SP706(专用复位芯片)

复位芯片资料

sPrecision Low Voltage Monitor: SP706P/R and SP708R at +2.63V SP706S and SP708S at +2.93V SP706T and SP708T at +3.08VsRESET Pulse Width - 200ms

sIndependent Watchdog Timer - 1.6 secTimeout (SP706P/S/R/T)

s40µA Maximum Supply Current

sDebounced TTL/CMOS Manual-Reset InputsRESET Asserted Down to VCC = 1VsRESET Output:

SP706P Active-High SP706R/S/T Active-Low

SP708R/S/T Both Active High + Active LowsWDI Can Be Left Floating, Disabling theWatchdog Function

DESCRIPTION

The SP706P/S/R/T, SP708R/S/T series is a family of microprocessor (µP) supervisory circuitsthat integrate myriad components involved in discrete solutions which monitor power-supply andbattery, in µP, and digital systems. The SP706P/S/R/T, SP708R/S/T series will significantlyimprove system reliability and operational efficiency when compared to results obtained withdiscrete components. The features of the SP706P/S/R/T, SP708R/S/T series include awatchdog timer, a µP reset, a Power Fail Comparator, and a manual-reset input. The SP706P/S/R/T, SP708R/S/T series is ideal for +3.0V or +3.3V applications in automotive systems,computers, controllers, and intelligent instruments. The SP706P/S/R/T, SP708R/S/T series isan ideal solution for systems in which critical monitoring of the power supply to the µP and relateddigital components is demanded.

PartNumberSP706PSP706RSP706SSP706TSP708RSP708SSP708T

RESETActive

HIGHLOWLOWLOWLOW/HIGHLOW/HIGHLOW/HIGH

RESETThreshold

2.63V2.63V2.93V3.08V2.63V2.93V3.08V

ManualReset

YESYESYESYESYESYESYES

PFIAccuracy

4%4%4%4%4%4%4%

WatchdogInput

YESYESYESYESNONONO

sBuilt-In Vcc Glitch Immunity

sAvailable in 8-pin PDIP, NSOIC, andµSOIC packages

sVoltage Monitor for Power Failure or LowBattery Warning

sPin Compatible Enhancement to IndustryStandards 706P/R/S/T and 708R/S/T

Rev. 10-17-00 SP706 +3.0/ +3.3 Low Power Microprocessor Circuits © Copyright 2000 Sipex Corporation

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复位芯片资料

ABSOLUTE MAXIMUM RATINGS

These are stress ratings only and functional operationof the device at these ratings or any other above thoseindicated in the operation sections of the specificationsbelow is not implied. Exposure to absolute maximumrating conditions for extended periods of time mayaffect reliability.

Terminal Voltage (with respect to GND):

VCC........................................................-0.3V to +6.0VAll Other Inputs (Note 1)..............-0.3V to (VCC +3.0V)Input Current:

VCC.....................................................................20mAGND...................................................................20mAOutput Current (all outputs)...............................20mAESD Rating...........................................................2kV

Continuous Power DissipationPlastic DIP

(derate 9.09mW/OC above +70OC)..................727mWSO

(derate 5.88mW/OC above +70OC)..................471mWMini SO

(derate 4.10mW/OC above +70OC)..................330mWStorage Temperature Range.............-65 C to +160 CLead Temperature (solding 10 sec)................+300 C

SPECIFICATIONS

Vcc = 2.7V to 5.5V for SP70_P/R, VCC = 3.0 to 5.5V for SP70_S, VCC = 3.15V to 5.5V for SP70_T, TA= TMIN to TMAX to TMAX, unless otherwise noted,typical at 25°C.

PARAMETER

OperatingVoltageRange,VCCSupplyCurrent,ISUPPLYResetThreshold

MIN.1.0

TYP.

