICAL CHARACTERISTICS(V CC = full range, T A = -40°C to +125°C, unless otherwise specified. Typical values are at T A = +25°C.) (Note 1)Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.V CC to GND..........................................................-0.3V to +6.0V RESET Open-Drain Output....................................-0.3V to +6.0V RESET , RESET (push-pull output)..............-0.3V to (V CC + 0.3V)MR , RESET IN.............................................-0.3V to (V CC + 0.3V)Input Current (V CC ).............................................................20mA Output Current (all pins).....................................................20mAContinuous Power Dissipation (T A = +70°C)3-Pin SC70 (derate 2.9mW/°C above +70°C)..............235mW 4-Pin SC70 (derate 3.1mW/°C above +70°C)..............245mW 6-Pin µDFN (derate 2.1mW/°C above +70°C)..........167.7mW Operating Temperature Range .........................-40°C to +125°C Storage Temperature Range.............................-65°C to +150°C Lead Temperature (soldering, 10s).................................+300°CMAX6381–MAX6390SC70/µDFN, Single/Dual Low-Voltage,Low-Power µP Reset Circuits_______________________________________________________________________________________3M A X 6381–M A X 6390SC70/µDFN, Single/Dual Low-Voltage, Low-Power µP Reset Circuits 4______________________________________________________________________________________Typical Operating Characteristics(T A = +25°C, unless otherwise noted.)215436789-40-105-25203550658095110125SUPPLY CURRENT vs. TEMPERATURE(NO LOAD)TEMPERATURE (°C)S U P P L Y C U R R E N T (µA )25292735333137394143-40-105-25203550658095110125POWER-DOWN RESET DELAYvs. TEMPERATURETEMPERATURE (°C)P O W E R -D O W N R E S E T D E L A Y (µs )0.940.980.961.021.001.061.041.08-40-10520-253550658095110125NORMALIZED POWER-UP RESET TIMEOUTvs. TEMPERATUREM A X 6381/90 t o c 03TEMPERATURE (°C)N O R M A L I Z E D R E S E T T I M E O U T P E R I O D0.9900.9851.0150.9950.9901.0001.0051.0101.020-40-10520-253550958011065125M A X 6381/90 t o c 04TEMPERATURE (°C)N O R M A L I Z E D R E S E T TH R E S H O L D NORMALIZED RESET THRESHOLDvs. TEMPERATURE00.40.20.80.61.01.2063912OUTPUT-VOLTAGE LOW vs. SINK CURRENTI SINK (mA)V O L (V )01.00.52.01.52.53.00500750250100012501500OUTPUT-VOLTAGE HIGH vs. SOURCE CURRENTI SOURCE (µA)V O H (V )45001100010010MAXIMUM TRANSIENT DURATION vs. RESET COMPARATOR OVERDRIVE15050350250500200100400300RESET COMPARATOR OVERDRIVE, V TH - V CC (mV)M A X I M U M T R A N S I E N T D U R A T I O N (µs )3.53.93.74.54.34.14.74.95.35.15.5-40-105-25203550658095110125RESET IN TO RESET DELAYvs. TEMPERATUREM A X 6381/90 t o c 08TEMPERATURE (°C)R E S E T I N D E L A Y (µs )MAX6381–MAX6390SC70/µDFN, Single/Dual Low-Voltage,Low-Power µP Reset CircuitsPin DescriptionM A X 6381–M A X 6390SC70/µDFN, Single/Dual Low-Voltage, Low-Power µP Reset Circuits 6_______________________________________________________________________________________Detailed DescriptionRESET OutputA µP reset input starts the µP in a known state. These µP supervisory circuits assert reset to prevent code execution errors during power-up, power-down, or brownout conditions.Reset asserts when V CC is below the reset threshold;once V CC exceeds the reset threshold, an internal timer keeps the reset output asserted for the reset timeout period. After this interval, reset output deasserts. Reset output is guaranteed to be in the correct logic state for V CC ≥1V.Manual Reset Input (MAX6384/MAX6385/MAX6386/MAX6390)Many µP-based products require manual reset capabil-ity, allowing the operator, a test technician, or external logic circuitry to initiate a reset. A logic low on MR asserts reset. Reset remains asserted while MR is low,and for the reset active timeout period (t RP ) after MR returns high. This input has an internal 63k Ωpullup resistor (1.56k Ωfor MAX6390), so it can be left uncon-nected if it is not used. MR can be driven with TTL or CMOS logic levels, or with open-drain/collector outputs.Connect a normally open momentary switch from MR to G ND to create a manual-reset function; external debounce circuitry is not required. If MR is driven from long cables or if the device is used in a noisy environ-ment, connecting a 0.1µF capacitor from MR to G ND provides additional noise immunity.RESET IN Comparator(MAX6387/MAX6388/MAX6389)RESET IN is compared to an internal +1.27V reference.If the voltage at RESET IN is less than 1.27V, reset asserts. Use the RESET IN comparator as a user-adjustable reset detector or as a secondary power-sup-ply monitor by implementing a resistor-divider at RESET IN (shown in Figure 1). Reset asserts when either V CC or RESET IN falls below its respective threshold volt-age. Use the following equation to set the threshold:V INTH = V THRST (R1/R2 + 1)where V THRST = +1.27V. To simplify the resistor selec-tion, choose a value of R2 and calculate R1:R1 = R2 [(V INTH /V THRST ) - 1]Since the input current at RESET IN is 50nA (max),large values can be used for R2 with no significant loss in accuracy.