LM50SOT-23Single-SupplyCentigradeTemperatureSensorFebruary2006
LM50
SOT-23Single-SupplyCentigradeTemperatureSensor
GeneralDescription
TheLM50isaprecisionintegrated-circuittemperaturesen-sorthatcansensea−40˚Cto+125˚Ctemperaturerangeusingasinglepositivesupply.TheLM50’soutputvoltageislinearlyproportionaltoCelsius(Centigrade)temperature(+10mV/˚C)andhasaDCoffsetof+500mV.Theoffsetallowsreadingnegativetemperatureswithouttheneedforanegativesupply.TheidealoutputvoltageoftheLM50rangesfrom+100mVto+1.75Vfora−40˚Cto+125˚Ctemperaturerange.TheLM50doesnotrequireanyexternalcalibrationortrimmingtoprovideaccuraciesof±3˚Catroomtemperatureand±4˚Coverthefull−40˚Cto+125˚Ctemperaturerange.TrimmingandcalibrationoftheLM50atthewaferlevelassurelowcostandhighaccuracy.TheLM50’slinearout-put,+500mVoffset,andfactorycalibrationsimplifycircuitryrequiredinasinglesupplyenvironmentwherereadingnega-tivetemperaturesisrequired.BecausetheLM50’squiescentcurrentislessthan130µA,self-heatingislimitedtoaverylow0.2˚Cinstillair.
Applications
nnnnnnnnn
ComputersDiskDrives
BatteryManagementAutomotiveFAXMachinesPrinters
PortableMedicalInstrumentsHVAC
PowerSupplyModules
Features
nnnnnnnnnnn
CalibrateddirectlyindegreeCelsius(Centigrade)Linear+10.0mV/˚Cscalefactor±2˚Caccuracyguaranteedat+25˚CSpecifiedforfull−40˚to+125˚CrangeSuitableforremoteapplications
Lowcostduetowafer-leveltrimmingOperatesfrom4.5Vto10VLessthan130µAcurrentdrain
Lowself-heating,lessthan0.2˚CinstillairNonlinearitylessthan0.8˚CovertempULRecognizedComponent
ConnectionDiagram
SOT-23
OrderNumberLM50BIM3LM50CIM3
01203001
DeviceTopMarkT5BT5CT5BT5C
SuppliedAs1000UnitsonTapeandReel
1000UnitsonTapeandReel
3000UnitsonTapeandReel
3000UnitsonTapeandReel
TopView
SeeNSPackageNumbermf03A
LM50BIM3XLM50CIM3X
©2006NationalSemiconductorCorporationDS012030www.national.com
元器件交易网www.cecb2b.com
LM50TypicalApplication
01203003
FIGURE1.Full-RangeCentigradeTemperatureSensor(−40˚Cto+125˚C)
www.national.com2
元器件交易网www.cecb2b.com
LM50AbsoluteMaximumRatings(Note1)
SupplyVoltageOutputVoltageOutputCurrentStorageTemperatureTJMAX,MaximumJunctionTemperatureESDSusceptibility(Note3):HumanBodyModelMachineModel
150˚C2000V250V
+12Vto−0.2V
(+VS+0.6V)to−1.0V
10mA
−65˚Cto+150˚C
OperatingRatings(Note1)
SpecifiedTemperatureRange:LM50CLM50B
OperatingTemperatureRangeθJA(Note4)
SupplyVoltageRange(+VS)
TMINtoTMAX−40˚Cto+125˚C−25˚Cto+100˚C−40˚Cto+150˚C
450˚C/W+4.5Vto+10V
SolderingprocessmustcomplywithNationalSemiconduc-tor’sReflowTemperatureProfilespecifications.Refertowww.national.com/packaging.(Note2)
ElectricalCharacteristics
Unlessotherwisenoted,thesespecificationsapplyforVS=+5VDCandILOAD=+0.5µA,inthecircuitofFigure1.BoldfacelimitsapplyforthespecifiedTA=TJ=TMINtoTMAX;allotherlimitsTA=TJ=+25˚C,unlessotherwisenoted.