MAX.5.5402.703.003.15280

UNITSVVmVms

CONDITIONS

2.552.853.001400.8xVCC

ResetThresholdHysteresisResetPulseWidth,tRSOutputVoltage

VOHVOLVOHVOL

RESETOutputVoltage

VOHVOLVOHVOL

WatchdogTimeoutPeriod,tWDWDIPulseWidth,tWPWDIInputThreshold,

VILVIHVILVIH

WDIInputCurrent

252.632.933.0820200

MR=VCCorFloating,WDIFloatingSP70_P/RSP70_SSP70_TNote2Note2

VRST(MAX)<VCC<3.6V,ISOURCE=500µAVRST(MAX)<VCC<3.6V,ISINK=1.2mA4.5V<VCC<5.5V,ISOURCE=800µA4.5V<VCC<5.5V,ISINK=3.2mAVRST(MAX)<VCC<3.6V,ISOURCE=215µAVRST(MAX)<VCC<3.6V,ISOURCE=1.2mA4.5V<VCC<5.5V,ISOURCE=800µA4.5V<VCC<5.5V,ISOURCE=3.2mAVCC<3.6V

VIL=0.4V,VIH=0.8xVCCVRST(MAX)<VCC<3.6VVRST(MAX)<VCC<3.6VVCC=5.0VVCC=5.0VWDI=0orVCC

0.3

VCC-1.5

0.4

VCC-0.6

0.3

VCC-1.51.0050

1.60

0.42.25

V

V

sns

0.6

0.7xVCC

3.5-1

V

0.8

0.02

1

µA

Rev. 10-17-00 SP706 +3.0/ +3.3 Low Power Microprocessor Circuits © Copyright 2000 Sipex Corporation

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复位芯片资料

SPECIFICATIONS (continued)

Vcc = 2.7V to 5.5V for SP70_P/R, VCC = 3.0 to 5.5V for SP70_S, VCC = 3.15V to 5.5V for SP70_T, TA= TMIN to TMAX to TMAX, unless otherwise noted,typical at 25°C.

PARAMETERWDOOutputVoltage

VOHVOLVOHVOL

MRPull-UpCurrentMRPulseWidth,tMRMRInputThreshold

VILVIHVILVIH

MRtoResetOutDelay,tMDPFIInputThresholdPFIInputCurrentPFOOutputVoltage

VOHVOLVOHVOL

MIN.TYP.MAX.UNITSCONDITIONS

0.8xVCC

0.3

VCC-1.5

0.4

25100500150

0.6

0.7xVCC

2.0

750250

1.20-25.000.8xVCCVCC-1.5

1.250.01

1.3025.00

nsVnAV

0.8

70250

250600

µAV

VRST(MAX)<VCC<3.6V,ISOURCE=500µAVRST(MAX)<VCC<3.6V,ISINK=1.2mA4.5V<VCC<5.5V,ISOURCE=800µA4.5V<VCC<5.5V,ISINK=3.2mAMR=0V,VRST(MAX)<VCC<3.6VMR=0V,4.5V<VCC<5.5VVRST(MAX)<VCC<3.6V4.5V<VCC<5.5VVRST(MAX)<VCC<3.6VVRST(MAX)<VCC<3.6V4.5V<VCC<5.5V4.5V<VCC<5.5V

VRST(MAX)<VCC<3.6V,NOTE24.5V<VCC<5.5V,NOTE2

VCC=3.0VfortheSP70_P/R,VCC=3.3VfortheSP70_S/T,PFIfalling

ns

0.30.4

V

VRST(MAX)<VCC<3.6V,ISOURCE=500µAVRST(MAX)<VCC<3.6V,ISINK=1.2mA4.5V<VCC<5.5V,ISOURCE=800µA4.5V<VCC<5.5V,ISINK=3.2mA

Rev. 10-17-00 SP706 +3.0/ +3.3 Low Power Microprocessor Circuits © Copyright 2000 Sipex Corporation

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复位芯片资料

Figure 1. Pinouts

Rev. 10-17-00 SP706 +3.0/ +3.3 Low Power Microprocessor Circuits © Copyright 2000 Sipex Corporation

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复位芯片资料

PINDESCRIPTION

NAME

FUNCTION

SP706P

DIP/SOIC

µSOIC

SP706R/S/T

DIP/SOIC

µSOIC

SP708R/S/T

DIP/SOIC

µSOIC

MR

ManualReset-Thisinputtriggersaresetpulsewhenpulledbelow0.8V.Thisactive-LOWinputhasaninternal70µApull-upcurrent.ItcanbedrivenfromaTTLorCMOSlogiclineorshortedtogroundwithaswitchVoltageinput.

