LMP2234 www.ti.com SNOSAW4D–SEPTEMBER2007–REVISEDMARCH2013 LMP2234 Quad Micropower, 1.6V, Precision, Operational Amplifier with CMOS Input CheckforSamples:LMP2234 FEATURES DESCRIPTION 1 (ForV =5V,TypicalUnlessOtherwiseNoted) The LMP2234 is a quad micropower precision 23 S amplifier designed for battery powered applications. • SupplyCurrentat1.8V31µA The 1.6 to 5.5V operating supply voltage range and • OperatingVoltageRange1.6Vto5.5V quiescent power consumption of only 50 μW extend • LowTCV ±0.75 µV/°C(max) the battery life in portable systems. The LMP2234 is OS part of the LMP™ precision amplifier family. The high • V ±150 µV(max) OS impedance CMOS input makes it ideal for • InputBiasCurrent±20fA instrumentation and other sensor interface • PSRR120dB applications. • CMRR97dB The LMP2234 has a maximum offset voltage of 150 • OpenLoopGain120dB μV and 0.3 μV/°C offset drift along with low bias current of only ±20 fA. These precise specifications • GainBandwidthProduct130kHz make the LMP2234 a great choice for maintaining • SlewRate58V/ms systemaccuracyandlongtermstability. • InputVoltageNoise,f=1kHz60nV/√Hz The LMP2234 has a rail-to-rail output that swings 15 • TemperatureRange–40°Cto125°C mV from the supply voltage, which increases system dynamic range. The common mode input voltage APPLICATIONS range extends 200 mV below the negative supply, thus the LMP2234 is ideal for ground sensing in • PrecisionInstrumentationAmplifiers singlesupplyapplications. • BatteryPoweredMedicalInstrumentation The LMP2234 is offered in 14-Pin SOIC and TSSOP • HighImpedanceSensors packages. • StrainGaugeBridgeAmplifier • ThermocoupleAmplifiers 1 Pleasebeawarethatanimportantnoticeconcerningavailability,standardwarranty,anduseincriticalapplicationsof TexasInstrumentssemiconductorproductsanddisclaimerstheretoappearsattheendofthisdatasheet. LMPisatrademarkofTexasInstruments. 2 Allothertrademarksarethepropertyoftheirrespectiveowners. 3 PRODUCTIONDATAinformationiscurrentasofpublicationdate. Copyright©2007–2013,TexasInstrumentsIncorporated Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarilyincludetestingofallparameters.

LMP2234 SNOSAW4D–SEPTEMBER2007–REVISEDMARCH2013 www.ti.com TYPICAL APPLICATION V+ V+ 3 2 ¼ - V+ LMP2234 6 LM4140A + 0.1 PF 1 PF 1,4,7,8 10 PF + V + ¼ 10 k: 40 k: VA LMP2234 - 12 k: R+’R R + V ADC121S021 - ¼ LMP2234 IN 1 k: + GND R R+’R + V 12 k: - ¼ LMP2234 10 k: 40 k: + Figure1. StrainGaugeBridgeAmplifier Thesedeviceshavelimitedbuilt-inESDprotection.Theleadsshouldbeshortedtogetherorthedeviceplacedinconductivefoam duringstorageorhandlingtopreventelectrostaticdamagetotheMOSgates. Absolute Maximum Ratings (1)(2) ESDTolerance(3) HumanBodyModel 2000V MachineModel 100V DifferentialInputVoltage ±300mV SupplyVoltage(V =V+-V–) 6V S VoltageonInput/OutputPins V++0.3V,V––0.3V StorageTemperatureRange −65°Cto150°C JunctionTemperature(4) 150°C MountingTemperature InfraredorConvection(20sec.) +235°C WaveSolderingLeadTemperature(10sec.) +260°C (1) AbsoluteMaximumRatingsindicatelimitsbeyondwhichdamagemayoccur.OperatingRatingsindicateconditionsforwhichthedevice isintendedtobefunctional,butspecificperformanceisnotensured.Forensuredspecificationsandtestconditions,seetheElectrical Characteristics. (2) IfMilitary/Aerospacespecifieddevicesarerequired,pleasecontacttheTISalesOffice/Distributorsforavailabilityandspecifications. (3) HumanBodyModel,applicablestd.MIL-STD-883,Method3015.7.MachineModel,applicablestd.JESD22-A115-A(ESDMMstd.of JEDEC)Field-InducedCharge-DeviceModel,applicablestd.JESD22-C101-C(ESDFICDMstd.ofJEDEC). (4) ThemaximumpowerdissipationisafunctionofT ,θ .Themaximumallowablepowerdissipationatanyambienttemperatureis J(MAX) JA P =(T –T )/θ .AllnumbersapplyforpackagessoldereddirectlyontoaPCBoard. D J(MAX) A JA 2 SubmitDocumentationFeedback Copyright©2007–2013,TexasInstrumentsIncorporated ProductFolderLinks:LMP2234

LMP2234 www.ti.com SNOSAW4D–SEPTEMBER2007–REVISEDMARCH2013 Operating Ratings (1) OperatingTemperatureRange (2) −40°Cto125°C SupplyVoltage(V =V+-V–) 1.6Vto5.5V S PackageThermalResistance(θ ) (2) 14-PinSOIC 101.5°C/W JA 14-PinTSSOP 121°C/W (1) AbsoluteMaximumRatingsindicatelimitsbeyondwhichdamagemayoccur.OperatingRatingsindicateconditionsforwhichthedevice isintendedtobefunctional,butspecificperformanceisnotensured.Forensuredspecificationsandtestconditions,seetheElectrical Characteristics. (2) ThemaximumpowerdissipationisafunctionofT ,θ .Themaximumallowablepowerdissipationatanyambienttemperatureis J(MAX) JA P =(T –T )/θ .AllnumbersapplyforpackagessoldereddirectlyontoaPCBoard. D J(MAX) A JA 5V DC Electrical Characteristics(1) Unlessotherwisespecified,alllimitsareensuredforT =25°C,V+=5V,V–=0V,V =V =V+/2,andR >1MΩ.Boldface A CM O L limitsapplyatthetemperatureextremes. Symbol Parameter Conditions Min Typ Max Units (2) (3) (2) V InputOffsetVoltage ±10 ±150 μV OS ±230 TCV InputOffsetVoltageDrift LMP2234A ±0.3 ±0.75 μV/°C OS LMP2234B ±0.3 ±2.5 I InputBiasCurrent ±0.02 ±1 pA BIAS ±50 I InputOffsetCurrent ±5 fA OS CMRR CommonModeRejectionRatio 0V≤V ≤4V 81 97 dB CM 80 PSRR PowerSupplyRejectionRatio 1.6V≤V+≤5.5V 83 120 dB V =0V 82 CM CMVR CommonModeVoltageRange CMRR≥80dB −0.2 4.2 V CMRR≥79dB −0.2 4.2 A LargeSignalVoltageGain V =0.3Vto4.7V 110 120 dB VOL O R =10kΩtoV+/2 108 L V OutputSwingHigh R =10kΩtoV+/2 17 50 mV O L V (diff)=100mV 50 fromeither IN OutputSwingLow R =10kΩtoV+/2 17 50 rail L V (diff)=−100mV 50 IN I OutputCurrent Sourcing,V toV− 27 30 mA O O (4) V (diff)=100mV 19 IN Sinking,V toV+ 17 22 O V (diff)=−100mV 12 IN I SupplyCurrent 36 48 µA S 50 (1) ElectricalTablevaluesapplyonlyforfactorytestingconditionsatthetemperatureindicated.Factorytestingconditionsresultinvery limitedself-heatingofthedevicesuchthatT =T .Noensuredspecificationofparametricperformanceisindicatedintheelectrical J A tablesunderconditionsofinternalself-heatingwhereT >T .AbsoluteMaximumRatingsindicatejunctiontemperaturelimitsbeyond J A whichthedevicemaybepermanentlydegraded,eithermechanicallyorelectrically. (2) Alllimitsarespecifiedbytesting,statisticalanalysisordesign. (3) Typicalvaluesrepresentthemostlikelyparametricnormasdeterminedatthetimeofcharacterization.Actualtypicalvaluesmayvary overtimeandwillalsodependontheapplicationandconfiguration.Thetypicalvaluesarenottestedandarenotensuredonshipped productionmaterial. (4) Theshortcircuittestisamomentaryopenlooptest. Copyright©2007–2013,TexasInstrumentsIncorporated SubmitDocumentationFeedback 3 ProductFolderLinks:LMP2234

