MAX6317HUK38BX中文资料

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MAX6387XS33D7-T中文资料

MAX6387XS33D7-T中文资料

General DescriptionThe 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 packages and the MAX6384–MAX6390 are avail-able in 4-pin SC70 packages.________________________ApplicationsComputers ControllersIntelligent InstrumentsCritical µP and µC Power Monitoring Portable/Battery-Powered Equipment Dual Voltage SystemsFeatureso Factory-Set Reset Threshold Voltages Ranging from +1.58V to +4.63V in Approximately 100mV Increments o ±2.5% Reset Threshold Accuracy Over Temperature (-40°C to +125°C)o Seven Reset Timeout Periods Available: 1ms,20ms, 140ms, 280ms, 560ms, 1120ms, 1200ms (min)o 3 Reset Output OptionsActive-Low Push-Pull Active-High Push-Pull Active-Low Open-Draino Reset Output State Guaranteed Valid Down to V CC = 1Vo Manual Reset Input (MAX6384/MAX6385/MAX6386)o Auxiliary RESET IN(MAX6387/MAX6388/MAX6389)o V CC Reset Timeout (1120ms or 1200ms)/Manual Reset Timeout (140ms or 150ms) (MAX6390)o Negative-Going V CC Transient Immunity o Low Power Consumption of 6µA at +3.6V and 3µA at +1.8V o Pin Compatible withMAX809/MAX810/MAX803/MAX6326/MAX6327/MAX6328/MAX6346/MAX6347/MAX6348, and MAX6711/MAX6712/MAX6713o Tiny 3-Pin SC70 and 4-Pin SC70 PackagesMAX6381–MAX6390SC70, Single/Dual Low-Voltage, Low-Power µP Reset Circuits________________________________________________________________Maxim Integrated Products1Pin Configurations19-1839; Rev 1; 04/01Ordering InformationOrdering Information continued at end of data sheet.Typical Operating Circuit appears at end of data sheet.Selector Guide appears at end of data sheet.Note:Insert reset threshold suffix (see Reset Threshold table)after "XR" or "XS". 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 (seeStandard 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.For pricing, delivery, and ordering information,please contact Maxim/Dallas Direct!at 1-888-629-4642, or visit Maxim’s website at .M A X 6381–M A X 6390SC70, Single/Dual Low-Voltage, Low-Power µP Reset CircuitsABSOLUTE MAXIMUM RATINGSELECTRICAL CHARACTERISTICSStresses 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 Operating Temperature Range .........................-40°C to +125°C Storage Temperature Range.............................-65°C to +150°C Lead Temperature (soldering, 10s).................................+300°CMAX6381–MAX6390SC70, Single/Dual Low-Voltage, Low-Power µP Reset Circuits_______________________________________________________________________________________3M A X 6381–M A X 6390SC70, 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 TT H 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, Single/Dual Low-Voltage, Low-Power µP Reset Circuits_______________________________________________________________________________________5M A X 6381–M A X 6390SC70, 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 (1.35k 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 magni-tude indicated (reset comparator overdrive). The graph indicates the typical maximum pulse width a negative-going V CC transient may have without causing a reset pulse to be issued. As the magnitude of the transient 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 = 0The MAX6381–MAX6390 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 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 output can no longer sink or source current. This scheme doesnot 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 adequate.MAX6381–MAX6390SC70, Single/Dual Low-Voltage, Low-Power µP Reset Circuits_______________________________________________________________________________________7M A X 6381–M A X 6390SC70, Single/Dual Low-Voltage, Low-Power µP Reset Circuits 8Selector GuideChip InformationTRANSISTOR COUNT: 647PROCESS: BiCMOS*MR is for MAX6384/MAX6385/MAX6386/MAX6390**RESET IN is for MAX6387/MAX6388/MAX6389( ) are for MAX6382/MAX6385/MAX6388Pin Configurations (continued)MAX6381–MAX6390SC70, Single/Dual Low-Voltage, Low-Power µP Reset Circuits_______________________________________________________________________________________9Ordering Information(continued)Note:Insert reset threshold suffix (see Reset Threshold table)after "XR" or "XS". 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 (seeStandard 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.M A X 6381–M A X 6390SC70, Single/Dual Low-Voltage, Low-Power µP Reset Circuits 10______________________________________________________________________________________Package InformationSC70, 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____________________11©2001 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.MAX6381–MAX6390Package Information (continued)元器件交易网。

MAX1722EZK-T中文资料

MAX1722EZK-T中文资料
GND 2
MAX1722
FB 3
4
OUT
THIN SOT23-5
Pin Configurations are continued at end of data sheet.
________________________________________________________________ Maxim Integrated Products
元器件交易网
19-1735; Rev 0; 7/01
1.5µA IQ, Step-Up DC-DC Converters in Thin SOT23-5
General Description
The MAX1722/MAX1723/MAX1724 compact, high-efficiency, step-up DC-DC converters are available in tiny, 5pin thin SOT23 packages. They feature an extremely low 1.5µA quiescent supply current to ensure the highest possible light-load efficiency. Optimized for operation from one to two alkaline or nickel-metal-hydride (NiMH) cells, or a single Li+ cell, these devices are ideal for applications where extremely low quiescent current and ultra-small size are critical. Built-in synchronous rectification significantly improves efficiency and reduces size and cost by eliminating the need for an external Schottky diode. All three devices feature a 0.5Ω N-channel power switch. The MAX1722/ MAX1724 also feature proprietary noise-reduction circuitry, which suppresses electromagnetic interference (EMI) caused by the inductor in many step-up applications. The family offers different combinations of fixed or adjustable outputs, shutdown, and EMI reduction (see Selector Guide). o o o o o o o o o o o

MAXIM MAX5417 5418 5419 说明书

MAXIM MAX5417 5418 5419 说明书

________________________________概述MAX5417/MAX5418/MAX5419是非易失、线性数字电位器,与机械电位器功能相似,但可通过简单的2线数字接口控制,允许多个器件进行通信。

每个器件具有分离电位器或可变电阻的功能,具有256个抽头点。

这些器件内置非易失EEPROM ,用于存储滑动端的位置,上电时进行初始化处理。

快速模式I 2C TM 兼容接口允许400kbps 的通信速率,在许多应用场合可有效减小电路板面积,简化电路连接。

每个器件有一个工厂预置地址,有四种地址选择(见选择指南),配合地址选择输入,共提供八个唯一的地址组合。

MAX5417/MAX5418/MAX5419提供了三个标称阻值:50kΩ(MAX5417)、100kΩ(MAX5418)和200kΩ(MAX5419)。

标称电阻的端到端温度系数为35ppm/°C, 比率温度系数仅为5ppm/°C ,非常适合低温漂可变电阻的应用,如低漂移、可编程增益放大器。

MAX5417/MAX5418/MAX5419采用3mm x 3mm 、8引脚TDFN 封装,工作在-40°C 至+85°C 扩展级温度范围。

________________________________应用替代机械电位器低漂移可编程增益放大器音量控制液晶显示屏(LCD)对比度控制________________________________特性♦上电后从非易失存储器调用滑动端位置♦微型3mm x 3mm 、8引脚TDFN 封装♦端到端电阻温度系数:35ppm/°C ♦比率温度系数:5ppm/°C ♦阻值:50k Ω/100k Ω/200k Ω♦快速I 2C 兼容串行接口♦500nA (典型值)静态电流♦单电源+2.7V 至+5.25V 供电♦256抽头♦分压模式下DNL 为:±0.5 LSB ♦分压模式下INL 为:±0.5 LSBMAX5417/MAX5418/MAX5419256抽头、非易失、I 2C 接口数字电位器________________________________________________________________Maxim Integrated Products1功能图19-3185; Rev 2; 8/04本文是Maxim 正式英文资料的译文,Maxim 不对翻译中存在的差异或由此产生的错误负责。

MAX6317HUK39BY-T中文资料

MAX6317HUK39BY-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。

最新max038芯片中文资料

最新max038芯片中文资料
低于2%。 5)采用±5V双电源供电,允许有5%变化范围,电源电流为80mA,
典型功耗400mW,工作温度范围为0~70℃。 6)内设2.5V电压基准,可利用该电压设定FADJ、DADJ的电压值,实
现频率微调和占空比调节。 7)低阻抗定压输出,输出电阻典型值0.1欧姆,具有输出过载/短路保
护。 8)内部功能齐全,外围电路简单,使用方便。
号周期为tX= to/(1- 0.12915×V FADJ ) , 其中, to 为V FADJ= 0V 时的输出信号周期。
接在REF (+ 2.5V ) 和FADJ 之间的可变电阻RF
可调整频率。R F 阻值按R F= (V REF - V FADJ )/250 (uA ) 计算。
占空比调节
改变DADJ端的电压,能控制波形的占空比D。当 VDADJ=0V时,D=50%;VDADJ=+2.3~-2.3v时,D从 15%变化到85%。欲获得完全对称的正弦波,需加一个校 准电压VDADJ,允许范围是-100~+100mV,经校准后可使 D严格等于50%。占空比的计算公式为: D=(50+17.4VDADJ)%
输出振荡频率控制
输出频率与外接振荡电容器COSC的容量、参考电流IIN及 频率调节电压VFADJ有关。
当VFADJ=0V时,输出振荡频率由下式决定: F0(MHZ)=IIN(uA)÷CF(PF) 式中:IIN为当前输入到IIN的电流( 2uA≤IIN≤750uA),
IIN可由电流源IIN或电压源VIN与电阻RIN串联来驱动 (接在 REF和IIN之间的电阻就可产生IIN)。使用电 压源与电阻串联的振荡器振荡频率按F0(MHz) =Vin/[Rin*Cf(pF) ]计算。推荐的参考电流IIN范围: 10uA到400uA。 CF=外接振荡电容器COSC的容量 (20pf≤COSC≤100uf) ;