Groundreferenceforallsignals

Power-FailInput-Whenthisvoltagemonitorinputislessthan1.25V,PFOgoesLOW.ConnectPFItogroundorVCCwhennotinuse.

Power-FailOutput-ThisoutputisHIGHuntilPFIislessthan1.25V.

WatchdogInput-IfthisinputremainsHIGHorLOWfor1.6s,theinternalwatchdogtimertimesoutandWDOgoesLOW.FloatingWDIorconnectingWDItoahigh-impedancetri-state

bufferdisablesthewatchdogfeature.TheinternalwatchdogtimerclearswheneverRESETis

asserted,WDIistri-stated,orwheneverWDIseesarisingorfallingedge.NoConnect.

Active-LOWRESETOutput-ThisoutputpulsesLOWfor200mswhentriggeredandstaysLOWwheneverVCCisbelowtheresetthreshold.ItremainsLOWfor200msafterVccrisesabovetheresetthresholdorMRgoesfromLOWtoHIGH.AwatchdogtimeoutwillnottriggerRESETunlessWDOisconnectedtoMR.

WatchdogOutput-ThisoutputpullsLOWwhentheinternalwatchdogtimerfinishesits1.6scountanddoesnotgoHIGHagainuntilthewatchdogiscleared.WDOalsogoesLOWduringlow-lineconditions.WheneverVCCisbelowtheresetlOstaysLOW.However,unlikeRESET,WDOdoesnothaveaminimumpulsewidth.AssoonasVCCisabovetheresetthreshold,WDOgoesHIGHwithnodelay.Active-HIGHRESETOutput-ThisoutputisthecomplementofRESET.WheneverRESETisHIGH,RESETisLOW,andviceversa.NotetheSP708R/S/Thasaresetoutputonly.

131313

VCCGNDPFI

234

456

234

456

234

456

PFO575757

WDI6868--

N.C.----68

RESET--7171

WDO8282--

RESET71--82

Table 1. Device Pin Description

Rev. 10-17-00 SP706 +3.0/ +3.3 Low Power Microprocessor Circuits © Copyright 2000 Sipex Corporation

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复位芯片资料

Rev. 10-17-00 SP706 +3.0/ +3.3 Low Power Microprocessor Circuits © Copyright 2000 Sipex Corporation

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复位芯片资料

Voltage.

Voltage vs. Supply Voltage.

Rev. 10-17-00 SP706 +3.0/ +3.3 Low Power Microprocessor Circuits © Copyright 2000 Sipex Corporation

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复位芯片资料

Time

3.2VRESET

2.8V

RESET

0V2V

0V2.8V0V

0V

Figure 8. SP708 RESET and RESET AssertionRev. 10-17-00 SP706 +3.0/ +3.3 Low Power Microprocessor Circuits © Copyright 2000 Sipex Corporation

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复位芯片资料

Voltage

Figure 13. Circuit for the SP708 RESET Output Voltage vs. Supply Voltage and the RESET Response TimeFigures

Rev. 10-17-00 SP706 +3.0/ +3.3 Low Power Microprocessor Circuits © Copyright 2000 Sipex Corporation

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复位芯片资料

FEATURES

The SP706P/R/S/T-SP708R/S/T series providesfour key functions:

1. A reset output during power-up, power-downand brownout conditions.

2. An independent watchdog output that goesLOW if the watchdog input has not been toggledwithin 1.6 sec.

3. A 1.25V threshold detector for power-failwarning, low battery detection, or monitoring apower supply other than +3.3V/+3.0V.