LMP2234 SNOSAW4D–SEPTEMBER2007–REVISEDMARCH2013 www.ti.com 5V AC Electrical Characteristics(1) Unlessotherwisespecified,alllimitsareensuredforT =25°C,V+=5V,V−=0V,V =V =V+/2,andR >1MΩ.Boldface A CM O L limitsapplyatthetemperatureextremes. Symbol Parameter Conditions Min Typ Max Units (2) (3) (2) GBWP GainBandwidthProduct C =20pF,R =10kΩ 130 kHz L L SR SlewRate A =+1 FallingEdge 33 58 V 32 V/ms RisingEdge 33 48 32 θ PhaseMargin C =20pF,R =10kΩ 68 deg m L L G GainMargin C =20pF,R =10kΩ 27 dB m L L e Input-ReferredVoltageNoiseDensity f=1kHz 60 nV/√Hz n Input-ReferredVoltageNoise 0.1Hzto10Hz 2.3 μV PP i Input-ReferredCurrentNoiseDensity f=1kHz 10 fA/√Hz n THD+N TotalHarmonicDistortion+Noise f=100Hz,R =10kΩ 0.002 % L (1) ElectricalTablevaluesapplyonlyforfactorytestingconditionsatthetemperatureindicated.Factorytestingconditionsresultinvery limitedself-heatingofthedevicesuchthatT =T .Noensuredspecificationofparametricperformanceisindicatedintheelectrical J A tablesunderconditionsofinternalself-heatingwhereT >T .AbsoluteMaximumRatingsindicatejunctiontemperaturelimitsbeyond J A whichthedevicemaybepermanentlydegraded,eithermechanicallyorelectrically. (2) Alllimitsarespecifiedbytesting,statisticalanalysisordesign. (3) Typicalvaluesrepresentthemostlikelyparametricnormasdeterminedatthetimeofcharacterization.Actualtypicalvaluesmayvary overtimeandwillalsodependontheapplicationandconfiguration.Thetypicalvaluesarenottestedandarenotensuredonshipped productionmaterial. 3.3V DC Electrical Characteristics(1) Unlessotherwisespecified,alllimitsareensuredforT =25°C,V+=3.3V,V−=0V,V =V =V+/2,andR >1MΩ. A CM O L Boldfacelimitsapplyatthetemperatureextremes. Symbol Parameter Conditions Min Typ Max Units (2) (3) (2) V InputOffsetVoltage ±10 ±160 μV OS ±250 TCV InputOffsetVoltageDrift LMP2234A ±0.3 ±0.75 μV/°C OS LMP2234B ±0.3 ±2.5 I InputBiasCurrent ±0.02 ±1 pA BIAS ±50 I InputOffsetCurrent ±5 fA OS CMRR CommonModeRejectionRatio 0V≤V ≤2.3V 79 92 dB CM 77 PSRR PowerSupplyRejectionRatio 1.6V≤V+≤5.5V 83 120 dB V =0V 82 CM CMVR CommonModeVoltageRange CMRR≥78dB −0.2 2.5 V CMRR≥77dB −0.2 2.5 A LargeSignalVoltageGain V =0.3Vto3V 108 120 dB VOL O R =10kΩtoV+/2 107 L V OutputSwingHigh R =10kΩtoV+/2 14 50 mV O L V (diff)=100mV 50 fromeither IN OutputSwingLow R =10kΩtoV+/2 14 50 rail L V (diff)=−100mV 50 IN (1) ElectricalTablevaluesapplyonlyforfactorytestingconditionsatthetemperatureindicated.Factorytestingconditionsresultinvery limitedself-heatingofthedevicesuchthatT =T .Noensuredspecificationofparametricperformanceisindicatedintheelectrical J A tablesunderconditionsofinternalself-heatingwhereT >T .AbsoluteMaximumRatingsindicatejunctiontemperaturelimitsbeyond J A whichthedevicemaybepermanentlydegraded,eithermechanicallyorelectrically. (2) Alllimitsarespecifiedbytesting,statisticalanalysisordesign. (3) Typicalvaluesrepresentthemostlikelyparametricnormasdeterminedatthetimeofcharacterization.Actualtypicalvaluesmayvary overtimeandwillalsodependontheapplicationandconfiguration.Thetypicalvaluesarenottestedandarenotensuredonshipped productionmaterial. 4 SubmitDocumentationFeedback Copyright©2007–2013,TexasInstrumentsIncorporated ProductFolderLinks:LMP2234

