MAX6362PUT中文资料
Maxxt中文使用说明书
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MAX262中文资料
M A X262中文资料(总5页) -CAL-FENGHAI.-(YICAI)-Company One1-CAL-本页仅作为文档封面，使用请直接删除在电子电路中，滤波器是不可或缺的部分，其中有源滤波器更为常用。
一般有源滤波器由运算放大器和RC元件组成，对元器件的参数精度要求比较高，设计和调试也比较麻烦。
美国Maxim公司生产的可编程滤波器芯片MAX262可以通过编程对各种低频信号实现低通、高通、带通、带阻以及全通滤波处理，且滤波的特性参数如中心频率、品质因数等，可通过编程进行设置，电路的外围器件也少。
本文介绍MAX262的情况以及由它构成的程控滤波器电路。
1 MAX262芯片介绍MAX262芯片是Maxim公司推出的双二阶通用开关电容有源滤波器，可通过微处理器精确控制滤波器的传递函数(包括设置中心频率、品质因数和工作方式)。
它采用CMOS工艺制造，在不需外部元件的情况下就可以构成各种带通、低通、高通、陷波和全通滤波器。
图1是它的引脚排列情况。
图1 MAX262引脚V+ ——正电源输入端。
V- ——负电源输入端。
GND ——模拟地。
CLKA ——外接晶体振荡器和滤波器A 部分的时钟输入端，在滤波器内部，时钟频率被2分频。
CLKB ——滤波器B 部分的时钟输入端，同样在滤波器内部，时钟频率被2分频。
CLKOUT ——晶体振荡器和R-C振荡的时钟输出端。
OSCOUT ——与晶体振荡器或R-C振荡器相连，用于自同步。
INA、INB ——滤波器的信号输入端。
BPA、BPB——带通滤波器输出端。
LPA、LPB——低通滤波器输出端。
HPA、HPB——高通、带阻、全通滤波器输出端。
WR ——写入有效输入端。
接V+时，输人数据不起作用；接V-时，数据可通过逻辑接口进入一个可编程的内存之中，以完成滤波器的工作模式、f0及Q的设置。
此外，还可以接收TTL电平信号，并上升沿锁存输人数据。
A0、A1、A2、A3 ——地址输人端，可用来完成对滤波器工作模式、f0和Q的相应设置。
MAX3232中文资料zhuanzai
MAX3222/MAX3232/MAX3237/MAX32413.0V至5.5V、低功耗、1Mbps、真RS-232收发器，使用四只0.1µF外部电容________________________________________________________________Maxim Integrated Products119-0273; Rev 7; 1/07MegaBaud和UCSP是Maxim Integrated Products, Inc.的商标。
本页已使用福昕阅读器进行编辑。
M A X 3222/M A X 3232/M A X 3237/M A X 32413.0V至5.5V、低功耗、1Mbps、真RS-232收发器，使用四只0.1µF外部电容2_______________________________________________________________________________________ABSOLUTE MAXIMUM RATINGSELECTRICAL CHARACTERISTICS(V CC = +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), T A = T MIN to T MAX , unless otherwise noted. Typical values are at T A = +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.Note 1:V+ and V- can have a maximum magnitude of 7V, but their absolute difference cannot exceed 13V.V CC ...........................................................................-0.3V to +6V V+ (Note 1)...............................................................-0.3V to +7V V- (Note 1)................................................................+0.3V to -7V V+ + V- (Note 1)...................................................................+13V Input VoltagesT_IN, SHDN , EN ...................................................-0.3V to +6V MBAUD...................................................-0.3V to (V CC + 0.3V)R_IN.................................................................................±25V Output VoltagesT_OUT...........................................................................±13.2V R_OUT....................................................-0.3V to (V CC + 0.3V)Short-Circuit DurationT_OUT....................................................................ContinuousContinuous Power Dissipation (T A = +70°C)16-Pin TSSOP (derate 6.7mW/°C above +70°C).............533mW 16-Pin Narrow SO (derate 8.70mW/°C above +70°C)....696mW 16-Pin Wide SO (derate 9.52mW/°C above +70°C)........762mW 16-Pin Plastic DIP (derate 10.53mW/°C above +70°C)...842mW 18-Pin SO (derate 9.52mW/°C above +70°C)..............762mW 18-Pin Plastic DIP (derate 11.11mW/°C above +70°C)..889mW 20-Pin SSOP (derate 7.00mW/°C above +70°C).........559mW 20-Pin TSSOP (derate 8.0mW/°C above +70°C).............640mW 28-Pin TSSOP (derate 8.7mW/°C above +70°C).............696mW 28-Pin SSOP (derate 9.52mW/°C above +70°C).........762mW 28-Pin SO (derate 12.50mW/°C above +70°C).....................1W Operating Temperature RangesMAX32_ _C_ _.....................................................0°C to +70°C MAX32_ _E_ _ .................................................-40°C to +85°C Storage Temperature Range.............................-65°C to +150°C Lead Temperature (soldering, 10s).................................+300°CMAX3222/MAX3232/MAX3237/MAX32413.0V至5.5V、低功耗、1Mbps、真RS-232收发器，使用四只0.1µF外部电容_______________________________________________________________________________________3TIMING CHARACTERISTICS—MAX3222/MAX3232/MAX3241(V CC = +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), T A = T MIN to T MAX , unless otherwise noted. Typical values are at T A = +25°C.)ELECTRICAL CHARACTERISTICS (continued)(V CC = +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), T A = T MIN to T MAX , unless otherwise noted. Typical values are at T A = +25°C.)M A X 3222/M A X 3232/M A X 3237/M A X 32413.0V至5.5V、低功耗、1Mbps、真RS-232收发器，使用四只0.1µF外部电容4________________________________________________________________________________________________________________________________________________________________典型工作特性(V CC = +3.3V, 235kbps data rate, 0.1µF capacitors, all transmitters loaded with 3k Ω, T A = +25°C, unless otherwise noted.)