4. An active-LOW manual-reset that allowsRESET to be triggered by a pushbutton switch.The SP706R/S/T devices are the same as theSP708R/S/T devices except for the active-HIGHRESET substitution of the watchdog timer. TheSP706P device is the same as the SP706R de-vice except an active-HIGH RESET is providedTHEORY OF OPERATION

The SP706P/R/S/T-SP708R/S/T series is a mi-croprocessor (µP) supervisory circuit that moni-tors the power supplied to digital circuits suchas microprocessors, microcontrollers, ormemory. The series is an ideal solution forportable, battery-powered equipment that re-quires power supply monitoring. Implementingthis series will reduce the number of compo-nents and overall complexity of a system. Thewatchdog functions of this product family willcontinuously oversee the operational status of asystem. The operational features and benefits ofthe SP706P/R/S/T-SP708R/S/T series are de-scribed, in more detail, below.RESET Output

A microprocessor's reset input starts the µPin a known state. The SP706P/R/S/T-SP708R/S/T series asserts reset during power-up andprevents code execution errors during power-down or brownout conditions.

During power-up, once VCCis a guaranteed logic LOW of 0.4V or less. AsVCC

rises, RESET stays LOW. When VCC rises above

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the reset threshold, an internal timer releasesever VCC dips below the reset threshold, such asin a brownout condition. When a brownoutcondition occurs in the middle of a previouslyinitiated reset pulse, the pulse continues for atleast another 140ms. During power-down, onceVCCstays LOW and is guaranteed to be 0.4V or lessuntil VCC drops below 1V.

The active-HIGH RESET output is simplyguaranteed to be valid with VCC down to 1.1V.Some µPs, such as Intel's 80C51, require anactive-HIGH reset pulse.Watchdog Timer

The SP706P/R/S/T-SP708R/S/T series watchdogcircuit monitors the µP's activity. If the µP doesnot toggle the watchdog input (WDI) within 1.6input is tri-stated, the watchdog timer will stayis released and WDI is driven HIGH or LOW,the timer will start counting. Pulses as short as50ns can be detected.

non-maskable interrupt input (NMI) of a µP.When VCCwill go LOW independent of the current statusof the watchdog timer. Normally this wouldneously, and thus overrides the NMI.a low-line output. Since floating WDI disablesVCC falls below the reset threshold, thusfunctioning as a low-line output.Power-Fail Comparator

The power-fail comparator can be used forvarious purposes because its output andnoninverting input are not internally connected.The inverting input is internally connected toa 1.25V reference.

Rev. 10-17-00 SP706 +3.0/ +3.3 Low Power Microprocessor Circuits © Copyright 2000 Sipex Corporation

复位芯片资料

Manual Reset

To build an early-warning circuit for powerfailure, connect the PFI pin to a voltage divideras shown in Figure 16. Choose the voltagedivider ratio so that the voltage at PFI fallsbelow 1.25V just before the +5V regulator dropsµP so it can preparefor an orderly power-down.

be triggered by a pushbutton switch. The switchis effectively debounced by the 140msCMOS logic compatible, so it can be driven bya watchdog timeout to generate a RESET pulsein the SP706P/R/S/T-SP708R/S/T series.Shown.

Rev. 10-17-00 SP706 +3.0/ +3.3 Low Power Microprocessor Circuits © Copyright 2000 Sipex Corporation

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复位芯片资料

Ensuring a Valid RESET Output Down toVCC = 0V

When VCClonger sinks current, it becomes an open circuit.High-impedance CMOS logic inputs can drift toundetermined voltages if left undriven. If a pull-stray charge or leakage currents will be shuntedvalue is not critical. It should be about 100K ,Monitoring Voltages Other Than theUnregulated DC Input

Monitor voltages other than the unregulated DCby connecting a voltage divider to PFI andadjusting the ratio appropriately. If required,add hysteresis by connecting a resistor (with avalue approximately 10 times the sum of thetwo resistors in the potential divider network)and GND will reduce the power-fail circuit'ssensitivity to high-frequency noise on themonitor voltages other than the +3.3V/+3.0V

VCCRESET pulse when PFI drops below 1.25V.Figure 17 shows the SP706R/S/T-SP708R/+3.3V/+3.0V supply falls below the RESETthreshold, or when the +12V supply falls belowapproximately 11V.