Parameter
Conditions
Typical
Accuracy(Note6)
Nonlinearity(Note7)SensorGain(AverageSlope)OutputResistanceLineRegulation(Note8)
QuiescentCurrent(Note9)
ChangeofQuiescentCurrent(Note9)
TemperatureCoefficientofQuiescentCurrent
LongTermStability(Note10)
TJ=125˚C,for1000hours
Note1:AbsoluteMaximumRatingsindicatelimitsbeyondwhichdamagetothedevicemayoccur.DCandACelectricalspecificationsdonotapplywhenoperatingthedevicebeyonditsratedoperatingconditions.
Note2:Reflowtemperatureprofilesaredifferentforlead-freeandnon-lead-freepackages.
Note3:Humanbodymodel,100pFdischargedthrougha1.5kΩresistor.Machinemodel,200pFdischargeddirectlyintoeachpin.Note4:ThermalresistanceoftheSOT-23packageisspecifiedwithoutaheatsink,junctiontoambient.Note5:LimitsareguaranteedtoNational’sAOQL(AverageOutgoingQualityLevel).
Note6:Accuracyisdefinedastheerrorbetweentheoutputvoltageand10mv/˚Ctimesthedevice’scasetemperatureplus500mV,atspecifiedconditionsofvoltage,current,andtemperature(expressedin˚C).
Note7:Nonlinearityisdefinedasthedeviationoftheoutput-voltage-versus-temperaturecurvefromthebest-fitstraightline,overthedevice’sratedtemperaturerange.
Note8:Regulationismeasuredatconstantjunctiontemperature,usingpulsetestingwithalowdutycycle.Changesinoutputduetoheatingeffectscanbecomputedbymultiplyingtheinternaldissipationbythethermalresistance.Note9:QuiescentcurrentisdefinedinthecircuitofFigure1.
Note10:Forbestlong-termstability,anyprecisioncircuitwillgivebestresultsiftheunitisagedatawarmtemperature,and/ortemperaturecycledforatleast46hoursbeforelong-termlifetestbegins.Thisisespeciallytruewhenasmall(Surface-Mount)partiswave-soldered;allowtimeforstressrelaxationtooccur.Themajorityofthedriftwilloccurinthefirst1000hoursatelevatedtemperatures.Thedriftafter1000hourswillnotcontinueatthefirst1000hourrate.
LM50B
Limit(Note5)
LM50C
Typical
Limit(Note5)
Units(Limit)˚C(max)˚C(max)˚C(max)˚C(max)mV/˚C(min)mV/˚C(max)Ω(max)mV/V(max)mV/V(max)µA(max)µA(max)µA(max)µA/˚C˚C
TA=+25˚CTA=TMAXTA=TMIN±2.0±3.0
+3.0,−3.5
±0.8
+9.7+10.3
2000
+4.5V≤VS≤+10V+4.5V≤VS≤+10V+4.5V≤VS≤+10V
+1.0
4000
2000
±3.0±4.0±4.0±0.8
+9.7+10.34000
±0.8±1.2
1301802.0
+2.0
±0.8±1.2
1301802.0
±0.08±0.08
3www.national.com
元器件交易网www.cecb2b.com
LM50TypicalPerformanceCharacteristics
circuitboardasshowninFigure2.