___________Applications InformationNegative-Going V CC TransientsIn addition to issuing a reset to the µP during power-up,power-down, and brownout conditions, the MAX6381–MAX6390 are relatively immune to short dura-tion negative-going V CC transients (glitches).The Typical Operating Characteristics section shows the Maximum Transient Durations vs. Reset Comparator Overdrive, for which the MAX6381–MAX6390 do not generate a reset pulse. This graph was generated usinga negative-going pulse applied to V CC , starting above the actual reset threshold and ending below it by the magnitude indicated (reset comparator overdrive). The graph indicates the typical maximum pulse width a neg-ative-going V CC transient may have without causing a reset pulse to be issued. As the magnitude of the tran-sient increases (goes farther below the reset threshold),the maximum allowable pulse width decreases. A 0.1µF capacitor mounted as close as possible to V CC provides additional transient immunity.Ensuring a Valid RESET Output Down to V CC = 0VThe MAX6381–MAX6390 are guaranteed to operate properly down to V CC = 1V. In applications that require valid reset levels down to V CC = 0V, a pulldown resistor to active-low outputs (push/pull only, Figure 2) and a pullup resistor to active-high outputs (push/pull only)will ensure that the reset line is valid while the reset out-put can no longer sink or source current. This schemedoes not work with the open-drain outputs of the MAX6383/MAX6386/MAX6389/MAX6390. The resistor value used is not critical, but it must be small enough not to load the reset output when V CC is above the reset threshold. For most applications, 100k Ωis ade-quate.MAX6381–MAX6390SC70/µDFN, Single/Dual Low-Voltage,Low-Power µP Reset Circuits_______________________________________________________________________________________7M A X 6381–M A X 6390SC70/µDFN, Single/Dual Low-Voltage, Low-Power µP Reset Circuits 8_______________________________________________________________________________________Selector GuideOrdering Information (continued)Note:Insert reset threshold suffix (see Reset Threshold table)after "XR", "XS", or "LT." Insert reset timeout delay (see Reset Timeout Delay table) after "D" to complete the part number.Sample stock is generally held on standard versions only (see Standard Versions table). Standard versions have an order increment requirement of 2500 pieces. Nonstandard versions have an order increment requirement of 10,000 pieces.Contact factory for availability of nonstandard versions.*MAX6390 is available with D4 or D7 timing only.+Denotes a lead-free package.MAX6381–MAX6390SC70/µDFN, Single/Dual Low-Voltage,Low-Power µP Reset Circuits_______________________________________________________________________________________9Chip InformationTRANSISTOR COUNT: 647PROCESS: BiCMOSPin Configurations (continued)M A X 6381–M A X 6390SC70/µDFN, Single/Dual Low-Voltage, Low-Power µP Reset Circuits 10______________________________________________________________________________________Package Information(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,go to /packages .)MAX6381–MAX6390SC70/µDFN, Single/Dual Low-Voltage,Low-Power µP Reset Circuits______________________________________________________________________________________11Package Information (continued)(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,go to /packages .)M A X 6381–M A X 6390SC70/µDFN, Single/Dual Low-Voltage, Low-Power µP Reset Circuits 12______________________________________________________________________________________Package Information (continued)(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,go to /packages .)SC70/µDFN, Single/Dual Low-Voltage,Low-Power µP Reset CircuitsMaxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600____________________13©2007 Maxim Integrated Productsis a registered trademark of Maxim Integrated Products, Inc.MAX6381–MAX6390Package Information (continued)(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,go to /packages .)Revision HistoryPages changed at Rev 4: Title on all pages, 1, 2, 5,7–13。

MAX6373中文资料

General DescriptionThe MAX6369–MAX6374 are pin-selectable watchdog timers that supervise microprocessor (µP) activity and signal when a system is operating improperly. During normal operation, the microprocessor should repeated-ly toggle the watchdog input (WDI) before the selected watchdog timeout period elapses to demonstrate that the system is processing code properly. If the µP does not provide a valid watchdog input transition before the timeout period expires, the supervisor asserts a watch-dog (WDO ) output to signal that the system is not exe-cuting the desired instructions within the expected time frame. The watchdog output pulse can be used to reset the µP or interrupt the system to warn of processing errors.The MAX6369–MAX6374 are flexible watchdog timer supervisors that can increase system reliability through notification of code execution errors. The family offers several pin-selectable watchdog timing options to match a wide range of system timing applications:•Watchdog startup delay: provides an initial delay before the watchdog timer is started.