LMP2234 www.ti.com SNOSAW4D–SEPTEMBER2007–REVISEDMARCH2013 3.3V DC Electrical Characteristics(1) (continued) Unlessotherwisespecified,alllimitsareensuredforT =25°C,V+=3.3V,V−=0V,V =V =V+/2,andR >1MΩ. A CM O L Boldfacelimitsapplyatthetemperatureextremes. Symbol Parameter Conditions Min Typ Max Units (2) (3) (2) I OutputCurrent Sourcing,V toV− 11 14 mA O O (4) V (diff)=100mV 8 IN Sinking,V toV+ 8 11 O V (diff)=−100mV 5 IN I SupplyCurrent 34 44 µA S 46 (4) Theshortcircuittestisamomentaryopenlooptest. 3.3V AC Electrical Characteristics(1) Unlessotherwiseisspecified,alllimitsareensuredforT =25°C,V+=3.3V,V−=0V,V =V =V+/2,andR >1MΩ. A CM O L Boldfacelimitsapplyatthetemperatureextremes. Symbol Parameter Conditions Min Typ Max Units (2) (3) (2) GBWP GainBandwidthProduct C =20pF,R =10kΩ 128 kHz L L SR SlewRate A =+1,C =20pF FallingEdge 58 V L R =10kΩ V/ms L RisingEdge 48 θ PhaseMargin C =20pF,R =10kΩ 66 deg m L L G GainMargin C =20pF,R =10kΩ 26 dB m L L e Input-ReferredVoltageNoiseDensity f=1kHz 60 nV/√Hz n Input-ReferredVoltageNoise 0.1Hzto10Hz 2.4 μV PP i Input-ReferredCurrentNoiseDensity f=1kHz 10 fA/√Hz n THD+N TotalHarmonicDistortion+Noise f=100Hz,R =10kΩ 0.003 % L (1) ElectricalTablevaluesapplyonlyforfactorytestingconditionsatthetemperatureindicated.Factorytestingconditionsresultinvery limitedself-heatingofthedevicesuchthatT =T .Noensuredspecificationofparametricperformanceisindicatedintheelectrical J A tablesunderconditionsofinternalself-heatingwhereT >T .AbsoluteMaximumRatingsindicatejunctiontemperaturelimitsbeyond J A whichthedevicemaybepermanentlydegraded,eithermechanicallyorelectrically. (2) Alllimitsarespecifiedbytesting,statisticalanalysisordesign. (3) Typicalvaluesrepresentthemostlikelyparametricnormasdeterminedatthetimeofcharacterization.Actualtypicalvaluesmayvary overtimeandwillalsodependontheapplicationandconfiguration.Thetypicalvaluesarenottestedandarenotensuredonshipped productionmaterial. 2.5V DC Electrical Characteristics(1) Unlessotherwisespecified,alllimitsareensuredforT =25°C,V+=2.5V,V−=0V,V =V =V+/2,andR >1MΩ. A CM O L Boldfacelimitsapplyatthetemperatureextremes. Symbol Parameter Conditions Min Typ Max Units (2) (3) (2) V InputOffsetVoltage ±10 ±190 OS μV ±275 TCV InputOffsetVoltageDrift LMP2234A ±0.3 ±0.75 OS μV/°C LMP2234B ±0.3 ±2.5 I InputBiasCurrent ±0.02 ±1.0 BIAS pA ±50 I InputOffsetCurrent ±5 fA OS (1) ElectricalTablevaluesapplyonlyforfactorytestingconditionsatthetemperatureindicated.Factorytestingconditionsresultinvery limitedself-heatingofthedevicesuchthatT =T .Noensuredspecificationofparametricperformanceisindicatedintheelectrical J A tablesunderconditionsofinternalself-heatingwhereT >T .AbsoluteMaximumRatingsindicatejunctiontemperaturelimitsbeyond J A whichthedevicemaybepermanentlydegraded,eithermechanicallyorelectrically. (2) Alllimitsarespecifiedbytesting,statisticalanalysisordesign. (3) Typicalvaluesrepresentthemostlikelyparametricnormasdeterminedatthetimeofcharacterization.Actualtypicalvaluesmayvary overtimeandwillalsodependontheapplicationandconfiguration.Thetypicalvaluesarenottestedandarenotensuredonshipped productionmaterial. Copyright©2007–2013,TexasInstrumentsIncorporated SubmitDocumentationFeedback 5 ProductFolderLinks:LMP2234

LMP2234 SNOSAW4D–SEPTEMBER2007–REVISEDMARCH2013 www.ti.com 2.5V DC Electrical Characteristics(1) (continued) Unlessotherwisespecified,alllimitsareensuredforT =25°C,V+=2.5V,V−=0V,V =V =V+/2,andR >1MΩ. A CM O L Boldfacelimitsapplyatthetemperatureextremes. Symbol Parameter Conditions Min Typ Max Units (2) (3) (2) CMRR CommonModeRejectionRatio 0V≤V ≤1.5V 77 91 CM dB 76 PSRR PowerSupplyRejectionRatio 1.6V≤V+≤5.5V 83 120 dB V =0V 82 CM CMVR CommonModeVoltageRange CMRR≥77dB −0.2 1.7 V CMRR≥76dB −0.2 1.7 A LargeSignalVoltageGain V =0.3Vto2.2V 104 120 VOL RO=10kΩtoV+/2 104 dB L V OutputSwingHigh R =10kΩtoV+/2 12 50 O L V (diff)=100mV 50 mV IN fromeither OutputSwingLow RL=10kΩtoV+/2 13 50 rail V (diff)=−100mV 50 IN I OutputCurrent Sourcing,V toV− 5 8 O O (4) V (diff)=100mV 4 IN mA Sinking,V toV+ 3.5 7 O V (diff)=−100mV 2.5 IN I SupplyCurrent 32 44 S µA 46 (4) Theshortcircuittestisamomentaryopenlooptest. 2.5V AC Electrical Characteristics(1) Unlessotherwisespecified,alllimitsareensuredforT =25°C,V+=2.5V,V−=0V,V =V =V+/2,andR >1MΩ. A CM O L Boldfacelimitsapplyatthetemperatureextremes. Symbol Parameter Conditions Min Typ Max Units (2) (3) (2) GBWP GainBandwidthProduct C =20pF,R =10kΩ 128 kHz L L SR SlewRate A =+1,C =20pF FallingEdge 58 V L R =10kΩ V/ms L RisingEdge 48 θ PhaseMargin C =20pF,R =10kΩ 64 deg m L L G GainMargin C =20pF,R =10kΩ 26 dB m L L e Input-ReferredVoltageNoiseDensity f=1kHz 60 nV/√Hz n Input-ReferredVoltageNoise 0.1Hzto10Hz 2.5 μV PP i Input-ReferredCurrentNoiseDensity f=1kHz 10 fA/√Hz n THD+N TotalHarmonicDistortion+Noise f=100Hz,R =10kΩ 0.005 % L (1) ElectricalTablevaluesapplyonlyforfactorytestingconditionsatthetemperatureindicated.Factorytestingconditionsresultinvery limitedself-heatingofthedevicesuchthatT =T .Noensuredspecificationofparametricperformanceisindicatedintheelectrical J A tablesunderconditionsofinternalself-heatingwhereT >T .AbsoluteMaximumRatingsindicatejunctiontemperaturelimitsbeyond J A whichthedevicemaybepermanentlydegraded,eithermechanicallyorelectrically. (2) Alllimitsarespecifiedbytesting,statisticalanalysisordesign. (3) Typicalvaluesrepresentthemostlikelyparametricnormasdeterminedatthetimeofcharacterization.Actualtypicalvaluesmayvary overtimeandwillalsodependontheapplicationandconfiguration.Thetypicalvaluesarenottestedandarenotensuredonshipped productionmaterial. 6 SubmitDocumentationFeedback Copyright©2007–2013,TexasInstrumentsIncorporated ProductFolderLinks:LMP2234