MAX3057ASA中文资料

MAX3057ASA中文资料

General DescriptionThe MAX3050/MAX3057 interface between the CAN protocol controller and the physical wires of the bus lines in a controller area network (CAN). They are pri-marily intended for automotive systems requiring data rates up to 2Mbps and feature ±80V fault protection against short circuits in high-voltage power buses. They provide differential transmit capability to the bus and differential receive capability to the CAN controller. The MAX3050/MAX3057 have four modes of operation:high speed, slope control, standby, and shutdown.High-speed mode allows data rates up to 2Mbps. In slope-control mode, data rates are 40kbps to 500kbps,so the effects of EMI are reduced, and unshielded twisted or parallel cable can be used. In standby mode,the transmitters are shut off and the receivers are put into low-current mode. In shutdown mode, the transmit-ter and receiver are switched off.The MAX3050 has an AutoShutdown™ function that puts the device into a 15µA shutdown mode when the bus or CAN controller is inactive for 4ms or longer.The MAX3050/MAX3057 are available in an 8-pin SO package and are specified for operation from -40°C to +125°C.ApplicationsAutomotive Systems HVAC Controls Telecom 72V systemsFeatureso ±80V Fault Protection for 42V Systems o Four Operating ModesHigh-Speed Operation Up to 2Mbps Slope-Control Mode to Reduce EMI (40kbps to 500kbps)Standby ModeLow-Current Shutdown Mode o AutoShutdown when Device Is Inactive (MAX3050)o Automatic Wake-Up from Shutdown (MAX3050)o Thermal Shutdown o Current Limitingo Fully Compatible with the ISO 11898 Standard*MAX3050/MAX3057±80V Fault-Protected, 2Mbps, Low SupplyCurrent CAN Transceivers________________________________________________________________Maxim Integrated Products 1Ordering InformationTypical Operating Circuit19-2670; Rev 0; 10/02For pricing, delivery, and ordering information,please contact Maxim/Dallas Direct!at1-888-629-4642, or visit Maxim’s website at .Pin ConfigurationAutoShutdown is a trademark of Maxim Integrated Products, Inc.*Pending completion of testing.M A X 3050/M A X 3057±80V Fault-Protected, 2Mbps, Low Supply Current CAN Transceivers 2_______________________________________________________________________________________ABSOLUTE MAXIMUM RATINGSDC ELECTRICAL CHARACTERISTICS(V CC = +5V ±10%, R L = 60Ω, RS = GND, T A = T MIN to T MAX . Typical values are at V CC = +5V and 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.V CC to GND ............................................................-0.3V to +6V TXD, RS, RXD, SHDN to GND....................-0.3V to (V CC + 0.3V)CANH, CANL to GND..............................................-80V to +80V RXD Shorted to GND.................................................Continuous Continuous Power Dissipation (T A = +70°C)8-Pin SO (derate 5.9mW/°C above +70°C) .................470mWOperating Temperature Range .........................-40°C to +125°C Junction Temperature......................................................+150°C Storage Temperature Range.............................-65°C to +150°C Lead Temperature (soldering, 10s) ................................+300°CMAX3050/MAX3057±80V Fault-Protected, 2Mbps, Low SupplyCurrent CAN Transceivers_______________________________________________________________________________________3DC ELECTRICAL CHARACTERISTICS (continued)M A X 3050/M A X 3057±80V Fault-Protected, 2Mbps, Low Supply Current CAN Transceivers 4_______________________________________________________________________________________Note 1:As defined by ISO, bus value is one of two complementary logical values: dominant or recessive. The dominant value repre-sents the logical 1 and the recessive represents the logical 0. During the simultaneous transmission of the dominant and recessive bits, the resulting bus value is dominant. For MAX3050 and MAX3057 values, see the truth table in the Transmitter and Receiver sections.TIMING CHARACTERISTICSMAX3050/MAX3057±80V Fault-Protected, 2Mbps, Low SupplyCurrent CAN Transceivers_______________________________________________________________________________________5Figure 1. AC Test CircuitFigure 2. Timing Diagram for Dynamic Characteristics Figure 3. Time to Wake Up (t WAKE ) (MAX3050)M A X 3050/M A X 3057±80V Fault-Protected, 2Mbps, Low Supply Current CAN Transceivers 6_______________________________________________________________________________________Typical Operating Characteristics(V CC = 5V, R L = 60Ω, C L = 100pF, T A = +25°C, unless otherwise specified.)MAX3057SLEW RATE vs. R RSR RS (k Ω)S L E W R A T E (V /µs )1621248648510152025010200M A X 50 t o c 02S L E E P T I M E (m s )3002001002040608010000400MAX3050AutoShutdown vs. C SHDNC SHDN (nF)SUPPLY CURRENT vs. DATA RATEDATA RATE (kbps)S U P P L Y C U R R E N T (m A )160012008004002729313335252000RECEIVER PROPAGATION DELAY vs. TEMPERATURE, R RS = GNDTEMPERATURE (°C)R E C E I V E R P R O P A G A T I O N D E L A Y (n s )905520-15253545556515-50125DRIVER PROPAGATION DELAY vs. TEMPERATURE, R RS = GNDTEMPERATURE (°C)D R I VE R P R O P A G A T I O N D E L A Y (n s )925926-72025303515-40125RECEIVER OUTPUT LOW vs. OUTPUT CURRENTOUTPUT CURRENT (mA)V O L T A G E R X D (m V )2015105400800120016000025RECEIVER OUTPUT HIGH vs. OUTPUT CURRENTOUTPUT CURRENT (mA)V O L T A G E (V C C - R X D ) (m V )201510560012001800300024000025DIFFERENTIAL VOLTAGE vs. DIFFERENTIAL LOAD R LDIFFERENTIAL LOAD R L (Ω)D I F FE R E N T I A L V O L T A G E (V )25020015010050123400300SUPPLY CURRENTvs. TEMPERATURE IN STANDBY MODEM A X 3050 t o c 09TEMPERATURE (°C)S U P P L Y C U R R E N T (µA )905520-157510012515017520050-50125MAX3050/MAX3057±80V Fault-Protected, 2Mbps, Low SupplyCurrent CAN TransceiversLOOPBACK PROPAGATION DELAY vs. R RSM A X 350 t o c 10R RS (k Ω)L O O P B A C K P R O P A G A T I O N D E L A Y (n s )1501005020040060080010001200140000200RECEIVER PROPAGATION DELAYMAX3050 toc1140ns/divRXD 2V/divCANH - CANLDRIVER PROPAGATION DELAYMAX3050 toc131µs/divTXD 5V/divR RS = 24k ΩR RS = 100k ΩR RS = 180k ΩDRIVER PROPAGATION DELAY40ns/divTXD 2V/div CANH - CANLTypical Operating Characteristics (continued)(V CC = 5V, R L = 60Ω, C L = 100pF, T A = +25°C, unless otherwise specified.)Pin DescriptionM A X 3050/M A X 3057Detailed DescriptionThe MAX3050/MAX3057 interface between the protocol controller and the physical wires of the bus lines in a CAN. They are primarily intended for automotive appli-cations requiring data rates up to 2Mbps and feature ±80V fault protection against shorts in high-voltage sys-tems. This fault protection allows the devices to with-stand up to ±80V with respect to ground with no damage to the device. The built-in fault tolerance allows the device to survive in industrial and automotive environments with no external protection devices. The devices provide differential transmit capability to the bus and differential receive capability to the CAN con-troller (Figure 4).The device has four modes of operation: high speed,slope control, standby, and shutdown. In high-speed mode, slew rates are not limited, making 2Mbps transmis-sion speeds possible. Slew rates are controlled in slope-control mode, minimizing EMI and allowing use of unshielded twisted or parallel cable. In standby mode,receivers are active and transmitters are in high imped-ance. In shutdown mode, transmitters and receivers are turned off.The transceivers are designed to operate from a single +5V supply and draw 56mA of supply current in domi-nant state and 3.6mA in recessive state. In standby mode, supply current is reduced to 125µA. In shutdown mode, supply current is 15µA.CANH and CANL are output short-circuit current limited and are protected against excessive power dissipation by thermal-shutdown circuitry that places the driver outputs into a high-impedance state.Fault ProtectionThe MAX3050/MAX3057 feature ±80V fault protection.This extended voltage range of CANH and CANL bus lines allows use in high-voltage systems and communi-cation with high-voltage buses. If data is transmitting at 2Mbps, the fault protection is reduced to ±70V.TransmitterThe transmitter converts a single-ended input (TXD)from the CAN controller to differential outputs for the bus lines (CANH, CANL). The truth table for the trans-mitter and receiver is given in Table 1.±80V Fault-Protected, 2Mbps, Low Supply Current CAN Transceivers 8_______________________________________________________________________________________Figure 4. Functional DiagramHigh SpeedConnect RS to ground to set the MAX3050/MAX3057 to high-speed mode. When operating in high-speed mode, the MAX3050/MAX3057 can achieve transmis-sion rates of up to 2Mbps. Line drivers are switched on and off as quickly as possible. However, in this mode,no measures are taken to limit the rise and fall slope of the data signal, allowing for potential EMI emissions. If using the MAX3050/MAX3057 in high-speed mode, use shielded twisted-pair cable to avoid EMI problems.Slope ControlConnect a resistor from RS to ground to select slope-control mode (Table 2). In slope-control mode, the gates of the line drivers are charged with a controlled current, proportional to the resistor connected to the RS pin. Transmission speed ranges from 40kbps to 500kbps. Controlling the rise and fall slope reduces EMI and allows the use of an unshielded twisted pair or a parallel pair of wires as bus lines. The transfer func-tion for selecting the resistor value is given by:R RS (k Ω) = 12000/speed (in kbps)See the Slew Rate vs. R RS graph in the Typical Operating Characteristics section.ReceiverThe receiver reads differential input from the bus lines (CANH, CANL) and transfers this data as a single-ended output (RXD) to the CAN controller. It consists of a comparator that senses the difference ∆V = (CANH -CANL) with respect to an internal threshold of 0.7V. If this difference is positive (i.e., ∆V > 0.7V), a logic low ispresent at the RXD pin. If negative (i.e., ∆V < 0.7V), a logic high is present.The receiver always echoes the transmitted data.The CANH and CANL common-mode range is -7V to +12V. RXD is logic high when CANH and CANL are shorted or terminated and undriven. If the differential receiver input voltage (CANH - CANL) is less than or equal to 0.5V, RXD is logic high. If (CANH - CANL) is greater than or equal to 0.9V, RXD is logic low.StandbyIf a logic high level is applied to RS, the MAX3050/MAX3057 enter a low-current standby mode. In this mode, the transmitter is switched off and the receiver is switched to a low-current state. If dominant bits are detected, RXD switches to a low level. The microcon-troller should react to this condition by switching the transceiver back to normal operation (through RS). Due to the reduced power mode, the receiver is slower in standby mode, and the first message may be lost at higher bit rates.Thermal ShutdownIf the junction temperature exceeds +160°C, the device is switched off. The hysteresis is approximately 20°C,disabling thermal shutdown once the temperature reaches +140°C.Shutdown (MAX3057)Drive SHDN low to enter shutdown mode. In shutdown mode, the device is switched off. The outputs are high impedance to ±80V. The MAX3057 features a pullup at SHDN . If shutdown is forced low and then left floating,the device switches back to normal operating mode.MAX3050/MAX3057±80V Fault-Protected, 2Mbps, Low SupplyCurrent CAN TransceiversTable 1. Transmitter and Receiver Truth Tablelogical 0 and the recessive represents the logical 1. During the simultaneous transmission of the dominant and recessive bits, the result-ing bus value is dominant.Table 2. Mode Selection Truth TableM A X 3050/M A X 3057AutoShutdown (MAX3050)To manage power consumption, AutoShutdown puts the device into shutdown mode after the device has been inactive for a period of time. The value of an external capacitor (C SHDN ) connected to SHDN deter-mines the threshold of inactivity time, after which the AutoShutdown triggers. F loating SHDN allows the MAX3050 to automatically change from active mode to shutdown.Use a 100nF capacitor as C SHDN for a typical thresh-old of 20ms. Change the capacitor value according to the following equation to change the threshold time period.V SHDN is the threshold of SHDN guaranteed to be less than 2V in the Electrical Characteristics table. Drive SHDN high to turn the MAX3050 on and disable AutoShutdown.When the MAX3050 is in shutdown mode, only the wake-up comparator is active, and normal bus commu-nication is ignored. The remote master of the CAN sys-tem wakes up the MAX3050 with a signal greater than 9V on CANH. Internal circuitry in the MAX3050 puts the device in normal operation by driving SHDN high. The MAX3057 does not have the AutoShutdown feature.Driver Output ProtectionThe MAX3050/MAX3057 have several features that pro-tect them from damage. Thermal shutdown switches off the device and puts CANH and CANL into high imped-ance if the junction temperature exceeds +160°C.Thermal protection is needed particularly when a bus line is short circuited. The hysteresis for the thermal shutdown is approximately 20°C.Additionally, a current-limiting circuit protects the trans-mitter output stage against short-circuits to positive and negative battery voltage. Although the power dissipa-tion increases during this fault condition, this featureprevents destruction of the transmitter output stage.±80V Fault-Protected, 2Mbps, Low Supply Current CAN Transceivers 10______________________________________________________________________________________Figure 5. FFT Dominant Bus at 2MbpsFigure 6. FFT Recessive Bus at 2MbpsFigure 7. FFT Dominant Bus at 500kbpsApplications InformationReduced EMI and ReflectionsIn slope-control mode, the CANH and CANL outputs are slew-rate limited, minimizing EMI and reducing reflections caused by improperly terminated cables. In general, a transmitter ’s rise time relates directly to the length of an unterminated stub, which can be driven with only minor waveform reflections. The following equation expresses this relationship conservatively:Length = t RISE / (15ns/ft)where t RISE is the transmitter ’s rise time.The MAX3050 and MAX3057 require no special layout considerations beyond common practices. Bypass V CC to GND with a 0.1µF ceramic capacitor mounted close to the IC with short lead lengths and wide trace widths.Chip InformationTRANSISTOR COUNT: 1214PROCESS: BiCMOSMAX3050/MAX3057±80V Fault-Protected, 2Mbps, Low SupplyCurrent CAN Transceivers______________________________________________________________________________________11Figure 8. FFT Recessive Bus at 500kbpsFigure 9. FFT Dominant Bus at 62.5kbpsFigure 10. FFT Recessive Bus at 62.5kbpsM A X 3050/M A X 3057±80V Fault-Protected, 2Mbps, Low Supply Current CAN Transceivers 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.12____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600©2002 Maxim Integrated ProductsPrinted USAis a registered trademark of Maxim Integrated Products.Package Information(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,go to /packages .)。

max3485中文资料

max3485中文资料

MAX3483, MAX3485, MAX3486, MAX3488, MAX3490以及MAX3491是用于RS-485与RS-422通信的3.3V,低功耗收发器,每个器件中都具有一个驱动器和一个接收器。

MAX3483和MAX3488具有限摆率驱动器,可以减小EMI,并降低由不恰当的终端匹配电缆引起的反射,实现最高250kbps的无差错数据传输。

MAX3486的驱动器摆率部分受限,可以实现最高2.5Mbps的传输速率。

MAX3485,MAX3490和MAX3491则可以实现最高10Mbps 的传输速率。

驱动器具有短路电流限制,并可以通过热关断电路将驱动器输出置为高阻状态,防止过度的功率损耗。

接收器输入具有失效保护特性,当输入开路时,可以确保逻辑高电平输出。

使用MAX3488, MAX3490和MAX3491可以实现全双工通信,而MAX3483,MAX3485与MAX3486则为半双工应用设计。

这篇文章介绍的就是MAX34852 芯片介绍2.1 主要特点半双工速率:10Mbps限摆率:NO接收允许控制:YES 关断电流:2 nA引脚数:82.2 引脚配置根据上图、上表可知:DE和RO为使能管脚。

DE为低电平、RE为低电平时为接收;DE 为高电平、RE为高电平时为发送;RO和DI为数据管脚。

RO为接收,DI为发送;因此我们经常将DE和RE直接连接,用一个IO口控制(见3.2 电路实现)。

3.1 应用场景工业控制局域网集成服务数字网络低功耗RS-485/RS-422收发器(我做的几个项目都是该功能)分组交换技术电信用于EMI敏感应用的收发器3.2 电路实现485是2线式,两个485接口的设备相连通过A、B两根线即可(也就是至少2个485芯片),连接方式如下图所示:我们使用MAX3485一般是用下图电路:从上图中我们可以看到:RO直接和TTL电平的UART_RX(或模拟串口的RX)相连,DI直接和TTL电平的UART_TX(或模拟串口的TX)相连,R34为1K。