-6-5-4-3-2-101234560MAX3222/MAX3232TRANSMITTER OUTPUT VOLTAGEvs. LOAD CAPACITANCELOAD CAPACITANCE (pF)T R A N S M I T T E R O U T P U T V O L T A G E (V )20003000100040005000246810121416182022150MAX3222/MAX3232SLEW RATEvs. LOAD CAPACITANCELOAD CAPACITANCE (pF)S L E W R A T E (V /µs )20003000100040005000510152025303540MAX3222/MAX3232SUPPLY CURRENT vs. LOAD CAPACITANCEWHEN TRANSMITTING DATALOAD CAPACITANCE (pF)S U P P L Y C U R R E N T (m A )20003000100040005000TIMING CHARACTERISTICS—MAX3237(V CC = +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), T A = T MIN to T MAX , unless otherwise noted. Typical values are at T A = +25°C.)Note 2:MAX3222/MAX3232/MAX3241: C1–C4 = 0.1µF tested at 3.3V ±10%; C1 = 0.047µF, C2–C4 = 0.33µF tested at 5.0V ±10%.MAX3237: C1–C4 = 0.1µF tested at 3.3V ±5%; C1–C4 = 0.22µF tested at 3.3V ±10%; C1 = 0.047µF, C2–C4 = 0.33µF tested at 5.0V ±10%.Note 3:Transmitter input hysteresis is typically 250mV.MAX3222/MAX3232/MAX3237/MAX32413.0V至5.5V、低功耗、1Mbps、真RS-232收发器，使用四只0.1µF外部电容_______________________________________________________________________________________5-7.5-5.0-2.502.55.07.50MAX3241TRANSMITTER OUTPUT VOLTAGEvs. LOAD CAPACITANCELOAD CAPACITANCE (pF)T R A N S M I T T E R O U T P U T V O L T A G E (V )2000300010004000500046810121416182022240MAX3241SLEW RATEvs. LOAD CAPACITANCELOAD CAPACITANCE (pF)S L E W R A T E (V /µs )20003000100040005000510152025303545400MAX3241SUPPLY CURRENT vs. LOADCAPACITANCE WHEN TRANSMITTING DATALOAD CAPACITANCE (pF)S U P P L Y C U R R E N T (m A )20003000100040005000-7.5-5.0-2.502.55.07.50MAX3237TRANSMITTER OUTPUT VOLTAGE vs. LOAD CAPACITANCE (MBAUD = GND)LOAD CAPACITANCE (pF)T R A N S M I T T E R O U T P U T V O L T A G E (V )200030001000400050000102030504060700MAX3237SLEW RATE vs. LOAD CAPACITANCE(MBAUD = V CC )LOAD CAPACITANCE (pF)S L E W R A T E (V /µs )500100015002000-7.5-5.0-2.502.55.07.50MAX3237TRANSMITTER OUTPUT VOLTAGE vs. LOAD CAPACITANCE (MBAUD = V CC )LOAD CAPACITANCE (pF)T R A N S M I T T E R O U T P U T V O L T A G E (V )5001000150020001020304050600MAX3237SUPPLY CURRENT vs.LOAD CAPACITANCE (MBAUD = GND)LOAD CAPACITANCE (pF)S U P P L Y C U R R E N T (m A )200030001000400050000246810120MAX3237SLEW RATE vs. LOAD CAPACITANCE(MBAUD = GND)LOAD CAPACITANCE (pF)S L E W R A T E (V /µs )2000300010004000500010302040506070MAX3237SKEW vs. LOAD CAPACITANCE(t PLH - t PHL )LOAD CAPACITANCE (pF)1000150050020002500____________________________________________________________________典型工作特性(续)(V CC = +3.3V, 235kbps data rate, 0.1µF capacitors, all transmitters loaded with 3k Ω, T A = +25°C, unless otherwise noted.)M A X 3222/M A X 3232/M A X 3237/M A X 32413.0V至5.5V、低功耗、1Mbps、真RS-232收发器，使用四只0.1µF外部电容6_________________________________________________________________________________________________________________________________________________________________引脚说明MAX3222/MAX3232/MAX3237/MAX32413.0V至5.5V、低功耗、1Mbps、真RS-232收发器，使用四只0.1µF外部电容_______________________________________________________________________________________7_______________________________详细说明双电荷泵电压转换器MAX3222/MAX3232/MAX3237/MAX3241的内部电源由两路稳压型电荷泵组成，只要输入电压(V CC )在3.0V至5.5V范围以内，即可提供+5.5V (倍压电荷泵)和-5.5V (反相电荷泵)输出电压。
MAX6368LKA23-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。
MAX232中文资料_数据手册_参数
MAX6362PUT23+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。
MAX6356RVUT中文资料
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at .
元器件交易网
Dual/Triple-Voltage µP Supervisory Circuits MAX6351–MAX6360
ABSOLUTE MAXIMUM RATINGS
VCC1, VCC2 to GND .................................................-0.3V to +6V RST (MAX6352/MAX6355/MAX6358)...................... -0.3V to +6V RST, MR, WDI, RST1, RSTIN (MAX6351/MAX6353/ MAX6356/MAX6359) ..............................-0.3V to (VCC1 + 0.3V) RST, RST2 (MAX6351/MAX6354/ MAX6357/MAX6360) ..............................-0.3V to (VCC2 + 0.3V) Input/Output Current, All Pins .............................................20mA Continuous Power Dissipation (TA = +70°C) 5-Pin SOT23 (derate 7.1mW/°C above +70°C)............571mW 6-Pin SOT23 (derate 8.7mW/°C above +70°C)............695mW Operating Temperature Range ...........................-40°C to +85°C Junction Temperature .....................................................+150°C Storage Temperature Range .............................-65°C to +150°C
MAX8632笔记本电脑内存供电控制芯片
MAX8632笔记本电脑内存供电控制芯片P O K 2P O K 1I L I MR E FO V P /U V PT O NS T B YＭＡＸ８６３２ＭＡＸ８６３２是笔记本电脑中常用的内存供电或芯片组供电控制芯片，内部集成了一路用于产生ＶＤＤＱ的同步降压ＰＷＭ控制器，一路用于产生ＶＴＴ电源输出和吸入电流的ＬＤＯ线性稳压器，另一路用于产生ＶＴＴＲ的１０ｍＡ基准输出缓冲器。
引脚号引脚名称引脚功能1TON 导通时间选择输入端。
该四电平逻辑输入用来设置额定DH 导通时间。
TON分别连接至GND、REF、AVDD及悬空时可选择不同额定开关频率2OVP/UVP 过压/欠压保护控制输入端。
该四电平逻辑输入用来使能/禁止过压/欠压保护。
过压门限值为额定输出电压的116%。
欠压门限值为额定输出电压的70%。
使能OVP的同时启动放电模式3REF +2.0V基准电压输出端。
用0.1μF电容旁路至GND。
REF 可为外部负载提供50μA电流。
可用于设置ILIM电压。
当SHDN为低电平，OUT<0.1V时，REF关断4ILIM Buck调节器的谷值限流门限调节端。
PGND与LX之间限流门限是ILIM端电压的0.1倍。
ILIM连接至REF和GND间的分压器，可将限流门限设置为25-200mV。
与之对应的ILIM 端电压范围为0.25-2V。
ILIM接至AVDD时限流门限为默认值50mV5POK1Buck电源就绪开漏输出端。
当buck输出电压比规定稳定电压高出或低出10%，或在软启动期间时，POK1为低电平。
当输出电压达到稳定器软启动电路停止工作时，POK1为高阻态。
关断模式下POK1为低电平6POK2LDO电源就绪开漏输出端。
在正常模式下，只要VTTR和VTTS电压中的任一个比额定稳压电压（通常为REFIN/2）高出或低出10%，POK2都为低电平。
待机模式下POK2仅对VTTR 输入响应。
关断模式下或当VREFIN小于0.8V时，POK2为低电平7STBY 待机控制端。
MAX5432_07中文资料
Operating Temperature Range ...........................-40°C to +85°C Junction Temperature ......................................................+150°C Storage Temperature Range .............................-60°C to +150°C Lead Temperature (soldering, 10s) .................................+300°C
The MAX5432–MAX5435 feature an internal, nonvolatile, electrically erasable programmable read-only memory (EEPROM) that returns the wiper to its previously stored position at power-up. The fast-mode I2C-compatible serial interface allows communication at data rates up to 400kbps, minimizing board space and reducing interconnection complexity. Each device is available with multiple factory-preset I2C addresses (see the Ordering Information/Selector Guide).
