Product Sample & Technical Tools & Support & Folder Buy Documents Software Community LMT88 SNIS175A–MARCH2013–REVISEDJANUARY2015 LMT88 2.4-V, 10-µA, SC-70 Temperature Sensor 1 Features 3 Description • Cost-EffectiveAlternativetoThermistors The LMT88 device is a precision analog output 1 CMOS integrated-circuit temperature sensor that • RatedforFull−55°Cto130°CRange operates over a temperature range of −55°C to • AvailableinanSC70Package 130°C . The power supply operating range is 2.4 V to • PredictableCurvatureError 5.5 V. The transfer function of LMT88 is predominately linear, yet has a slight predictable • SuitableforRemoteApplications parabolic curvature. The accuracy of the LMT88 when specified to a parabolic transfer function is 2 Applications typically ±1.5°C at an ambient temperature of 30°C. • Industrial The temperature error increases linearly and reaches a maximum of ±2.5°C at the temperature range • HVAC extremes. The temperature range is affected by the • DiskDrives power supply voltage. At a power supply voltage of • Automotive 2.7 V to 5.5 V, the temperature range extremes are • PortableMedicalInstruments 130°C and −55°C. Decreasing the power supply voltage to 2.4 V changes the negative extreme to • Computers −30°C,whilethepositiveremainsat130°C. • BatteryManagement The LMT88 quiescent current is less than 10 μA. • Printers Therefore, self-heating is less than 0.02°C in still air. • PowerSupplyModules Shutdown capability for the LMT88 is intrinsic • FAXMachines because its inherent low power consumption allows it to be powered directly from the output of many logic • MobilePhones gatesordoesnotnecessitateshutdownatall. • Automotive The LMT88 is a cost-competitive alternative to thermistors. DeviceInformation(1) PARTNUMBER PACKAGE BODYSIZE(NOM) LMT88 SOT(5) 2.00mm×1.25mm (1) For all available packages, see the orderable addendum at theendofthedatasheet. SimplifiedSchematic OutputVoltagevsTemperature +2.4V to +5.5V To MCU ADC V+ VO LMT88 GND NC 1 An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications, intellectualpropertymattersandotherimportantdisclaimers.PRODUCTIONDATA.

LMT88 SNIS175A–MARCH2013–REVISEDJANUARY2015 www.ti.com Table of Contents 1 Features.................................................................. 1 7.4 DeviceFunctionalModes..........................................8 2 Applications........................................................... 1 8 ApplicationandImplementation.......................... 9 3 Description............................................................. 1 8.1 ApplicationInformation..............................................9 4 RevisionHistory..................................................... 2 8.2 TypicalApplications................................................10 8.3 SystemExamples...................................................13 5 PinConfigurationandFunctions......................... 3 9 PowerSupplyRecommendations...................... 13 6 Specifications......................................................... 4 10 Layout................................................................... 14 6.1 AbsoluteMaximumRatings......................................4 6.2 ESDRatings..............................................................4 10.1 LayoutGuidelines.................................................14 6.3 RecommendedOperatingConditions.......................4 10.2 LayoutExample....................................................14 6.4 ThermalInformation..................................................4 10.3 ThermalConsiderations........................................14 6.5 ElectricalCharacteristics...........................................5 11 DeviceandDocumentationSupport................. 16 6.6 TypicalCharacteristics..............................................6 11.1 Trademarks...........................................................16 7 DetailedDescription.............................................. 7 11.2 ElectrostaticDischargeCaution............................16 7.1 Overview...................................................................7 11.3 Glossary................................................................16 7.2 FunctionalBlockDiagram.........................................7 12 Mechanical,Packaging,andOrderable Information........................................................... 16 7.3 FeatureDescription...................................................7 4 Revision History ChangesfromOriginal(March2013)toRevisionA Page • AddedPinConfigurationandFunctionssection,ESDRatingstable,FeatureDescriptionsection,DeviceFunctional Modes,ApplicationandImplementationsection,PowerSupplyRecommendationssection,Layoutsection,Device andDocumentationSupportsection,andMechanical,Packaging,andOrderableInformationsection............................... 1 2 SubmitDocumentationFeedback Copyright©2013–2015,TexasInstrumentsIncorporated ProductFolderLinks:LMT88