MAX6340UK30中文资料

MAX6340UK30中文资料

General DescriptionThe MAX6340/MAX6421–MAX6426 low-power micro-processor supervisor circuits monitor system voltages from 1.6V to 5V. These devices perform a single function:they assert a reset signal whenever the V CC supply volt-age falls below its reset threshold. The reset output remains asserted for the reset timeout period after V CC rises above the reset threshold. The reset timeout is exter-nally set by a capacitor to provide more flexibility.The MAX6421/MAX6424 have an active-low, push-pull reset output. The MAX6422 has an active-high,push-pull reset output and the MAX6340/MAX6423/MAX6425/MAX6426 have an active-low, open-drain reset output. The MAX6421/MAX6422/MAX6423 are offered in 4-pin SC70 or SOT143 packages. The MAX6340/MAX6424/MAX6425/MAX6426 are available in 5-pin SOT23-5 packages.ApplicationsPortable EquipmentBattery-Powered Computers/Controllers Automotive Medical Equipment Intelligent Instruments Embedded Controllers Critical µP Monitoring Set-Top Boxes ComputersFeatures♦Monitor System Voltages from 1.6V to 5V ♦Capacitor-Adjustable Reset Timeout Period ♦Low Quiescent Current (1.6µA typ)♦Three RESET Output OptionsPush-Pull RESET Push-Pull RESET Open-Drain RESET ♦Guaranteed Reset Valid to V CC = 1V ♦Immune to Short V CC Transients♦Small 4-Pin SC70, 4-Pin SOT143, and 5-Pin SOT23Packages ♦MAX6340 Pin Compatible with LP3470♦MAX6424/MAX6425 Pin Compatible with NCP300–NCP303, MC33464/MC33465,S807/S808/S809, and RN5VD ♦MAX6426 Pin Compatible with PST92XXMAX6340/MAX6421–MAX6426Low-Power, SC70/SOT µP Reset Circuits with Capacitor-Adjustable Reset Timeout Delay________________________________________________________________Maxim Integrated Products1Ordering InformationPin Configurations19-2440; Rev 4; 12/05For pricing, delivery, and ordering information,please contact Maxim/Dallas Direct!at 1-888-629-4642, or visit Maxim’s website at .Selector Guide appears at end of data sheet.Note: The MAX6340/MAX6421–MAX6426 are available with fac-tory-trimmed reset thresholds from 1.575V to 5.0V in approxi-mately 0.1V increments. Insert the desired nominal reset threshold suffix (from Table 1) into the blanks. There are 50 stan-dard versions with a required order increment of 2500 pieces.S ample stock is generally held on standard versions only (see S tandard Versions Table). Required order increment is 10,000pieces for nonstandard versions. Contact factory for availability.All devices are available in tape-and-reel only.Devices are available in both leaded and lead-free packaging.Specify lead-free by replacing "-T" with "+T" when ordering.Typical Operating Circuit appears at end of data sheet.M A X 6340/M A X 6421–M A X 6426Low-Power, SC70/SOT µP Reset Circuits with Capacitor-Adjustable Reset Timeout Delay2_______________________________________________________________________________________ABSOLUTE MAXIMUM RATINGSELECTRICAL CHARACTERISTICSStresses 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.All Voltages Referenced to GNDV CC ........................................................................-0.3V to +6.0V SRT, RESET , RESET (push-pull).................-0.3V to (V CC + 0.3V)RESET (open drain)...............................................-0.3V to +6.0V Input Current (all pins)......................................................±20mA Output Current (RESET , RESET)......................................±20mAContinuous Power Dissipation (T A = +70°C)4-Pin SC70 (derate 3.1mW/°C above +70°C)..............245mW 4-Pin SOT143 (derate 4mW/°C above +70°C).............320mW 5-Pin SOT23 (derate 7.1mW/°C above +70°C)............571mW Operating Temperature Range .........................-40°C to +125°C Storage Temperature Range.............................-65°C to +150°C Junction Temperature......................................................+150°C Lead Temperature (soldering, 10s).................................+300°CMAX6340/MAX6421–MAX6426Low-Power, SC70/SOT µP Reset Circuits with Capacitor-Adjustable Reset Timeout Delay_______________________________________________________________________________________300.51.01.52.02.53.03.54.00213456SUPPLY CURRENT vs. SUPPLY VOLTAGESUPPLY VOLTAGE (V)S U P P L Y C U R R E N T (µA )0.1110010100010,0000.0010.10.011101001000RESET TIMEOUT PERIOD vs. C SRTM A X 6421/26 t o c 02C SRT (nF)R E S E T T I M E O U T P E R I O D (ms )4.104.204.154.254.30-50-25255075100125RESET TIMEOUT PERIOD vs. TEMPERATURETEMPERATURE (°C)R E S E T T I M E O U T P E R I O D (m s )RESET TIMEOUT PERIOD vs. TEMPERATURE200250350300500550450400600R E S E T T I M E O U T P E R I O D (µs )-5025-255075100125TEMPERATURE (°C)050251007515012517504002006008001000MAXIMUM TRANSIENT DURATION vs. RESET THRESHOLD OVERDRIVERESET THRESHOLD OVERDRIVE (mV)T R A N S I E N T D U R A T I O N (µs )V CC TO RESET DELAYvs. TEMPERATURE (V CC FALLING)8090110100140150130120160V C CT O R E S E T D E L A Y (µs )-5025-255075100125TEMPERATURE (°C)POWER-UP/POWER-DOWNCHARACTERISTIC1V/div1V/div400µs/div0.9940.9980.9961.0021.0001.0041.006-502550-25075100125NORMALIZED RESET THRESHOLDvs. TEMPERATUREM A X 6421/26 t o c 08TEMPERATURE (°C)N O R M A L I Z E D R E S E T T H R E S H O L DTypical Operating Characteristics(V CC = 5V, C SRT = 1500pF, T A = +25°C, unless otherwise noted.)M A X 6340/M A X 6421–M A X 6426Low-Power, SC70/SOT µP Reset Circuits with Capacitor-Adjustable Reset Timeout Delay4_______________________________________________________________________________________Detailed DescriptionReset OutputThe reset output is typically connected to the reset input of a µP. A µP’s reset input starts or restarts the µP in a known state. The MAX6340/MAX6421–MAX6426 µP supervisory circuits provide the reset logic to prevent code-execution errors during power-up, power-down,and brownout conditions (see Typical Operating Characteristics ).RESET changes from high to low whenever V CC drops below the threshold voltage. Once V CC exceeds the threshold voltage, RESET remains low for the capacitor-adjustable reset timeout period.The MAX6422 active-high RESET output is the inverse logic of the active-low RESET output. All device outputs are guaranteed valid for V CC > 1V.The MAX6340/MAX6423/MAX6425/MAX6426 are open-drain RESET outputs. Connect an external pullup resis-tor to any supply from 0 to 5.5V. Select a resistor value large enough to register a logic low when RESET is asserted and small enough to register a logic high while supplying all input current and leakage paths connected to the RESET line. A 10k Ωto 100k Ωpullup is sufficient in most applications.Selecting a Reset CapacitorThe reset timeout period is adjustable to accommodate a variety of µP applications. Adjust the reset timeout period (t RP ) by connecting a capacitor (C SRT ) between SRT and ground. Calculate the reset timeout capacitor as follows:Figure 1. MAX6340/MAX6423/MAX6425/MAX6426 Open-Drain RESET Output Allows Use with Multiple SuppliesMAX6340/MAX6421–MAX6426Low-Power, SC70/SOT µP Reset Circuits with Capacitor-Adjustable Reset Timeout Delay_______________________________________________________________________________________5C SRT = (t RP - 275µs) / (2.73 ✕106)where t RP is in seconds and C SRT is in farads.The reset delay time is set by a current/capacitor-con-trolled ramp compared to an internal 0.65V reference.An internal 240nA ramp current source charges the external capacitor. The charge to the capacitor is cleared when a reset condition is detected. Once the reset condition is removed, the voltage on the capacitor ramps according to the formula: dV/dt = I/C. The C SRT capacitor must ramp to 0.65V to deassert the reset.C SRT must be a low-leakage (<10nA) type capacitor;ceramic is recommended.Operating as a Voltage DetectorThe MAX6340/MAX6421–MAX6426 can be operated in a voltage detector mode by floating the SRT pin. The reset delay times for V CC rising above or falling below the threshold are not significantly different. The reset output is deasserted smoothly without false pulses.Applications InformationInterfacing to Other Voltages for LogicCompatibilityThe open-drain outputs of the MAX6340/MAX6423/MAX6425/MAX6426 can be used to interface to µPs with other logic levels. As shown in Figure 1, the open-drain output can be connected to voltages from 0 to 5.5V. This allows for easy logic compatibility to various µPs.Wired-OR ResetTo allow auxiliary circuitry to hold the system in reset,an external open-drain logic signal can be connected to the open-drain RESET of the MAX6340/MAX6423/MAX6425/MAX6426, as shown in Figure 2. This config-uration can reset the µP, but does not provide the reset timeout when the external logic signal is released.Negative-Going V CC TransientsIn addition to issuing a reset to the µP during power-up,power-down, and brownout conditions, these supervisors are relatively immune to short-duration negative-going transients (glitches). The graph Maximum Transient Duration vs. Reset Threshold Overdrive in the Typical Operating Characteristics shows this relationship.The area below the curve of the graph is the region in which these devices typically do not generate a reset pulse. This graph was generated using a negative-going pulse applied to V CC , starting above the actual reset threshold (V TH ) and ending below it by the magni-tude indicated (reset-threshold overdrive). As the mag-nitude of the transient decreases (farther below the reset threshold), the maximum allowable pulse width decreases. Typically, a V CC transient that goes 100mV below the reset threshold and lasts 50µs or less does not cause a reset pulse to be issued.Ensuring a Valid RESET or RESETDown to V CC = 0When V CC falls below 1V, RESET /RESET current-sink-ing (sourcing) capabilities decline drastically. In the case of the MAX6421/MAX6424, high-impedance CMOS-logic inputs connected to RESET can drift to undetermined voltages. This presents no problems in most applications, since most µPs and other circuitry do not operate with V CC below 1V.In those applications where RESET must be valid down to zero, adding a pulldown resistor between RESET and ground sinks any stray leakage currents, holding RESET low (Figure 3). The value of the pulldown resis-tor is not critical; 100k Ωis large enough not to load RESET and small enough to pull RESET to ground. For applications using the MAX6422, a 100k Ωpullup resis-M A X 6340/M A X 6421–M A X 6426Low-Power, SC70/SOT µP Reset Circuits with Capacitor-Adjustable Reset Timeout Delay6_______________________________________________________________________________________tor between RESET and V CC holds RESET high when V CC falls below 1V (F igure 4). Open-drain RESET ver-sions are not recommended for applications requiring valid logic for V CC down to zero.Layout ConsiderationSRT is a precise current source. When developing the layout for the application, be careful to minimize board capacitance and leakage currents around this pin.Traces connected to SRT should be kept as short as possible. Traces carrying high-speed digital signals and traces with large voltage potentials should be rout-ed as far from SRT as possible. Leakage current and stray capacitance (e.g., a scope probe) at this pin could cause errors in the reset timeout period. When evaluating these parts, use clean prototype boards to ensure accurate reset periods.Figure 3. Ensuring RESET Valid to V CC= 0CCMAX6340/MAX6421–MAX6426Low-Power, SC70/SOT µP Reset Circuits with Capacitor-Adjustable Reset Timeout Delay7factory for availability of nonstandard versions.Typical Operating CircuitM A X 6340/M A X 6421–M A X 6426Low-Power, SC70/SOT µP Reset Circuits with Capacitor-Adjustable Reset Timeout Delay8_______________________________________________________________________________________Pin Configurations (continued)Chip InformationTRANSISTOR COUNT: 295PROCESS: BiCMOSMAX6340/MAX6421–MAX6426Low-Power, SC70/SOT µP Reset Circuits with Capacitor-Adjustable Reset Timeout Delay_______________________________________________________________________________________9Package 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 A X 6340/M A X 6421–M A X 6426Low-Power, SC70/SOT µP Reset Circuits with Capacitor-Adjustable Reset Timeout DelayMaxim 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.10____________________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.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 .)。

MAX3471中文资料

MAX3471中文资料

MAX3471
1.6µA, RS-485/RS-422, Half-Duplex, Differential Transceiver for Battery-Powered Systems
ABSOLUTE MAXIMUM RATINGS (Note 1)
Supply Voltage (VCC) ..............................................................7V Control Input Voltage (RE, DE)...................-0.3V to (VCC + 0.3V) Driver Input Voltage (DI).............................-0.3V to (VCC + 0.3V) Driver Output/Receiver Input Voltage (A, B).....................±10.5V Receiver Output Voltage (RO)....................-0.3V to (VCC + 0.3V) Continuous Power Dissipation
Three-State Current at Receiver Output
Receiver Input Resistance
∆VOC VIH VIL VHYS IIN1 IIN2
IOSD
VTH ∆VTH VOH VOL IOZR RIN
Figure 1, R = 750Ω or 27Ω
DE, DI, RE DE, DI, RE
The MAX3471 is available in an 8-pin µMAX package.

