HZHY-AL200-硬件设计-数据手册-alm92

SNIS110D–MARCH2000–REVISEDMARCH±0.33°CAccurate,12-Bit+SignTemperatureSensorandThermalWindowComparatorWithTwo-WireInterfaceCheckforSamples: WindowComparisonSimplifiesDesignofACPI-CompatibleTemperatureMonitoringand

TheLM92isadigitaltemperaturesensorandthermalwindowcomparatorwithanI2C™SerialBusinterfaceandanaccuracyof±0.33°C.Thewindow-comparatorarchitectureoftheLM92easesthedesignSerialBus open-SeparateOpen-DrainOutputsforInterruptandCriticalTemperatureShutdownShutdownModetoMinimizePower

Interrupt(INT)outputbecomesactivewhenevertemperaturegoesoutsideaprogrammablewindow,whileaseparateCriticalTemperatureAlarm(T_CRIT_A)outputbecomesactivewhenthetemperatureexceedsaprogrammablecriticalUptoFourLM92scanbeConnectedto TheINToutputcanoperateineitheracomparatorSingle eventmode,whiletheT_CRIT_Aoutputoperates12-Bit+SignOperationupto

comparatormodeThehostcanprogramboththeupperandlowerlimitsofthewindowaswellasthecriticaltemperaturelimit.ProgrammableHysteresisaswellasafaultqueueareavailabletominimizefalsetripping.Twopins(A0,A1)areavailableforaddressselection.TheMedical powersupwithdefaultthresholdsof2°CTHYST,ElectronicTestSystemThermalPersonalOffice

TLOW,64°CTHIGH,and80°CTheLM92's2.7Vto5.5Vsupplyvoltagerange,SerialBusinterface,12-bit+signoutput,andfull-scalerangeofover128°Cmakeitidealforawiderangeofapplications.Theseincludethermalmanagement test KEYSupplyVoltage2.7VtoSupplyCurrentoperating350μA(typ)625μA(max)shutdown5μA(typ)Temperature–30°C,±0.33°C–10°Cto50°C,±0.50°C–−10°Cto85°C,±1.0°C–125°C,±1.25°C–−25°Cto150°C,±1.5°CLinearity±0.5°CResolution

automotive,medicalandHVACPleasebeawarethatanimportantnoticeconcerningavailability,standardwarranty,anduseincriticalapplicationsofTexasInstrumentssemiconductorproductsanddisclaimerstheretoappearsattheendofthisdatasheet.I2CisatrademarkofAllothertrademarksarethepropertyoftheirrespectivePRODUCTIONDATAinformationiscurrentasofpublication Copyright©2000–2013,TexasInstrumentsProductsconformtospecificationsperthetermsoftheInstrumentsstandardwarranty.Productionprocessingdoesnotnecessarilyincludetestingofallparameters.SNIS110D–SNIS110D–MARCH2000–REVISEDMARCHSNIS110DSNIS110D–MARCH2000–REVISEDMARCHSubmitSubmitDocumentationCopyright©2000–2013,TexasInstrumentsProductFolderLinks:SubmitDocumentationSubmitDocumentationCopyright©2000–2013,TexasInstrumentsProductFolderLinks:SimplifiedBlockConnection

PinTypical1PinTypical1SerialBi-DirectionalDataLine.OpenDrainFrom2SerialBusClockFrom3CriticalTemperatureAlarmOpenDrainPullUpResistor,ControllerInterruptLineorSystemHardwareShutdown4PowerSupply5InterruptOpenDrainPullUpResistor,ControllerInterrupt+V8PositiveSupplyVoltageDCVoltagefrom2.7VtoUser-SetAddressGround(Low,“0”)or+VS(High,TypicalFigureThesedeviceshavelimitedbuilt-inESDprotection.TheleadsshouldbeshortedtogetherorthedeviceplacedinconductivefoamduringstorageorhandlingtopreventelectrostaticdamagetotheMOSgates.AbsoluteMaximumRatingsSupply−0.3VtoVoltageatany−0.3Vto(+VS+InputCurrentatany5PackageInputCurrent20T_CRIT_AandINTOutputSink10T_CRIT_AandINTOutputStorage−65°CtoESDSusceptibilityHumanBodyMachineSolderingprocessmustcomplywithReflowTemperatureProfilespecifications.RefertoAbsoluteMaximumRatingsindicatelimitsbeyondwhichdamagetothedevicemayoccur