LMT88 www.ti.com SNIS175A–MARCH2013–REVISEDJANUARY2015 5 Pin Configuration and Functions DCKPackage 5-PinSOT TopView 4 3 V+ VO LMT88 2 GND 5 1 GND NC PinFunctions PIN TYPE DESCRIPTION NAME NO. NC(pin1)mustbeleftfloatingorgrounded.Othersignaltracesmustnotbeconnectedto NC 1 — thispin. Devicesubstrateanddieattachpaddle,connecttopowersupplynegativeterminal.For GND 2 GND optimumthermalconductivitytothePCBgroundplane,pin2mustbegrounded.Thispin mayalsobeleftfloating. Analog V 3 Temperaturesensoranalogoutput O Output V+ 4 Power Positivepowersupplypin GND 5 GND Devicegroundpin,connecttopowersupplynegativeterminal. Copyright©2013–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 3 ProductFolderLinks:LMT88

LMT88 SNIS175A–MARCH2013–REVISEDJANUARY2015 www.ti.com 6 Specifications 6.1 Absolute Maximum Ratings See (1)(2). MIN MAX UNIT SupplyVoltage −0.2 6.5 V OutputVoltage (V++0.6 −0.6V V) OutputCurrent 10 mA InputCurrentatanypin (3) 5 mA MaximumJunctionTemperature(T ) 150 °C JMAX Storagetemperature(T ) −65 150 °C stg (1) StressesbeyondthoselistedunderAbsoluteMaximumRatingsmaycausepermanentdamagetothedevice.Thesearestressratings only,whichdonotimplyfunctionaloperationofthedeviceattheseoranyotherconditionsbeyondthoseindicatedunderRecommended OperatingConditions.Exposuretoabsolute-maximum-ratedconditionsforextendedperiodsmayaffectdevicereliability. (2) SolderingprocessmustcomplywiththeReflowTemperatureProfilespecifications.Refertohttp://www.ti.com/packaging.Reflow temperatureprofilesaredifferentforlead-freeandnon-lead-freepackages. (3) Whentheinputvoltage(V)atanypinexceedspowersupplies(V <GNDorV >V+),thecurrentatthatpinshouldbelimitedto5mA. I I I 6.2 ESD Ratings VALUE UNIT Human-bodymodel(HBM),perANSI/ESDA/JEDECJS-001(1) ±2500 V(ESD) Electrostaticdischarge Charged-devicemodel(CDM),perJEDECspecificationJESD22- ±250 V C101(2) (1) JEDECdocumentJEP155statesthat500-VHBMallowssafemanufacturingwithastandardESDcontrolprocess. (2) JEDECdocumentJEP157statesthat250-VCDMallowssafemanufacturingwithastandardESDcontrolprocess. 6.3 Recommended Operating Conditions overoperatingfree-airtemperaturerange(unlessotherwisenoted) MIN MAX UNIT LMT88with2.4V≤V+≤2.7VTemperatureRange −30 130 °C LMT88with2.7V≤V+≤5.5VTemperatureRange −55 130 °C SupplyVoltageRange(V+) 2.4 5.5 V 6.4 Thermal Information LMT88 THERMALMETRIC(1) DCK UNIT 5PINS R Junction-to-ambientthermalresistance 282 θJA R Junction-to-case(top)thermalresistance 93 θJC(top) R Junction-to-boardthermalresistance 62 θJB °C/W ψ Junction-to-topcharacterizationparameter 1.6 JT ψ Junction-to-boardcharacterizationparameter 62 JB R Junction-to-case(bottom)thermalresistance — θJC(bot) (1) Formoreinformationabouttraditionalandnewthermalmetrics,seetheICPackageThermalMetricsapplicationreport,SPRA953.For measuredthermalresistanceusingspecificprintedcircuitboardlayoutsfortheLMT88pleaseseeLayout. 4 SubmitDocumentationFeedback Copyright©2013–2015,TexasInstrumentsIncorporated ProductFolderLinks:LMT88