LMP2234 www.ti.com SNOSAW4D–SEPTEMBER2007–REVISEDMARCH2013 1.8V DC Electrical Characteristics (1) Unlessotherwisespecified,alllimitsareensuredforT =25°C,V+=1.8V,V−=0V,V =V =V+/2,andR >1MΩ. A CM O L Boldfacelimitsapplyatthetemperatureextremes. Symbol Parameter Conditions Min Typ Max Units (2) (3) (2) V InputOffsetVoltage ±10 ±230 μV OS ±325 TCV InputOffsetVoltageDrift LMP2234A ±0.3 ±0.75 μV/°C OS LMP2234B ±0.3 ±2.5 I InputBiasCurrent ±0.02 ±1.0 pA BIAS ±50 I InputOffsetCurrent ±5 fA OS CMRR CommonModeRejectionRatio 0V≤V ≤0.8V 76 92 dB CM 75 PSRR PowerSupplyRejectionRatio 1.6V≤V+≤5.5V 83 120 dB V =0V 82 CM CMVR CommonModeVoltageRange CMRR≥76dB -0.2 1.0 V CMRR≥75dB 0 1.0 A LargeSignalVoltageGain V =0.3Vto1.5V 103 120 dB VOL O R =10kΩtoV+/2 103 L V OutputSwingHigh R =10kΩtoV+/2 12 50 mV O L V (diff)=100mV 50 fromeither IN OutputSwingLow R =10kΩtoV+/2 13 50 rail L V (diff)=−100mV 50 IN I OutputCurrent (4) Sourcing,V toV− 2.5 5 mA O O V (diff)=100mV 2 IN Sinking,V toV+ 2 5 O V (diff)=−100mV 1.5 IN I SupplyCurrent 31 42 µA S 44 (1) ElectricalTablevaluesapplyonlyforfactorytestingconditionsatthetemperatureindicated.Factorytestingconditionsresultinvery limitedself-heatingofthedevicesuchthatT =T .Noensuredspecificationofparametricperformanceisindicatedintheelectrical J A tablesunderconditionsofinternalself-heatingwhereT >T .AbsoluteMaximumRatingsindicatejunctiontemperaturelimitsbeyond J A whichthedevicemaybepermanentlydegraded,eithermechanicallyorelectrically. (2) Alllimitsarespecifiedbytesting,statisticalanalysisordesign. (3) Typicalvaluesrepresentthemostlikelyparametricnormasdeterminedatthetimeofcharacterization.Actualtypicalvaluesmayvary overtimeandwillalsodependontheapplicationandconfiguration.Thetypicalvaluesarenottestedandarenotensuredonshipped productionmaterial. (4) Theshortcircuittestisamomentaryopenlooptest. Copyright©2007–2013,TexasInstrumentsIncorporated SubmitDocumentationFeedback 7 ProductFolderLinks:LMP2234

LMP2234 SNOSAW4D–SEPTEMBER2007–REVISEDMARCH2013 www.ti.com 1.8V AC Electrical Characteristics (1) Unlessotherwiseisspecified,alllimitsareensuredforT =25°C,V+=1.8V,V−=0V,V =V =V+/2,andR >1MΩ. A CM O L Boldfacelimitsapplyatthetemperatureextremes. Symbol Parameter Conditions Min Typ Max Units (2) (3) (2) GBWP GainBandwidthProduct C =20pF,R =10kΩ 127 kHz L L SR SlewRate A =+1,C =20pF FallingEdge 58 V L R =10kΩ V/ms L RisingEdge 48 θ PhaseMargin C =20pF,R =10kΩ 70 deg m L L G GainMargin C =20pF,R =10kΩ 25 dB m L L e Input-ReferredVoltageNoiseDensity f=1kHz 60 nV/√Hz n Input-ReferredVoltageNoise 0.1Hzto10Hz 2.4 μV PP i Input-ReferredCurrentNoiseDensity f=1kHz 10 fA/√Hz n THD+N TotalHarmonicDistortion+Noise f=100Hz,R =10kΩ 0.005 % L (1) ElectricalTablevaluesapplyonlyforfactorytestingconditionsatthetemperatureindicated.Factorytestingconditionsresultinvery limitedself-heatingofthedevicesuchthatT =T .Noensuredspecificationofparametricperformanceisindicatedintheelectrical J A tablesunderconditionsofinternalself-heatingwhereT >T .AbsoluteMaximumRatingsindicatejunctiontemperaturelimitsbeyond J A whichthedevicemaybepermanentlydegraded,eithermechanicallyorelectrically. (2) Alllimitsarespecifiedbytesting,statisticalanalysisordesign. (3) Typicalvaluesrepresentthemostlikelyparametricnormasdeterminedatthetimeofcharacterization.Actualtypicalvaluesmayvary overtimeandwillalsodependontheapplicationandconfiguration.Thetypicalvaluesarenottestedandarenotensuredonshipped productionmaterial. Connection Diagram Figure2. 14-PinTSSOP/SOIC 8 SubmitDocumentationFeedback Copyright©2007–2013,TexasInstrumentsIncorporated ProductFolderLinks:LMP2234

LMP2234 www.ti.com SNOSAW4D–SEPTEMBER2007–REVISEDMARCH2013 Typical Performance Characteristics UnlessotherwiseSpecified:T =25°C,V =5V,V =V /2,whereV =V+-V− A S CM S S OffsetVoltageDistribution TCV Distribution OS 16 10 VS = 5V VS = 5V 14 TA = 25°C VCM = VS/2 12 VCM = VS/2 8 -40°C d(cid:3)TA d(cid:3)125°C )% )% ( E 10 ( E 6 G G A A T 8 T N N E E C C 4 R 6 R E E P P 4 2 2 0 0 -150 -100 -50 0 50 100 150 -2.5 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 2.5 VOS (PV) TCVOS (PV/°C) Figure3. Figure4. OffsetVoltageDistribution TCV Distribution OS 14 10 VS = 3.3V -40°C d(cid:3)TA d(cid:3)125°C 12 TA = 25°C VS = 3.3V VCM = VS/2 8 VCM = VS/2 )% 10 )% ( E ( E 6 G 8 G A A TN TN EC 6 EC 4 R R E E P 4 P 2 2 0 0 -150 -100 -50 0 50 100 150 -2.5 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 2.5 VOS (PV) TCVOS (PV/°C) Figure5. Figure6. OffsetVoltageDistribution TCV Distribution OS 14 10 VS = 2.5V VS = 2.5V 12 TA = 25°C VCM = VS/2 VCM = VS/2 8 -40°C d(cid:3)TA d(cid:3)125°C )% 10 )% ( E ( E 6 G 8 G A A TN TN EC 6 EC 4 R R E E P 4 P 2 2 0 0 -150 -100 -50 0 50 100 150 -2.5 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 2.5 VOS (PV) TCVOS (PV/°C) Figure7. Figure8. Copyright©2007–2013,TexasInstrumentsIncorporated SubmitDocumentationFeedback 9 ProductFolderLinks:LMP2234

LMP2234 SNOSAW4D–SEPTEMBER2007–REVISEDMARCH2013 www.ti.com Typical Performance Characteristics (continued) UnlessotherwiseSpecified:T =25°C,V =5V,V =V /2,whereV =V+-V− A S CM S S OffsetVoltageDistribution TCV Distribution OS 12 25 VS = 1.8V VS = 1.8V 10 TA = 25°C VCM = VS/2 VCM = VS/2 20 -40°C d(cid:3)TA d(cid:3)125°C )% 8 )% ( E ( E 15 G G A A T 6 T N N E E C C 10 RE 4 RE P P 5 2 0 0 -150 -100 -50 0 50 100 150 -2.5 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 2.5 VOS (PV) TCVOS (PV/°C) Figure9. Figure10. OffsetVoltagevs.V OffsetVoltagevs.V CM CM 250 250 VS = 5V VS = 3.3V -40°C 150 150 )VP 25°C -40°C ( E 25°C GA 50 85°C )V 50 85°C T P LO 125°C ( S V O 125°C T -50 V -50 E S F F O -150 -150 -250 -250 -0.2 0.8 1.8 2.8 3.8 4.3 -0.2 0.2 0.6 1 1.4 1.8 2.2 2.6 3 VCM (V) VCM (V) Figure11. Figure12. OffsetVoltagevs.V OffsetVoltagevs.V CM CM 250 250 VS = 2.5V VS = 1.8V 150 150 -40°C 25°C -40°C 85°C 25°C )V 50 )V 50 P P ( S ( S 85°C O O V -50 V -50 125°C 125°C -150 -150 -250 -250 -0.2 0.2 0.6 1 1.4 1.8 2.2 -0.2 0 0.2 0.4 0.6 0.8 1 1.2 1.4 VCM (V) VCM (V) Figure13. Figure14. 10 SubmitDocumentationFeedback Copyright©2007–2013,TexasInstrumentsIncorporated ProductFolderLinks:LMP2234