ADM6316AY29ARJZ-R7中文资料

ADM6316AY29ARJZ-R7中文资料
Manual reset input Reset output stages
Push-pull active low Open-drain active low Push-pull active high Low power consumption: 5 μA Guaranteed reset output valid to VCC = 1 V Power supply glitch immunity Specified over industrial temperature range 5-lead SOT-23 package
RESET
Push-pull No Push-pull Push-pull Open-drain Open-drain Open-drain
Output Stage
RESET No Push-pull Push-pull Push-pull No Push-pull Push-pull
Rev. D
Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners.

max3485中文资料

max3485中文资料

max3485中文资料MAX3483,MAX3485,MAX3486,MAX3488,MAX3490以及MAX3491是用于RS-485与RS-422通信的3.3V,低功耗收发器,每个器件中都具有一个驱动器和一个接收器。

MAX3483和MAX3488具有限摆率驱动器,可以减小EMI,并降低由不恰当的终端匹配电缆引起的反射,实现最高250kbps的无差错数据传输。

MAX3486的驱动器摆率部分受限,可以实现最高2.5Mbps的传输速率。

MAX3485,MAX3490和MAX3491则可以实现最高10Mbps 的传输速率。

驱动器具有短路电流限制,并可以通过热关断电路将驱动器输出置为高阻状态,防止过度的功率损耗。

接收器输入具有失效保护特性,当输入开路时,可以确保逻辑高电平输出。

特性●半双工●速率:10Mbps●限摆率:NO●接收允许控制:YES●关断电流:2nA●引脚数:8这些收发器在驱动器禁用的空载或满载状态下,吸取的电源电流在120&micro;A至500&micro;A之间。

另外,MAX481、MAX483与MAX487具有低电流关断模式,仅消耗0.1&micro;A。

所有器件都工作在5V单电源下。

采用单一电源+5 V工作,额定电流为300 μA,采用半双工通讯方式。

它完成将TTL电平转换为RS-485电平的功能。

MAX485芯片的结构和引脚都非常简单,内部含有一个驱动器和接收器。

RO和DI 端分别为接收器的输出和驱动器的输入端,与单片机连接时只需分别与单片机的RXD和TXD相连即可;/RE和DE端分别为接收和发送的使能端,当/RE为逻辑0时,器件处于接收状态;当DE为逻辑1时,器件处于发送状态,因为MAX485工作在半双工状态,所以只需用单片机的一个管脚控制这两个引脚即可;A端和B端分别为接收和发送的差分信号端,当A引脚的电平高于B时,代表发送的数据为1;当A的电平低于B端时,代表发送的数据为0。

MAX6387XS26D7-T中文资料

MAX6387XS26D7-T中文资料

MAX6387XS26D7-T中文资料元器件交易网19-1839; Rev 1; 04/01SC70, Single/Dual Low-Voltage, Low-Power µP Reset CircuitsGeneral DescriptionFeaturesThe MAX6381�CMAX6390 microprocessor (µP) supervisorycircuits monitor power supply voltages from +1.8V tooFactory-Set Reset Threshold Voltages Ranging+5.0V while consuming only 3µA of supply current atfrom +1.58V to+4.63V in Approximately 100mV+1.8V. Whenever VCCfalls below the factory-set resetIncrementsthresholds, the reset output asserts and remains assert-o±2.5% Reset Threshold Accuracy Overed for a minimum reset timeout period after VCCrisesTemperature (-40°C to +125°C)above the reset threshold. Re set thresholds are availablefrom +1.58V to +4.63V, in approximately 100mV incre-oSeven Reset Timeout Periods Available: 1ms,ments. Seven minimum reset timeout delays ranging20ms, 140ms, 280ms, 560ms, 1120ms, from 1ms to 1200ms are available.1200ms (min)The MAX6381/MAX6384/MAX6387 have a push-pullo3 Reset Output Optionsactive-low reset output. The MAX6382/MAX6385/Active-Low Push-PullMAX6388 have a push-pull active-high reset output,Active-High Push-Pulland theMAX6383/MAX6386/MAX6389/MAX6390 have an open-drain active-low reset output. TheActive-Low Open-DrainMAX6384/MAX6385/MAX6386 also feature aoReset Output State Guaranteed Valid debounced manual reset input (with internal pullupDown to VCC= 1Vresistor). The MAX6387/MAX6388/MAX6389 have anauxiliary input for monitoring a second voltage. TheoManual Reset Input(MAX6384/MAX6385/MAX6386)MAX6390 offers a manual reset input with a longer VoAuxiliary RESETINreset timeout period (1120ms or 1200ms) and ashorterCC(MAX6387/MAX6388/MAX6389)manual reset timeout (140ms or 150ms).oVCCReset Timeout (1120ms or 1200ms)/ManualThe MAX6381/MAX6382/MAX6383 are available in 3-pinReset Timeout (140ms or 150ms) (MAX6390)SC70 packages and the MAX6384�CMAX6390 are avail-able in 4-pin SC70 packages.oNegative-Going VCCTransient Immunity________________________ApplicationsoLow Power Consumption of 6µA at +3.6V and 3µA at +1.8VComputersoPin Compatible withControllersMAX809/MAX810/MAX803/MAX6326/MAX6327/Intelligent InstrumentsMAX6328/MAX6346/MAX6347/MAX6348, Critical µP and µC Power Monitoringand MAX6711/MAX6712/MAX6713Portable/Battery-Powered EquipmentoTiny 3-Pin SC70 and 4-Pin SC70 PackagesDual Voltage SystemsPin ConfigurationsNote:Insert reset threshold suffix (see Reset Threshold table)after "XR" or "XS". Insert reset timeout delay (see Reset TimeoutDelay table) after "D" to complete the part number. Samplestock 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.*MAX6390 is available with D4 or D7 timing only.Ordering Information continuedat end of data sheet.Typical Operating Circuit appears at end of data sheet.Selector Guide appears at end of data sheet.________________________________________________________________Maxim Integrated Products1For pricing, delivery, and ordering information,please contactMaxim/Dallas Direct!at 1-888-629-4642, or visit Maxim’s website at .MAX6381�CMAX6390SC70, Single/Dual Low-Voltage, Low-Power µP Reset CircuitsMAX6381�CMAX6390ABSOLUTE MAXIMUM RATINGSVCC to GND..........................................................-0.3Vto +6.0VRESETOpen-Drain Output....................................-0.3V to+6.0VRESET, RESET (Push-Pull Output).............-0.3V to (VCC+ 0.3V)MR, RESET IN.............................................-0.3V to (VCC+ 0.3V)Input Current (VCC).............................................................20mAOutput Current (All Pins).....................................................20mAContinuous Power Dissip ation (TA= +70°C)3-Pin SC70 (derate 2.9mW/°C above +70°C)........235mW4-Pin SC70 (derate 3.1mW/°C above +70°C)........245mWOperating Temperature Range.........................-40°C to +125°CStorage Temperature Range.............................-65°C to +150°CLead Temperature (soldering, 10s).................................+300°CStresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functionaloperation of the device at these or any other conditions beyondthose indicated in the operational sections of the specifications is not implied. Exposure toabsolute maximum rating conditions for extended periodsmay affect device reliability.ELECTRICAL CHARACTERISTICSSC70, Single/Dual Low-Voltage, Low-Power µP Reset Circuits_______________________________________________________________________________________3MAX6381�CMAX6390SC70, Single/Dual Low-Voltage, Low-Power µP Reset CircuitsMAX6381�CMAX6390Typical Operating Characteristics(TA = +25°C, unless otherwise noted.)SUPPLY CURRENT vs. TEMPERATURE(NO LOAD)POWER-DOWN RESET DELAYvs. TEMPERATURENORMALIZED RESET TIMEOUT PERIOD8SUPPLY CURRENT (µA)7654321041POWER-DOWN RESET DELAY (µs)393735333129271.061.041.021.000.980.960.94-40-25-105203550658095110125TEMPERATURE (°C)25-40-25-105203550658095110125TEMPERATURE (°C)-40-25-105203550658095110125TEMPERATURE (°C)NORMALIZED RESET THRESHOLDvs. TEMPERATUREMAX6381/90 toc04OUTPUT VOLTAGE LOWvs. SINK CURRENTOUTPUT VOLTAGE HIGHvs. SOURCE CURRENT1.020NORMALIZED RESETTHRESHOLD1.0151.0101.0051.0000.9950.9900.985 1.21.00.8VOL (V)0.60.40.20036ISINK (mA)93.02.52.0VOH (V)1.51.00.500250500750100012500.990-40-25-105203550658095110125TEMPERATURE (°C)121500ISOURCE (µA)MAXIMUM TRANSIENT DURATIONvs. RESET COMPARATOR OVERDRIVERESET IN TO RESET DELAYvs. TEMPERATURE5.35.1RESET IN DELAY (µs)4.94.74.54.34.13.93.73.5MAX6381/90 toc08500MAXIMUM TRANSIENT DURATION (µs)450400350300250200150100501101005.51000-40-25-105203550658095110125TEMPERATURE (°C)RESET COMPARATOR OVERDRIVE, VTH - VCC (mV)4_____________________________________________________________________________ _________MAX6381/90 toc039NORMALIZED POWER-UP RESET TIMEOUTvs. TEMPERATURE1.0843SC70, Single/Dual Low-Voltage, Low-Power µP Reset Circuits______________________________________________________________________________ _________5MAX6381�CMAX6390SC70, Single/Dual Low-Voltage, Low-Power µP ResetCircuitsMAX6381�CMAX6390Detailed DescriptionRESET OutputA µP reset input starts the µP in a known state. TheseµP supervisory circuits assert reset to prevent codeexecution errors during power-up, power-down, orbrownout conditions.Reset asserts when VCCis below the reset threshold;once VCCexceeds the reset threshold, an internal timerkeeps the reset output asserted for the reset timeoutperiod. After this interval, reset output deasserts. Resetoutput is guaranteed to be in the correct logic state forVCC≥1V.Manual Reset Input (MAX6384/MAX6385/MAX6386/MAX6390)Man y µP-based products require manual reset capabil-ity, allowing the operator, a test technician, or externallogic circuitry to initiate a reset. A logic low on MRasserts reset. Reset remains asserted while MRis low,and for the reset active timeout period (tRP) after MRreturns high. This input has an internal 63k pullupresistor (1.35k for MAX6390), so it can be left uncon-nected if it is not used. MRcan be driven with TTL orCMOS logic levels, or with open-drain/collector outputs.Connect a normally open momentary switch from MRtoGND to create a manual-reset function; externaldebounce circuitry is not required. If MRis driven fromlong cables or if the device is used in anoisy environ-ment, connecting a 0.1µF capacitor from MRto GNDprovides 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, resetasserts. 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 RESETIN (shown in Figure 1). Reset asserts when either VCCor RESET IN falls below its respective threshold volt-age. Use the following equation to set the threshold:VINTH= VTHRST (R1/R2 + 1)where VTHRST= +1.27V. To simplify the resistor selec-tion, choose a value of R2 and calculate R1:R1 = R2 [(VINTH/VTHRST) - 1]Since the input current at RESET IN is 50nA (max),large values can be used for R2 with no significant lossin accuracy.___________Applications InformationIn addition to issuing a reset to the µP during power-up,power-down, and brownout conditions, theMAX6381�CMAX6390 are relatively immune to short dura-tion negative-going VCCtransients (glitches).The Typical Operating Characteristicssection shows theMaximum Transient Durations vs. Reset ComparatorOverdrive, for which the MAX6381�CMAX6390 do notgenerate a reset pulse. This graph was generated usingNegative-Going VCCTransients6_____________________________________________________________________________ __________SC70, Single/Dual Low-Voltage, Low-Power µP Reset CircuitsMAX6381�CMAX6390not work with the open-drain outputs of theMAX6383/MAX6386/MAX6389/MAX6390. The resistorvalue used is not critical, but it must be small enoughnot to load the reset output when VCCis above the resetthreshold. For most applications, 100k is adequate.a negative-going pulse applied to VCC, starting above theactual reset threshold and ending below it by the magni-tude indicated (reset comparator overdrive). The graphindicates the typical maximum pulse width a negative-going VCCtransient may have without causing a resetpulse to be issued. As the magnitude of the transientincreases (goes farther below the reset threshold), themaximum allowable pulse width decreases. A 0.1µFcapacitor mounted as close as possible to VCCprovidesadditional transient immunity.The MAX6381�CMAX6390 are guaranteed to operateproperly down to VCC= 1V.In applications that requirevalid reset levels down to VCC= 0, a pulldown resistor toactive-low outputs (push/pull only, Figure 2) and apullup resistorto active-high outputs (push/pull only) willensure that the reset line isvalid while the reset outputcan no longer sink or source current. This scheme doesEnsuring a Valid RESETOutput Down to VCC= 0_______________________________________________________________________________________7SC70, Single/Dual Low-Voltage, Low-Power µP ResetCircuitsMAX6381�CMAX6390Pin Configurations (continued)*MRis for MAX6384/MAX6385/MAX6386/MAX6390**RESET IN is forMAX6387/MAX6388/MAX6389( ) are for MAX6382/MAX6385/MAX6388Chip InformationTRANSISTOR COUNT: 647PROCESS: BiCMOSSC70, Single/Dual Low-Voltage, Low-Power µP Reset CircuitsOrdering InformationNote:Insert reset threshold suffix (see Reset Threshold table)after "XR" or "XS". Insert reset timeout delay (see Reset TimeoutDelay table) after "D" to complete the part number. Samplestock 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.*MAX6390 is available with D4 or D7 timing only.______________________________________________________________________________ _________9MAX6381�CMAX6390SC70, Single/Dual Low-Voltage, Low-Power µP ResetCircuitsMAX6381�CMAX6390Package Information10____________________________________________________________________________ __________SC70, Single/Dual Low-Voltage, Low-Power µP Reset CircuitsPackage Information (continued)Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses areimplied. Maxim reserves the right to change the circuitry and specifications without notice at any time.Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600____________________11©2001 Maxim Integrated ProductsPrinted USAis a registered trademark of Maxim Integrated Products.MAX6381�CMAX6390感谢您的阅读,祝您生活愉快。