.DCandACelectricalspecificationsdonotapplywhenoperatingthedevicebeyonditsratedoperatingconditions.Whentheinputvoltage(VI)atanypinexceedsthepowersupplies(VI<GNDorVI>+VS)thecurrentatthatpinshouldbelimitedto5mA.The20mAmaximumpackageinputcurrentratinglimitsthenumberofpinsthatcansafelyexceedthepowersupplieswithaninputcurrentof5mAtofour.Humanbodymodel,100pFdischargedthrougha1.5kΩresistor.Machinemodel,200pFdischargeddirectlyintoeachReflowtemperatureprofilesaredifferentforlead-freeandnon-lead-freeOperatingRatings(1)SpecifiedTemperatureRange(3),TMINto−55°CtoSupplyVoltageRange+2.7VtoAbsoluteMaximumRatingsindicatelimitsbeyondwhichdamagetothedevicemayoccur.DCandACelectricalspecificationsdonotapplywhenoperatingthedevicebeyonditsratedoperatingconditions.LM92θJA(thermalresistance,junction-to-ambient)whenattachedtoaprintedcircuitboardwith2oz.foilis200WhiletheLM92hasafull-scale-rangeinexcessof128°C,prolongedoperationattemperaturesabove125°CisnotElectricalCharacteristicsTemperature-to-DigitalConverterUnlessotherwisenoted,thesespecificationsapplyfor+VS=+2.7Vto+5.5VforLM92CIM.BoldfacelimitsapplyforTA==TMINtoTMAX;allotherlimitsTA=TJ=+25°C,unlessotherwiseAccuracy(Thisisasummary.Formoredetailedinformationpleasesee(3))TA=+30°C,+VS=3.3Vto°CTA=10°Cor+50°C,+VS=3.3VtoTA=−10°Cor+85°C,+VS=toTA=+125°C,+VS=TA=−25°Cto150°C,+VS=Linearity°COffsetErrorofTransferFunction+VS=°COffsetErrorofTransferFunctionSupply2.7V≤+VS<°C/V3.6V≤+VS≤°C/VTemperatureConversionQuiescentI2CI2CmAShutdown5THYSTDefaultTLOWDefaultTHIGHDefaultTCDefaultTypicalvaluesareatTA=25°CandrepresentmostlikelyparametricLimitsareguaranteedtoTI'sAOQL(AverageOutgoingQualityThelimitsfoundinTable1supersedethelimitsshownintheElectricalCharacteristicsTable.TheAccuracyspecificationincludeserrorsduetolinearity,offsetandgain.Theaccuracyspecificationincludeseffectsofselfheatingwithnegligibledigitaloutputloading.Pull-upresistorsshouldbemaximized(10ktypicalrecommended),sothatselfheatingduetodigitaloutputloadingisnegligible.LimitsatintermediatetemperaturescanbecalculatedusingastraightlineinterpolationasshowninFigure2andFigureLinearityErrorisdefinedastheworsecasedifferenceofanactualreadingtothatofacalculatedreadingderivedfromthestraightlinewhoseendpointsaremeasuredat30°Cand125°Cfortherangeof30°Cto125°Corwhoseendpointsaremeasuredat30°Cand−25°Cfortherangeof30°CtoOffsetErrorcalibrationshouldbedoneat30°C.TheresidualerrorofthetransferfunctionisthenequivalenttotheAccuracyLimitminustheOffsetLimit.Thisdoesnottakeintoaccountthepowersupplysensitivityoftheoffseterror.Nor,doesittakeintoaccounttheerrorintroducedbythecalibrationsystemused.Thisspecificationisprovidedonlytoindicatehowoftentemperaturedataisupdated.TheLM92canbereadatanytimewithoutregardtoconversionstate(andwillyieldlastconversionresult).Ifaconversionisinprocessitwillbeinterruptedandrestartedaftertheendoftheread.12bits+sign,two'sDefaultvaluessetatpowerFigure2.AccuracyvsTemperaturewith+Vs=Figure3.AccuracyvsTemperaturewith+Vs=Table1.TemperatureAccuracyParameterTA=°CTA=°CTA=°CTA=°CTA=°CTA=°CTA=°CTA=°CTA=°CDigitalDCUnlessotherwisenoted,thesespecificationsapplyfor+VS=+2.7Vto+5.5VforLM92CIM.BoldfacelimitsapplyforTA==TMINtoTMAX;allotherlimitsTA=TJ=+25°C,unlessotherwiseVSDAandSCLLogical“1”Input+VS×VVVSDAandSCLLogical“0”