MAX471MAX472的中文资料大全
MAX471/MAX472的特点、功能美国美信公司生产的精密高端电流检测放大器是一个系列化产品，有MAX471/MAX472、MAX4172/MAX4173等。
它们均有一个电流输出端，可以用一个电阻来简单地实现以地为参考点的电流/电压的转换，并可工作在较宽电压内。
MAX471/MAX472具有如下特点：●具有完美的高端电流检测功能；●内含精密的内部检测电阻（MAX471）；●在工作温度范围内，其精度为2%；●具有双向检测指示，可监控充电和放电状态；●内部检测电阻和检测能力为3A，并联使用时还可扩大检测电流范围；●使用外部检测电阻可任意扩展检测电流范围（MAX472）；●最大电源电流为100μA；●关闭方式时的电流仅为5μA；●电压范围为3～36V；●采用8脚DIP/SO/STO三种封装形式。
MAX471/MAX472的引脚排列如图1所示，图2所示为其内部功能框图。
表1为MAX471/MAX472的引脚功能说明。
MAX471的电流增益比已预设为500μA/A，由于2kΩ的输出电阻（ROUT）可产生1V/A的转换，因此±3A时的满度值为3V.用不同的ROUT电阻可设置不同的满度电压。
但对于MAX471，其输出电压不应大于VRS+。
对于MAX472，则不能大于。
MAX471引脚图如图１所示，MAX472引脚图如图２所示。
MAX471/MAX472的引脚功能说明引脚名称功能MAX471MAX47211SHDN关闭端。
正常运用时连接到地。
当此端接高电平时，电源电流小于5μA2，3-RS+内部电流检测电阻电池（或电源端）。
“+”仅指示与SIGN输出有关的流动方向。
封装时已将2和3连在了一起-2空脚88OUT 电流输出，它正比于流过TSENSE被测电路的幅度，在MAX741中，此引脚到地之间应接一个2kΩ电阻，每一安培被测电流将产生大小等于1V的电压OUT端为电流幅度输出端，而SIGN端可用来指示输出电流的方向。
MAX6321HPUK26DZ-T中文资料
___________________________________________________________________Selector Guide________________General DescriptionThe MAX6316–MAX6322 family of microprocessor (µP)supervisory circuits monitors power supplies and microprocessor activity in digital systems. It offers sev-eral combinations of push/pull, open-drain, and bidirec-tional (such as Motorola 68HC11) reset outputs, along with watchdog and manual reset features. The Selector Guide below lists the specific functions available from each device. These devices are specifically designed to ignore fast negative transients on V CC . Resets are guaranteed valid for V CC down to 1V.These devices are available in 26 factory-trimmed reset threshold voltages (from 2.5V to 5V, in 100mV incre-ments), featuring four minimum power-on reset timeout periods (from 1ms to 1.12s), and four watchdog timeout periods (from 6.3ms to 25.6s). Thirteen standard ver-sions are available with an order increment requirement of 2500 pieces (see Standard Versions table); contact the factory for availability of other versions, which have an order increment requirement of 10,000 pieces.The MAX6316–MAX6322 are offered in a miniature 5-pin SOT23 package.________________________ApplicationsPortable Computers Computers ControllersIntelligent InstrumentsPortable/Battery-Powered Equipment Embedded Control Systems____________________________Features♦Small 5-Pin SOT23 Package♦Available in 26 Reset Threshold Voltages2.5V to 5V, in 100mV Increments ♦Four Reset Timeout Periods1ms, 20ms, 140ms, or 1.12s (min)♦Four Watchdog Timeout Periods6.3ms, 102ms, 1.6s, or 25.6s (typ) ♦Four Reset Output StagesActive-High, Push/Pull Active-Low, Push/Pull Active-Low, Open-Drain Active-Low, Bidirectional♦Guaranteed Reset Valid to V CC = 1V♦Immune to Short Negative V CC Transients ♦Low Cost♦No External ComponentsMAX6316–MAX63225-Pin µP Supervisory Circuits withWatchdog and Manual Reset________________________________________________________________Maxim Integrated Products 119-0496; Rev 7; 11/07_______________Ordering InformationOrdering Information continued at end of data sheet.*The MAX6318/MAX6319/MAX6321/MAX6322 feature two types of reset output on each device.Typical Operating Circuit and Pin Configurations appear at end of data sheet.For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,or visit Maxim’s website at .Specify lead-free by replacing “-T” with “+T” when ordering.ELECTRICAL CHARACTERISTICS(V CC = 2.5V to 5.5V, T A = -40°C to +125°C, unless otherwise noted. Typical values are at T A = +25°C.) (Note 1)M A X 6316–M A X 63225-Pin µP Supervisory Circuits with Watchdog and Manual Reset 2_______________________________________________________________________________________ABSOLUTE MAXIMUM RATINGSStresses 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.Voltage (with respect to GND)V CC ......................................................................-0.3V to +6V RESET (MAX6320/MAX6321/MAX6322 only)...... -0.3V to +6V All Other Pins.........................................-0.3V to (V CC + 0.3V)Input/Output Current, All Pins.............................................20mAContinuous Power Dissipation (T A = +70°C)SOT23-5 (derate 7.1mW/°C above +70°C)...............571mW Operating Temperature Range..........................-40°C to +125°C Junction Temperature......................................................+150°C Storage Temperature Range..............................-65°C to +160°C Lead Temperature (soldering, 10s).................................+300°CTH available in 100mV increments from 2.5V to 5V (see Table 1 at end of data sheet).Note 3:Guaranteed by design.MAX6316–MAX63225-Pin µP Supervisory Circuits withWatchdog and Manual Reset_______________________________________________________________________________________3Note 5:Measured from RESET V OL to (0.8 x V CC ), R LOAD = ∞.Note 6:WDI is internally serviced within the watchdog period if WDI is left unconnected.Note 7:The WDI input current is specified as the average input current when the WDI input is driven high or low. The WDI input is designed for a three-stated-output device with a 10µA maximum leakage current and capable of driving a maximum capac-itive load of 200pF. The three-state device must be able to source and sink at least 200µA when active.ELECTRICAL CHARACTERISTICS (continued)M A X 6316–M A X 63225-Pin µP Supervisory Circuits with Watchdog and Manual Reset 4_________________________________________________________________________________________________________________________________Typical Operating Characteristics(T A = +25°C, unless otherwise noted.)021*********-4020-20406080100MAX6316/MAX6317/MAX6318/MAX6320/MAX6321SUPPLY CURRENT vs. TEMPERATURETEMPERATURE (°C)S U P P L Y C U R R E N T (μA )302010504090807060100-40-20020406080100V CC FALLING TO RESET PROPAGATIONDELAY vs. TEMPERATURETEMPERATURE (°C)R E S E T P R O P A G A T I O N D E L A Y (μs )140180160240220200300280260320-40020-20406080100MAX6316/MAX6317/MAX6319/MAX6320/MAX6322MANUAL RESET TO RESETPROPAGATION DELAY vs. TEMPERATURETEMPERATURE (°C)P R O P A G A T I O N D E L A Y (n s )0.950.980.970.961.000.991.041.031.021.011.05-40-2020406080100NORMALIZED RESET TIMEOUT PERIOD vs. TEMPERATUREM A X 6316t o c 04TEMPERATURE (°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 D0.950.980.970.961.000.991.041.031.021.011.05-40-2020406080100MAX6316/MAX6317/MAX6318/MAX6320/MAX6321NORMALIZED WATCHDOG TIMEOUTPERIOD vs. TEMPERATUREM A X 6316t o c 05TEMPERATURE (°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 D800101001000MAXIMUM V CC TRANSIENT DURATION vs. RESET THRESHOLD OVERDRIVE2010RESET THRESHOLD OVERDRIVE (mV) V RST - V CCT RA N S I E N T D U R A T I O N (μs )3050604070200ns/divMAX6316M/6318MH/6319MHBIDIRECTIONALPULLUP CHARACTERISTICSMAX6316–MAX63225-Pin µP Supervisory Circuits withWatchdog and Manual Reset_______________________________________________________________________________________5______________________________________________________________Pin DescriptionM A X 6316–M A X 63225-Pin µP Supervisory Circuits with Watchdog and Manual Reset 