•Watchdog timeout period: normal operating watch-dog timeout period after the initial startup delay.•Watchdog output/timing options: open drain (100ms)or push-pull (1ms).The MAX6369–MAX6374 operate over a +2.5V to +5.5V supply range and are available in miniature 8-pin SOT23 packages.________________________ApplicationsEmbedded Control Systems Industrial ControllersCritical µP and Microcontroller (µC) Monitoring AutomotiveTelecommunications NetworkingFeatureso Precision Watchdog Timer for Critical µP Applications o Pin-Selectable Watchdog Timeout Periods o Pin-Selectable Watchdog Startup Delay Periods o Ability to Change Watchdog Timing Characteristics Without Power Cycling o Open-Drain or Push-Pull Pulsed Active-Low Watchdog Output o Watchdog Timer Disable Feature o +2.5V to +5.5V Operating Voltage o 8µA Low Supply Currento No External Components Required o Miniature 8-Pin SOT23 PackageMAX6369–MAX6374Pin-Selectable Watchdog Timers19-1676; Rev 2; 2/03Ordering InformationPin Configuration appears at end of data sheet.Note:All devices are available in tape-and-reel only. Required order increment is 2,500 pieces.Selector GuideFor pricing, delivery, and ordering information,please contact Maxim/Dallas Direct!at1-888-629-4642, or visit Maxim’s website at .M A X 6369–M A X 6374Pin-Selectable Watchdog Timers 2_______________________________________________________________________________________ABSOLUTE MAXIMUM RATINGSELECTRICAL CHARACTERISTICS(V= +2.5V to +5.5V, SET_ = V or GND, T = -40°C to +85°C, unless otherwise noted. Typical values are at T = +25°C and Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.Terminal Voltage (with respect to GND)V CC .....................................................................-0.3V to +6V WDI.....................................................................-0.3V to +6V WDO (Open Drain: MAX6369/71/73).................-0.3V to +6V WDO (Push-Pull: MAX6370/72/74 .......-0.3V to (V CC + 0.3V)SET0, SET1, SET2................................-0.3V to (V CC + 0.3V)Maximum Current, Any Pin (input/output)...........................20mAContinuous Power Dissipation (T A = +70°C)SOT23-8 (derate 8.75mW/°C above +70°C)...............700mW Operating Temperature Range ...........................-40°C to +85°C Storage Temperature Range.............................-65°C to +150°C Junction Temperature......................................................+150°C Lead Temperature (soldering, 10s).................................+300°C V CC Rise or Fall Rate......................................................0.05V/µsMAX6369–MAX6374Pin-Selectable Watchdog Timers_______________________________________________________________________________________3ELECTRICAL CHARACTERISTICS (continued)M A X 6369–M A X 6374Pin-Selectable Watchdog Timers 4_______________________________________________________________________________________461081214-4010-15356085SUPPLY CURRENT vs. TEMPERATURETEMPERATURE (°C)S U P P L Y C U R R E N T (µA )Typical Operating Characteristics(Circuit of Figure 1, T A = +25°C, unless otherwise noted .)0.9970.9990.9981.0011.0001.0021.003-4010-15356085WATCHDOG TIMEOUT PERIODvs. TEMPERATUREM A X 6369/74-02TEMPERATURE (°C)N O R M A L I Z E D W A T C H D O G T I M E O U T P E R I O DELECTRICAL CHARACTERISTICS (continued)Note 2:Guaranteed by design.Note 3:In this setting the watchdog timer is inactive and startup delay ends when WDI sees its first level transition. See SelectingDevice Timing for more information.Note 4:After power-up, or a setting change, there is an internal setup time during which WDI is ignored.MAX6369–MAX6374Pin-Selectable Watchdog Timers_______________________________________________________________________________________5Pin DescriptionDetailed DescriptionThe MAX6369–MAX6374 are flexible watchdog circuits for monitoring µP activity. During normal operation, the internal timer is cleared each time the µP toggles the WDI with a valid logic transition (low to high or high to low) within the selected timeout period (t WD ). The WDO remains high as long as the input is strobed within the selected timeout period. If the input is not strobed before the timeout period expires, the watchdog output is asserted low for the watchdog output pulse width (t WDO ). The device type and the state of the three logic control pins (SET0, SET1, and SET2) determine watch-dog timing characteristics. The three basic timing varia-tions for the watchdog startup delay and the normalTable 1 for the timeout characteristics for all devices in the family):•Watchdog Startup Delay:Provides an initial delay before the watchdog timer is started.Allows time for the µP system to power up and initial-ize before assuming responsibility for normal watch-dog timer updates.Includes several fixed or pin-selectable startup delay options from 200µs to 60s, and an option to wait for the first watchdog input transition before starting the watchdog timer.M A X 6369–M A X 6374Pin-Selectable Watchdog Timers 6_______________________________________________________________________________________•Watchdog Timeout Period:Normal operating watchdog timeout period after the initial startup delay.A watchdog output pulse is asserted if a valid watch-dog input transition is not received before the timeout period elapses.Eight pin-selectable timeout period options for each device, from 30µs to 60s.Pin-selectable watchdog timer disable feature.