InputV+VS×VSDAandSCLDigitalInputmVVA0andA1Logical“1”InputVVVA0andA1Logical“0”InputVVILogical“1”InputVIN=+µAILogical“0”InputVIN=0µACCapacitanceofAllDigitalIHighLevelOutputVOH=+µAVLowLevelOutputIOL=3VTypicalvaluesareatTA=25°CandrepresentmostlikelyparametricLimitsareguaranteedtoTI'sAOQL(AverageOutgoingQualityDigitalDCCharacteristicsUnlessotherwisenoted,thesespecificationsapplyfor+VS=+2.7Vto+5.5VforLM92CIM.BoldfacelimitsapplyforTA==TMINtoTMAX;allotherlimitsTA=TJ=+25°C,unlessotherwiseT_CRIT_AOutputSaturationIOUT=4.0VT_CRIT_A1tOutputFallCL=400nsIO=3Forbestaccuracy,minimizeoutputloading.10kpull-upsresistorsshouldbesufficient.Highersinkcurrentscanaffectsensoraccuracywithinternalheating.Thiscancauseanerrorof0.64°Catfullratedsinkcurrentandsaturationvoltagebasedonjunction-to-ambientthermalresistance.SerialBusDigitalSwitchingUnlessotherwisenoted,thesespecificationsapplyfor+VS=+2.7Vto+5.5VforLM92CIM.BoldfacelimitsapplyforTA==TMINtoTMAX;allotherlimitsTA=TJ=+25°C,unlessotherwisenoted.CL(loadcapacitance)onoutputlines=80pFunlessotherwisespecified.BoldfacelimitsapplyforTA=TJ=TMINtoTMAX;allotherlimitsTA=TJ=+25°C,unlessotherwiseLimits(2)tSCL(Clock)1tDatainSet-UpTimetoSCLtDataOutStableafterSCL0tSDALowSet-UpTimetoSCLLow(StarttSDAHighHoldTimeafterSCLHigh(StopSDAandSCLTimeLowforResetofSerialInterfacems(min)msTypicalvaluesareatTA=25°CandrepresentmostlikelyparametricLimitsareguaranteedtoTI'sAOQL(AverageOutgoingQualityTimingspecificationsaretestedatthebusinputlogiclevels(Vin(0)=0.3xVAforafallingedgeandVin(1)=0.7xVAforarisingedge)whentheSCLandSDAedgeratesaresimilar.HoldingtheSDAand/orSCLlinesLowforatimeintervalgreaterthantTIMEOUTwillcausetheLM92toresetSCLandSDAtotheIDLEstateoftheserialbuscommunication(SDAandSCLsetHigh).Figure4.SerialBusFigure5.Temperature-to-DigitalTransferFunction(Non-linearscaleforFUNCTIONALTheLM92temperaturesensorincorporatesaband-gaptypetemperaturesensor,13-bitADC,andadigitalcomparatorwithuser-programmableupperandlowerlimitvalues.ThecomparatoractivateseithertheINTlinefortemperaturesoutsidetheTLOWandTHIGHwindow,ortheT_CRIT_AlinefortemperatureswhichexceedT_CRIT.Thelinesareprogrammableformodeandpolarity.TEMPERATURELM92providesawindowcomparisonagainstalower(TLOW)andupper(THIGH)trippoint.Aseconduppertrippoint(T_CRIT)functionsasacriticalalarmshutdown.Figure7depictsthecomparisonfunctionaswellasthemodesofoperation.StatusTheinternalStatusbitsoperateas“True”:TemperatureaboveaTHIGHorT_CRITis“true”forthoserespectivebits.A“true”forTLOWistemperaturebelowTLOW.“False”:AssumingtemperaturehaspreviouslycrossedaboveTHIGHorT_CRIT,thenthetemperaturemustdropbelowthepointscorrespondingTHYST(THIGH−THYSTorT_CRIT−THYST)inorderfortheconditiontobefalse.ForTLOW,assumingtemperaturehaspreviouslycrossedbelowTLOW,a“false”occurswhentemperaturegoesaboveTLOW+THYST.TheStatusbitsarenotaffectedbyreadsoranyotheractions,andalwaysrepresentthestateoftemperaturevs.HardwireTheT_CRIT_AhardwireoutputmirrorstheT_CRIT_Aflag,whentheflagistrue,theT_CRIT_Aoutputisassertedatalltimesregardlessofmode.ReadingtheLM92hasnoeffectontheT_CRIT_Aoutput,althoughtheinternalconversionisrestarted.ThebehavioroftheINThardwireoutputisasComparatorInterruptMode(Default):Userreadingpartresetsoutputuntilnextmeasurementcompletes.Ifconditionisstilltrue,