6______________________________________________________________________________________________________Detailed DescriptionA microprocessor’s (µP) reset input starts or restarts the µP in a known state. The reset output of the MAX6316–MAX6322 µP supervisory circuits interfaces with the reset input of the µP, preventing code-execution errors during power-up, power-down, and brownout condi-tions (see the Typical Operating Circuit ). The MAX6316/MAX6317/MAX6318/MAX6320/MAX6321 are also capa-ble of asserting a reset should the µP become stuck in an infinite loop.Reset OutputThe MAX6316L/MAX6318LH/MAX6319LH feature an active-low reset output, while the MAX6317H/MAX6318_H/MAX6319_H/MAX6321HP/MAX6322HP feature an active-high reset output. RESET is guaran-teed to be a logic low and RESET is guaranteed to be a logic high for V CC down to 1V.The MAX6316–MAX6322 assert reset when V CC is below the reset threshold (V RST ), when MR is pulled low (MAX6316_/MAX6317H/MAX6319_H/MAX6320P/MAX6322HP only), or if the WDI pin is not serviced withinthe watchdog timeout period (t WD ). Reset remains assert-ed for the specified reset active timeout period (t RP ) after V CC rises above the reset threshold, after MR transitions low to high, or after the watchdog timer asserts the reset (MAX6316_/MAX6317H/MAX6318_H/MAX6320P/MAX6321HP). After the reset active timeout period (t RP )expires, the reset output deasserts, and the watchdog timer restarts from zero (Figure 2).Figure 1. Functional DiagramFigure 2. Reset Timing DiagramMAX6316–MAX63225-Pin µP Supervisory Circuits withWatchdog and Manual Reset_______________________________________________________________________________________7Bidirectional R E S E T OutputThe MAX6316M/MAX6318MH/MAX6319MH are designed to interface with µPs that have bidirectional reset pins,such as the Motorola 68HC11. Like an open-drain output,these devices allow the µP or other devices to pull the bidirectional reset (RESET ) low and assert a reset condi-tion. However, unlike a standard open-drain output, it includes the commonly specified 4.7k Ωpullup resistor with a P-channel active pullup in parallel.This configuration allows the MAX6316M/MAX6318MH/MAX6319MH to solve a problem associated with µPs that have bidirectional reset pins in systems where sev-eral devices connect to RESET (F igure 3). These µPs can often determine if a reset was asserted by an exter-nal device (i.e., the supervisor IC) or by the µP itself (due to a watchdog fault, clock error, or other source),and then jump to a vector appropriate for the source of the reset. However, if the µP does assert reset, it does not retain the information, but must determine the cause after the reset has occurred.The following procedure describes how this is done in the Motorola 68HC11. In all cases of reset, the µP pulls RESET low for about four external-clock cycles. It then releases RESET , waits for two external-clock cycles,then checks RESET ’s state. If RESET is still low, the µP concludes that the source of the reset was external and, when RESET eventually reaches the high state, it jumps to the normal reset vector. In this case, stored-state information is erased and processing begins fromscratch. If, on the other hand, RESET is high after a delay of two external-clock cycles, the processor knows that it caused the reset itself and can jump to a different vector and use stored-state information to determine what caused the reset.A problem occurs with faster µPs; two external-clock cycles are only 500ns at 4MHz. When there are several devices on the reset line, and only a passive pullup resis-tor is used, the input capacitance and stray capacitance can prevent RESET from reaching the logic high state (0.8✕V CC ) in the time allowed. If this happens, all resets will be interpreted as external. The µP output stage is guaran-teed to sink 1.6mA, so the rise time can not be reduced considerably by decreasing the 4.7k Ωinternal pullup resistance. See Bidirectional Pullup Characteristics in the Typical Operating Characteristics .The MAX6316M/MAX6318MH/MAX6319MH overcome this problem with an active pullup FET in parallel with the 4.7k Ωresistor (F igures 4 and 5). The pullup transistor holds RESET high until the µP reset I/O or the supervisory circuit itself forces the line low. Once RESET goes below V PTH , a comparator sets the transition edge flip-flop, indi-cating that the next transition for RESET will be low to high. When RESET is released, the 4.7k Ωresistor pulls RESET up toward V CC . Once RESET rises above V PTH but is below (0.85 x V CC ), the active P-channel pullup turns on. Once RESET rises above (0.85 x V CC ) or the 2µs one-shot times out, the active pullup turns off. The parallel combination of the 4.7k Ωpullup and theFigure 3. MAX6316M/MAX6318MH/MAX6319MH Supports Additional Devices on the Reset BusM A X 6316–M A X 63225-Pin µP Supervisory Circuits with Watchdog and Manual Reset 8_______________________________________________________________________________________Figure 4. MAX6316/MAX6318MH/MAX6319MH Bidirectional Reset Output Functional DiagramMAX6316–MAX63225-Pin µP Supervisory Circuits withWatchdog and Manual Reset_______________________________________________________________________________________9P-channel transistor on-resistance quickly charges stray capacitance on the reset line, allowing RESET to transition from low to high within the required two elec-tronic-clock cycles, even with several devices on the reset line. This process occurs regardless of whether the reset was caused by V CC dipping below the reset threshold, the watchdog timing out, MR being asserted,or the µP or other device asserting RESET . The parts do not require an external pullup. To minimize supply cur-rent consumption, the internal 4.7k Ωpullup resistor dis-connects from the supply whenever the MAX6316M/MAX6318MH/MAX6319MH assert reset.Open-Drain R E S E T OutputThe MAX6320P/MAX6321HP/MAX6322HP have an active-low, open-drain reset output. This output struc-ture will sink current when RESET is asserted. Connect a pullup resistor from RESET to any supply voltage up to 6V (Figure 6). Select a resistor value large enough toregister a logic low (see Electrical Characteristics ), and small enough to register a logic high while supplying all input current and leakage paths connected to the RESET line. A 10k Ωpullup is sufficient in most applications.Manual-Reset InputThe MAX6316_/MAX6317H/MAX6319_H/MAX6320P/MAX6322HP feature a manual reset input. A logic low on MR asserts a reset. After MR transitions low to high, reset remains asserted for the duration of the reset timeout peri-od (t RP ). The MR input is connected to V CC through an internal 52k Ωpullup resistor and therefore can be left unconnected when not in use. MR can be driven with TTL-logic levels in 5V systems, with CMOS-logic levels in 3V systems, or with open-drain or open-collector output devices. A normally-open momentary switch from MR to