MAX038中文Data Sheet

MAX038中文Data Sheet

高频信号发生器_______________概述MAX038是一种只需极少外围电路就能实现高 频、高精度输出三角波、锯齿波、正弦波、方波 和脉冲波的精密高频函数发生器芯片。

内部提供 的2.5V 基准电压和一个外接电阻和电容可以控制 输出频率范围在0.1Hz 到20MHz 。

占空比可在较大 的范围内由一个±2.3V的线性信号控制变化,便 于进行脉冲宽度调制和产生锯齿波。

频率调整和 频率扫描可以用同样的方式实现。

占空比和频率 控制是独立的。

通过设置2个TTL 逻辑地址引脚合适的逻辑电 平,能设定正弦波,方波或三角波的输出。

所有 波形的输出都是峰-峰值为±2VP -P 的信号。

低阻 抗输出能力可以达到±20mA。

____________________________性能o 频率调节范围:0.1Hz 到20MHzo 三角波, 锯齿波, 正弦波, 方波和脉冲波 o 频率和占空比独立可调 o 频率扫描范围:350:1 o 可控占空比:15%到85% o 低阻抗输出缓冲器: 0.1Ω o 低失真正弦波: 0.75% o 低温度漂移: 200ppm/°C______________型号信息TTL 逻辑地址引脚SYNC 从内部振荡器输出占 空比固定为50%的信号,不受其它波占空比的影 响,从而同步系统中其它振荡器。

内部振荡器 允许被连接着相位检波器输入端(PDI )的外部 TTL 时钟同步。

型号 MAX038CPP MAX038CWP MAX038C/D MAX038EPP MAX038EWP工作温度 0°C 到 +70°C 0°C 到 +70°C 0°C 到 +70°C -40°C 到 +85°C -40°C 到 +85°C引脚--封装 20 Plastic DIP 20 SO Dice* 20 Plastic DIP 20 SO.__________________应用精密函数信号发生器 压控振荡器 频率调制器*Contact factory for dice specifications.__________________引脚图脉宽调制器 锁相环 频率合成器FSK 发生器(正弦波和方波)________________________________________________________________ Maxim Integrated Products1For free samples & the latest literature: , or phone 1-800-998-8800. For small orders, phone 408-737-7600 ext. 3468MAX038高频信号发生器图1. 内部结构及基本工作电路_______________ 详细说明MAX038是一种高频函数信号发生器,它可以使 用最少的外部元件而产生低失真正弦波,三角波, 锯齿波,方波(脉冲波)。

MAX471MAX472的中文资料大全

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。

MAX306中文资料

MAX306中文资料

_______________General DescriptionThe MAX306/MAX307 precision, monolithic, CMOS analog multiplexers (muxes) offer low on-resistance (less than 100Ω), which is matched to within 5Ωbetween channels and remains flat over the specified analog signal range (7Ωmax). They also offer low leak-age over temperature (I NO(OFF)less than 2.5nA at +85°C) and fast switching speeds (t TRANS less than 250ns). The MAX306 is a single-ended 1-of-16 device,and the MAX307 is a differential 2-of-8 device.The MAX306/MAX307 are fabricated with Maxim’s improved 44V silicon-gate process. Design improve-ments yield extremely low charge injection (less than 10pC) and guarantee electrostatic discharge (ESD)protection greater than 2000V.These muxes operate with a single +4.5V to +30V sup-ply, or bipolar ±4.5V to ±20V supplies, while retaining TTL/CMOS-logic input compatibility and fast switching.CMOS inputs provide reduced input loading. These improved parts are plug-in upgrades for the industry-standard DG406, DG407, DG506A, and DG507A.________________________ApplicationsSample-and-Hold Circuits Test Equipment Heads-Up DisplaysGuidance and Control Systems Military RadiosCommunications Systems Battery-Operated Systems PBX, PABXAudio Signal Routing____________________________Featureso Guaranteed On-Resistance Match Between Channels, <5ΩMaxo Low On-Resistance, <100ΩMaxo Guaranteed Flat On-Resistance over Specified Signal Range, 7ΩMaxo Guaranteed Charge Injection, <10pC o I NO(OFF)Leakage <2.5nA at +85°C o I COM(OFF)Leakage <20nA at +85°C o ESD Protection >2000Vo Plug-In Upgrade for Industry-Standard DG406/DG407/DG506A/DG507Ao Single-Supply Operation (+4.5V to +30V)Bipolar-Supply Operation (±4.5V to ±20V)o Low Power Consumption, <1.25mW o Rail-to-Rail Signal Handling o TTL/CMOS-Logic CompatibleMAX306/MAX307Precision, 16-Channel/Dual 8-Channel,High-Performance, CMOS Analog Multiplexers________________________________________________________________Maxim Integrated Products 1_____________________Pin Configurations/Functional Diagrams/Truth TablesCall toll free 1-800-998-8800 for free samples or literature.19-0270; Rev 0; 8/94Ordering Information continued at end of data sheet.* Contact factory for dice specifications.M A X 306/M A X 307Precision, 16-Channel/Dual 8-Channel,High-Performance, CMOS Analog Multiplexers 2_______________________________________________________________________________________ABSOLUTE MAXIMUM RATINGSELECTRICAL CHARACTERISTICS—Dual Supplies(V+ = +15V, V- = -15V, GND = 0V, V AH = +2.4V, V AL = +0.8V, T A = T MIN to T MAX , unless otherwise noted.)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.Voltage Referenced to V-V+............................................................................-0.3V, 44V GND.........................................................................-0.3V, 25V Digital Inputs, NO, COM (Note 1)...........(V- - 2V) to (V+ + 2V) or30mA (whichever occurs first)Continuous Current (any terminal)......................................30mA Peak Current, NO or COM(pulsed at 1ms, 10% duty cycle max)..........................100mA Continuous Power Dissipation (T A = +70°C)Plastic DIP (derate 9.09mW/°C above +70°C)............727mW Wide SO (derate 12.50mW/°C above +70°C)............1000mW PLCC (derate 10.53mW/°C above +70°C)..................842mW CERDIP (derate 16.67mW/°C above +70°C).............1333mW Operating Temperature RangesMAX30_C_ _.......................................................0°C to +70°C MAX30_E_ _.....................................................-40°C to +85°C MAX30_MJI....................................................-55°C to +125°C Storage Temperature Range.............................-65°C to +150°C Lead Temperature (soldering, 10sec).............................+300°CNote 1:Signals on NO, COM, A0, A1, A2, A3, or EN exceeding V+ or V- are clamped by internal diodes. Limit forward current to maximum current ratings.MAX306/MAX307Precision, 16-Channel/Dual 8-Channel,High-Performance, CMOS Analog Multiplexers_______________________________________________________________________________________3ELECTRICAL CHARACTERISTICS—Dual Supplies (continued)(V+ = +15V, V- = -15V, GND = 0V, V= +2.4V, V = +0.8V, T = T to T , unless otherwise noted.)M A X 306/M A X 307Precision, 16-Channel/Dual 8-Channel,High-Performance, CMOS Analog Multiplexers 4_______________________________________________________________________________________ELECTRICAL CHARACTERISTICS—Single Supply(V+ = +12V, V- = 0V, GND = 0V, V AH = +2.4V, V AL = +0.8V, T A = T MIN to T MAX , unless otherwise noted.)Note 2:The algebraic convention where the most negative value is a minimum and the most positive value a maximum is used inthis data sheet.Note 3:Guaranteed by design.Note 4:∆R ON = R ON(MAX)- R ON(MIN).On-resistance match between channels and flatness are guaranteed only with specifiedvoltages. Flatness is defined as the difference between the maximum and minimum value of on-resistance as measured at the extremes of the specified analog signal range.Note 5:Leakage parameters are 100% tested at the maximum rated hot temperature and guaranteed by correlation at +25°C.Note 6:Off isolation = 20log V COM /V NO , where V COM = output and V NO = input to off switch.MAX306/MAX307Precision, 16-Channel/Dual 8-Channel,High-Performance, CMOS Analog Multiplexers_______________________________________________________________________________________5120140160ON-RESISTANCE vs. V COM(DUAL SUPPLIES)1000204060-2020-1515-1010-5580V COM (V)R O N (Ω)120ON-RESISTANCE vs. V COM AND TEMPERATURE (DUAL SUPPLIES)1000204060-1515-1010-55080V COM (V)R O N (Ω)280320360400ON-RESISTANCE vs. V COM (SINGLE SUPPLY)24040801201601520105200V COM (V)R O N (Ω)120140160ON-RESISTANCE vs. V COM AND TEMPERATURE (SINGLE SUPPLY)10002040601510580V COM (V)R O N (Ω)30CHARGE INJECTION vs. V COM20-30-20-100-1515-1010-55010V COM (V)Q j (p C )100.0001-55125OFF LEAKAGE vs. TEMPERATURE1TEMPERATURE (°C)O F F L E A K A G E (n A )250.010.001-35-15650.1100100045851055100.0001-55125ON LEAKAGE vs. TEMPERATURE1TEMPERATURE (°C)O N L E A K A G E (n A )250.010.001-35-15650.11001000458510551000.001-55125SUPPLY CURRENT vs. TEMPERATURE10TEMPERATURE (°C)I +, I - (µA )250.10.01-35-1565145851055__________________________________________Typical Operating Characteristics(T A = +25°C, unless otherwise noted.)__________Applications InformationOperation with Supply VoltagesOther than ±15VUsing supply voltages other than ±15V will reduce the analog signal range. The MAX306/MAX307 switches operate with ±4.5V to ±20V bipolar supplies or with a +4.5V to +30V single supply; connect V- to GND when operating with a single supply. Also, both device types can operate with unbalanced supplies such as +24V and -5V. The Typical Operating Characteristics graphs show typical on-resistance with 20V, 15V, 10V, and 5V supplies. (Switching times increase by a factor of two or more for operation at 5V.)Overvoltage ProtectionProper power-supply sequencing is recommended for all CMOS devices. Do not exceed the absolute maxi-mum ratings because stresses beyond the listed rat-ings may cause permanent damage to the devices.Always sequence V+ on first, then V-, followed by either the logic inputs, NO, or COM. If power-supply sequencing is not possible, add two small signal diodes in series with supply pins for overvoltage pro-tection (Figure 1). Adding diodes reduces the analogsignal range to 1V above V+ and 1V below V-, but low switch resistance and low leakage characteristics are unaffected. Device operation is unchanged, and the difference between V+ and V- should not exceed +44V.M A X 306/M A X 307Precision, 16-Channel/Dual 8-Channel,High-Performance, CMOS Analog Multiplexers 6_______________________________________________________________________________________Output–bidirectionalCOM28Address Inputs A3–A014–17Enable InputsEN 18Analog Inputs–bidirectional NO1–NO819–26Negative Supply Voltage Input V-27Ground GND 12Analog Inputs–bidirectional NO16–NO94–11MAX306PINNo Internal Connections N.C.2, 3, 13Positive Supply Voltage Input V+1FUNCTIONNAME_____________________________________________________________Pin DescriptionsDiodesMAX306/MAX307Precision, 16-Channel/Dual 8-Channel,High-Performance, CMOS Analog Multiplexers_______________________________________________________________________________________7______________________________________________Test Circuits/Timing DiagramsM A X 306/M A X 307Precision, 16-Channel/Dual 8-Channel,High-Performance, CMOS Analog Multiplexers 8________________________________________________________________________________________________________________________Test Circuits/Timing Diagrams (continued)Figure 5. Charge InjectionMAX306/MAX307Precision, 16-Channel/Dual 8-Channel,High-Performance, CMOS Analog Multiplexers_______________________________________________________________________________________9_________________________________Test Circuits/Timing Diagrams (continued)Figure 8. NO/COM CapacitanceM A X 306/M A X 307Precision, 16-Channel/Dual 8-Channel,High-Performance, CMOS Analog Multiplexers 10______________________________________________________________________________________________Pin Configurations/Functional Diagrams/Truth Tables (continued)A2A1A0EN ON Switch X 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1X 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1X 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 10 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1None 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16MAX306LOGIC “0” V AL ≤ 0.8V, LOGIC “1” = V AH ≥ 2.4VA3X 0 0 0 0 0 0 0 0 1 1 1 1 1 1 11A2A1A0EN ON Switch X 0 0 0 0 1 1 1 1X 0 0 1 1 0 0 1 1X 0 1 0 1 0 1 0 10 1 1 1 1 1 1 1 1None 1 2 3 4 5 6 7 8MAX307LOGIC “0” V AL ≤ 0.8V, LOGIC “1” = V AH ≥ 2.4VMAX306/MAX307Precision, 16-Channel/Dual 8-Channel,High-Performance, CMOS Analog Multiplexers______________________________________________________________________________________11________Pin Configurations/Functional Diagrams/Truth Tables (continued)_Ordering Information (continued)* Contact factory for dice specifications.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.12__________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 (408) 737-7600©1994 Maxim Integrated ProductsPrinted USAis a registered trademark of Maxim Integrated Products.M A X 306/M A X 307Precision, 16-Channel/Dual 8-Channel,High-Performance, CMOS Analog Multiplexers __________________________________________________________Chip TopographiesGNDNO1 NO2 NO3 N04 NO5 NO6 NO7 NO80.184" (4.67mm)0.078" (1.98mm)NO9NO10NO11NO12N013NO14NO15NO16N.C.V-COM V+GND NO1A NO2A NO3A N04A NO5A NO6A NO7A NO8A0.184" (4.67mm)0.078" (1.98mm)NO1B NO2B NO3B NO4B N05B NO6B NO7B NO8B COMBV-COMA V+TRANSISTOR COUNT: 269SUBSTRATE IS INTERNALLY CONNECTED TO V+TRANSISTOR COUNT: 269SUBSTRATE IS INTERNALLY CONNECTED TO V+MAX306MAX307N.C. = NO INTERNAL CONNECTION。

