OPA378 OPA2378 www.ti.com SBOS417D–JANUARY2008–REVISEDOCTOBER2009 Low-Noise, 900kHz, RRIO, Precision OPERATIONAL AMPLIFIER Zerø-Drift Series CheckforSamples:OPA378OPA2378 FEATURES DESCRIPTION 1 • LOWNOISE The OPA378 and OPA2378 represent a new 23 – 0.4μV ,0.1Hzto10Hz generation of Zerø-Drift, microPOWER™ operational PP amplifiers that use a proprietary auto-calibration – 20nV/√Hzat1kHz technique to provide minimal input offset voltage • ZERØ-DRIFTSERIES (20μV) and offset voltage drift (0.1μV/°C). The – LOWOFFSETVOLTAGE:20μV combination of low input voltage noise, high gain bandwidth (900kHz), and low power (150μA max) – LOWOFFSETDRIFT:0.1μV/°C enable these devices to achieve optimum • QUIESCENTCURRENT:125μA performance for low-power precision applications. In • GAINBANDWIDTH:900kHz addition, the excellent PSRR performance, coupled • RAIL-TO-RAILINPUT/OUTPUT with a wide input supply range of 2.2V to 5.5V and rail-to-rail input and output, makes it an outstanding • EMIFILTERING choice for single-supply applications that run directly • SUPPLYVOLTAGE:2.2Vto5.5V frombatterieswithoutregulation. • microSIZEPACKAGES:SC70andSOT23 The OPA378 (single version) is available in both a microSIZE SC70-5 and a SOT23-5 package. The APPLICATIONS OPA2378 (dual version) is offered in a SOT23-8 • PORTABLEMEDICALDEVICES package. All versions are specified for operation from – GLUCOSEMETERS –40°Cto+125°C. – OXYGENMETERING – HEARTRATEMONITORS • WEIGHSCALES • BATTERY-POWEREDINSTRUMENTS • THERMOPILEMODULES • HANDHELDTESTEQUIPMENT • SENSORSIGNALCONDITIONING 0.1Hz TO 10Hz NOISE NOISE SPECTRAL DENSITY vs FREQUENCY 1k Continues with No 1/f (flicker) Noise )z H Current Noise Ö 00nV/div se Density (nV/ÖNoise (fA/)Hz 100 Voltage Noise 1 ge Noiurrent 10 aC olt V 1 TTiimmee ((11ss//ddiivv)) 1 10 100 1k 10k FFrreeqquueennccyy ((HHzz)) 1 Pleasebeawarethatanimportantnoticeconcerningavailability,standardwarranty,anduseincriticalapplicationsofTexas Instrumentssemiconductorproductsanddisclaimerstheretoappearsattheendofthisdatasheet. microPOWERisatrademarkofTexasInstrumentsIncorporated. 2 Allothertrademarksarethepropertyoftheirrespectiveowners. 3 PRODUCTIONDATAinformationiscurrentasofpublicationdate. Copyright©2008–2009,TexasInstrumentsIncorporated Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarilyincludetestingofallparameters.

OPA378 OPA2378 SBOS417D–JANUARY2008–REVISEDOCTOBER2009 www.ti.com This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriateprecautions.Failuretoobserveproperhandlingandinstallationprocedurescancausedamage. ESDdamagecanrangefromsubtleperformancedegradationtocompletedevicefailure.Precisionintegratedcircuitsmaybemore susceptibletodamagebecauseverysmallparametricchangescouldcausethedevicenottomeetitspublishedspecifications. PACKAGEINFORMATION(1) PRODUCT PACKAGE-LEAD PACKAGEDESIGNATOR PACKAGEMARKING OPA378 SOT23-5 DBV OAZI OPA378 SC70-5 DCK BTS OPA2378 SOT23-8 DCN OCAI (1) Forthemostcurrentpackageandorderinginformation,seethePackageOptionAddendumattheendofthisdocument,orseetheTI websiteatwww.ti.com. ABSOLUTE MAXIMUM RATINGS(1) Overoperatingfree-airtemperaturerange(unlessotherwisenoted). OPA378,OPA2378 UNIT SupplyVoltage,V =(V+)–(V–) +7 V S Voltage(2) (V–)–0.3≤V ≤(V+)+0.3 V IN SignalInputTerminals Current(2) ±10 mA OutputShort-Circuit(3) Continuous OperatingTemperature,T –55to+150 °C A StorageTemperature,T –65to+150 °C A JunctionTemperature,T +150 °C J HumanBodyModel(HBM) 4000 V ESDRatings ChargedDeviceModel(CDM) 1000 V MachineModel(MM) 200 V (1) Stressesabovetheseratingsmaycausepermanentdamage.Exposuretoabsolutemaximumconditionsforextendedperiodsmay degradedevicereliability.Thesearestressratingsonly,andfunctionaloperationofthedeviceattheseoranyotherconditionsbeyond thosespecifiedisnotsupported. (2) Inputterminalsarediode-clampedtothepower-supplyrails.Inputsignalsthatcanswingmorethan0.3Vbeyondthesupplyrailsshould becurrentlimitedto10mAorless. (3) Short-circuittoground,oneamplifierperpackage. PIN CONFIGURATIONS OPA378 OPA378 OPA2378 SC70-5 SOT23-5 SOT23-8 (TOP VIEW) (TOP VIEW) (TOP VIEW) +In 1 5 V+ Out 1 5 V+ Out A 1 8 V+ V- 2 V- 2 -In A 2 A 7 Out B -In 3 4 Out +In 3 4 -In +In A 3 B 6 -In B V- 4 5 +In B 2 SubmitDocumentationFeedback Copyright©2008–2009,TexasInstrumentsIncorporated ProductFolderLink(s):OPA378OPA2378