LMT88 www.ti.com SNIS175A–MARCH2013–REVISEDJANUARY2015 6.5 Electrical Characteristics Unlessotherwisenoted,thesespecificationsapplyforV+=+2.7V .AlllimitsT =T =T toT unlessotherwisenoted. DC A J MIN MAX PARAMETER TESTCONDITIONS MIN(1) TYP(2) MAX(1) UNIT T =25°Cto30°C -4.0 ±1.5 4.0 °C A T =130°C -5.0 5.0 °C A T =125°C -5.0 5.0 °C A T =100°C -4.7 ±4.7 °C A TemperaturetoVoltageErrorwhenusing: T =85°C -4.6 4.6 °C V =(−3.88×10−6×T2)+(−1.15×10−2×T)+ A O 1.8639V(3) TA=80°C -4.5 4.5 °C T =0°C -4.4 4.4 °C A T =–30°C -4.7 4.7 °C A T =–40°C -4.8 4.8 °C A T =–55°C -5.0 5.0 °C A OutputVoltageat0°C 1.8639 V VariancefromCurve ±1.0 °C Non-Linearity (4) –20°C≤T ≤80°C ±0.4% A SensorGain(TemperatureSensitivityor AverageSlope)toequation:V =−11.77mV/ –30°C≤T ≤100°C −12.6 −11.77 −11.0 mV/°C O A °C×T+1.860V OutputImpedance 0μA≤I ≤16μA (5) (6) 160 Ω L LoadRegulation(7) SourcingI 0μAto16μA (5) (6) −2.5 mV L 2.4V≤V+≤5.0V 3.7 mV/V LineRegulation(8) 5.0V≤V+≤5.5V 11 mV 2.4V≤V+≤5.0V;T =25°C 4.5 7 μA A QuiescentCurrent 5.0V≤V+≤5.5V;T =25°C 4.5 9 μA A 2.4V≤V+≤5.0V 4.5 10 μA ChangeofQuiescentCurrent 2.4V≤V+≤5.5V 0.7 μA TemperatureCoefficientofQuiescent −11 nA/°C Current ShutdownCurrent V+≤0.8V 0.02 μA (1) LimitsarespecifiedtoTI'sAOQL(AverageOutgoingQualityLevel). (2) TypicalsareatT =T =25°Candrepresentmostlikelyparametricnorm. J A (3) Accuracyisdefinedastheerrorbetweenthemeasuredandcalculatedoutputvoltageatthespecifiedconditionsofvoltage,current,and temperature(expressedin°C). (4) Non-Linearityisdefinedasthedeviationofthecalculatedoutput-voltage-versus-temperaturecurvefromthebest-fitstraightline,over thetemperaturerangespecified. (5) TheLMT88canatmostsink−1μAandsource16μA. (6) Loadregulationoroutputimpedancespecificationsapplyoverthesupplyvoltagerangeof2.4Vto5.5V. (7) Regulationismeasuredatconstantjunctiontemperature,usingpulsetestingwithalowdutycycle.Changesinoutputduetoheating effectscanbecomputedbymultiplyingtheinternaldissipationbythethermalresistance. (8) Lineregulationiscalculatedbysubtractingtheoutputvoltageatthehighestsupplyinputvoltagefromtheoutputvoltageatthelowest supplyinputvoltage. Copyright©2013–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 5 ProductFolderLinks:LMT88

LMT88 SNIS175A–MARCH2013–REVISEDJANUARY2015 www.ti.com 6.6 Typical Characteristics 8 MIN MAX 6 Median 4 C) 2 ƒy ( c 0 a ur cc±2 A ±4 ±6 ±8 ±60 ±40 ±20 0 20 40 60 80 100 120 140 160 DUT Temperature (ƒC) C001 Figure1.TemperatureSensorAccuracy 6 SubmitDocumentationFeedback Copyright©2013–2015,TexasInstrumentsIncorporated ProductFolderLinks:LMT88

LMT88 www.ti.com SNIS175A–MARCH2013–REVISEDJANUARY2015 7 Detailed Description 7.1 Overview The LMT88 device is a precision analog output CMOS integrated-circuit temperature sensor that operates over a temperature range of −55°C to 130°C . The power supply operating range is 2.4 V to 5.5 V. The transfer function of LMT88 is predominately linear, yet has a slight predictable parabolic curvature. The accuracy of the LMT88 when specified to a parabolic transfer function is typically ±1.5°C at an ambient temperature of 30°C. The temperature error increases linearly and reaches a maximum of ±5°C at the temperature range extremes. The temperature range is affected by the power supply voltage. At a power supply voltage of 2.7 V to 5.5 V, the temperature range extremes are 130°C and −55°C. Decreasing the power supply voltage to 2.4 V changes the negativeextremeto−30°C,whilethepositiveremainsat130°C. The LMT88 quiescent current is less than 10 μA. Therefore, self-heating is less than 0.02°C in still air. Shutdown capability for the LMT88 is intrinsic because its inherent low power consumption allows it to be powered directly fromtheoutputofmanylogicgatesordoesnotnecessitateshutdownatall. The temperature sensing element is comprised of a simple base emitter junction that is forward biased by a current source. The temperature sensing element is then buffered by an amplifier and provided to the OUT pin. The amplifier has a simple class A output stage thus providing a low impedance output that can source 16 µA andsink1µA. 7.2 Functional Block Diagram V+ V O Thermal Diodes GND 7.3 Feature Description 7.3.1 LMT88TransferFunction The LMT88 transfer function can be described in different ways with varying levels of precision. A simple linear transferfunction,withgoodaccuracynear25°C,is: V =−11.69mV/°C×T+1.8663V (1) O Over the full operating temperature range of −55°C to 130°C, best accuracy can be obtained by using the parabolictransferfunction. Copyright©2013–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 7 ProductFolderLinks:LMT88