MAX5937LBESA+中文资料

MAX5937LBESA+中文资料

MAX5936/MAX5937-48V Hot-Swap Controllers with V INStep Immunity and No R SENSE________________________________________________________________Maxim Integrated Products 119-3281; Rev 1; 1/05For pricing, delivery, and ordering information,please contact Maxim/Dallas Direct!at 1-888-629-4642, or visit Maxim’s website at .General DescriptionThe MAX5936/MAX5937 are hot-swap controllers for -10V to -80V rails. The MAX5936/MAX5937 allow circuit line cards to be safely hot-plugged into a live back-plane without causing a glitch on the power supply.These devices integrate a circuit-breaker function requiring no R SENSE .The MAX5936/MAX5937 provide a controlled turn-on for circuit cards, limiting inrush, preventing glitches on the power-supply rail, and preventing damage to board connectors and components. Before startup, the devices perform a Load Probe™ test to detect the presence of a short-circuit condition. If a short-circuit condition does not exist, the device limits the inrush current drawn by the load by gradually turning on the external MOSFET. Once the external MOSFET is fully enhanced, the MAX5936/MAX5937 provides overcur-rent and short-circuit protection by monitoring the volt-age drop across the R DS(ON)of the external power MOSFET. The MAX5936/MAX5937 integrate a 400mA fast G ATE pulldown to guarantee that the power MOSFET is rapidly turned off in the event of an overcur-rent or short-circuit condition.The MAX5936/MAX5937 protect the system against input voltage (V IN ) steps by providing V IN step immuni-ty. The MAX5936/MAX5937 provide an accurate UVLO voltage. The MAX5936 has an open-drain, active-low PGOOD output and the MAX5937 has an open-drain,active-high PGOOD output.The MAX5936/MAX5937 are offered with 100mV,200mV, and 400mV circuit-breaker thresholds, in addi-tion to a non-circuit-breaker option. These devices are offered in latched and autoretry fault management, are available in 8-pin SO packages, and specified for the extended (-40°C to +85°C) temperature range (see the Selector Guide ).ApplicationsServersTelecom Line Cards Network Switches Solid-State Circuit Breaker Network RoutersFeatures♦-10V to -80V Operation ♦No R SENSE Required♦Drives Large Power MOSFETS♦Programmable Inrush Current Limit During Hot Plug ♦100mV, 200mV, 400mV, and No-Circuit-Breaker Threshold Options ♦Circuit-Breaker Fault with Transient Rejection ♦Shorted Load Detection (Load Probe) Before Power MOSFET Turn-On ♦±2.4% Accurate Undervoltage Lockout (UVLO)♦Autoretry and Latched Fault Management Available ♦Low Quiescent CurrentPin ConfigurationLoad Probe is a trademark of Maxim Integrated Products, Inc.Ordering InformationNote:The first “_” represents A for the autoretry and L for the latched fault management option.The second “_” represents the circuit-breaker threshold. See the Selector Guide for additional information.Selector Guide and Typical Operating Circuit appear at end of data sheet.M A X 5936/M A X 5937-48V Hot-Swap Controllers with V IN Step Immunity and No R SENSE 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.V EE , V OUT , PGOOD (PGOOD ), LP,STEP_MON to GND............................................+0.3V to -85V PGOOD (PGOOD ) to V OUT ....................................-0.3V to +85V PGOOD (PGOOD ), LP, STEP_MON to V EE ............-0.3V to +85V GATE to V EE ...........................................................-0.3V to +20V UVLO to V EE .............................................................-0.3V to +6V Input CurrentLP (internally, duty-cycle limited).........................................1A PGOOD (PGOOD ) (continuous).....................................80mAGATE (during 15V clamp, continuous)...........................30mA GATE (during 2V clamp, continuous).............................50mA GATE (during gate pulldown, continuous)......................50mA Continuous Power Dissipation (T A = +70°C)8-Pin SO (derate 5.9mW/°C above +70°C)..................471mW 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°CELECTRICAL CHARACTERISTICS(V= -10V to -80V, V = GND - V , V =V , R = 200Ω, UVLO open, T = -40°C to +85°C, unless otherwise noted.MAX5936/MAX5937-48V Hot-Swap Controllers with V INStep Immunity and No R SENSEELECTRICAL CHARACTERISTICS (continued)M A X 5936/M A X 5937-48V Hot-Swap Controllers with V IN Step Immunity and No R SENSE 4_______________________________________________________________________________________Note 2:All limits are 100% tested at +25°C and +85°C. Limits at -40°C and -10°C are guaranteed by characterization.Note 3:Delay time from a valid on-condition until the load probe test begins.Note 4:V EE or UVLO voltages below V UVLO,F or V UVLO_REF,F , respectively, are ignored during this time.Note 5:The time (V OUT - V EE ) > V SC + overdrive until (V GATE - V EE ) drops to approximately 90% of its initial high value.Note 6:The time when the PGOOD (PGOOD ) condition is met until the PGOOD (PGOOD ) signal is asserted.ELECTRICAL CHARACTERISTICS (continued)MAX5936/MAX5937-48V Hot-Swap Controllers with V INStep Immunity and No R SENSE_______________________________________________________________________________________5SUPPLY CURRENT vs. INPUT VOLTAGEM A Z 5936 t o c 01INPUT VOLTAGE (V)S U P P L Y C U R R E N T (m A )7060405030200.20.40.60.81.01.21.41.61.82.001080SUPPLY CURRENT vs. TEMPERATURETEMPERATURE (°C)S U P P L Y C U R R E N T (m A )603510-150.20.40.60.81.01.20-4085GATE-DRIVE VOLTAGE vs. INPUT VOLTAGEM A X 536 t o c 03INPUT VOLTAGE (V)G A T E -D R I V E V O L T A G E (V )7060405030206.57.07.58.08.59.09.510.010.56.01080GATE PULLDOWN CURRENTvs. GATE VOLTAGEM A X 5936 t o c 04V GATE (V)G A T E P U L L D O W N C U R R E N T (m A )986723451501001502002503003504004505000010RETRY TIME vs. TEMPERATURETEMPERATURE (°C)R E T R Y T I M E (s )603510-153.13.23.33.43.53.63.73.83.94.03.0-4085STARTUP WAVEFORMMAX5936 toc0640ms/divV IN 50V/div V GATE 10V/div V OUT 50V/div I IN 2A/divV PGOOD 50V/div MAX5936_A CIRCUIT-BREAKER EVENTMAX5936 toc071ms/divV GATE 10V/divV OUT 50V/divI IN 2A/divV PGOOD 50V/div Typical Operating Characteristics(V EE = -48V, GND = 0V, V IN = GND - V EE , all voltages are referenced to V EE , T A = +25°C, unless otherwise noted.)M A X 5936/M A X 5937-48V Hot-Swap Controllers with V IN Step Immunity and No R SENSE 6_______________________________________________________________________________________MAX5936_A SHORT-CIRCUIT EVENTMAX5936 toc08400ns/divV GATE 10V/divV OUT 50V/div I IN10A/divV PGOOD 50V/divNORMALIZED CIRCUIT-BREAKER THRESHOLD vs. TEMPERATUREM A X 5936 t o c 09TEMPERATURE (°C)N O R M A L I Z E D C I R C U I T -B R E A K E R T H R E S H O L D (%)603510-150.60.81.01.21.41.60.4-4085V OUT SLEW RATE vs. TEMPERATURETEMPERATURE (°C)S L E W R A T E (V /m s )603510-155.56.0 6.57.07.58.08.59.09.510.05.0-4085MAX5936_A INPUT VOLTAGE STEP EVENT (NO FAULT)4ms/divGATE OUT IN V PGOOD IN R LOAD = 75ΩMAX5936_A INPUT VOLTAGESTEP EVENT (FAULT)4ms/divGATE OUT IN V PGOODIN R LOAD = 75ΩGATE TO V EE CLAMP VOLTAGEAT POWER OFFI SINK (mA)G A T E C L A M P I N G V O L T A G E (V )181614121086420.51.01.52.02.53.00020GATE TO V EE CLAMP VOLTAGE MOSFET FULLY ENHANCEDI SINK (mA)G A T E C L A M P I N G V O L T A G E (V )1816121446810291011121314151617188020Typical Operating Characteristics (continued)(V EE = -48V, GND = 0V, V IN = GND - V EE , all voltages are referenced to V EE , T A = +25°C, unless otherwise noted.)MAX5936/MAX5937-48V Hot-Swap Controllers with V INStep Immunity and No R SENSE_______________________________________________________________________________________7Detailed DescriptionThe MAX5936/MAX5937 hot-swap controllers incorpo-rate overcurrent fault management and are intended for negative-supply-rail applications. The MAX5936/MAX5937 eliminate the need for an external R SENSE and include V IN input-step protection and load probe,which prevents powering up into a shorted load. They are intended for negative 48V telecom power systems where low cost, flexibility, multifault management, and compact size are required. The MAX5936/MAX5937 are ideal for the widest range of systems from those requiring low current with small MOSFETs to high-current systems requiring large power MOSFETs and low on-resistance.The MAX5936/MAX5937 control an external n-channel power MOSFET placed in the negative supply path of an external load. When no power is applied, the GATE output of the MAX5936/MAX5937 clamps the V GS of the MOSFET to 2V, keeping the MOSFET turned off. When power is applied to the MAX5936/MAX5937, the 2Vdown device pulling G ATE to V EE and the V GS of the MOSFET to 0V. As shown in Figure 2, this transition enables the MAX5936/MAX5937 to keep the power MOSFET continually off during the board insertion phase when the circuit board first makes contact with the backplane. Without this clamp, the GATE output of a powered-down controller would be floating and the MOSFET reverse transfer capacitance (gate-to-drain)would pull up and turn on the MOSFET gate when the MOSFET drain is rapidly pulled up by the V IN step dur-ing backplane contact. The MAX5936/MAX5937 G ATE clamp can overcome the gate-to-drain capacitance of large power MOSFETs with added slew-rate control (C SLEW ) capacitors while eliminating the need for addi-tional gate-to-source capacitance. The MAX5936/MAX5937 will keep the MOSFET off indefinitely if the supply voltage is below the user-set UVLO threshold or if a short circuit is detected in the load connected to the drain of the power MOSFET.M A X 5936/M A X 5937-48V Hot-Swap Controllers with V IN Step Immunity and No R SENSE 8_______________________________________________________________________________________The MAX5936/MAX5937 conduct a load-probe test after contact transients from the hot plug-in have settled. This follows the MAX5936/MAX5937 power-up (when the UVLO condition has been met for 220ms (t LP )) and prior to the turn-on of the power MOSFET. This test pulls a user-programmable current through the load (1A, max)for up to 220ms and tests for a voltage of 200mV across the load at V OUT . This current is set by an external resis-tor, R LP , between V OUT and LP (Figure 14). When the voltage across the load exceeds 200mV, the test is trun-cated and the GATE turn-on sequence is started. If at the end of the 220ms test period the voltage across the load has not reached 200mV, the load is assumed to be short-ed and the current to the load from the LP pin is shut off.The MAX5936A_/MAX5937A_ will timeout for 16 x t LP then retry the load-probe test. The MAX5936L_/MAX5937L_ will latch the fault condition indefinitely untilthe UVLO is brought below 1.125V for 1.5ms or the power is recycled. See the Applications Information section for recommendations on selecting R LP to set the current level.Upon successful completion of the load-probe test, the MAX5936/MAX5937 enter the power-up GATE cycle and begin ramping the G ATE voltage with a 52µA current source. This current source is restricted if V OUT begins to ramp down faster than the default 9V/ms slew rate.Charging up G ATE enhances the power MOSFET in a controlled manner and ramping V OUT at a user-settable rate controls the inrush current from the backplane. The MAX5936/MAX5937 continue to charge up the G ATE until one of two events occurs: a normal power-up GATE cycle is completed or a power-up to fault management is detected (see the GATE Cycles section in Appendix A ).Figure 1. Functional Block DiagramMAX5936/MAX5937-48V Hot-Swap Controllers with V INStep Immunity and No R SENSE_______________________________________________________________________________________9In a normal power-up GATE cycle, the voltage at V OUT (referenced to V EE ) ramps to below 72% of the circuit-breaker threshold voltage, V CB . At this time, the remaining GATE voltage is rapidly pulled up to full enhancement.PGOOD is asserted 1.26ms after GATE is fully enhanced (see Figure 4). If the voltage at V OUT remains above 72%of the V CB (when GATE reaches 90% of full enhance-ment), then a power-up to fault management fault has occurred (see Figure 5). GATE is rapidly pulled to V EE ,turning off the power MOSFET and disconnecting the load. PGOOD remains deasserted and the MAX5936/MAX5937 enter the fault management mode.When the power MOSFET is fully enhanced, the MAX5936/MAX5937 monitor the drain voltage (V OUT ) for circuit-breaker and short-circuit faults. The MAX5936/MAX5937 make use of the power MOSFET’s R DS(ON) as the current-sense resistance to detect excessive current through the load. The short-circuit threshold voltage,V SC , is twice V CB (V SC = 2 x V CB ) and is available in 100mV, 200mV, and 400mV thresholds. V CB and V SC are temperature-compensated (increasing with tempera-ture) to track the normalized temperature coefficient of R DS(ON) for typical power MOSFETs.When the load current is increased during full enhance-ment, this causes V OUT to exceed V CB but remains less than V SC , and starts the 1.2ms circuit-breaker glitch rejection timer. At the end of the glitch rejection period,if V OUT still exceeds V CB , the G ATE is immediately pulled to V EE (330ns), PGOOD (PGOOD ) is deasserted,and the part enters fault