outputissetagainatendofnextconversioncycle.Forexample,ifauserneverreadsthepart,andtemperaturegoesbelowTLOWthenINTbecomesactive.ItwouldstaythatwayuntiltemperaturegoesaboveTLOW+THYST.Howeveriftheuserreadsthepart,theoutputwouldbereset.Attheendofthenextconversioncycle,iftheconditionistrue,itissetagain.Ifnot,itremainsreset.EventInterruptMode:Userreadingpartresetsoutputuntilnextcondition"event"occurs(inotherwords,outputisonlysetonceforatruecondition,ifresetbyaread,itremainsresetuntilthenexttriggeringthresholdhasbeencrossed).Conversely,ifauserneverreadthepart,theoutputwouldstaysetindefinitelyafterthefirsteventthatsettheoutput.An“event”forEventInterruptModeisdefinedas:Transitioningupwardacrossasetpoint,Transitioningdownwardacrossasetpoint'scorrespondinghysteresis(afterhavingexceededthatForexample,ifauserneverreadthepart,andtemperaturewentbelowTLOWthenINTwouldbecomeactive.Itwouldstaythatwayforeverifauserneverreadthepart.Howeveriftheuserreadthepart,theoutputwouldbereset.Eveniftheconditionistrue,itwillremainreset.ThetemperaturemustcrossaboveTLOW+THYSTtosettheoutputagain.Ineithermode,readinganyregisterintheLM92restartstheconversion.ThisallowsadesignertoknowexactlywhentheLM92beginsacomparison.ThispreventsunnecessaryInterruptsjustafterreprogrammingsetpoints.Typically,systemInterruptinputsaremaskedpriortoreprogrammingtrippoints.Bydoingareadjustafterresettingtrippoints,butpriortounmasking,unexpectedInterruptsareprevented.Avoidprogrammingsetpointssoclosethattheirhysteresisvaluesoverlap.AnexamplewouldbethatwithaTHYSTvalueof2°CthensettingTHIGHandTLOWtowithin4°Cofeachotherwillviolatethisrestriction.Tobemorespecific,withTHYSTsetto2°CassumeTHIGHsetto64°C.IfTLOWissetequalto,orhigherthan60°Cthisrestrictionisviolated.DEFAULTTheLM92alwayspowersupinaknownstate.LM92powerupdefaultconditionsComparatorInterruptTLOWsetto10THIGHsetto64T_CRITsetto80THYSTsetto2INTandT_CRIT_AactivePointersetto“00”;TemperatureTheLM92registerswillalwaysresettothesedefaultvalueswhenthepowersupplyvoltageisbroughtupfromzerovoltsasthesupplycrossesthevoltagelevelplottedinthefollowingcurve.TheLM92registerswillresetagainwhenthepowersupplydropsbelowthevoltageplottedinthiscurve.Figure6.AveragePoweronResetVoltagevsSERIALBUSTheLM92operatesasaslaveontheSerialBus,sotheSCLlineisaninput(noclockisgeneratedbytheLM92)andtheSDAlineisabi-directionalserialdataline.AccordingtoSerialBusspecifications,theLM92hasa7-bitslaveaddress.ThefivemostsignificantbitsoftheslaveaddressarehardwiredinsidetheLM92andare“10010”.ThetwoleastsignificantbitsoftheaddressareassignedtopinsA1–A0,andaresetbyconnectingthesepinstogroundforalow,(0);orto+VSforahigh,(1).Therefore,thecompleteslaveaddress10010Note:EventInterruptmodeisdrawnasiftheuserisreadingthepart.Iftheuserdoesn'tread,theoutputswouldgolowandstaythatwayuntiltheLM92isread.ComparatorInterruptModeisdrawnasiftheuserneverreadsthepart.Iftheuserdoesread,theoutputswillgohighoncereadinstructionisexecutedand,ifthefaultconditionstillexists,golowattheendofthenextconversion.Figure7.TemperatureResponseTEMPERATUREDATATemperaturedatacanbereadfromtheTemperatureandSetPointregisters;andwrittentotheSetPointregisters.Temperaturedatacanbereadatanytime,althoughreadingfasterthantheconversiontimeoftheLM92willpreventdatafrombeingupdated.Temperaturedataisrepresentedbya13-bit,two'scomplementwordwithanLSB(LeastSignificantBit)equalto0.0625°C:Table2.TemperatureDataDigital01000001008+12500111110107+8000101000005+6400100000004+2500001100101+1000000101000+200000001000Table2.TemperatureDataOutputDigital+0.062500000000000000000000−0.06251111111111F−251111001111E−551110010011CSHUTDOWNShutdownmodeisenabledbysettingtheshutdownbitintheConfigurationregisterviatheSerialBus.Shutdownmodereducespowersupplycurrentto5µAtypical.T_CRIT_Aisresetifpreviouslyset.Sinceconversionsarestoppedduringshutdown,T_CRIT_AandINTwillnotbeoperational.TheSerialBusinterfaceremainsactive.ActivityontheclockanddatalinesoftheSerialBusmayslightlyincreaseshutdownmodequiescentcurrent.Registerscanbereadfromandwrittentoinshutdownmode.TheLM92takesmillisecondstorespondtotheshutdowncommand.INTANDT_CRIT_ATheINTandT_CRIT_Aoutputsareopen-drainoutputsanddonothaveinternalpull-ups.A"high"levelwillnotbeobservedonthesepinsuntilpull-upcurrentisprovidedfromsomeexternalsource,typicallyapull-upresistor.Choiceofresistorvaluedependsonmanysystemfactorsbut,ingeneral,thepull-upresistorshouldbeaslargeaspossible.ThiswillminimizeanyerrorsduetointernalheatingoftheLM92.Themaximumresistanceofthepullup,basedonLM92specificationforHighLevelOutputCurrent,toprovidea2volthighlevel,is30Kohms.FAULTAfaultqueueof4faultsisprovidedtopreventfalsetrippingwhentheLM92isusedinnoisyenvironments.The4faultsmustoccurconsecutivelytosetflagsaswellasINTandT_CRIT_Aoutputs.Thefaultqueueisenabledbysettingbit4oftheConfigurationRegisterhigh(seeCONFIGURATIONREGISTER).INTERNALREGISTERFigureTherearefourdataregistersintheLM92,selectedbythePointerregister.Atpower-upthePointerissetto“00”;thelocationfortheTemperatureRegister.ThePointerregisterlatchesthelastlocationitwassetto.InInterruptMode,areadfromtheLM92resetstheINToutput.PlacingthedeviceinShutdownmoderesetstheINTandT_CRIT_Aoutputs.Allregistersarereadandwrite,excepttheTemperatureregisterwhichisreadonly.AwritetotheLM92willalwaysincludetheaddressbyteandthePointerbyte.AwritetotheConfigurationregisterrequiresonedatabyte,whiletheTLOW,THIGH,andT_CRITregistersrequiretwodatabytes.ReadingtheLM92cantakeplaceeitheroftwoways:IfthelocationlatchedinthePointeriscorrect(mostofthetimeitisexpectedthatthePointerwillpointtotheTemperatureregisterbecauseitwillbethedatamostfrequentlyreadfromtheLM92),thenthereadcansimplyconsistofanaddressbyte,followedbyretrievingthecorrespondingnumberofdatabytes.IfthePointerneedstobeset,thenanaddressbyte,pointerbyte,repeatstart,andanotheraddressbyteplusrequirednumberofdatabyteswillaccomplisharead.Thefirstdatabyteisthemostsignificantbytewithmostsignificantbitfirst,permittingonlyasmuchdataasnecessarytobereadtodeterminethetemperaturecondition.Forinstance,ifthefirstfourbitsofthetemperaturedataindicatesacriticalcondition,thehostprocessorcouldimmediatelytakeactiontoremedytheexcessivetemperature.Attheendofaread,theLM92canaccepteitherAcknowledgeorNoAcknowledgefromtheMaster(NoAcknowledgeistypicallyusedasasignalfortheslavethattheMasterhasreaditslastbyte).Aninadvertent8-bitreadfroma16-bitregister,withtheD7bitlow,cancausetheLM92tostopinastatewheretheSDAlineisheldlowasshowninFigure9.Thiscanpreventanyfurtherbuscommunicationuntilatleast9additionalclockcycleshaveoccurred.Alternatively,themastercanissueclockcyclesuntilSDAgoeshigh,atwhichtimeissuinga“Stop”conditionwillresettheLM92.Figure9.Inadvertent8-BitReadfrom16-BitRegisterwhereD7isZeroPOINTER(Selectswhichregisterswillbereadfromorwritten00000RegisterP0–P2:Register000Temperature(Readonly)(Power-up001Configuration010THYST011T_CRIT100TLOW101THIGH111Manufacturer'sP3–P7:MustbekeptTEMPERATURETable3.