ground can also be used; it requires no external debouncing circuitry. MR is designed to reject fast, negative-going transients (typically 100ns pulses). A 0.1µF capacitor from MR to ground provides additional noise immunity.The MR input pin is equipped with internal ESD-protection circuitry that may become forward biased. Should MR be driven by voltages higher than V CC , excessive current would be drawn, which would damage the part. F or example, assume that MR is driven by a +5V supply other than V CC . If V CC drops lower than +4.7V, MR ’s absolute maximum rating 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, use the same supply for MR as the supply monitored by V CC . This guarantees that the voltage at MR will never exceed V CC .Watchdog InputThe MAX6316_/MAX6317H/MAX6318_H/MAX6320P/MAX6321HP feature a watchdog circuit that monitors the µP’s activity. If the µP does not toggle the watchdog input (WDI) within the watchdog timeout period (t WD ),reset asserts. The internal watchdog timer is cleared by reset or by a transition at WDI (which can detect pulses as short as 50ns). The watchdog timer remains cleared while reset is asserted. Once reset is released, the timer begins counting again (Figure 7).The WDI input is designed for a three-stated output device with a 10µA maximum leakage current and the capability of driving a maximum capacitive load of 200pF.The three-state device must be able to source and sink at least 200µA when active. Disable the watchdog function by leaving WDI unconnected or by three-stating the driver connected to WDI. When the watchdog timer is left open circuited, the timer is cleared internally at intervals equal to 7/8 of the watchdog period.Figure 6. MAX6320P/MAX6321HP/MAX6322HP Open-Drain RESET Output Allows Use with Multiple SuppliesFigure 5. Bidirectional RESET Timing DiagramM A X 6316–M A X 63225-Pin µP Supervisory Circuits with Watchdog and Manual Reset 10______________________________________________________________________________________Applications InformationWatchdog Input CurrentThe WDI input is internally driven through a buffer and series resistor from the watchdog counter. For minimum watchdog input current (minimum overall power con-sumption), leave WDI low for the majority of the watch-dog timeout period. When high, WDI can draw as much as 160µA. Pulsing WDI high at a low duty cycle will reduce the effect of the large input current. When WDI is left unconnected, the watchdog timer is serviced within the watchdog timeout period by a low-high-low pulse from the counter chain.Negative-Going V CC TransientsThese supervisors are immune to short-duration, nega-tive-going V CC transients (glitches), which usually do not require the entire system to shut down. Typically,200ns large-amplitude pulses (from ground to V CC ) on the supply will not cause a reset. Lower amplitude puls-es result in greater immunity. Typically, a V CC transient that goes 100mV under the reset threshold and lasts less than 4µs will not trigger a reset. An optional 0.1µF bypass capacitor mounted close to V CC provides addi-tional transient immunity.Ensuring Valid Reset OutputsDown to V CC = 0The MAX6316_/MAX6317H/MAX6318_H/MAX6319_H/MAX6321HP/MAX6322HP are guaranteed to operate properly down to V CC = 1V. In applications that require valid reset levels down to V CC = 0, a pulldown resistor to active-low outputs (push/pull and bidirectional only,F igure 8) and a pullup resistor to active-high outputs(push/pull only, Figure 9) will ensure that the reset line is valid while the reset output can no longer sink orsource current. This scheme does not work with the open-drain outputs of the MAX6320/MAX6321/MAX6322.The resistor value used is not critical, but it must be large enough not to load the reset output when V CC is above the reset threshold. F or most applications,100k Ωis adequate.Watchdog Software Considerations(MAX6316/MAX6317/MAX6318/MAX6320/MAX6321)One way to help the watchdog timer monitor software execution more closely is to set and reset the watchdog input at different points in the program, rather than pulsing the watchdog 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 watchdog from timing out.Figure 7. Watchdog Timing RelationshipFigure 9. Ensuring RESET Valid to V CC = 0 on Active-High Push/Pull OutputsFigure 8. Ensuring RESET Valid to V CC = 0 on Active-Low Push/Pull and Bidirectional OutputsMAX6316–MAX6322Watchdog and Manual Reset______________________________________________________________________________________11F igure 10 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 pro-gram returns to the beginning. If the program 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 a reset or interrupt to be issued. As described in the Watchdog Input Current section, this scheme results in higher time average WDI current than does leaving WDI low for the majority of the timeout period and periodically pulsing it low-high-low.Figure 10. Watchdog Flow Diagram__________________Pin ConfigurationsTypical Operating CircuitTable 2. Standard VersionsTable 1. Factory-Trimmed Reset ThresholdsM A X 6316–M A X 6322Watchdog and Manual ResetTable 3. Reset/Watchdog Timeout PeriodsMAX6316–MAX6322Watchdog and Manual Reset______________________________________________________________________________________13__Ordering Information (continued)a watchdog feature (see Selector Guide) are factory-trimmed to one of four watchdog timeout periods. Insert the letter corre-sponding to the desired watchdog timeout period (W, X, Y, or Z from Table 3) into the blank following the reset timeout suffix.TRANSISTOR COUNT: 191SUBSTRATE IS INTERNALLY CONNECTED TO V+Chip Informationdard versions only. The required order increment for nonstandard versions is 10,000 pieces. Contact factory for availability.M A X 6316–M A X 6322Watchdog and Manual Reset 14______________________________________________________________________________________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 .)M axim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a M axim 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©2007 Maxim Integrated Productsis a registered trademark of Maxim Integrated Products, Inc.MAX6316–MAX6322 Watchdog and Manual ResetRevision History。
MAX6326XR中文资料