LMP2234 www.ti.com SNOSAW4D–SEPTEMBER2007–REVISEDMARCH2013 Typical Performance Characteristics (continued) UnlessotherwiseSpecified:T =25°C,V =5V,V =V /2,whereV =V+-V− A S CM S S OffsetVoltagevs.Temperature OffsetVoltagevs.SupplyVoltage 120 100 100 VS = 1.8V, 2.5V, 3.3V, 5V VCM = 0V 5 TYPICAL PARTS 80 80 OFFSET VOLTAGE (V)P --22464000000 )V( EGATLOPV TESFFO 2460000 -40°C 25°C 85°C -20 -60 125°C -80 -40 -40 -20 0 20 40 60 80 100 120 1.5 2 2.5 3 3.5 4 4.5 5 5.5 TEMPERATURE (°C) SUPPLY VOLTAGE (V) Figure15. Figure16. 0.1Hzto10HzVoltageNoise 0.1Hzto10HzVoltageNoise Figure17. Figure18. 0.1Hzto10HzVoltageNoise 0.1Hzto10HzVoltageNoise Figure19. Figure20. Copyright©2007–2013,TexasInstrumentsIncorporated SubmitDocumentationFeedback 11 ProductFolderLinks:LMP2234

LMP2234 SNOSAW4D–SEPTEMBER2007–REVISEDMARCH2013 www.ti.com Typical Performance Characteristics (continued) UnlessotherwiseSpecified:T =25°C,V =5V,V =V /2,whereV =V+-V− A S CM S S InputBiasCurrentvs.V InputBiasCurrentvs.V CM CM 40 10 VS = 2V 8 VS = 2V 30 )Af( T 20 25°C )Ap( T 46 NER 10 NER 2 85°C R R UC 0 UC 0 S -40°C S A A -2 IB -10 IB T T -4 125°C UP -20 UP N N -6 I I -30 -8 -40 -10 0 0.25 0.5 0.75 1 1.25 1.5 0 0.25 0.5 0.75 1 1.25 1.5 VCM (V) VCM (V) Figure21. Figure22. InputBiasCurrentvs.V InputBiasCurrentvs.V CM CM 40 10 30 VS = 2.5V 8 VS = 2.5V )A )A 6 f( TN 20 -40°C p( TN 4 E 10 E 85°C R R 2 R R UC 0 UC 0 S S AIB -10 AIB -2 TUP -20 25°C TUP -4 125°C N N -6 I I -30 -8 -40 -10 0 0.5 1 1.5 2 0 0.5 1 1.5 2 VCM (V) VCM (V) Figure23. Figure24. InputBiasCurrentvs.V InputBiasCurrentvs.V CM CM 100 20 VS = 3.3V VS = 3.3V 75 15 )A )A f( T 50 25°C p( T 10 125°C N N E 25 E 5 R R R R U U C 0 C 0 SAIB -25 -40°C SAIB -5 85°C T T UP -50 UP -10 N N I I -75 -15 -100 -20 0 0.5 1 1.5 2 2.5 0 0.5 1 1.5 2 2.5 VCM (V) VCM (V) Figure25. Figure26. 12 SubmitDocumentationFeedback Copyright©2007–2013,TexasInstrumentsIncorporated ProductFolderLinks:LMP2234

LMP2234 www.ti.com SNOSAW4D–SEPTEMBER2007–REVISEDMARCH2013 Typical Performance Characteristics (continued) UnlessotherwiseSpecified:T =25°C,V =5V,V =V /2,whereV =V+-V− A S CM S S InputBiasCurrentvs.V InputBiasCurrentvs.V CM CM 600 30 VS = 5V 25 VS = 5V 500 400 A) 20 T (fA) 300 NT (p 1105 125°C N E RE 200 RR 5 UR 25°C CU 0 S C 100 AS -5 85°C BIA 0 T BI -10 UT -100 PU -15 NP -40°C IN -20 I -200 -25 -300 -30 0 1 2 3 4 0 1 2 3 4 VCM (V) VCM (V) Figure27. Figure28. PSRRvs.Frequency SupplyCurrentvs.SupplyVoltage(perchannel) 0 11 VS = 2V, 2.5V, 3.3V, 5V -20 10 125°C -40 +PSRR )AP 85°C ( T 9 )B -60 NE d R ( RRSP -1-0800 VS = 2V -PSRR RUC Y 8 -40°C 25°C LP 7 P -120 U S 6 -140 VS = 5V -160 5 10 100 1k 10k 100k 1.5 2.5 3.5 4.5 5.5 FREQUENCY (Hz) SUPPLY VOLTAGE (V) Figure29. Figure30. SinkingCurrentvs.SupplyVoltage SourcingCurrentvs.SupplyVoltage 30 40 35 25 -40°C 30 -40°C 20 )A 25 )Am( IKNIS 1105 85°C25°C m( IECRUOS 1250 85°C 25°C 125°C 125°C 10 5 5 0 0 1.5 2.5 3.5 4.5 5.5 1.5 2.5 3.5 4.5 5.5 SUPPLY VOLTAGE (V) SUPPLY VOLTAGE (V) Figure31. Figure32. Copyright©2007–2013,TexasInstrumentsIncorporated SubmitDocumentationFeedback 13 ProductFolderLinks:LMP2234

LMP2234 SNOSAW4D–SEPTEMBER2007–REVISEDMARCH2013 www.ti.com Typical Performance Characteristics (continued) UnlessotherwiseSpecified:T =25°C,V =5V,V =V /2,whereV =V+-V− A S CM S S OutputSwingHighvs.SupplyVoltage OutputSwingLowvs.SupplyVoltage 25 30 RL = 10 k: RL = 10 k: 125°C 25 )V 125°C )V m m 85°C ( L 20 ( L IA 85°C IA 20 R R M M O 25°C O R R 15 F F T 15 T U U O O V V 10 25°C -40°C -40°C 10 5 1.5 2.5 3.5 4.5 5.5 1.5 2.5 3.5 4.5 5.5 SUPPLY VOLTAGE (V) SUPPLY VOLTAGE (V) Figure33. Figure34. OpenLoopFrequencyResponse OpenLoopFrequencyResponse 100 120 100 120 PHASE -40°C PHASE 75 25°C 90 75 90 85°C )Bd( NIAG 2550 GAIN 1-4205°°CC 3600 )°( ESAHP )Bd( NIAG 2550 GAIN 3600 )(° ESAHP 25°C 0 VS = 5V 125°C 0 0 VS = 1.8V, 2.5V, 3.3V, 5V 0 RL = 10 k: RL = 10 k:, 100 k:, 10 M: CL = 20 pF 85°C CL = 20 pF, 50 pF, 100 pF -25 -30 -25 -30 10 100 1k 10k 100k 1M 10 100 1k 10k 100k 1M FREQUENCY (Hz) FREQUENCY (Hz) Figure35. Figure36. PhaseMarginvs.CapacitiveLoad SlewRatevs.SupplyVoltage 90 60 VS = 5V RL = 100 k: 56 FALLING EDGE 80 )°( NIGR VS = 2.5V VS = 1.8V )sm/V( E 52 A 70 T M A ES R W 48 A E H L RISING EDGE P 60 S VS = 3.3V RL = 10 k: 44 50 40 20 40 60 80 100 1.5 2 2.5 3 3.5 4 4.5 5 5.5 CAPACITIVE LOAD (pF) SUPPLY VOLTAGE (V) Figure37. Figure38. 14 SubmitDocumentationFeedback Copyright©2007–2013,TexasInstrumentsIncorporated ProductFolderLinks:LMP2234