•Watchdog Output/Timing Options:Open drain, active low with 100ms minimum watch-dog output pulse (MAX6369/MAX6371/MAX6373).Push-pull, active low with 1ms minimum watchdog output pulse (MAX6370/MAX6372/MAX6374).Each device has a watchdog startup delay that is initi-ated when the supervisor is first powered or after the user modifies any of the logic control set inputs. The watchdog timer does not begin to count down until theFigure 1. Functional Diagramcompletion of the startup delay period, and no watch-dog output pulses are asserted during the startup delay. When the startup delay expires, the watchdog begins counting its normal watchdog timeout period and waiting for WDI transitions. The startup delay allows time for the µP system to power up and fully ini-tialize before assuming responsibility for the normal watchdog timer updates. Startup delay periods vary between the different devices and may be altered by the logic control set pins. To ensure that the system generates no undesired watchdog outputs, the routine watchdog input transitions should begin before the selected minimum startup delay period has expired. The normal watchdog timeout period countdown is initi-ated when the startup delay is complete. If a valid logic transition is not recognized at WDI before the watchdog timeout period has expired, the supervisor asserts a watchdog output. Watchdog timeout periods vary between the different devices and may be altered by the logic control set pins. To ensure that the system generates no undesired watchdog outputs, the watch-dog input transitions should occur before the selected minimum watchdog timeout period has expired.The startup delay and the watchdog timeout period are determined by the states of the SET0, SET1, and SET2 pins, and by the particular device within the family. For the MAX6369 and MAX6370, the startup delay is equal to the watchdog timeout period. The startup and watchdog timeout periods are pin selectable from 1ms to 60s (minimum).For the MAX6371 and MAX6372, the startup delay is fixed at 60s and the watchdog timeout period is pin selectable from 1ms to 60s (minimum).The MAX6373/MAX6374 provide two timing variations for the startup delay and normal watchdog timeout. Five of the pin-selectable modes provide startup delays from 200µs to 60s minimum, and watchdog timeout delays from 3ms to 10s minimum. Two of the selectable modes do not initiate the watchdog timer until the device receives its first valid watchdog input transition (there is no fixed period by which the first input must be received). These two extended startup delay modesare useful for applications requiring more than 60s for system initialization.All the MAX6369–MAX6374 devices may be disabledwith the proper logic control pin setting (Table 1).Applications InformationInput Signal Considerations Watchdog timing is measured from the last WDI risingor falling edge associated with a pulse of at least 100nsin width. WDI transitions are ignored when WDO is asserted, and during the startup delay period (Figure2). Watchdog input transitions are also ignored for asetup period, t SETUP, of up to 300µs after power-up ora setting change (Figure 3).Selecting Device TimingSET2, SET1, and SET0 program the startup delay and watchdog timeout periods (Table 1). Timeout settingscan be hard wired, or they can be controlled with logicgates and modified during operation. To ensure smooth transitions, the system should strobe WDI immediately before the timing settings are changed. This minimizesthe risk of initializing a setting change too late in thetimer countdown period and generating undesired watchdog outputs. After changing the timing settings,two outcomes are possible based on WDO. If the change is made while WDO is asserted, the previous setting is allowed to finish, the characteristics of thenew setting are assumed, and the new startup phase is entered after a 300µs setup time (t SETUP) elapses. Ifthe change is made while WDO is not asserted, thenew setting is initiated immediately, and the new start-up phase is entered after the 300µs setup time elapses.MAX6369–MAX6374Pin-Selectable Watchdog Timers_______________________________________________________________________________________7 Figure 3. Setting Change TimingM A X 6369–M A X 6374Pin-Selectable Watchdog TimersSelecting 011 (SET2 = 0, SET1 = 1, SET0 = 1) disables the watchdog timer function on all devices in the family.Operation can be reenabled without powering down by changing the set inputs to the new desired setting. The device assumes the new selected timing characteris-tics and enter the startup phase after the 300µs setup time elapses (Figure 3).The MAX6373/MAX6374 offer a first-edge feature. In first-edge mode (settings 101 or 110, Table 1), the internal timer does not control the startup delay period.Instead, startup terminates when WDI sees a transition.If changing to