Monitoring a Negative Voltage SupplyThe power-fail comparator can also monitor anegative supply rail, shown in Figure 18.When the negative rail is good (a negativevoltage of large magnitude), PFO is LOW. Byadding the resistors and transistor as shown, aHIGH PFO triggers RESET. As long as PFOremains HIGH, the SP706P/R/S/T-SP708R/S/T series will keep RESET asserted (wherethis circuit's accuracy depends on the PFIthreshold tolerance, the VCC line, and the resis-tors.

Interfacing to mPs with BidirectionalRESET Pins

µPs with bidirectional RESET pins, such as theMotorola 68HC11 series, can contend with thePower Supplies

Rev. 10-17-00 SP706 +3.0/ +3.3 Low Power Microprocessor Circuits © Copyright 2000 Sipex Corporation

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复位芯片资料

output is driven HIGH and the µP wants to pullit LOW, indeterminate logic levels may result.

To correct this, connect a 4.7k resistorµP resetI/O, as shown if Figure 19. Buffer theNegative-Going VCC Transients

While issuing resets to the µP during power-up,power-down, and brownout conditions, thesesupervisors are relatively immune to short-duration negative-going VCC transients (glitches).It is usually undesirable to reset the µP when VCCexperiences only small glitches.

Figure 20 shows maximum transient dura-tion vs. reset-comparator overdrive, for whichreset pulses are not generated. The data was gen-erated using negative-going VCC pulses, startingat 3.3V and ending below the reset threshold by

the magnitude indicated (reset comparator over-drive). The graph shows the maximum pulsewidth a negative-going VCC transient maytypically have without causing a reset pulse tobe issued. As the amplitude of the transientincreases (i.e. goes farther below the resetthreshold), the maximum allowable pulse widthdecreases. Typically, a VCC transient that goes100mV below the reset threshold and lasts for40µs or less will not cause a reset pulse to beissued. A 100nF bypass capacitor mounted closeto the VCC pin provides additional transientimmunity.Applications

The SP706P/R/S/T-SP708R/S/T series offersunmatched performance and the lowest powerconsumption for these industry standard de-vices. Refer to Figures 21 and 22 for supplycurrent performance characteristics rated againsttemperature and supply voltages.

Figure 18. Monitoring a Negative Voltage Supply

Figure 19. Interfacing to Microprocessors with

Bidirectional RESET I/O for the SP706

Rev. 10-17-00 SP706 +3.0/ +3.3 Low Power Microprocessor Circuits © Copyright 2000 Sipex Corporation

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复位芯片资料

Causing a Reset Pulse vs. Reset Comparator Overdrive

Rev. 10-17-00 SP706 +3.0/ +3.3 Low Power Microprocessor Circuits © Copyright 2000 Sipex Corporation

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复位芯片资料

Rev. 10-17-00 SP706 +3.0/ +3.3 Low Power Microprocessor Circuits © Copyright 2000 Sipex Corporation

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复位芯片资料

Rev. 10-17-00 SP706 +3.0/ +3.3 Low Power Microprocessor Circuits © Copyright 2000 Sipex Corporation

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复位芯片资料

Rev. 10-17-00 SP706 +3.0/ +3.3 Low Power Microprocessor Circuits © Copyright 2000 Sipex Corporation