LMP2234 www.ti.com SNOSAW4D–SEPTEMBER2007–REVISEDMARCH2013 Typical Performance Characteristics (continued) UnlessotherwiseSpecified:T =25°C,V =5V,V =V /2,whereV =V+-V− A S CM S S THD+Nvs.Amplitude THD+Nvs.Frequency 10 1 RL = 10 k: CL = 20 pF 1 0.1 VO = VS – 1V )%( N+D 0.1 VS = 2V VS = 2.5V )%( N+D 0.01 VS = 2.5V VS = 2V H H T T 0.01 RL = 10 k: VS = 3.3V VS = 5V 0.001 VS = 3.3V VS = 5V CL = 20 pF f = 1 kHz 0.001 0.0001 0.01 0.1 1 10 1 10 100 1k 10k 100k VOUT (VPP) FREQUENCY (Hz) Figure39. Figure40. LargeSignalStepResponse SmallSignalStepResponse VID/Vm VVSIN = = 5 2V VPP VID/Vm VVSIN = = 5 2V00 mVPP 005 f = 1 kHz 05 f = 1 kHz AV = +1 AV = +1 RL = 10 k: RL = 10 k: CL = 20 pF CL = 20 pF 100 Ps/DIV 100 Ps/DIV Figure41. Figure42. LargeSignalStepResponse SmallSignalStepResponse V V VS = 5V ID VS = 5V ID/V1 Vf =IN 1 = k 4H0z0 mVPP /Vm 00 Vf =IN 1 = k 5H0z mVPP 1 AV = +10 AV = +10 RL = 10 k: RL = 10 k: CL = 20 pF CL = 20 pF 100 Ps/DIV 100 Ps/DIV Figure43. Figure44. Copyright©2007–2013,TexasInstrumentsIncorporated SubmitDocumentationFeedback 15 ProductFolderLinks:LMP2234

LMP2234 SNOSAW4D–SEPTEMBER2007–REVISEDMARCH2013 www.ti.com Typical Performance Characteristics (continued) UnlessotherwiseSpecified:T =25°C,V =5V,V =V /2,whereV =V+-V− A S CM S S CMRRvs.Frequency InputVoltageNoisevs.Frequency 140 1000 VS = 2.5V VS = 5V 120 VS = 3.3V z) 100 H 100 )Bd( R 80 VS = 5V /Vn ES R IO M 60 N C E G 10 40 A T L O 20 V 0 1 10 100 1k 10k 100k 1 10 100 1k 10k FREQUENCY (Hz) FREQUENCY (Hz) Figure45. Figure46. 16 SubmitDocumentationFeedback Copyright©2007–2013,TexasInstrumentsIncorporated ProductFolderLinks:LMP2234

LMP2234 www.ti.com SNOSAW4D–SEPTEMBER2007–REVISEDMARCH2013 APPLICATION INFORMATION LMP2234 The LMP2234 is a quad CMOS precision amplifier that offers low offset voltage, low offset voltage drift, and high gainwhileconsuminglessthan10μAofsupplycurrentperchannel. The LMP2234 is a micropower op amp, consuming only 36 μA of current. Micropower op amps extend the run time of battery powered systems and reduce energy consumption in energy limited systems. The ensured supply voltagerangeof1.8Vto5.5Valongwiththeultra-lowsupplycurrentextendthebatteryruntimeintwoways.The extended power supply voltage range of 1.8V to 5.5V enables the op amp to function when the battery voltage has depleted from its nominal value down to 1.8V. In addition, the lower power consumption increases the life of thebattery. The LMP2234 has input referred offset voltage of only ±150 μV maximum at room temperature. This offset is ensuredtobelessthan±230 μVovertemperature.ThisminimaloffsetvoltagealongwithverylowTCV ofonly OS 0.3µV/°Ctypicalallowsmoreaccuratesignaldetectionandamplificationinprecisionapplications. The low input bias current of only ±20 fA gives the LMP2234 superiority for use in high impedance sensor applications. Bias current of an amplifier flows through source resistance of the sensor and the voltage resulting from this current flow appears as a noise voltage on the input of the amplifier. The low input bias current enables the LMP2234 to interface with high impedance sensors while generating negligible voltage noise. Thus the LMP2234 provides better signal fidelity and a higher signal-to-noise ratio when interfacing with high impedance sensors. Texas Instruments is heavily committed to precision amplifiers and the market segments they serve. Technical support and extensive characterization data is available for sensitive applications or applications with a constrainederrorbudget. The operating voltage range of 1.8V to 5.5V over the extensive temperature range of −40°C to 125°C makes the LMP2234anexcellentchoiceforlowvoltageprecisionapplicationswithextensivetemperaturerequirements. The LMP2234 is offered in the 14-pin TSSOP and 14-pin SOIC package. These small packages are ideal solutionsforareaconstrainedPCboardsandportableelectronics. TOTAL NOISE CONTRIBUTION The LMP2234 has very low input bias current, very low input current noise, and low input voltage noise for micropower amplifiers. As a result, this amplifier makes a great choice for circuits with high impedance sensor applications. showsthetypicalinputnoiseoftheLMP2234asafunctionofsourceresistanceatf=1kHzwhere: • e denotestheinputreferredvoltagenoise n • e isthevoltagedropacrosssourceresistanceduetoinputreferredcurrentnoiseore =R i i i S* n • e showsthethermalnoiseofthesourceresistance t • e showsthetotalnoiseontheinput. ni Where: 2 2 2 e = e +e +e ni n i t (1) The input current noise of the LMP2234 is so low that it will not become the dominant factor in the total noise unless source resistance exceeds 300 MΩ, which is an unrealistically high value. As is evident in Figure 47, at lower R values, total noise is dominated by the amplifier’s input voltage noise. Once R is larger than 100 kΩ, S S then the dominant noise factor becomes the thermal noise of R . As mentioned before, the current noise will not S bethedominantnoisefactorforanypracticalapplication. Copyright©2007–2013,TexasInstrumentsIncorporated SubmitDocumentationFeedback 17 ProductFolderLinks:LMP2234