first-edge mode while the device is oper-ating, disable mode must be entered first. It is then safe to select first-edge mode. Entering disable mode first ensures the output is unasserted when selecting first-edge mode and removes the danger of WDI being masked out.OutputThe MAX6369/MAX6371/MAX6373 have an active-low,open-drain output that provides a watchdog output pulse of 100ms. This output structure sinks current when WDO is asserted. Connect a pullup resistor from WDO to any supply voltage up to +5.5V.Select a resistor value large enough to register a logic low (see Electrical Characteristics ), and small enoughto register a logic high while supplying all input current and leakage paths connected to the WDO line. A 10k Ωpullup is sufficient in most applications. The MAX6370/MAX6372/MAX6374 have push-pull outputs that pro-vide an active-low watchdog output pulse of 1ms.When WDO deasserts, timing begins again at the beginning of the watchdog timeout period (Figure 2).Usage in Noisy EnvironmentsIf using the watchdog timer in an electrically noisy envi-ronment, a bypass capacitor of 0.1µF should be con-nected between V CC and GND as close to the device as possible, and no further away than 0.2 inches.________________Watchdog SoftwareConsiderationsTo help the watchdog timer monitor software execution more closely, set and reset the watchdog input at differ-ent points in the program, rather than pulsing the watch-dog input high-low-high or low-high-low. This technique avoids a stuck loop, in which the watchdog timer would continue to be reset inside the loop, keeping the watch-dog from timing out. Figure 4 shows an example of a flow diagram where the I/O driving the watchdog input is set high at the beginning of the program, set low at the end of every subroutine or loop, then set high again when the program returns to the beginning. If the pro-gram should hang in any subroutine, the problem would be quickly corrected, since the I/O is continually set low and the watchdog timer is allowed to time out, causing WDO to pulse.Figure 4. Watchdog Flow DiagramChip InformationTRANSISTOR COUNT: 1500PROCESS: BiCMOSPin ConfigurationMaxim cannot assume responsibility f or use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.8_____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600©2003 Maxim Integrated ProductsPrinted USAis a registered trademark of Maxim Integrated Products.。

MAX6367PKA44+T中文资料

General DescriptionThe MAX6365–MAX6368 supervisory circuits simplify power-supply monitoring, battery-backup control func-tions, and memory write protection in microprocessor (µP) systems. The circuits significantly improve the size,accuracy, and reliability of modern systems with an ultra-small integrated solution.These devices perform four basic system functions:1) Provide a µP reset output during V CC supply power-up, power-down, and brownout conditions.2) Internally control V CC to backup-battery switching tomaintain data or low-power operation for CMOS RAM, CMOS µPs, real-time clocks, and other digital logic when the main supply fails.3) Provide memory write protection through internalchip-enable gating during supply or processor faults.4) Include one of the following options: a manual resetinput (MAX6365), a watchdog timer function (MAX6366), a battery-on output (MAX6367), or an auxiliary user-adjustable reset input (MAX6368).The MAX6365–MAX6368 operate from V CC supply volt-ages as low as 1.2V. The factory preset reset threshold voltages range from 2.32V to 4.63V (see the Ordering Information ). In addition, each part is offered in three reset output versions: push-pull active low, open-drain active low, or open-drain active high (see the Selector Guide ). The MAX6365–MAX6368 are available in minia-ture 8-pin SOT23 packages.ApplicationsCritical µP/µC Power Portable/Battery-Monitoring Powered Equipment Fax Machines Set-Top Boxes Industrial Control POS EquipmentComputers/ControllersFeatures♦Low +1.2V Operating Supply Voltage (V CC or V BATT )♦Precision Monitoring of +5.0V, +3.3V, +3.0V, and +2.5V Power-Supply Voltages♦On-Board Gating of Chip-Enable Signals, 1.5ns Propagation Delay♦Debounced Manual Reset Input (MAX6365)♦Watchdog Timer, 1.6s Timeout (MAX6366)♦Battery-On Output Indicator (MAX6367)♦Auxiliary User-Adjustable RESET IN (MAX6368)♦Low 10µA Quiescent Supply Current ♦Three Available Output StructuresPush-Pull RESET Open-Drain RESET Open-Drain RESET♦RESET/RESET Valid Down to 1.2V Guaranteed (V CC or V BATT )♦Power-Supply Transient Immunity ♦150ms min Reset Timeout Period ♦Miniature 8-Pin SOT23 PackageMAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating________________________________________________________________Maxim Integrated Products1Pin Configurations19-1658; Rev 3; 12/05For pricing, delivery, and ordering information,please contact Maxim/Dallas Direct!at 1-888-629-4642, or visit Maxim’s website at .Ordering Information*These parts offer a choice of reset threshold voltages. From the Reset Threshold Ranges table, insert the desired threshold volt-age code in the blank to complete the part number. SOT parts come in tape-and-reel only and must be ordered in 2500-piece increments. See Device Marking Codes for a complete parts list,including SOT top marks and standard threshold versions. See Selector Guide for a listing of device features.Devices are available in both leaded and lead-free packaging.Specify lead-free by replacing “-T” with “+T” when ordering.Typical Operating Circuit appears at end of data sheet.M A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable GatingABSOLUTE MAXIMUM RATINGSELECTRICAL CHARACTERISTICS(V = +2.4V to +5.5V, V = +3.0V, CE IN = V , reset not asserted, T = -40°C to +85°C. Typical values are at T = +25°C,Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.Terminal Voltages (with respect to GND)V CC , BATT, OUT.......................................................