LMT88 SNIS175A–MARCH2013–REVISEDJANUARY2015 www.ti.com Feature Description (continued) V =(−3.88×10−6×T2)+(−1.15×10−2×T)+1.8639 (2) O solvingforT: (1.8639(cid:16)V ) T (cid:16)1481.96(cid:14) 2.1962u106(cid:14) O 3.88u10(cid:16)6 (3) UsingEquation2thefollowingtemperaturetovoltageoutputcharacteristictablecanbegenerated. Table1.TemperaturetoVoltageOutputCharacteristicTable TEMP VOUT TEMP VOUT TEMP VOUT TEMP VOUT TEMP VOUT TEMP VOUT TEMP VOUT (°C) (V) (°C) (V) (°C) (V) (°C) (V) (°C) (V) (°C) (V) (°C) (V) -55 2.4847 -28 2.1829 -1 1.8754 26 1.5623 53 1.2435 80 0.9191 107 0.5890 -54 2.4736 -27 2.1716 0 1.8639 27 1.5506 54 1.2316 81 0.9069 108 0.5766 -53 2.4625 -26 2.1603 1 1.8524 28 1.5389 55 1.2197 82 0.8948 109 0.5643 -52 2.4514 -25 2.1490 2 1.8409 29 1.5271 56 1.2077 83 0.8827 110 0.5520 -51 2.4403 -24 2.1377 3 1.8294 30 1.5154 57 1.1958 84 0.8705 111 0.5396 -50 2.4292 -23 2.1263 4 1.8178 31 1.5037 58 1.1838 85 0.8584 112 0.5272 -49 2.4181 -22 2.1150 5 1.8063 32 1.4919 59 1.1719 86 0.8462 113 0.5149 -48 2.4070 -21 2.1037 6 1.7948 33 1.4802 60 1.1599 87 0.8340 114 0.5025 -47 2.3958 -20 2.0923 7 1.7832 34 1.4684 61 1.1480 88 0.8219 115 0.4901 -46 2.3847 -19 2.0810 8 1.7717 35 1.4566 62 1.1360 89 0.8097 116 0.4777 -45 2.3735 -18 2.0696 9 1.7601 36 1.4449 63 1.1240 90 0.7975 117 0.4653 -44 2.3624 -17 2.0583 10 1.7485 37 1.4331 64 1.1120 91 0.7853 118 0.4529 -43 2.3512 -16 2.0469 11 1.7369 38 1.4213 65 1.1000 92 0.7731 119 0.4405 -42 2.3401 -15 2.0355 12 1.7253 39 1.4095 66 1.0880 93 0.7608 120 0.4280 -41 2.3289 -14 2.0241 13 1.7137 40 1.3977 67 1.0760 94 0.7486 121 0.4156 -40 2.3177 -13 2.0127 14 1.7021 41 1.3859 68 1.0640 95 0.7364 122 0.4032 -39 2.3065 -12 2.0013 15 1.6905 42 1.3741 69 1.0519 96 0.7241 123 0.3907 -38 2.2953 -11 1.9899 16 1.6789 43 1.3622 70 1.0399 97 0.7119 124 0.3782 -37 2.2841 -10 1.9785 17 1.6673 44 1.3504 71 1.0278 98 0.6996 125 0.3658 -36 2.2729 -9 1.9671 18 1.6556 45 1.3385 72 1.0158 99 0.6874 126 0.3533 -35 2.2616 -8 1.9557 19 1.6440 46 1.3267 73 1.0037 100 0.6751 127 0.3408 -34 2.2504 -7 1.9442 20 1.6323 47 1.3148 74 0.9917 101 0.6628 128 0.3283 -33 2.2392 -6 1.9328 21 1.6207 48 1.3030 75 0.9796 102 0.6505 129 0.3158 -32 2.2279 -5 1.9213 22 1.6090 49 1.2911 76 0.9675 103 0.6382 130 0.3033 -31 2.2167 -4 1.9098 23 1.5973 50 1.2792 77 0.9554 104 0.6259 — — -30 2.2054 -3 1.8984 24 1.5857 51 1.2673 78 0.9433 105 0.6136 — — -29 2.1941 -2 1.8869 25 1.5740 52 1.2554 79 0.9312 106 0.6013 — — SolvingEquation2forT: (1.8639(cid:16)V T (cid:16)1481.96(cid:14) 2.1962u106 (cid:14) O 3.88u10(cid:16)6 (4) ForothermethodsofcalculatingTseeDetailedDesignProcedure. 7.4 Device Functional Modes TheLMT88'sonlyfunctionalmodeisthatithasananalogoutputinverselyproportionaltotemperature. 8 SubmitDocumentationFeedback Copyright©2013–2015,TexasInstrumentsIncorporated ProductFolderLinks:LMT88