LMP2234 SNOSAW4D–SEPTEMBER2007–REVISEDMARCH2013 www.ti.com 1000 Hz) en eni /Vn 100 ( Y T ISN et ED 10 ES ei IO N E 1 G A T L O V 0.1 10 100 1k 10k 100k 1M 10M RS (:) Figure47. TotalInputNoise VOLTAGE NOISE REDUCTION The LMP2234 has an input voltage noise of 60 nV/√Hz . While this value is very low for micropower amplifiers, this input voltage noise can be further reduced by placing multiple amplifiers in parallel as shown in Figure 48. The total voltage noise on the output of this circuit is divided by the square root of the number of amplifiers used in this parallel combination. This is because each individual amplifier acts as an independent noise source, and the average noise of independent sources is the quadrature sum of the independent sources divided by the numberofsources.ForNidenticalamplifiers,thismeans: (cid:17)(cid:17)(cid:17)(cid:17) 1 REDUCED INPUT VOLTAGE NOISE = N en21+e2n2+ +e2nN = N1 Ne2n = NN en 1 = en N (2) Figure 48 shows a schematic of this input voltage noise reduction circuit using the LMP2234. Typical resistor valuesare:R =10Ω,R =1kΩ,andR =1kΩ. G F O 18 SubmitDocumentationFeedback Copyright©2007–2013,TexasInstrumentsIncorporated ProductFolderLinks:LMP2234

LMP2234 www.ti.com SNOSAW4D–SEPTEMBER2007–REVISEDMARCH2013 + V VIN + VOUT - RO RG V- RF + V + - RO RG V- RF + V + - RO RG V- RF + V + - RO RG V- RF Figure48. NoiseReductionCircuit PRECISION INSTRUMENTATION AMPLIFIER Measurement of very small signals with an amplifier requires close attention to the input impedance of the amplifier, the gain of the signal on the inputs, and the gain on each input of the amplifier. This is because the difference of the input signal on the two inputs is of interest and the common signal is considered noise. A classic circuit implementation that is used is an instrumentation amplifier. Instrumentation amplifiers have a finite, accurate, and stable gain. They also have extremely high input impedances and very low output impedances. Finally they have an extremely high CMRR so that the amplifier can only respond to the differential signal. A typicalinstrumentationamplifierisshowninFigure49. V1 + V01 R2 KR2 - R1 - R1 R11 = a + VOUT - R1 V2 + V02 R2 KR2 Figure49. InstrumentationAmplifier Copyright©2007–2013,TexasInstrumentsIncorporated SubmitDocumentationFeedback 19 ProductFolderLinks:LMP2234

LMP2234 SNOSAW4D–SEPTEMBER2007–REVISEDMARCH2013 www.ti.com There are two stages in this amplifier. The last stage, the output stage, is a differential amplifier. In an ideal case thetwoamplifiersofthefirststage,theinputstage,wouldbeconfiguredasbufferstoisolatetheinputs.However they cannot be connected as followers because of mismatch in amplifiers. That is why there is a balancing resistor between the two. The product of the two stages of gain will give the gain of the instrumentation amplifier. Ideally, the CMRR should be infinite. However the output stage has a small non-zero common mode gain which resultsfromresistormismatch. In the input stage of the circuit, current is the same across all resistors. This is due to the high input impedance andlowinputbiascurrentoftheLMP2234. GIVEN: I = I R1 R11 (3) ByOhm’sLaw: VO1 - VO2 = (2R1 + R11) IR11 = (2a + 1) R11xIR11 = (2a + 1) V R11 (4) However: V R11 = V1 - V2 (5) Sowehave: V –V =(2a+1)(V –V ) (6) O1 O2 1 2 Nowlookingattheoutputoftheinstrumentationamplifier: KR2 VO = (VO2 - VO1) R2 = -K (VO1 - VO2) (7) SubstitutingfromEquation6: VO = -K (2a + 1) (V1 - V2) (8) Thisshowsthegainoftheinstrumentationamplifiertobe: −K(2a+1) (9) Typicalvaluesforthiscircuitcanbeobtainedbysetting:a=12andK=4.Thisresultsinanoverallgainof−100. SINGLE SUPPLY STRAIN GAUGE BRIDGE AMPLIFIER Strain gauges are popular electrical elements used to measure force or pressure. Strain gauges are subjected to an unknown force which is measured as the deflection on a previously calibrated scale. Pressure is often measured using the same technique; however this pressure needs to be converted into force using an appropriate transducer. Strain gauges are often resistors which are sensitive to pressure or to flexing. Sense resistorvaluesrangefromtensofohmstoseveralhundredkilo-ohms.Theresistancechangewhichisaresultof applied force across the strain gauge might be 1% of its total value. An accurate and reliable system is needed tomeasurethissmallresistancechange.Bridgeconfigurationsofferareliablemethodforthismeasurement. Bridge sensors are formed of four resistors, connected as a quadrilateral. A voltage source or a current source is used across one of the diagonals to excite the bridge while a voltage detector across the other diagonal measurestheoutputvoltage. Bridges are mainly used as null circuits or to measure differential voltages. Bridges will have no output voltage if the ratios of two adjacent resistor values are equal. This fact is used in null circuit measurements. These are particularly used in feedback systems which involve electrochemical elements or human interfaces. Null systems forceanactiveresistor,suchasastraingauge,tobalancethebridgebyinfluencingthemeasuredparameter. 20 SubmitDocumentationFeedback Copyright©2007–2013,TexasInstrumentsIncorporated ProductFolderLinks:LMP2234

LMP2234 www.ti.com SNOSAW4D–SEPTEMBER2007–REVISEDMARCH2013 Often in sensor applications at lease one of the resistors is a variable resistor, or a sensor. The deviation of this activeelementfromitsinitialvalueismeasuredasanindicationofchangeinthemeasuredquantity.Achangein output voltage represents the sensor value change. Since the sensor value change is often very small, the resulting output voltage is very small in magnitude as well. This requires an extensive and very precise amplificationcircuitrysothatsignalfidelitydoesnotchangeafteramplification. Sensitivityofabridgeistheratioofitsmaximumexpectedoutputchangetotheexcitationvoltagechange. Figure 50(a) shows a typical bridge sensor and Figure 50(b) shows the bridge with four sensors. R in Figure 50(b) is the nominal value of the sense resistor and the deviations from R are proportional to the quantity beingmeasured. R1 R2 VOUT EXCITATION SOURCE R3 R4 (a) R3 R4 - R1 R2 VOUT = x VSOURCE ¤¤§1 + R3¤¤'¤¤§1 + R4¤¤' ' R1§' R2§ R + ’R R - ’R VOUT EXCITATION SOURCE R - ’R R + ’R (b) ’R VOUT = x VSOURCE R Figure50. BridgeSensor Instrumentation amplifiers are great for interfacing with bridge sensors. Bridge sensors often sense a very small differential signal in the presence of a larger common mode voltage. Instrumentation amplifiers reject this commonmodesignal. Figure 51 shows a strain gauge bridge amplifier. In this application one of the LMP2234 amplifiers is used to buffer the LM4140A's precision output voltage. The LM4140A is a precision voltage reference. The other three amplifiers in the LMP2234 are used to form an instrumentation amplifier. This instrumentation amplifier uses the LMP2234's high CMRR and low V and TCV to accurately amplify the small differential signal generated by OS OS theoutputofthebridgesensor.ThisamplifiedsignalisthenfedintotheADC121S021whichisa12-bitanalogto digitalconverter.Thiscircuitworksonasinglesupplyvoltageof5V. Copyright©2007–2013,TexasInstrumentsIncorporated SubmitDocumentationFeedback 21 ProductFolderLinks:LMP2234