-0.3V to +6V RESET (open drain), RESET (open drain)................-0.3V to +6V BATT ON, RESET (push-pull), RESET IN,WDI, CE IN, CE OUT...........................-0.3V to (V OUT + 0.3V)MR ..............................................................-0.3V to (V CC + 0.3V)Input CurrentV CC Peak ..............................................................................1A V CC Continuous.............................................................250mA BATT Peak.....................................................................250mA BATT Continuous.............................................................40mAGND...............................................................................75mA Output CurrentOUT...............................Short-Circuit Protected for up to 10s RESET, RESET , BATT ON, CE OUT...............................20mA Continuous Power Dissipation (T A = +70°C)8-Pin SOT23 (derate 8.75mW/°C above +70°C)........700mW Operating Temperature Range ...........................-40°C to +85°C Storage Temperature Range.............................-65°C to +150°C Junction Temperature .....................................................+150°C Lead Temperature (soldering, 10s).................................+300°CMAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating_______________________________________________________________________________________3ELECTRICAL CHARACTERISTICS (continued)(V CC = +2.4V to +5.5V, V BATT = +3.0V, CE IN = V CC , reset not asserted, T A = -40°C to +85°C. Typical values are at T A = +25°C,M A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating 4_______________________________________________________________________________________Typical Operating Characteristics(T A = +25°C, unless otherwise noted.)8109121115141316-400-2020406080SUPPLY CURRENTvs. TEMPERATURE (NO LOAD)TEMPERATURE (°C)S U P P L Y C U R R E N T (µA )0.20.60.40.81.01.2BATTERY SUPPLY CURRENT (BACKUP MODE) vs. TEMPERATURETEMPERATURE (°C)B A T T E R Y S U P P L YC U R R E N T (µA )-402040-200608021437658-40-2020406080BATT-TO-OUT ON-RESISTANCEvs. TEMPERATURETEMPERATURE (°C)B A T T -T O -O U T O N -R E S I S T A NC E (Ω)ELECTRICAL CHARACTERISTICS (continued)(V= +2.4V to +5.5V, V = +3.0V, CE IN = V , reset not asserted, T = -40°C to +85°C. Typical values are at T = +25°C,Note 2:V BATT can be 0 anytime, or V CC can go down to 0 if V BATT is active (except at startup).Note 3:RESET is pulled up to OUT. Specifications apply for OUT = V CC or OUT = BATT.Note 4:The chip-enable resistance is tested with V CC = V TH(MAX)and CE IN = V CC / 2.MAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating_______________________________________________________________________________________5Typical Operating Characteristics (continued)(T A = +25°C, unless otherwise noted.)00.40.20.80.61.21.01.4-4020-20406080V CC TO OUT ON-RESISTANCEvs. TEMPERATURETEMPERATURE (°C)V C C T O O U T O N -R E S I S T A N C E (Ω)190195205200210RESET TIMEOUT PERIOD vs. TEMPERATUREM A X 6365/8-05TEMPERATURE (°C)R E S E T T I M E O U T P E R I O D (m s )-402040-206080301575604513512010590TEMPERATURE (°C)P R O P A G A T I O N D E L A Y (µs )-402040-206080V CC TO RESET PROPAGATION DELAYvs. TEMPERATURE2.03.02.55.04.54.03.5RESET THRESHOLD vs. TEMPERATURETEMPERATURE (°C)T H R E S H O L D (V )-402040-206080110010100010,000MAXIMUM TRANSIENT DURATION vs. RESET THRESHOLD OVERDRIVERESET THRESHOLD OVERDRIVE V TH - V CC (mV)M A X I M U M T R A N S I E N T D U R A T I O N (µs )40030035025020005015010003215498761000.5 1.0 1.5 2.0 2.5 3.03.5BATTERY SUPPLY CURRENT vs. SUPPLY VOLTAGEV CC (V)B A T T E R Y S U P P L YC U R R E N T (µA )M A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating 6_______________________________________________________________________________________1.2341.2351.236MAX6368RESET IN THRESHOLD vs. TEMPERATUREM A X 6365/8 -10TEMPERATURE (°C)V R T H (V )-402040-2060801.01.91.61.32.82.52.2MAX6368RESET IN TO RESET PROPAGATION DELAYvs. TEMPERATURETEMPERATURE (°C)P R O P A G A T I O N D E L A Y (µs )-402040-206080013245C LOAD (pF)P R O P A G A T I O N D E L A Y (n s )10050150200CHIP-ENABLE PROPAGATION DELAY vs. CE OUT LOAD CAPACITANCE515102025-40-2020406080TEMPERATURE (°C)C E I N T O C E O U T O N -R E S I S T A N C E (Ω)CE IN TO CE OUT ON-RESISTANCEvs. TEMPERATURE1.01.31.21.11.51.41.91.81.71.62.0-40-2020406080TEMPERATURE (°C)W A T C H D O G T I M E O U T P E R I O D (s )MAX6366WATCHDOG TIMEOUT PERIODvs. TEMPERATURETypical Operating Characteristics (continued)(T A = +25°C, unless otherwise noted.)MAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating_______________________________________________________________________________________7M A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating 8_______________________________________________________________________________________Detailed DescriptionThe Typical Operating Circuit shows a typical connec-tion for the MAX6365–MAX6368. OUT powers the static random-access memory (SRAM). If V CC is greater than the reset threshold (V TH ), or if V CC is lower than V TH but higher than V BATT , V CC is connected to OUT. If V CC is lower than V TH and V CC is less than V BATT ,BATT is connected to OUT. OUT supplies up to 150mA from V CC . In battery-backup mode, an internal MOSFET connects the backup battery to OUT. The on-resistance of the MOSFET is a function of backup-battery voltage and is shown in the BATT-to-OUT On-Resistance vs.Temperature graph in the T ypical Operating Char-acteristics .Chip-Enable Signal GatingThe MAX6365–MAX6368 provide internal gating of CE signals to prevent erroneous data from being written toCMOS RAM in the event of a power failure. During nor-mal operation, the CE gate is enabled and passes all CE transitions. When reset asserts, this path becomes disabled, preventing erroneous data from corrupting the CMOS RAM. All of these devices use a series trans-mission gate from CE IN to CE OUT. The 2ns propaga-tion delay from CE IN to CE OUT allows the devices to be used with most µPs and high-speed DSPs.During normal operation, CE IN is connected to CE OUT through a low on-resistance transmission gate.This is valid when reset is not asserted. If CE IN is high when reset is asserted, CE OUT remains high regard-less of any subsequent transitions on CE IN during the reset event.If CE IN is low when reset is asserted, CE OUT is held low for 12µs to allow completion of the read/write oper-ation (F igure 1). After the 12µs delay expires, the CEFunctional DiagramMAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating_______________________________________________________________________________________9OUT goes high and stays high regardless of any sub-sequent transitions on CE IN during the reset event.When CE OUT is disconnected from CE IN, CE OUT is actively pulled up to OUT.The propagation delay through the chip-enable circuit-ry depends on both the source impedance of the drive to CE IN and the capacitive loading at CE OUT. The chip-enable propagation delay is production tested from the 50% point of CE IN to the 50% point of CE OUT, using a 50Ωdriver and 50pF load capacitance.Minimize the capacitive load at CE OUT to minimize propagation delay, and use a low-output-impedance driver.Backup-Battery SwitchoverIn a brownout or power failure, it may be necessary to preserve the contents of the RAM. With a backup bat-tery installed at BATT, the MAX6365–MAX6368 auto-matically switch the RAM to backup power when V CC falls. The MAX6367 has a BATT ON output that goes high in battery-backup mode. These devices require two conditions before switching to battery-backup mode:1) V CC must be below the reset threshold.2) V CC must be below V BATT .Table 1 lists the status of the inputs and outputs in bat-tery-backup mode. The devices do not power up if the only voltage source is on BATT. OUT only powers upfrom V CC at startup.Many µP-based products require manual reset capabili-ty, allowing the user or external logic circuitry to initiate a reset. For the MAX6365, a logic low on MR asserts reset.Reset remains asserted while MR is low and for a mini-mum of 150ms (t RP ) after it returns high. MR has an inter-nal 20k Ωpullup resistor to V CC . This input can be driven with TTL/CMOS logic levels or with open-drain/collector outputs. Connect a normally open momentary switch from MR to GND to create a manual reset function; exter-nal debounce circuitry is not required. If MR is driven from long cables or the device is used in a noisy environ-ment, connect a 0.1µF capacitor from MR to GND to pro-vide additional noise immunity.Figure 1. Reset and Chip-Enable TimingM A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating 10______________________________________________________________________________________Watchdog Input (MAX6366 Only)The watchdog monitors µP activity through the watch-dog input (WDI). If the µP becomes inactive, reset asserts. To use the watchdog function, connect WDI to a bus line or µP I/O line. A change of state (high to low,low to high, or a minimum 100ns pulse) resets the watchdog timer. If WDI remains high or low for longer than the watchdog timeout period (t WD ), the internal watchdog timer runs out and a reset pulse is triggered for the reset timeout period (t RP ). The internal watchdog timer clears whenever reset asserts or whenever WDI sees a rising or falling edge. If WDI remains in either a high or low state, a reset pulse asserts periodically after every t WD (Figure 2).BATT