LMT88 www.ti.com SNIS175A–MARCH2013–REVISEDJANUARY2015 8 Application and Implementation NOTE Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validateandtesttheirdesignimplementationtoconfirmsystemfunctionality. 8.1 Application Information The LMT88 has very low supply current and a wide supply range therefore it can easily be driven by a battery as showninFigure4. 8.1.1 CapacitiveLoads The LMT88 handles capacitive loading well. Without any precautions, the LMT88 can drive any capacitive load less than 300 pF, as shown in Figure 2. Over the specified temperature range the LMT88 has a maximum output impedance of 160 Ω. In an extremely noisy environment it may be necessary to add some filtering to minimize noise pickup. TI recommends adding 0.1 μF from V+ to GND to bypass the power supply voltage, as shown in Figure 3. In a noisy environment it may even be necessary to add a capacitor from the output to ground with a series resistor as shown in Figure 3. A 1-μF output capacitor with the 160-Ω maximum output impedance and a 200-Ω series resistor will form a 442-Hz lowpass filter. Because the thermal time constant of the LMT88 is much slower,theoverallresponsetimeoftheLMT88willnotbesignificantlyaffected. In situations where a transient load current is placed on the circuit output the series resistance value may be increasedtocompensateforanyringingthatmaybeobserved. + Heavy Capacitive Load, Wiring, Etc. LMT88 To A High-Impedance Load OUT d(cid:3) Figure2. LMT88NoDecouplingRequiredforCapacitiveLoadsLessThan300pF Table2.CapacitiveLoadingIsolation MinimumR(Ω) C(µF) 200 1 470 0.1 680 0.01 1k 0.001 Copyright©2013–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 9 ProductFolderLinks:LMT88

LMT88 SNIS175A–MARCH2013–REVISEDJANUARY2015 www.ti.com spacerbetweenthetableandgraphic + Heavy Capacitive Load, Wiring, Etc. LMT88 0.1 µF Bypass OUT Optional d(cid:3) R C + Heavy Capacitive Load, Wiring, Etc. R LMT88 0.1 µF Bypass OUT Optional d(cid:3) C Figure3. LMT88WithFilterforNoisyEnvironmentandCapacitiveLoadingGreaterThan300pF NOTE EitherplacementofresistorasshowninFigure2 andFigure3isjustaseffective. 8.2 Typical Applications 8.2.1 Full-RangeCentigradeTemperatureSensor +2.4V to +5.5V To MCU ADC V+ VO LMT88 GND NC Figure4. Full-RangeCelsius(Centigrade)TemperatureSensor(−55°Cto130°C) 8.2.1.1 DesignRequirements Because the LMT88 is a simple temperature sensor that provides an analog output, design requirements related tolayoutareimportant,refertoLayout fordetaileddescription. 8.2.1.2 DetailedDesignProcedure TheLMT88outputfollowsEquation5. V =(−3.88×10−6×T2)+(−1.15×10−2×T)+1.8639 (5) O 10 SubmitDocumentationFeedback Copyright©2013–2015,TexasInstrumentsIncorporated ProductFolderLinks:LMT88