management. Alternatively,during full enhancement when V OUT exceeds V SC ,there is no glitch rejection timer. G ATE is immediately pulled to V EE , PG OOD is deasserted, and the part enters fault management.Figure 3. Load Probe Test During Initial Power-Up40ms/divV 20V/divV 20V/divV 20V/divALL VOLTAGESREFERENCED TO GND Figure 2. GATE Voltage Clamp During Power-Up 4ms/divC IN = 100µFFigure 4. MAX5936 Normal Condition 40ms/divFigure 5. MAX5936 Startup in Fault Condition40ms/divM A X 5936/M A X 5937-48V Hot-Swap Controllers with V IN Step Immunity and No R SENSE10______________________________________________________________________________________The V IN step immunity provides a means for transition-ing through a large step increase in V IN with minimal backplane inrush current and without shutting down the load. Without V IN step immunity (when the power MOSFET is fully enhanced), a step increase in V IN will result in a high inrush current and a large step in V OUT ,which can trip the circuit breaker. With V IN step immu-nity, the STEP_MON input detects the step before a short circuit is detected at V OUT and alters the MAX5936/MAX5937 response to V OUT exceeding V SC due to the step. The 1.25V voltage threshold at STEP_MON and a 10µA current source at STEP_MON allow the user to set the sensitivity of the step detection with an external resistor to V EE . A capacitor is placed between GND and the STEP_MON input, which, in con-junction with the resistor, sets the STEP_MON time con-stant. When a step is detected by the STEP_MON input to rise above its threshold (STEP TH ), the overcurrent fault management is blocked and remains blocked as long as STEP TH is exceeded. When STEP TH is exceed-ed, the MAX5936/MAX5937 take no action until V OUT rises above V SC or above V CB for the 1.2ms circuit-breaker glitch rejection period. When either of these conditions occurs, a step G ATE cycle begins and the GATE is immediately brought to V EE , which turns off the power MOSFET to minimize the resulting inrush current surge from the backplane and PGOOD remains assert-ed. GATE is held at V EE for 350µs, and after about 1ms,begins to ramp up thereby enhancing the power MOSFET in a controlled manner as in the power-up G ATE cycle. This provides a controlled inrush current to charge the load capacitance to the new supply volt-age (see the GATE Cycles section in Appendix A ).As in the case of the power-up G ATE cycle, if V OUT drops to less than 72% of the programmed V CB , inde-pendent of the state of STEP_MON, the G ATE voltageis rapidly pulled to full enhancement. PGOOD remains asserted throughout the step. Otherwise, if the STEP_MON input has decayed below its threshold but V OUT remains above 72% of the programmed V CB (when G ATE reaches 90% of full enhancement), (a step-to-fault management fault has occurred). GATE is rapidly pulled to V EE , turning off the power MOSFET and disconnecting the load, PG OOD (PGOOD ) is deasserted, and the MAX5936/MAX5937 enter the fault management mode.Fault ManagementFault management can be triggered by the following conditions:•V OUT exceeds 72% of V CB during G ATE ramp at 90% of full enhancement,•V OUT exceeds the V CB for longer than 1.2ms during full enhancement,•V OUT exceeds the V SC during full enhancement, and •Load-probe test fails.Once in the fault management mode, GATE will always be pulled to V EE to turn off the external MOSFET and PG OOD (PGOOD ) will always be deasserted. The MAX5936A_/MAX5937A_ have automatic retry following a fault while the MAX5936L_/MAX5937L remain latched in the fault condition.Autoretry Fault Management(MAX5936A_/MAX5937A_)If the MAX5936A_/MAX5937A_entered fault management due to circuit-breaker and short-circuit faults, the autoretry timer starts immediately. The timer times out in 3.5s (typ) and at the end of the timeout, the sequencer initiates a load-probe test. If this is successful, it starts a normal power-up GATE cycle.Figure 6. MAX5936 Response to a Step Input (V OUT < 0.74V CB )2ms/divC LOAD = 100µF R LOAD = 100ΩFigure 7. MAX5936 Response to a Step Input (V OUT > 0.74V CB )4ms/div40V 20VC LOAD = 100µF R LOAD = 20ΩMAX5936/MAX5937-48V Hot-Swap Controllers with V INStep Immunity and No R SENSE______________________________________________________________________________________11Latched Fault Management (MAX5936L_/MAX5937L_)When the MAX5936L_/MAX5937L_ enter fault manage-ment, they remain in this condition indefinitely until the power is recycled or until UVLO is brought below 1.125V for 1.5ms (typ) (when the short-circuit or circuit-breaker fault has cleared, the sequencer initiates a load-probe test). If this is successful, it starts a normal power-up GATE cycle. A manual reset circuit (Figure 8)can be used to clear the latch.Circuit-Breaker ThresholdsThe MAX5936/MAX5937 are available with 100mV,200mV, and 400mV circuit-breaker thresholds. The short-circuit voltage threshold (V SC ) is twice the circuit-breaker threshold voltage (V CB ). In the MAX5936/MAX5937, V CB and V SC are temperature-compensated (increasing with temperature) to track the normalized temperature gradient of typical power MOSFETs.The proper circuit-breaker threshold for an application depends on the R DS(ON) of the external power MOSFET and the maximum current the load is expected to draw.To avoid false fault indication and dropping of the load,the designer must take into account the load response to voltage ripples and noise from the backplane power supply, as well as switching currents in the downstream DC-DC converter that is loading the circuit. While the circuit-breaker threshold has glitch rejection that ignores ripples and noise lasting less than 1.2ms, the short-circuit detection is designed to respond very quickly (less than 330ns) to a short circuit. V SC and V CB must be selected from the three available rangeswith an adequate margin to cover all possible ripples,noise, and system current transients.The short-circuit and circuit-breaker voltages are sensed at V OUT , which is the drain of the power MOSFET. The R DS(ON)of the MOSFET is the current-sense resis-tance, so the total current through the load and load capacitance is the drain current of the power MOSFET.Accordingly, the voltage at V OUT as a function of MOSFET drain current is:V OUT = I D,MOSFET x R DS(ON)The temperature compensation of the MAX5936/MAX5937 is designed to track the R DS(ON) of the typi-cal power MOSFET. Figure 9 shows the typical normal-ized tempco of the circuit-breaker threshold along with the normalized tempco of R DS(ON) for two typical power MOSFETS. When determining the circuit-breaker threshold in an application, go to the data sheet of the power MOSFET and locate the manufacturer’s maxi-mum R DS(ON)at +25°C with a V GS of 10V. Next, find the figure presenting the tempco of normalized R DS(ON)or on-resistance vs. temperature. Because this curve is in normalized units typically with a value of 1 at +25°C,it is possible to multiply the curve by the drain voltage at +25°C and convert the curve to drain voltage. Now compare this curve to that of the MAX5936/MAX5937 normalized tempco of the circuit-breaker threshold to make a determination of the tracking error in mV between the power MOSFET [I D,MOSFET x R DS(ON)]and the MAX5936/MAX5937 over the application’s operating temperature range. If the tempco of the power MOSFET is greater than that of the MAX5936/MAX5937, then additional margin will be required in selecting the circuit-breaker and short-circuit voltages at higher temperatures as compared to +25°C. When dissipation in the power MOSFET is expected to lead to local temperature elevation relative to ambient condi-tions, then it becomes imperative that the MAX5936/MAX5937 be located as close as possible to the power MOSFET. The marginal effect of temperature differ-ences on circuit-breaker and short-circuit voltages can be estimated from a comparative plot such as Figure 9.MAX5936LN and MAX5937LNThe MAX5936LN and MAX5937LN do not have circuit-breaker and short-circuit thresholds and these faults are ignored. For these devices PG OOD (PGOOD )asserts 1.26ms after G ATE has ramped to 90% of full enhancement. The step detection function of the MAX5936LN and MAX5937LN responds to V IN and V OUT steps with the same voltage thresholds as the MAX5936_C and MAX5937_C.Figure 8. Resetting MAX5936L/MAX5937L after a Fault Condition Using a Push-Button SwitchM A X 5936/M A X 5937-48V Hot-Swap Controllers with V IN Step Immunity and No R SENSE12______________________________________________________________________________________PGOOD (PGOOD ) Open-Drain OutputThe power-good outputs, PG OOD (PGOOD ), are open drain and are referenced to V OUT . They assert and latch if V OUT ramps below 72% of V CB , and with the built-in delay this occurs 1.26ms after the external MOSFET becomes fully enhanced. PG OOD (PGOOD ) deasserts any time the part enters fault management. PG OOD (PGOOD ) has a delayed response to UVLO. The GATE goes to V EE when UVLO is brought below 1.125V for 1.5ms. This turns off the power MOSFET and allows V OUT to rise depending on the RC time constant of the load. PG OOD (PGOOD ), in this situation, deasserts when V OUT rises above V CB for more than 1.4ms or above V SC , whichever occurs first (see Figure 12b).Due to the open-drain driver, PG OOD (PGOOD )requires an external pullup resistor to GND. Due to this external pullup, PG OOD will not follow positive V IN steps as well as if it were driven by an active pullup. As a result, when PG OOD (PGOOD) is asserted high, an apparent negative glitch appears at PGOOD (PGOOD )during a positive V IN step. This negative glitch is a result of the RC time constant of the external resistor and the PGOOD pin capacitance lagging the V IN step.It is not due to switching of the internal logic. To mini-mize this negative transient, it may be necessary to increase the pullup current and/or to add a small amount of capacitance from PGOOD (PGOOD ) to GND to compensate for the pin capacitance.WARNING:For the MAX5936_N/MAX5937_N, PGOOD (PGOOD ) asserts 1.26ms after the power MOSFET is fully enhanced, independent of V OUT . Once the MOSFET is fully enhanced and UVLO is pulled below its respective threshold, G ATE pulls to V EE to turn off the power MOSFET and disconnect the load. When UVLO is cycled low, PG OOD (PGOOD ) is deasserted. In sum-mary, once the MOSFET is fully enhanced, the MAX5936_N/ MAX5937_N ignore V OUT and deassert PG OOD (PGOOD ) when UVLO goes low or when the power to the MAX5936_N/ MAX5937_N is fully recy-cled.Undervoltage Lockout (UVLO)UVLO provides an accurate means to set the turn-on volt-age level for the MAX5936/MAX5937. Use a resistor-divider network from G ND to V EE to set the desired turn-on voltage (Figure 11). UVLO has hysteresis with a rising threshold of 1.25V and a falling threshold of 1.125V.A startup delay of 220ms allows contacts and voltages to settle prior to initiating the startup sequence (Figure 12a).Figure 9. MAX5936/MAX5937 Normalized Circuit-Breaker Threshold (V CB )Figure 10. Circuit-Breaker Voltage Margin for High and Low Tempco Power MOSFETSMAX5936/MAX5937-48V Hot-Swap Controllers with V INStep Immunity and No R SENSE______________________________________________________________________________________13This startup delay is from a valid UVLO condition until the start of the load-probe test. There is glitch rejection on UVLO going low, which requires that V UVLO remains below its falling threshold for 1.5ms to turn off the part (Figure 12b). Use the following formula to calculate the MAX5936/MAX59337 turn-on voltage:Where V ON is the desired turn-on voltage of theMAX5936/MAX5937 and V UVLO_REF,R is the 1.25V UVLO rising threshold.Output Voltage (V OUT )Slew-Rate ControlThe V OUT slew rate controls the inrush current required to charge the load capacitor. The MAX5936/MAX5937have a default internal slew rate set for 9V/ms. The inter-nal circuit establishing this slew rate accommodates up to about 1000pF of reverse transfer capacitance (miller capacitance) in the external power MOSFET without effecting the default slew rate. Using the default slew rate, the inrush current required to charge the load capacitance is given by:I INRUSH (mA) = C LOAD (µF) x SR (V/ms)where SR = 9V/ms (default, typ).Applications InformationSelecting Resistor and Capacitorfor Step MonitorWhen a positive V IN step or ramp occurs, the V IN increase results in a voltage rise at both STEP_MON and V OUT relative to V EE . When the voltage at STEP_MON is above STEP TH the MAX5936/MAX5937block short-circuit and circuit-breaker faults. During this STEP_MON high condition, if V OUT rises above V SC , the MAX5936/MAX5937 immediately and very rapidly pull GATE to V EE . This turns off the power MOSFET to avoid inrush current spiking. G ATE is held low for 350µs.About 1ms after the start of G ATE pulldown, the MAX5936/MAX5937 begin to ramp GATE up to turn on the MOSFET in a controlled manner, which results in ramping V OUT down to the new supply level (see the GATE Cycles section in Appendix A ).Figure 11. Setting the MAX5936/MAX5937 Turn-On VoltageFigure 12. UVLO Timing Diagram。