ON Indicator (MAX6367 Only)BATT ON is a push-pull output that drives high when in battery-backup mode. BATT ON typically sinks 3.2mA at 0.1V saturation voltage. In battery-backup mode, this terminal sources approximately 10µA from OUT. Use BATT ON to indicate battery-switchover status or to supply base drive to an external pass transistor for higher current applications (Figure 3).RESET IN Comparator (MAX6368 Only)RESET IN is compared to an internal 1.235V reference.If the voltage at RESET IN is less than 1.235V, reset asserts. Use the RESET IN comparator as an undervolt-age detector to signal a failing power supply or as a secondary power-supply reset monitor.To program the reset threshold (V RTH ) of the secondary power supply, use the following (see Typical Operating Circuit ):V RTH = V REF (R1 / R2 + 1)where V REF = 1.235V. To simplify the resistor selection,choose a value for R2 and calculate R1:R1 = R2 [(V RTH / V REF ) - 1]Since the input current at RESET IN is 25nA (max),large values (up to 1M Ω) can be used for R2 with no significant loss in accuracy. For example, in the Typical Operating Circuit , the MAX6368 monitors two supply voltages. To monitor the secondary 5V logic or analog supply with a 4.60V nominal programmed reset thresh-old, choose R2 = 100k Ω, and calculate R1 = 273k Ω.Reset OutputA µP’s reset input starts the µP in a known state. The MAX6365–MAX6368 µP supervisory circuits assert a reset to prevent code-execution errors during power-up, power-down, and brownout conditions. RESET is guaranteed to be a logic low or logic high, depending on the device chosen (see the Ordering Information ).RESET or RESET asserts when V CC is below the reset threshold and for at least 150ms (t RP ) after V CC rises above the reset threshold. RESET or RESET also asserts when MR is low (MAX6365) and when RESET IN is less than 1.235V (MAX6368). The MAX6366 watch-dog function will cause RESET (or RESET ) to assert in pulses following a watchdog timeout (Figure 2).Applications InformationOperation Withouta Backup Power SourceThe MAX6365–MAX6368 provide battery-backup func-tions. If a backup power source is not used, connect BATT to GND and OUT to V CC .Watchdog Software ConsiderationsOne way to help the watchdog timer monitor the soft-ware execution more closely is to set and reset the watchdog at different points in the program rather than pulsing the watchdog input periodically. F igure 4shows a flow diagram in which the I/O driving theFigure 2. MAX6366 Watchdog Timeout Period and Reset Active TimeMAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating______________________________________________________________________________________11watchdog is set low in the beginning of the program,set high at the beginning of every subroutine or loop,and set low again when the program returns to the beginning. If the program should hang in any subrou-tine, the problem would be quickly corrected.Replacing the Backup BatteryWhen V CC is above V TH , the backup power source can be removed without danger of triggering a reset pulse.The device does not enter battery-backup mode when V CC stays above the reset threshold voltage.Negative-Going V CC TransientsThese supervisors are relatively immune to short-dura-tion, negative-going V CC transients. Resetting the µP when V CC experiences only small glitches is usually not desirable.The T ypical Operating Characteristics section has a Maximum Transient Duration vs. Reset Threshold Overdrive graph for which reset is not asserted. The graph was produced using negative-going V CC pulses,starting at V CC and ending below the reset threshold by the magnitude indicated (reset threshold overdrive).The graph shows the maximum pulse width that a neg-ative-going V CC transient can typically have without triggering a reset pulse. As the amplitude of the tran-sient increases (i.e., goes further below the reset threshold), the maximum allowable pulse width decreases. Typically, a V CC transient that goes 100mV below the reset threshold and lasts for 30µs will not trig-ger a reset pulse.A 0.1µF bypass capacitor mounted close to the V CC pin provides additional transient immunity.M A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating 12______________________________________________________________________________________standard versions only. Contact factory for availability of nonstandard versions.MAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating______________________________________________________________________________________13Pin Configurations (continued)M A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating 14______________________________________________________________________________________Typical Operating CircuitChip InformationTRANSISTOR COUNT: 729PROCESS: CMOSSOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable GatingMAX6365–MAX6368Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________15©2005 Maxim Integrated ProductsPrinted USAis a registered trademark of Maxim Integrated Products, Inc.Package Information(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to /packages .)。