For free samples & the latest literature: , or phone 1-800-998-8800.For small orders, phone 1-800-835-8769.General DescriptionThe MAX6326/MAX6327/MAX6328/MAX6346/MAX6347/MAX6348 microprocessor (µP) supervisory circuits moni-tor the power supplies in µP and digital systems. These devices provide excellent circuit reliability and low cost by eliminating external components and adjustments when used with 2.5V, 3V, 3.3V, and 5V powered circuits.These circuits perform a single function: they assert a reset signal whenever the V CC supply voltage declines below a preset threshold, keeping it asserted for at least 100ms after V CC has risen above the reset threshold.The only difference between the devices is their output.The MAX6326/MAX6346 (push-pull) and MAX6328/MAX6348 (open-drain) have an active-low reset output.The MAX6327/MAX6347 have an active-high push-pull reset output. All of these parts are guaranteed to be in the correct state for V CC down to 1V. The reset compara-tor is designed to ignore fast transients on V CC . Reset thresholds are factory-trimmable between 2.2V and 4.63V, in approximately 100mV increments. Twenty-one standard versions are available. Contact the factory for availability of nonstandard versions.Ultra-low supply currents (1µA max for the MAX6326/MAX6327/MAX6328) make these parts ideal for use in portable equipment. All six devices are available in space-saving SOT23 and SC70 packages.ApplicationsComputers Intelligent Instruments Controllers AutomotiveCritical µP and µC Portable/Battery-Powered Power MonitoringEquipmentFeatureso Ultra-Low 1µA (max) Supply Current (MAX6326/MAX6327/MAX6328)o Precision Monitoring of 2.5V, 3V, 3.3V, and 5V Power-Supply Voltageso Reset Thresholds Available from 2.2V to 4.63V o Fully Specified Over Temperatureo 100ms (min) Power-On Reset Pulse Width o Low Costo Available in Three Versions: Push-Pull RESET ,Push-Pull RESET, and Open-Drain RESET o Power-Supply Transient Immunity o No External Componentso 3-Pin SC70/SOT23 Packageso Pin Compatible with MAX803/MAX809/MAX810MAX6326/MAX6327/MAX6328/MAX6346/MAX6347/MAX63483-Pin, Ultra-Low-Power SC70/SOTµP Reset Circuits________________________________________________________________Maxim Integrated Products 1Pin Configuration19-1294; Rev 3; 1/00†The MAX6326/MAX6327/MAX6328/MAX6346/MAX6347/MAX6348 are available in factory-set V CC reset thresholds from 2.2V to 4.63V, in approximately 0.1V increments. Choose the desired reset-threshold suffix from Table 1 and insert it in the blank spaces following “R.”There are 21 standard versions witha required order increment of 2500 pieces. Sample stock is gen-erally held on the standard versions only (see the SelectorGuide). Required order increment is 10,000 pieces for nonstan-dard versions (Table 2). Contact factory for availability. All devices available in tape-and-reel only.Selector Guide appears at end of data sheet.M A X 6326/M A X 6327/M A X 6328/M A X 6346/M A X 6347/M A X 63483-Pin, Ultra-Low-Power SC70/SOT µP Reset Circuits 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 RESET, RESET (push-pull).........................-0.3V to (V CC + 0.3V)RESET (open drain)..................................................-0.3V to +6V Input Current (V CC ).............................................................20mA Output Current (RESET, RESET ).........................................20mA Rate of Rise (V CC )...........................................................100V/µsContinuous Power Dissipation (T A = +70°C)3-Pin SC70 (derate 2.7mW/°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 Lead Temperature (soldering, 10s).................................+300°CNote 1:Overtemperature limits are guaranteed by design and not production tested.MAX6326/MAX6327/MAX6328/MAX6346/MAX6347/MAX63483-Pin, Ultra-Low-Power SC70/SOTµP Reset Circuits_______________________________________________________________________________________3__________________________________________Typical Operating Characteristics(T A = +25°C, unless otherwise noted.)00.30.20.10.40.50.60.70.80.91.0-400-2020406080SUPPLY CURRENT vs. TEMPERATURE TEMPERATURE (°C)S U P P L Y C U R R E N T(µA)050100150200-400-2020406080POWER-DOWN RESET DELAY vs. TEMPERATURE TEMPERATURE (°C)R E S E T D E L A Y(µs)130150140160170180190200210-400-2020406080POWER-UP RESET TIMEOUT vs. TEMPERATURE M A X6326-03TEMPERATURE (°C)P O W E R-U P R E S E T T I M E O U T(m s)500011001000MAXIMUM TRANSIENT DURATION vs. RESET THRESHOLD OVERDRIVE (SC70)100300400200M A X6326-04RESET 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)10______________________________________________________________Pin DescriptionM A X 6326/M A X 6327/M A X 6328/M A X 6346/M A X 6347/M A X 63483-Pin, Ultra-Low-Power SC70/SOT µP Reset Circuits 4___________________________________________________________________________________________________Applications InformationInterfacing to µPs with Bidirectional Reset PinsSince the RESET output on the MAX6328/MAX6348 is open drain, these devices interface easily with micro-processors (µPs) that have bidirectional reset pins,such as the Motorola 68HC11. Connecting the µP supervisor’s RESET output directly to the microcon-troller’s (µC’s) RESET pin with a single pull-up resistor allows either device to assert reset (Figure 1).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 Maxi-mum Transient Duration vs. Reset Threshold Overdrive graph, for which reset pulses are not generated. The graph shows the maximum pulse width that a negative-going V CC transient may typically have when issuing a reset signal. As the amplitude of the transient increas-es, the maximum allowable pulse width decreases.Figure 1. Interfacing to µPs with Bidirectional Reset PinsTable 1. Factory-Trimmed Reset Thresholds ‡‡Factory-trimmed reset thresholds are available in approximately 100mV increments with a 1.5% room-temperature variance.MAX6326/MAX6327/MAX6328/MAX6346/MAX6347/MAX63483-Pin, Ultra-Low-Power SC70/SOTµP Reset Circuits_______________________________________________________________________________________5Table 1. Factory-Trimmed Reset Thresholds‡(continued)‡Factory-trimmed reset thresholds are available in approximately 100mV increments with a 1.5% room-temperature variance.Table 2. Device Marking Codes and Minimum Order IncrementsM A X 6326/M A X 6327/M A X 6328/M A X 6346/M A X 6347/M A X 63483-Pin, Ultra-Low-Power SC70/SOT µP Reset Circuits 6__________________________________________________________________________________________________________Chip InformationTRANSISTOR COUNT: 419Table 2. Device Marking Codes and Minimum Order Increments (continued)Selector Guide(standard versions*)*Sample stock is generally held on all standard versions.________________________________________________________Package InformationMAX6326/MAX6327/MAX6328/MAX6346/MAX6347/MAX63483-Pin, Ultra-Low-Power SC70/SOTµP Reset Circuits_______________________________________________________________________________________7M A X 6326/M A X 6327/M A X 6328/M A X 6346/M A X 6347/M A X 63483-Pin, Ultra-Low-Power SC70/SOT µP Reset Circuits 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.8_____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600©2000 Maxim Integrated ProductsPrinted USAis a registered trademark of Maxim Integrated Products.Package Information (continued)。
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.。
MAX6387XS30D2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。
MAX6323-MAX6324中文资料
SUFFIX
FAST
MAX
UNITS
SLOW
MIN
UNITS
A
1.5
ms
10
B
15
ms
100
ms
C
15
ms
300
D
15
ms
10
s
E
15
ms
60
F
23
ms
47
ms
G
39
ms
82
H
719
ms
1.3
s
*See Figure 1 for operation.