LMP2234 SNOSAW4D–SEPTEMBER2007–REVISEDMARCH2013 www.ti.com V+ V+ 3 2 ¼ - V+ LMP2234 6 LM4140A + 0.1 PF 1 PF 1,4,7,8 10 PF + V + ¼ 10 k: 40 k: VA LMP2234 - 12 k: R+’R R + V ADC121S021 - ¼ LMP2234 IN 1 k: + GND R R+’R + V 12 k: - ¼ LMP2234 10 k: 40 k: + Figure51. StrainGaugeBridgeAmplifier PORTABLE GAS DETECTION SENSOR Gas sensors are used in many different industrial and medical applications. They generate a current which is proportional to the percentage of a particular gas sensed in an air sample. This current goes through a load resistor and the resulting voltage drop is measured. Depending on the sensed gas and sensitivity of the sensor, the output current can be in the order of tens of microamperes to a few milliamperes. Gas sensor datasheets oftenspecifyarecommendedloadresistorvalueortheysuggestarangeofloadresistorstochoosefrom. Oxygen sensors are used when air quality or oxygen delivered to a patient needs to be monitored. Fresh air contains 20.9% oxygen. Air samples containing less than 18% oxygen are considered dangerous. Oxygen sensors are also used in industrial applications where the environment must lack oxygen. An example is when food is vacuum packed. There are two main categories of oxygen sensors, those which sense oxygen when it is abundantly present (i.e. in air or near an oxygen tank) and those which detect very small traces of oxygen in ppm. Figure 52 shows a typical circuit used to amplify the output signal of an oxygen detector. The LMP2234 makes anexcellentchoiceforthisapplicationasitdrawsonly36µAofcurrentandoperatesonsupplyvoltagesdownto 1.8V. This application detects oxygen in air. The oxygen sensor outputs a known current through the load resistor. This value changes with the amount of oxygen present in the air sample. Oxygen sensors usually recommend a particular load resistor value or specify a range of acceptable values for the load resistor. Oxygen sensors typically have a life of one to two years. The use of the micropower LMP2234 means minimal power usage by the op amp and it enhances the battery life. Depending on other components present in the circuit design, the battery could last for the entire life of the oxygen sensor. The precision specifications of the LMP2234, such as its very low offset voltage, low TCV , low input bias current, low CMRR, and low PSRR are OS otherfactorswhichmaketheLMP2234agreatchoiceforthisapplication. 22 SubmitDocumentationFeedback Copyright©2007–2013,TexasInstrumentsIncorporated ProductFolderLinks:LMP2234

LMP2234 www.ti.com SNOSAW4D–SEPTEMBER2007–REVISEDMARCH2013 99 k: + 1 k: V - 1 k: VOUT + - V RL OXYGEN SENSOR Figure52. PrecisionOxygenSensor Copyright©2007–2013,TexasInstrumentsIncorporated SubmitDocumentationFeedback 23 ProductFolderLinks:LMP2234

LMP2234 SNOSAW4D–SEPTEMBER2007–REVISEDMARCH2013 www.ti.com REVISION HISTORY ChangesfromRevisionC(March2013)toRevisionD Page • ChangedlayoutofNationalDataSheettoTIformat.......................................................................................................... 22 24 SubmitDocumentationFeedback Copyright©2007–2013,TexasInstrumentsIncorporated ProductFolderLinks:LMP2234

PACKAGE OPTION ADDENDUM www.ti.com 23-Aug-2017 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) LMP2234AMA/NOPB ACTIVE SOIC D 14 55 Green (RoHS CU SN Level-1-260C-UNLIM -40 to 125 LMP2234 & no Sb/Br) AMA LMP2234AMAE/NOPB ACTIVE SOIC D 14 250 Green (RoHS CU SN Level-1-260C-UNLIM -40 to 125 LMP2234 & no Sb/Br) AMA LMP2234AMAX/NOPB ACTIVE SOIC D 14 2500 Green (RoHS CU SN Level-1-260C-UNLIM -40 to 125 LMP2234 & no Sb/Br) AMA LMP2234AMT/NOPB ACTIVE TSSOP PW 14 94 Pb-Free CU SN Level-1-260C-UNLIM -40 to 125 LMP223 (RoHS) 4AMT LMP2234AMTE/NOPB ACTIVE TSSOP PW 14 250 Pb-Free CU SN Level-1-260C-UNLIM -40 to 125 LMP223 (RoHS) 4AMT LMP2234BMA/NOPB ACTIVE SOIC D 14 55 Green (RoHS CU SN Level-1-260C-UNLIM -40 to 125 LMP2234 & no Sb/Br) BMA LMP2234BMAE/NOPB ACTIVE SOIC D 14 250 Green (RoHS CU SN Level-1-260C-UNLIM -40 to 125 LMP2234 & no Sb/Br) BMA LMP2234BMAX/NOPB ACTIVE SOIC D 14 2500 Green (RoHS CU SN Level-1-260C-UNLIM -40 to 125 LMP2234 & no Sb/Br) BMA LMP2234BMT/NOPB ACTIVE TSSOP PW 14 94 Pb-Free CU SN Level-1-260C-UNLIM -40 to 125 LMP223 (RoHS) 4BMT LMP2234BMTE/NOPB ACTIVE TSSOP PW 14 250 Pb-Free CU SN Level-1-260C-UNLIM -40 to 125 LMP223 (RoHS) 4BMT LMP2234BMTX/NOPB ACTIVE TSSOP PW 14 2500 Pb-Free CU SN Level-1-260C-UNLIM -40 to 125 LMP223 (RoHS) 4BMT (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. Addendum-Page 1

PACKAGE OPTION ADDENDUM www.ti.com 23-Aug-2017 (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 2

PACKAGE MATERIALS INFORMATION www.ti.com 24-Aug-2017 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) LMP2234AMAE/NOPB SOIC D 14 250 178.0 16.4 6.5 9.35 2.3 8.0 16.0 Q1 LMP2234AMAX/NOPB SOIC D 14 2500 330.0 16.4 6.5 9.35 2.3 8.0 16.0 Q1 LMP2234AMTE/NOPB TSSOP PW 14 250 178.0 12.4 6.95 5.6 1.6 8.0 12.0 Q1 LMP2234BMAE/NOPB SOIC D 14 250 178.0 16.4 6.5 9.35 2.3 8.0 16.0 Q1 LMP2234BMAX/NOPB SOIC D 14 2500 330.0 16.4 6.5 9.35 2.3 8.0 16.0 Q1 LMP2234BMTE/NOPB TSSOP PW 14 250 178.0 12.4 6.95 5.6 1.6 8.0 12.0 Q1 LMP2234BMTX/NOPB TSSOP PW 14 2500 330.0 12.4 6.95 5.6 1.6 8.0 12.0 Q1 PackMaterials-Page1

PACKAGE MATERIALS INFORMATION www.ti.com 24-Aug-2017 *Alldimensionsarenominal Device PackageType PackageDrawing Pins SPQ Length(mm) Width(mm) Height(mm) LMP2234AMAE/NOPB SOIC D 14 250 210.0 185.0 35.0 LMP2234AMAX/NOPB SOIC D 14 2500 367.0 367.0 35.0 LMP2234AMTE/NOPB TSSOP PW 14 250 210.0 185.0 35.0 LMP2234BMAE/NOPB SOIC D 14 250 210.0 185.0 35.0 LMP2234BMAX/NOPB SOIC D 14 2500 367.0 367.0 35.0 LMP2234BMTE/NOPB TSSOP PW 14 250 210.0 185.0 35.0 LMP2234BMTX/NOPB TSSOP PW 14 2500 367.0 367.0 35.0 PackMaterials-Page2

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