ThermalResistanceJunctiontoAir
TogeneratethesecurvestheLM50wasmountedtoaprinted
ThermalTimeConstant
0120302101203022
ThermalResponseinStillAirwithHeatSink(Figure2)
ThermalResponseinStirredOilBathwithHeatSink
01203023
01203024
Start-UpVoltagevsTemperatureThermalResponseinStillAirwithoutaHeatSink
0120302501203026
www.national.com4
元器件交易网www.cecb2b.com
LM50TypicalPerformanceCharacteristicsTogeneratethesecurvestheLM50wasmountedtoaprinted
circuitboardasshowninFigure2.(Continued)
QuiescentCurrentvsTemperature(Figure1)
AccuracyvsTemperature
0120302701203028
NoiseVoltage
SupplyVoltagevsSupplyCurrent
01203029
01203030
Start-UpResponse
01203031
5www.national.com
元器件交易网www.cecb2b.com
LM50PrintedCircuitBoard
TemperatureRiseofLM50DuetoSelf-Heating
(ThermalResistance,θJA)
SOT-23noheatsink*
StillairMovingair
450˚C/W
SOT-23smallheatfin**
260˚C/W180˚C/W
*Partsolderedto30gaugewire.
**Heatsinkusedis1⁄2\"squareprintedcircuitboardwith2oz.foilwithpartattachedasshowninFigure2.
2.0CapacitiveLoads
01203019
FIGURE2.PrintedCircuitBoardUsedforHeatSinktoGenerateAllCurves.1⁄2\"SquarePrintedCircuitBoard
with2oz.FoilorSimilar
01203007
FIGURE3.LM50NoDecouplingRequired
forCapacitiveLoad
1.0Mounting
TheLM50canbeappliedeasilyinthesamewayasotherintegrated-circuittemperaturesensors.Itcanbegluedorcementedtoasurfaceanditstemperaturewillbewithinabout0.2˚Cofthesurfacetemperature.
Thispresumesthattheambientairtemperatureisalmostthesameasthesurfacetemperature;iftheairtemperatureweremuchhigherorlowerthanthesurfacetemperature,theactualtemperatureoftheLM50diewouldbeataninterme-diatetemperaturebetweenthesurfacetemperatureandtheairtemperature.
ToensuregoodthermalconductivitythebacksideoftheLM50dieisdirectlyattachedtotheGNDpin.ThelandsandtracestotheLM50will,ofcourse,bepartoftheprintedcircuitboard,whichistheobjectwhosetemperatureisbeingmeasured.TheseprintedcircuitboardlandsandtraceswillnotcausetheLM50stemperaturetodeviatefromthede-siredtemperature.
Alternatively,theLM50canbemountedinsideasealed-endmetaltube,andcanthenbedippedintoabathorscrewedintoathreadedholeinatank.AswithanyIC,theLM50andaccompanyingwiringandcircuitsmustbekeptinsulatedanddry,toavoidleakageandcorrosion.Thisisespeciallytrueifthecircuitmayoperateatcoldtemperatureswhereconden-sationcanoccur.Printed-circuitcoatingsandvarnishessuchasHumisealandepoxypaintsordipsareoftenusedtoensurethatmoisturecannotcorrodetheLM50oritsconnec-tions.
01203008
FIGURE4.LM50CwithFilterforNoisyEnvironmentTheLM50handlescapacitiveloadingverywell.Withoutanyspecialprecautions,theLM50candriveanycapacitiveload.TheLM50hasanominal2kΩoutputimpedance(ascanbeseenintheblockdiagram).Thetemperaturecoefficientoftheoutputresistorsisaround1300ppm/˚C.TakingintoaccountthistemperaturecoefficientandtheinitialtoleranceoftheresistorstheoutputimpedanceoftheLM50willnotexceed4kΩ.Inanextremelynoisyenvironmentitmaybenecessarytoaddsomefilteringtominimizenoisepickup.Itisrecommendedthat0.1µFbeaddedfromVINtoGNDtobypassthepowersupplyvoltage,asshowninFigure4.Inanoisyenvironmentitmaybenecessarytoaddacapacitorfromtheoutputtoground.A1µFoutputcapacitorwiththe4kΩoutputimpedancewillforma40Hzlowpassfilter.SincethethermaltimeconstantoftheLM50ismuchslowerthanthe25mstimeconstantformedbytheRC,theoverallresponsetimeoftheLM50willnotbesignificantlyaffected.Formuchlargercapacitorsthisadditionaltimelagwillin-creasetheoverallresponsetimeoftheLM50.
www.national.com6
元器件交易网www.cecb2b.com
LM502.0CapacitiveLoads
(Continued)
01203017
*R2≈2kwithatypical1300ppm/˚Cdrift.