(ReadBitBitBitBitBitBitBitBitBitBitBitStatusD0–D2:StatusD3–D15:TemperatureData.OneLSB=0.0625°C.Two'scomplementCONFIGURATIONTable4.000FaultINTINTD0:Shutdown-Whensetto1theLM92goestolowpowershutdownmode.Powerupdefaultof“0”.D1:Interruptmode-0isComparatorInterruptmode,1isEventInterruptmode.Powerupdefaultof“0”.D2,D3:T_CRIT_AandINTPolarity-0isactivelow,1isactivehigh.Outputsareopen-drain.Powerupdefaultof“0”D4:FaultQueue-Whensetto1theFaultQueueisenabled,seeFAULTQUEUE.Powerupdefaultof“0”.D5–D7:Thesebitsareusedforproductiontestingandmustbekeptzerofornormaloperation.THYST,TLOW,THIGHANDT_CRIT_ATable5.BitBitBitBitBitBitBitBitXXXD0–D2:D3–D15:THYST,TLOW,THIGHorT_CRITTripTemperatureData.PowerupdefaultisTLOW=10°C,THIGH=64°C,T_CRIT=80°C,THYST=2°C.THYSTissubtractedfromTHIGH,andT_CRIT,andaddedtoAvoidprogrammingsetpointssoclosethattheirhysteresisvaluesoverlap.SeeTEMPERATUREManufacturer'sIdentificationTable6.(Read1000000000000001D0–D15:ManufacturesI2CTIMINGFigure10.Typical2-ByteReadFromPresetPointerLocationSuchasTemporComparisonFigure11.TypicalPointerSetFollowedbyImmediateReadfor2-ByteRegistersuchasTemporComparisonRegistersFigure12.Typical1-ByteReadfromConfigurationRegisterwithPresetFigure13.TypicalPointerSetFollowedbyImmediateReadfromConfigurationFigure14.ConfigurationRegisterFigure15.ComparisonRegisterAPPLICATIONThetemperatureresponsegraphinFigure16depictsatypicalapplicationdesignedtomeetACPIrequirements.Inthistypeofapplication,thetemperaturescaleisgivenanarbitraryvalueof"granularity",orthewindowwithinwhichtemperaturenotificationeventsshouldoccur.TheLM92canbeprogrammedtothewindowsizechosenbythedesigner,andwillissueinterruptstotheprocessorwheneverthewindowlimitshavebeencrossed.Theinternalflagspermitquickdeterminationofwhetherthetemperatureisrisingorfalling.TheT_CRITlimitwouldtypicallyuseitsseparateoutputtoactivatehardwareshutdowncircuitryseparatefromtheprocessor.Thisisdonebecauseitisexpectedthatiftemperaturehasgottenthishighthattheprocessormaynotberesponding.Theseparatecircuitrycanthenshutdownthesystem,usuallybyshuttingdownthepowerNotethattheINTandT_CRIT_Aoutputsareseparate,butcanbewire-ORedtogether.AlternativelytheT_CRIT_AcanbediodeORedtotheINTlineinsuchawaythataT_CRIT_AeventactivatestheINTline,butanINTeventdoesnotactivatetheT_CRIT_Aline.ThismaybeusefulintheeventthatitisdesirabletonotifyboththeprocessorandseparateT_CRIT_Ashutdowncircuitryofacriticaltemperaturealarmatthesametime(maybetheprocessorisstillworkingandcancoordinateagracefulshutdownwiththeseparateshutdownToimplementACPIcompatiblesensingitisnecessarytosensewheneverthetemperaturegoesoutsidethewindow,issueaninterrupt,servicetheinterrupt,andreprogramthewindowaccordingtothedesiredgranularityofthetemperaturescale.Thereprogrammedwindowwillnowhavethecurrenttemperatureinsideit,readytoissueaninterruptwheneverthetemperaturedeviatesfromthecurrentwindow.Tounderstandthisgraph,assumethatatthelefthandsidethesystemisatsomenominaltemperature.Forthe1steventtemperaturerisesabovetheupperwindowlimit,THIGH,causingINTtogoactive.ThesystemrespondstotheinterruptbyqueryingtheLM92'sstatusbitsanddeterminesthatTHIGHwasexceeded,indicatingthattemperatureisrising.Thesystemthenprogramsthetemperaturelimitstoavaluehigherbyanamountequaltothedesiredgranularity.NotethatinEventInterruptMode,reprogrammingthelimitshascausedasecond,known,interrupttobeissuedsincetemperaturehasbeenreturnedwithinthewindow.InComparatorInterruptMode,theLM92simplystopsissuinginterrupts.The2ndeventisanotheridenticalriseintemperature.The3rdeventistypicalofadropintemperature.ThisisoneoftheconditionsthatdemonstratesthepoweroftheLM92,astheuserreceivesnotificationthatalowerlimitisexceededinsuchawaythattemperatureisdropping.TheCriticalAlarmEventactivatestheseparateT_CRIT_Aoutput.Typically,thiswouldfeedcircuitryseparatefromtheprocessorontheassumptionthatifthesystemreachedthistemperature,theprocessormightnotbeNote:EventInterruptmodeisdrawnasiftheuserisreadingthepart.Iftheuserdoesn'tread,theoutputswouldgolowandstaythatwayuntiltheLM92isread.Figure16.TemperatureResponseDiagramforACPITypicalFigure17.TypicalFigure18.RemoteHVACtemperaturesensorcommunicatesvia3wires,includingthermostatFigure19.ACPICompatibleTerminalAlarmBypoweringtheLM92fromauxiliaryoutputofthepowersupply,anon-functioningoverheatedcomputercanbepowereddowntopreserveasmuchofthesystemaspossible.REVISIONChangesfromRevisionC(March2013)toRevision ChangedlayoutofNationalDataSheettoTI PACKAGEOPTION 1-Nov-PACKAGINGOrderablePackageEcoLead/BallMSLPeakOpTempDeviceD8CallCall-55toD8Green(RoHS&noSb/Br)CULevel-1-260C--55toD8CallCall-55toD8Green(RoHS&noSb/Br)CULevel-1-260C--55to(1)ThemarketingstatusvaluesaredefinedasACTIVE:ProductdevicerecommendedfornewLIFEBUY:TIhasannouncedthatthedevicewillbediscontinued,andalifetime-buyperiodisinNRND:Notrecommendedfornewdesigns.Deviceisinproductiontosupportexistingcustomers,butTIdoesnotrecommendusingthispartinanewPREVIEW:Devicehasbeenannouncedbutisnotinproduction.SamplesmayormaynotbeOBSOLETE:TIhasdiscontinuedtheproductionofthe(2)EcoPlan-Theplannedeco-friendlyclassification:Pb-Free(RoHS),Pb-Free(RoHSExempt),orGreen(RoHS&noSb/Br)-pleasecheck/productcontentforthelatestavailabilityinformationandadditionalproductcontentdetails.TBD:ThePb-Free/GreenconversionplanhasnotbeenPb-Free(RoHS):TI'sterms"Lead-Free"or"Pb-Free"meansemiconductorproductsthatarecompatiblewiththecurrentRoHSrequirementsforall6substances,includingtherequirementthatleadnotexceed0.1%byweightinhomogeneousmaterials.Wheredesignedtobesolderedathightemperatures,TIPb-Freeproductsaresuitableforuseinspecifiedlead-freeprocesses.Pb-Free(RoHSExempt):ThiscomponenthasaRoHSexemptionforeither1)lead-basedflip-chipsolderbumpsusedbetweenthedieandpackage,or2)lead-baseddieadhesiveusedbetweenthedieandleadframe.ThecomponentisotherwiseconsideredPb-Free(RoHScompatible)asdefinedabove.Green(RoHS&noSb/Br):TIdefines"Green"tomeanPb-Free(RoHScompatible),andfreeofBromine(Br)andAntimony(Sb)basedflameretardants(BrorSbdonotexceed0.1%byweightinhomogeneousmaterial)(3)MSL,PeakTemp.-TheMoistureSensitivityLevelratingaccordingtotheJEDECindustrystandardclassifications,andpeaksolder(4)Theremaybeaddition