________________________________________________________________ Maxim Integrated Products 1
Medical
Embedded Control Systems
Features
♦ Min/Max (Windowed) Watchdog, 8 Factory-Trimmed Timing Options
♦ Pulsed Open-Drain, Active-Low Watchdog Output ♦ Power-On Reset ♦ Precision Monitoring of +2.5V, +3.0V, +3.3V,
MAX232中文资料(官方版)
________________________________ 应用
便携式计算机 低功耗调制解调器 接口转换 电池供电 RS-232 系统 多点 RS-232 网络
_____________________________ 定购信息
PART MAX220CPE MAX220CSE MAX220CWE MAX220C/D MAX220EPE MAX220ESE MAX220EWE MAX220EJE MAX220MJE TEMP RANGE 0°C to +70°C 0°C to +70°C 0°C to +70°C 0°C to +70°C -40°C to +85°C -40°C to +85°C -40°C to +85°C -40°C to +85°C -55°C to +125°C PIN-PACKAGE 16 Plastic DIP 16 Narrow SO 16 Wide SO Dice* 16 Plastic DIP 16 Narrow SO 16 Wide SO 16 CERDIP 16 CERDIP
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+5V 供电、多通道 RS-232 驱动器/接收器 MAX220–MAX249
ABSOLUTE MAXIMUM RATINGS—MAX220/222/232A/233A/242/243
Supply Voltage (VCC) ...............................................-0.3V to +6V V+ (Note 1) ..................................................(VCC - 0.3V) to +14V V- (Note 1) .............................................................+0.3V to +14V Input Voltages TIN..............................................................-0.3V to (VCC - 0.3V) RIN (Except MAX220) ........................................................±30V RIN (MAX220).....................................................................±25V TOUT (Except MAX220) (Note 2) .......................................±15V TOUT (MAX220)...............................................................±13.2V Output Voltages TOUT ...................................................................................±15V ROUT .........................................................-0.3V to (VCC + 0.3V) Driver/Receiver Output Short Circuited to GND.........Continuous Continuous Power Dissipation (TA = +70°C) 16-Pin Plastic DIP (derate 10.53mW/°C above +70°C) .842mW 18-Pin Plastic DIP (derate 11.11mW/°C above +70°C)..889mW 20-Pin Plastic DIP (derate 8.00mW/°C above +70°C) ..440mW 16-Pin Narrow SO (derate 8.70mW/°C above +70°C) ...696mW 16-Pin Wide SO (derate 9.52mW/°C above +70°C)......762mW 18-Pin Wide SO (derate 9.52mW/°C above +70°C)......762mW 20-Pin Wide SO (derate 10.00mW/°C above +70°C)....800mW 20-Pin SSOP (derate 8.00mW/°C above +70°C) ..........640mW 16-Pin CERDIP (derate 10.00mW/°C above +70°C).....800mW 18-Pin CERDIP (derate 10.53mW/°C above +70°C).....842mW Operating Temperature Ranges MAX2_ _AC_ _, MAX2_ _C_ _ .............................0°C to +70°C MAX2_ _AE_ _, MAX2_ _E_ _ ..........................-40°C to +85°C MAX2_ _AM_ _, MAX2_ _M_ _ .......................-55°C to +125°C Storage Temperature Range .............................-65°C to +160°C Lead Temperature (soldering, 10s) (Note 3) ...................+300°C
MAX232中文资料_数据手册_参数
ቤተ መጻሕፍቲ ባይዱ
ESD保护， 5V RS-232收发器输出.所以经过PC板组装之后，机器模型与I / O端口不太相关.应用信息电容选择用于C1-C4的电容器类 型不是关键正确的操作. MAX202E，MAX206-MAX208E， MAX232E和MAX213E需要0.1μF电容， MAX232E和MAX241E需要1μF电 容 - 尽管在所有情况下电容器都可以达到10μF使用没有伤害.陶瓷，铝电解，或钽电容建议1μF建议使用电容器和陶瓷电介质 0.1μF电容.当使用小的推荐值时，修补电容值，确保电容价值不会像操作那样过度降低温度变化.如果有疑问，请使用电容器较大 （例如2倍）的标称值.电容器的有效性 TIVE串联电阻（ESR），通常在低位上升温度影响V +上的纹波量和V-.使用更大的电容（高 达10μF）来减少输出 V +和V-下的阻抗MAX232.这可能是有用的时候从V +或V-“窃取”电源. MAX232和 MAX205E具有内部电荷 泵电容. 旁路V CC 到地面至少0.1μF. 在应用中，对由此产生的电源噪声敏感 电荷泵， 通过电容去 耦V CC 到地，与电荷泵的尺寸 相同（或大于）电容器（C1-C4）. V +和V-作为电源可以从V +和V-中获取少量功率，尽管这会减少驾驶员的输出摆动和噪音边际. 增加电荷泵的价值电容器（高达10μF）有助于保持性能当电源从V +或V-引出时.驱动多个接收器每个发射器都设计用来驱动一个 接收器.变送器可以并联驱动多个接收器.退出关机时的驱动程序输出驱动器输出不显示振铃或不合需要当他们从关机时出现瞬态.高 数据速率这些收发器保持RS-232±5.0V MINI-妈妈驱动器输出电压数据速率超过 120KBPS.对于120KBPS以上的数据速率，请参考发 射机输出电压与负载电容在图表中典型. 驱动器输出关闭并只吸取漏电流 - MAX232即使他们是反向驱动电压在0V和 12V.在关机时低于-0.5V，变送器输出为二极管钳位到地 面与1KΩ串联阻抗 - ANCE. RS-232接收器接收器将RS-232信号转换为CMOS逻辑产出水平.保证0.8V和2.4V接收器输入阈值比±3V严 格得多 EIA / TIA-232E规范要求的阈值.这允许接收器输入响应TTL / CMOS-逻辑电平以及RS-232电平.保证0.8V输入低阈值确保接地 短路的接收器具有逻辑1输出.该 5KΩ输入电阻接地保证了MAX232接收器其输入保持打开状态也将具有逻辑1输出.接收器输入具有 大约0.5V的滞后.这提供了干净的输出转换，即使MAX232速度很慢上升/下降时间信号，噪音适中并响起.关断时，MAX213E的R4和 R5接收器具有没有滞后.关机和启用控制 （MAX205E / MAX206E / MAX232E / MAX213E / MAX241E）在关机模式下，充电泵关闭， V +被拉低至V CC ，V-拉至接地，并且变送器输出被禁用.这减少了支持，通常为1μA（MAX213E为15μA）.退出关机所需的时间 低于1MS，如如图5所示.接收器除R4和R5外，所有MAX213E接收机都被放入在关断模式下的高阻状态（见表 1A和1B）. MAX213E的 R4和R5接收器依然如此功能在关机模式下.这两个清醒的，下行接收机可以监控外部活动，保持小的功耗.启用控件用于将接收器输 出插入一个高阻状态，以允许线或连接两个EIA / TIA-232E端口（或不同类型的端口） UART.它不影响RS-232驱动程序或者充电泵. MAXIM器件，ESD保护结构一样并入所有引脚以防止电 - MAX232处理过程中遇到静电放电部件.驱动器输出和接收器输入额外的防 静电保护. MAXIM的英文 - NEERS开发了先进的结构来保护这些引脚对±15KV的ESD没有损坏.该在所有状态下，ESD结构都能承受 高ESD操作，关机和关机.在ESD之后事件，MAXIM的E版本继续工作，没有闭锁，而竞争的RS-232产品可以锁定和必须断电以消除 闩锁. ESD保护可以通过各种方式进行测试;该本产品的发射机输出和接收机输入家庭的特点.
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.。