FIGURE5.BlockDiagram
3.0TypicalApplications
01203011
FIGURE6.CentigradeThermostat/FanController
01203013
FIGURE7.TemperatureToDigitalConverter(SerialOutput)(+125˚CFullScale)
7www.national.com
元器件交易网www.cecb2b.com
LM503.0TypicalApplications
(Continued)
01203014
FIGURE8.TemperatureToDigitalConverter(ParallelTRI-STATE®Outputsfor
StandardDataBustoµPInterface)(125˚CFullScale)
01203016
FIGURE9.LM50WithVoltage-To-FrequencyConverterAndIsolatedOutput
(−40˚Cto+125˚C;100Hzto1750Hz)
www.national.com8
元器件交易网www.cecb2b.com
LM50SOT-23Single-SupplyCentigradeTemperatureSensorPhysicalDimensions
inches(millimeters)unlessotherwisenoted
SOT-23MoldedSmallOutlineTransistorPackage(M3)
OrderNumberLM50BIM3,orLM50CIM3
NSPackageNumbermf03a
Nationaldoesnotassumeanyresponsibilityforuseofanycircuitrydescribed,nocircuitpatentlicensesareimpliedandNationalreservestherightatanytimewithoutnoticetochangesaidcircuitryandspecifications.Forthemostcurrentproductinformationvisitusatwww.national.com.LIFESUPPORTPOLICY
NATIONAL’SPRODUCTSARENOTAUTHORIZEDFORUSEASCRITICALCOMPONENTSINLIFESUPPORTDEVICESORSYSTEMSWITHOUTTHEEXPRESSWRITTENAPPROVALOFTHEPRESIDENTANDGENERALCOUNSELOFNATIONALSEMICONDUCTORCORPORATION.Asusedherein:
1.Lifesupportdevicesorsystemsaredevicesorsystemswhich,(a)areintendedforsurgicalimplantintothebody,or(b)supportorsustainlife,andwhosefailuretoperformwhenproperlyusedinaccordancewithinstructionsforuseprovidedinthelabeling,canbereasonablyexpectedtoresultinasignificantinjurytotheuser.BANNEDSUBSTANCECOMPLIANCE
NationalSemiconductormanufacturesproductsandusespackingmaterialsthatmeettheprovisionsoftheCustomerProductsStewardshipSpecification(CSP-9-111C2)andtheBannedSubstancesandMaterialsofInterestSpecification(CSP-9-111S2)andcontainno‘‘BannedSubstances’’asdefinedinCSP-9-111S2.LeadfreeproductsareRoHScompliant.
NationalSemiconductorAmericasCustomerSupportCenter
Email:new.feedback@nsc.comTel:1-800-272-9959
www.national.com
NationalSemiconductor
EuropeCustomerSupportCenter
Fax:+49(0)180-5308586Email:europe.support@nsc.com
DeutschTel:+49(0)6995086208EnglishTel:+44(0)8702402171FrançaisTel:+33(0)141918790
NationalSemiconductorAsiaPacificCustomerSupportCenter
Email:ap.support@nsc.com
NationalSemiconductor
JapanCustomerSupportCenterFax:81-3-5639-7507
Email:jpn.feedback@nsc.comTel:81-3-5639-7560
2.Acriticalcomponentisanycomponentofalifesupportdeviceorsystemwhosefailuretoperformcanbereasonablyexpectedtocausethefailureofthelifesupportdeviceorsystem,ortoaffectitssafetyoreffectiveness.
因篇幅问题不能全部显示，请点此查看更多更全内容