LMT88 www.ti.com SNIS175A–MARCH2013–REVISEDJANUARY2015 Typical Applications (continued) SolvingforT: (1.8639(cid:16)V ) T (cid:16)1481.96(cid:14) 2.1962u106(cid:14) O 3.88u10(cid:16)6 where • Tistemperature,andV isthemeasuredoutputvoltageoftheLMT88.Equation6isthemostaccurate O equationthatcanbeusedtocalculatethetemperatureoftheLMT88. (6) Analternativetothequadraticequationasecondordertransferfunctioncanbedeterminedusing"leastsquares" method: T=(−2.3654×V 2)+(−78.154×V )+153.857 O O where • Tistemperatureexpressin°CandV istheoutputvoltageexpressedinvolts. (7) O Alineartransferfunctioncanbeusedoveralimitedtemperaturerangebycalculatingaslopeandoffsetthatgive best results over that range. A linear transfer function can be calculated from the parabolic transfer function of theLMT88.Theslopeofthelineartransferfunctioncanbecalculatedusingthefollowingequation: m=−7.76×10−6×T−0.0115, where • TisthemiddleofthetemperaturerangeofinterestandmisinV/°C.Forexampleforthetemperaturerangeof T =−30toT =100°C: (8) MIN MAX T=35°C (9) and m=−11.77mV/°C (10) Theoffsetofthelineartransferfunctioncanbecalculatedusingthefollowingequation: b=(V (T )+V (T)−m×(T +T))/2 OP MAX OP MAX where • V (T )isthecalculatedoutputvoltageatT usingtheparabolictransferfunctionforV . OP MAX MAX O • V (T)isthecalculatedoutputvoltageatTusingtheparabolictransferfunctionforV . (11) OP O Using this procedure, the best fit linear transfer function for many popular temperature ranges was calculated in Table 3. As shown in Table 3, the error that is introduced by the linear transfer function increases with wider temperatureranges. Table3.FirstOrderEquationsOptimizedforDifferentTemperatureRanges TEMPERATURERANGE MAXIMUMDEVIATIONOFLINEAREQUATION LINEAREQUATION T (°C) T (°C) FROMPARABOLICEQUATION(°C) min max −55 130 V =−11.79mV/°C×T+1.8528V ±1.41 O −40 110 V =−11.77mV/°C×T+1.8577V ±0.93 O −30 100 V =−11.77mV/°C×T+1.8605V ±0.70 O -40 85 V =−11.67mV/°C×T+1.8583V ±0.65 O −10 65 V =−11.71mV/°C×T+1.8641V ±0.23 O 35 45 V =−11.81mV/°C×T+1.8701V ±0.004 O 20 30 V =–11.69mV/°C×T+1.8663V ±0.004 O Copyright©2013–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 11 ProductFolderLinks:LMT88

LMT88 SNIS175A–MARCH2013–REVISEDJANUARY2015 www.ti.com 8.2.1.3 ApplicationCurve Figure5. OutputVoltagevsTemperature 8.2.2 CentigradeThermostat V+ R3 R4 4.1V R1 VT (High = overtemp alarm) + U1 VOUT LM4040 U3 0.1 PF - R2 LM7211 V+ LMT88 VTemp U2 Figure6. CentigradeThermostat 8.2.2.1 DesignRequirements A simple thermostat can be created by using a reference (LM4040) and a comparator (LM7211) as shown in Figure6. 8.2.2.2 DetailedDesignProcedure Thethresholdvaluescanbecalculatedusingthefollowingequations. (4.1)R2 VT1 = R2 + R1||R3 (12) (4.1)R2||R3 VT2 = R1 + R2||R3 (13) 12 SubmitDocumentationFeedback Copyright©2013–2015,TexasInstrumentsIncorporated ProductFolderLinks:LMT88