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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/MAX6363/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 sig-nificantly improve system reliability and accuracy com-pared to that obtainable with separate ICs or discrete components. Their functions include µP reset, backup-battery switchover, and power failure warning.The MAX6361/MAX6363/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), 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 push-pull reset, an active-low open-drain reset, and an active-high push-pull reset (see Selector Guide at end of data sheet).ApplicationsFeatureso 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 Debounced Manual Reset Input (MAX6361)o Battery-On Output Indicator (MAX6363)o Auxiliary User-Adjustable RESET IN (MAX6364)o Three Available Output StructuresPush-Pull RESET , Open-Drain RESET , Push-Pull 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 Small 6-Pin SOT23 PackageMAX6361/MAX6363/MAX6364SOT23, Low-Power µP Supervisory Circuitswith Battery Backup________________________________________________________________Maxim Integrated Products119-1615; Rev 0; 1/00Ordering InformationPin ConfigurationsNote:These parts offer a choice of reset threshold voltages.From Table 1, 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 mini-mum on the SOT package (tape-and-reel only).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 6363/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)..............................................-0.3V to +6V BATT ON, MR , RESET IN .....................-0.3V to (V OUT + 0.3V)RESET, RESET ......................................-0.3V to (V OUT + 0.3V)Input CurrentV CC Peak ............................................................................1A V CC Continuous............................................................250mA BATT Peak....................................................................250mA BATT Continuous............................................................40mA GND................................................................................75mAOutput 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 RangeMAX636_.........................................................-40°C to +85°C Storage Temperature Range.............................-65°C to +150°C Lead Temperature (soldering, 10s).................................+300°CMAX6361/MAX6363/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:Overtemperature limits are guaranteed by design and not production tested.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 6363/M A X 6364SOT23, Low-Power µP Supervisory Circuits with Battery Backup 4Typical 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 YC U R R E N T (µA )-402040-200608001432567BATTERY TO OUT ON-RESISTANCEvs. TEMPERATURETEMPERATURE (°C)B A T T T O O U T O N -R E S I S T A N C 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 G A G A T I O N D E L AY (µs )-402040-2060802.03.02.55.04.54.03.5RESET THRESHOLD vs. TEMPERATURETEMPERATURE (°C)T H R E S H O L D (V )-402040-2060801100101k10kMAXIMUM 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 )4003003502502000501501000321456789101234BATTERY SUPPLY CURRENT vs. SUPPLY VOLTAGEB A T T E R Y S U P P L YC U R R E N T (µA )MAX6361/MAX6363/MAX6364SOT23, Low-Power µP Supervisory Circuitswith Battery Backup_______________________________________________________________________________________51.2341.2351.236MAX6364RESET 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 DescriptionDetailed DescriptionThe Typic al Operating Circ uit shows a typical connec-tion for the MAX6361/MAX6363/MAX6364 family. OUT powers the static random-access memory (SRAM). OUT is internally connected to V CC if V CC is greater than the reset threshold, or to the greater of V CC or V BATT when 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 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 Battery to Out On-Resistance vs. Temperature graph in the Typical Operating Characteristics section.M A X 6361/M A X 6363/M A X 6364Backup-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/MAX6363/MAX6364 automatically 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 2 lists the statusof the inputs and outputs in battery-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.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 G ND 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 capaci-tor from MR to GND to provide additional noise immunity.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.Reset OutputA µP’s reset input starts the µP in a known state. The MAX6361/MAX6363/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 depend-ing 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).Applications InformationOperation Without a BackupPower SourceThe MAX6361/MAX6363/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 µP when 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 widthSOT23, Low-Power µP Supervisory Circuits with Battery Backup 6MAX6361/MAX6363/MAX6364SOT23, Low-Power µP Supervisory Circuitswith Battery Backup_______________________________________________________________________________________7*Sample stock generally held on standard versions only. Contact factory for availability of nonstandard versions.Device Marking CodesSelector Guidethat 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.M A X 6361/M A X 6363/M A X 6364SOT23, Low-Power µP Supervisory Circuits with Battery Backup Maxim c annot assume responsibility for use of any c irc uitry other than c irc uitry entirely embodied in a Maxim produc t. No c irc uit patent lic enses 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©2000 Maxim Integrated ProductsPrinted USAis a registered trademark of Maxim Integrated Products.Package InformationPin Configurations (continued)Typical Operating CircuitChip InformationTRANSISTOR COUNT: 720。