MAX8533_cn

MAX8533_cn

___________________________________概述MAX8533是一款单端口、12V、InfiniBand ®兼容(IB) 的通用热插拔控制器。

该器件可应用于IB I类(非隔离型)和IB II类(隔离型) 电源拓扑应用。

此外,MAX8533能够在12V 总线供电的可热插拔刀片式服务器、RAID卡和网络交换机或路由器中充当可靠的电源控制器。

MAX8533内部集成有多种功能,允许电路板可靠地插入和拔出,同时还可实时监视异常事件。

开启输入电压时,MAX8533实现可调的软启动斜率,并提供过流保护。

该器件可在一段用户设定的时间内提供精确、稳定的电流调节输出,用于在过流情况(OC) 下完成闭锁和软启动。

此外,MAX8533还提供了第二级严重过流(SOC) 保护功能,在100ns内能够对短路故障做出响应。

MAX8533还具有可调的过压保护功能。

MAX8533具有欠压锁定(UVLO)功能,以及可连接至DC-DC转换器的电源就绪信号(POK),以确认工作时电源输出电压的状态。

两个使能输入引脚EN (逻辑使能)和LPEN (本地电源使能) 提供灵活的上电顺序。

MAX8533可工作在扩展级温度范围,能在电路板拔出时承受最高额定值为16V的电感感生电压。

MAX8533采用节省空间的10引脚µMAX封装。

___________________________________应用12V热插拔InfiniBand电路供电热插拔/插头/坞站电源管理刀片式服务器RAID网络路由器和交换机___________________________________特性♦12V热插拔控制器,用于25W或50W InfiniBand端口♦可编程过流保护电流调节输出♦EN和LPEN输入引脚可实现灵活的上电顺序♦电源就绪信号♦可承受最高16V的电感感生电压♦开启过程中提供软启动过流保护♦定时的电流调节周期(可调)♦输出完全短路时100ns IC响应时间♦可调过压保护♦欠压锁定♦可调启动斜率MAX8533尺寸最小、高可靠性、12V、InfiniBand兼容的热插拔控制器________________________________________________________________Maxim Integrated Products 119-2849; Rev 0; 4/03本文是Maxim正式英文资料的译文,Maxim不对翻译中存在的差异或由此产生的错误负责。

MAX6307UK50D2-T中文资料

MAX6307UK50D2-T中文资料
nfigurations and Typical Operating Circuit appear at end of data sheet. Ordering Information continued at end of data sheet. Standard Versions Table appears at end of data sheet.
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.
PARAMETER VCC Range Supply Current ICC SYMBOL VCC = 5.5V MAX6306/MAX6307/ MAX6309/MAX6310/ MAX6312/MAX6313 VTH MAX6306E/MAX6307/ MAX6309E/MAX6310E/ MAX6312E/MAX6313E Reset Threshold Reset Threshold VTH/°C VTH HYST D1 Reset Timeout Period tRP D2 D3 D4 VCC > 4.25V, ISINK = 3.2mA VOL RESET Output Voltage VOH MAX6305–MAX6310 VCC > 2.5V, ISINK = 1.2mA VCC > 1.2V, ISINK = 500µA VCC > 1.0V, ISINK = 50µA VCC > 4.25V, MAX6308/MAX6309/ ISOURCE = 800µA MAX6310 VCC > 2.5V, ISOURCE = 500µA VCC > 4.25V, ISINK = 3.2mA VCC > 2.5V, ISINK = 1.2mA MAX6311/MAX6312/ VCC > 1.8V, MAX6313 ISOURCE = 150µA VCC > 1.0V, ISOURCE = 10µA 0.8 x VCC 0.8 x VCC VCC - 1.5 V 0.8 x VCC 0.4 0.3 V 1.0 20 140 1120 TA = +25°C TA = 0°C to +70°C VTH 1.5% VTH 2.5% VTH 2.5% CONDITIONS TA = -40°C to +85°C (Note 2) MIN 1.0 8 VTH VTH TYP MAX 5.5 16 VTH + 1.5% VTH + 2.5% VTH + 2.5% ppm/°C mV 2.0 40 280 2240 0.4 0.3 0.3 0.3 V ms V UNITS

MAX633UR17D中文资料

MAX633UR17D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 MAX6332/MAX6333/MAX6334 microprocessor (µP)supervisory circuits monitor the power supplies in 1.8V to 3.3V µP and digital systems. They increase circuit reliability and reduce cost by eliminating external com-ponents and adjustments.These devices perform a single function: they assert a reset signal whenever the V CC supply voltage declines below a preset threshold, keeping it asserted for a pre-set timeout period after V CC has risen above the reset threshold. The only difference among the three devices is their output. The MAX6333 (push/pull) and MAX6334(open-drain) have an active-low RESET output, while the MAX6332 (push/pull) has an active-high RESET out-put. The MAX6332/MAX6333 are guaranteed to be in the correct state for V CC down to 0.7V. The MAX6334 is guaranteed to be in the correct state for V CC down to 1.0V.The reset comparator in these ICs is designed to ignore fast transients on V CC . Reset thresholds are factory-trimmable between 1.6V and 2.5V, in approximately 100mV increments. There are 15 standard versions available (2,500 piece minimum-order quantity); con-tact the factory for availability of nonstandard versions (10,000 piece minimum-order quantity). For space-criti-cal applications, the MAX6332/MAX6333/MAX6334come packaged in a 3-pin SOT23.ApplicationsPentium II™ Computers Computers ControllersIntelligent InstrumentsCritical µP/µC Power Monitoring Portable/Battery-Powered Equipment AutomotiveFeatureso Ultra-Low 0.7V Operating Supply Voltageo Low 3.3µA Supply Currento Precision Monitoring of 1.8V and 2.5V Power-Supply Voltages o Reset Thresholds Available from 1.6V to 2.5V,in Approximately 100mV Increments o Fully Specified over Temperatureo Three Power-On Reset Pulse Widths Available (1ms min, 20ms min, 100ms min)o Low Costo Three Available Output Structures: Push/Pull RESET , Push/Pull RESET, Open-Drain RESET o Guaranteed RESET/RESET Valid to V CC = 0.7V (MAX6332/MAX6333)o Power-Supply Transient Immunity o No External Components o 3-Pin SOT23 Packageo Pin-Compatible with MAX809/MAX810 and MAX6326/MAX6327/MAX6328MAX6332/MAX6333/MAX63343-Pin, Ultra-Low-Voltage, Low-PowerµP Reset Circuits________________________________________________________________Maxim Integrated Products119-1411; Rev 0; 12/98Ordering Information* These devices are available in factory-set V CC reset thresh-olds from 1.6V to 2.5V, in approximately 0.1V increments.Choose the desired reset threshold suffix from Table 1 and insert it in the blanks following “UR” in the part number.Factory-programmed reset timeout periods are also available.Insert the number corresponding to the desired nominal reset timeout period (1 = 1ms min, 2 = 20ms min, 3 = 100ms min) in the blank following “D” in the part number. There are 15 stan-dard versions with a required order increment of 2500 pieces.Sample stock is generally held on the standard versions only (see Selector Guide). Contact the factory for availability of non-standard versions (required order increment is 10,000 pieces).All devices available in tape-and-reel only.Typical Operating Circuit and Pin Configuration appear at end of data sheet.Selector Guide appears at end of data sheet.Pentium II is a trademark of Intel Corp.M A X 6332/M A X 6333/M A X 63343-Pin, Ultra-Low-Voltage, Low-Power 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, reset not asserted.)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 Push/Pull RESET, RESET .......................-0.3V to (V CC + 0.3V)Open-Drain RESET ..............................................-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)SOT23-3 (derate 4mW/°C above +70°C)....................320mW Operating Temperature Range ...........................-40°C to +85°C Storage Temperature Range.............................-65°C to +160°C Lead Temperature (soldering, 10sec).............................+300°C3-Pin, Ultra-Low-Voltage, Low-PowerµP Reset Circuits_______________________________________________________________________________________32.02.62.23.03.63.83.43.24.0-602.4-40-202.820406080100SUPPLY CURRENT vs. TEMPERATURETEMPERATURE (°C)I C C (µA )0.9500.9900.9701.0001.0301.0401.0201.0101.050-60-400.980-2000.96020406080100NORMALIZED RESET TIMEOUT PERIODvs. TEMPERATURETEMPERATURE (°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 D1020-20403070605080-600-4020406080100V CC FALLING PROPAGATION DELAYvs. TEMPERATURETEMPERATURE (°C)P R O P A G A T I O N D E L A Y (µs )10010001002004003005006000.1110MAXIMUM TRANSIENT DURATION vs. RESET COMPARATOR OVERDRIVERESET COMPARATOR OVERDRIVE (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 )402080601001201401600.5 1.0 1.250.75 1.5 1.75 2.0 2.25 2.5OUTPUT VOLTAGE HIGH vs. SUPPLY VOLTAGEV CC (V)O U T P U T V O L T A G E H I G H (V C C - V O H ) (m V )20103060705040800.5 1.00 1.50 2.00 2.50 3.00OUTPUT VOLTAGE LOW vs. SUPPLY VOLTAGEV CC (V)O U T P U T V O L T A G E L O W (m V )Typical Operating Characteristics(Reset not asserted, T A = +25°C, unless otherwise noted.)MAX6332/MAX6333/MAX6334Pin DescriptionM A X 6332/M A X 6333/M A X 63343-Pin, Ultra-Low-Voltage, Low-Power µP Reset Circuits 4_____________________________________________________________________________________________________Applications InformationInterfacing to µPs with BidirectionalReset PinsSince the RESET output on the MAX6334 is open-drain,this device interfaces easily with µPs that have bidirec-tional reset pins, such as the Motorola 68HC11.Connecting the µP supervisor’s RESET output directly to the microcontroller’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 Maximum Transient Duration vs. Reset Comparator Overdrive graph. The graph shows the maxi-mum pulse width that a negative-going V CC transient may typically have without issuing a reset signal. As the ampli-tude of the transient increases, the maximum allowable pulse width decreases.Ensuring a Valid Reset OutputDown to V CC = 0When V CC falls below 1V and approaches the minimum operating voltage of 0.7V, push/pull-structured reset sinking (or sourcing) capabilities decrease drastically.High-impedance CMOS-logic inputs connected to the RESET pin can drift to indeterminate voltages. This does not present a problem in most cases, since most µPs and circuitry do not operate at V CC below 1V. For the MAX6333, where RESET must be valid down to 0,adding a pull-down resistor between RESET and GND removes stray leakage currents, holding RESET low (Figure 2a). The pull-down resistor value is not critical;100k Ωis large enough not to load RESET and small enough to pull it low. For the MAX6332, where RESET must be valid to V CC = 0, a 100k Ωpull-up resistor between RESET and V CC will hold RESET high when V CC falls below 0.7V (Figure 2b).Since the MAX6334 has an open-drain, active-low out-put, it typically uses a pull-up resistor. With this device,RESET will most likely not maintain an active condition,but will drift to a non-active level due to the pull-up resistor and the reduced sinking capability of the open-drain device. Therefore, this device is not recommend-ed for applications where the RESET pin is required to be valid down to V CC = 0.* Factory-trimmed reset thresholds are available in approximately 100mV increments, with a ±1.8% room-temperature variance.Table 1. Factory-Trimmed Reset Thresholds*Figure 1. Interfacing to µPs with Bidirectional Reset PinsFigure 2. Ensuring Reset Valid Down to V CC = 03-Pin, Ultra-Low-Voltage, Low-PowerµP Reset Circuits_______________________________________________________________________________________5MAX6332/MAX6333/MAX6334Pin ConfigurationSelector Guide (standard versions *)Typical Operating Circuit* Sample stock is generally held on all standard versions.M A X 6332/M A X 6333/M A X 63343-Pin, Ultra-Low-Voltage, Low-Power 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.6_____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600©1998 Maxim Integrated ProductsPrinted USAis a registered trademark of Maxim Integrated Products.TRANSISTOR COUNT:505Chip InformationPackage Information。

MAX4173中文资料

MAX4173中文资料

Pin Configurations appear at end of data sheet.
________________________________________________________________ Maxim Integrated Products
1
For free samples & the latest literature: , or phone 1-800-998-8800. For small orders, phone 1-800-835-8769.
MAX4173T/F/H
A/D CONVERTER OUT GND LOAD/ BATTERY
OrderingX4173TEUT-T MAX4173TESA MAX4173FEUT-T MAX4173FESA MAX4173HEUT-T MAX4173HESA GAIN (V/V) 20 20 50 50 100 100 TEMP. RANGE -40°C to +85°C -40°C to +85°C -40°C to +85°C -40°C to +85°C -40°C to +85°C -40°C to +85°C PIN-PACKAGE 6 SOT23-6 8 SO 6 SOT23-6 8 SO 6 SOT23-6 8 SO SOT TOP MARK AABN – AABD – AABP –
2
_______________________________________________________________________________________
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.
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___________________________________________________________________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。

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