LMT88 www.ti.com SNIS175A–MARCH2013–REVISEDJANUARY2015 8.2.2.3 ApplicationCurve VTEMP VT1 VT2 VOUT Figure7. ThermostatOutputWaveform 8.3 System Examples TheLMT88drawsverylittlepowerthereforeitcansimplybeshutdownbydrivingitssupplypinwiththeoutputof anlogicgateasshowninFigure8. SHUTDOWN +VS VO LMT88 Any logic device output Figure8. ConservingPowerDissipationWithShutdown Most CMOS ADCs found in ASICs have a sampled data comparator input structure that is notorious for causing problems for analog output devices such as the LMT88 and many operational amplifiers. The cause of this difficulty is the requirement of instantaneous charge of the input sampling capacitor in the ADC. This requirement is easily accommodated by the addition of a capacitor. Because not all ADCs have identical input stages, the charge requirements will vary necessitating a different value of compensating capacitor. This ADC is shown as anexampleonly.Ifadigitaloutputtemperatureisrequired,refertodevicessuchastheLM74. V+ (+5.0V) 1 k 1 V+ 0.1 PF 4 3 470 Ÿ 3 6 CS V+ VO VIN 5 LMT88 2 DO GND 4 CLK 5 1 LM4040BIM3-4.1 GND NC 0.1 PF ADCV0831 2 GND Figure9. SuggestedConnectiontoaSamplingAnalog-to-DigitalConverterInputStage 9 Power Supply Recommendations The LMT88 has a very wide 2.4-V to 5.5-V power supply voltage range making it ideal for many applications. In noisy environments, TI recommends adding at minimum 0.1 μF from V+ to GND to bypass the power supply voltage.Largercapacitancesmayberequiredandaredependentonthepowersupplynoise. Copyright©2013–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 13 ProductFolderLinks:LMT88

LMT88 SNIS175A–MARCH2013–REVISEDJANUARY2015 www.ti.com 10 Layout 10.1 Layout Guidelines The LMT88 can be applied easily in the same way as other IC temperature sensors. The device can be glued or cemented to a surface. The temperature that the LMT88 is sensing will be within about 0.02°C of the surface temperaturetowhichtheleadsofLMT88areattached. This presumes that the ambient air temperature is almost the same as the surface temperature; if the air temperature were much higher or lower than the surface temperature, the actual temperature measured would beatanintermediatetemperaturebetweenthesurfacetemperatureandtheairtemperature. To ensure good thermal conductivity the backside of the LMT88 die is directly attached to the pin 2 GND pin. The temperatures of the lands and traces to the other leads of the LMT88 will also affect the temperature that is beingsensed. Alternatively, the LMT88 can be mounted inside a sealed-end metal tube, and can then be dipped into a bath or screwedintoathreadedholeinatank.AswithanyIC,theLMT88andaccompanyingwiringandcircuitsmustbe kept insulated and dry, to avoid leakage and corrosion. This is especially true if the circuit may operate at cold temperatures where condensation can occur. Printed-circuit coatings and varnishes such as a conformal coating andepoxypaintsordipsareoftenusedtoensurethatmoisturecannotcorrodetheLMT88oritsconnections. 10.2 Layout Example NC GND GND Vo V+ Figure10. LayoutUsedforNoHeatSinkMeasurements NC GND GND NC Vo V+ Figure11. LayoutUsedforMeasurementsWithSmallHeatSink 10.3 Thermal Considerations The thermal resistance junction to ambient (R ) is the parameter used to calculate the rise of a device junction θJA temperature due to its power dissipation. For the LMT88, Equation 14 is used to calculate the rise in the die temperature: T =T +θ [(V+I )+(V+−V )I ] J A JA Q O L where • I isthequiescentcurrentandI istheloadcurrentontheoutput. (14) Q L Because the junction temperature of the LMT88 is the actual temperature being measured, take care to minimize theloadcurrentthattheLMT88isrequiredtodrive. 14 SubmitDocumentationFeedback Copyright©2013–2015,TexasInstrumentsIncorporated ProductFolderLinks:LMT88

LMT88 www.ti.com SNIS175A–MARCH2013–REVISEDJANUARY2015 Thermal Considerations (continued) Table 4 summarizes the rise in die temperature of the LMT88 without any loading, and the thermal resistance for differentconditions. Table4.TemperatureRiseofLMT88DuetoSelf-HeatingandThermalResistance(θ )(1) JA SC70-5 SC70-5 NOHEATSINK SMALLHEATSINK θ T −T θ T −T JA J A JA J A (°C/W) (°C) (°C/W) (°C) Stillair 412 0.2 350 0.19 Movingair 312 0.17 266 0.15 (1) Seeforsamples. Copyright©2013–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 15 ProductFolderLinks:LMT88