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复位芯片资料

ORDERING INFORMATION

SP706PCP.....................................................................................0°C to +70°C...................................................................................8–pin PDIPSP706PCN.....................................................................................0°C to +70°C................................................................................8–pin NSOICSP706PCU.....................................................................................0°C to +70°C.................................................................................8-pin µSOICSP706RCP.....................................................................................0°C to +70°C...................................................................................8–pin PDIPSP706RCN.....................................................................................0°C to +70°C................................................................................8–pin NSOICSP706RCU.....................................................................................0°C to +70°C.................................................................................8-pin µSOICSP706SCP.....................................................................................0°C to +70°C...................................................................................8–pin PDIPSP706SCN.....................................................................................0°C to +70°C................................................................................8–pin NSOICSP706SCU.....................................................................................0°C to +70°C.................................................................................8-pin µSOICSP706TCP.....................................................................................0°C to +70°C...................................................................................8–pin PDIPSP706TCN.....................................................................................0°C to +70°C................................................................................8–pin NSOICSP706TCU.....................................................................................0°C to +70°C.................................................................................8-pin µSOICSP706PEP...................................................................................SP706PEN...................................................................................SP706PEU...................................................................................SP706REP...................................................................................SP706REN...................................................................................SP706REU...................................................................................SP706SEP...................................................................................SP706SEN...................................................................................SP706SEU...................................................................................SP706TEP...................................................................................SP706TEN...................................................................................SP706TEU...................................................................................

-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-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

.................................................................................8–pin PDIP..............................................................................8–pin NSOIC...............................................................................8-pin µSOIC.................................................................................8–pin PDIP..............................................................................8–pin NSOIC...............................................................................8-pin µSOIC.................................................................................8–pin PDIP..............................................................................8–pin NSOIC...............................................................................8-pin µSOIC.................................................................................8–pin PDIP..............................................................................8–pin NSOIC...............................................................................8-pin µSOIC

SP708RCP.....................................................................................0°C to +70°CSP708RCN.....................................................................................0°C to +70°CSP708RCU.....................................................................................0°C to +70°CSP708SCP.....................................................................................0°C to +70°CSP708SCN.....................................................................................0°C to +70°CSP708SCU.....................................................................................0°C to +70°CSP708TCP.....................................................................................0°C to +70°CSP708TCN.....................................................................................0°C to +70°CSP708TCU.....................................................................................0°C to +70°CSP708REP...................................................................................SP708REN...................................................................................SP708REU...................................................................................SP708SEP...................................................................................SP708SEN...................................................................................SP708SEU...................................................................................SP708TEP...................................................................................SP708TEN...................................................................................SP708TEU...................................................................................

...................................................................................8–pin PDIP................................................................................8–pin NSOIC.................................................................................8-pin µSOIC...................................................................................8–pin PDIP................................................................................8–pin NSOIC.................................................................................8-pin µSOIC...................................................................................8–pin PDIP................................................................................8–pin NSOIC.................................................................................8-pin µSOIC.................................................................................8–pin PDIP..............................................................................8–pin NSOIC...............................................................................8-pin µSOIC.................................................................................8–pin PDIP..............................................................................8–pin NSOIC...............................................................................8-pin µSOIC.................................................................................8–pin PDIP..............................................................................8–pin NSOIC...............................................................................8-pin µSOIC

-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-40°C to +85°C-40°C to +85°C-40°C to +85°C

Please consult the factory for pricing and availability on a Tape-On-Reel option.

Sipex CorporationHeadquarters andSales Office22 Linnell CircleBillerica, MA 01821TEL: (978) 667-8700FAX: (978) 670-9001e-mail: sales@http://www.77cn.com.cnSales Office

233 South Hillview DriveMilpitas, CA 95035TEL: (408) 934-7500FAX: (408) 935-7600

Sipex Corporation reserves the right to make changes to any products described herein. Sipex does not assume any liability arising out of theapplication or use of any product or circuit described herein; neither does it convey any license under its patent rights nor the rights of others.Rev. 10-17-00 SP706 +3.0/ +3.3 Low Power Microprocessor Circuits © Copyright 2000 Sipex Corporation

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