LMT88 SNIS175A–MARCH2013–REVISEDJANUARY2015 www.ti.com 11 Device and Documentation Support 11.1 Trademarks Alltrademarksarethepropertyoftheirrespectiveowners. 11.2 Electrostatic Discharge Caution Thesedeviceshavelimitedbuilt-inESDprotection.Theleadsshouldbeshortedtogetherorthedeviceplacedinconductivefoam duringstorageorhandlingtopreventelectrostaticdamagetotheMOSgates. 11.3 Glossary SLYZ022—TIGlossary. Thisglossarylistsandexplainsterms,acronyms,anddefinitions. 12 Mechanical, Packaging, and Orderable Information The following pages include mechanical, packaging, and orderable information. This information is the most current data available for the designated devices. This data is subject to change without notice and revision of thisdocument.Forbrowser-basedversionsofthisdatasheet,refertotheleft-handnavigation. 16 SubmitDocumentationFeedback Copyright©2013–2015,TexasInstrumentsIncorporated ProductFolderLinks:LMT88

PACKAGE OPTION ADDENDUM www.ti.com 6-Feb-2020 PACKAGING INFORMATION Orderable Device Status Package Type Package Pins Package Eco Plan Lead/Ball Finish MSL Peak Temp Op Temp (°C) Device Marking Samples (1) Drawing Qty (2) (6) (3) (4/5) LMT88DCKR ACTIVE SC70 DCK 5 3000 Green (RoHS SN Level-1-260C-UNLIM -55 to 130 T9C & no Sb/Br) LMT88DCKT ACTIVE SC70 DCK 5 250 Green (RoHS SN Level-1-260C-UNLIM -55 to 130 T9C & no Sb/Br) (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may reference these types of products as "Pb-Free". RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption. Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of <=1000ppm threshold. Antimony trioxide based flame retardants must also meet the <=1000ppm threshold requirement. (3) MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. (4) There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device. (5) Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation of the previous line and the two combined represent the entire Device Marking for that device. (6) Lead/Ball Finish - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead/Ball Finish values may wrap to two lines if the finish value exceeds the maximum column width. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release. In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis. Addendum-Page 1

PACKAGE OPTION ADDENDUM www.ti.com 6-Feb-2020 Addendum-Page 2

PACKAGE MATERIALS INFORMATION www.ti.com 29-Sep-2014 TAPE AND REEL INFORMATION *Alldimensionsarenominal Device Package Package Pins SPQ Reel Reel A0 B0 K0 P1 W Pin1 Type Drawing Diameter Width (mm) (mm) (mm) (mm) (mm) Quadrant (mm) W1(mm) LMT88DCKR SC70 DCK 5 3000 178.0 8.4 2.25 2.45 1.2 4.0 8.0 Q3 LMT88DCKT SC70 DCK 5 250 178.0 8.4 2.25 2.45 1.2 4.0 8.0 Q3 PackMaterials-Page1

PACKAGE MATERIALS INFORMATION www.ti.com 29-Sep-2014 *Alldimensionsarenominal Device PackageType PackageDrawing Pins SPQ Length(mm) Width(mm) Height(mm) LMT88DCKR SC70 DCK 5 3000 210.0 185.0 35.0 LMT88DCKT SC70 DCK 5 250 210.0 185.0 35.0 PackMaterials-Page2

None

None

IMPORTANTNOTICEANDDISCLAIMER TI PROVIDES TECHNICAL AND RELIABILITY DATA (INCLUDING DATASHEETS), DESIGN RESOURCES (INCLUDING REFERENCE DESIGNS), APPLICATION OR OTHER DESIGN ADVICE, WEB TOOLS, SAFETY INFORMATION, AND OTHER RESOURCES “AS IS” AND WITH ALL FAULTS, AND DISCLAIMS ALL WARRANTIES, EXPRESS AND IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT OF THIRD PARTY INTELLECTUAL PROPERTY RIGHTS. These resources are intended for skilled developers designing with TI products. You are solely responsible for (1) selecting the appropriate TI products for your application, (2) designing, validating and testing your application, and (3) ensuring your application meets applicable standards, and any other safety, security, or other requirements. These resources are subject to change without notice. TI grants you permission to use these resources only for development of an application that uses the TI products described in the resource. Other reproduction and display of these resources is prohibited. No license is granted to any other TI intellectual property right or to any third party intellectual property right. TI disclaims responsibility for, and you will fully indemnify TI and its representatives against, any claims, damages, costs, losses, and liabilities arising out of your use of these resources. TI’s products are provided subject to TI’s Terms of Sale (www.ti.com/legal/termsofsale.html) or other applicable terms available either on ti.com or provided in conjunction with such TI products. TI’s provision of these resources does not expand or otherwise alter TI’s applicable warranties or warranty disclaimers for TI products. Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265 Copyright © 2020, Texas Instruments Incorporated