OPA378 OPA2378 www.ti.com SBOS417D–JANUARY2008–REVISEDOCTOBER2009 ELECTRICAL CHARACTERISTICS: V = +2.2V to +5.5V S Boldfacelimitsapplyoverthespecifiedtemperaturerange,T =–40°Cto+125°C. A AtT =+25°C,R =10kΩconnectedtoV /2,V =V /2,andV =V /2,unlessotherwisenoted. A L S CM S OUT S OPA378,OPA2378 PARAMETER TESTCONDITIONS MIN TYP MAX UNIT OFFSETVOLTAGE InputOffsetVoltage,OPA378 VOS VCM=V– 20 50 μV vsTemperature dVOS/dT 0.1 0.25 μV/°C InputOffsetVoltage,OPA2378 20 70 µV vsTemperature dVOS/dT -40°Cto+125°C 0.25 0.4 µV/°C –40°Cto+85°C 0.15 0.25 µV/°C vsPowerSupply,OPA378 PSRR VCM=0V,VS=+2.2Vto+5.5V 1.5 5 μV/V overTemperature VCM=0V,VS=+2.2Vto+5.5V 3 8 μV/V vsPowerSupply,OPA2378 VCM=0V,VS=+2.2Vto+5.5V 10 μV/V overTemperature VCM=0V,VS=+2.2Vto+5.5V 3 13 μV/V ChannelSeparation(DualVersion) Atdc 135 dB INPUTBIASCURRENT InputBiasCurrent,OPA378 IB ±150 ±550 pA InputBiasCurrent,OPA2378 ±150 ±670 pA overTemperature,OPA378andOPA2378 ±2 nA InputOffsetCurrent,OPA378 IOS ±0.3 ±1.1 nA InputOffsetCurrent,OPA2378 ±0.3 ±1.34 nA NOISE InputVoltageNoise en f=0.1Hzto10Hz,VS=+5.5V 0.4 μVPP InputVoltageNoiseDensity en f=1kHz 20 nV/√Hz InputCurrentNoise in f=10Hz 200 fA/√Hz INPUTVOLTAGERANGE Common-ModeVoltageRange VCM (V–)–0.05 (V+)+0.05 V Common-ModeRejectionRatio CMRR (V–)–0.05V<VCM<(V+)+0.05V,VS=5.5V 100 112 dB (V–)–0.05V<VCM<(V+)+0.05V,VS=2.2V 94 106 dB overTemperature (V–)–0.05V<VCM<(V+)+0.05V,VS=5.5V 96 dB (V–)–0.05V<VCM<(V+)+0.05V,VS=2.2V 90 dB INPUTCAPACITANCE Differential CIN 4 pF Common-Mode 5 pF OPEN-LOOPGAIN Open-LoopVoltageGain AOL 50mV<VO<(V+)–50mV,RL=100kΩ 110 134 dB 100mV<VO<(V+)–100mV,RL=10kΩ 110 130 dB overTemperature 100mV<VO<(V+)–100mV,RL=10kΩ 106 dB FREQUENCYRESPONSE Gain-BandwidthProduct GBW 900 kHz SlewRate SR G=+1 0.4 V/μs SettlingTime0.1% tS VS=5.5V,2VStep,G=+1 7 μs SettlingTime0.01% tS VS=5.5V,2VStep,G=+1 9 μs OverloadRecoveryTime VIN×Gain>VS 4 μs THD+Noise THD+N VS=5V,VO=3VPP,G=+1,f=1kHz 0.003 % Copyright©2008–2009,TexasInstrumentsIncorporated SubmitDocumentationFeedback 3 ProductFolderLink(s):OPA378OPA2378

OPA378 OPA2378 SBOS417D–JANUARY2008–REVISEDOCTOBER2009 www.ti.com ELECTRICAL CHARACTERISTICS: V = +2.2V to +5.5V (continued) S Boldfacelimitsapplyoverthespecifiedtemperaturerange,T =–40°Cto+125°C. A AtT =+25°C,R =10kΩconnectedtoV /2,V =V /2,andV =V /2,unlessotherwisenoted. A L S CM S OUT S OPA378,OPA2378 PARAMETER TESTCONDITIONS MIN TYP MAX UNIT OUTPUT VoltageOutputSwingfromRail, OPA378 VO RL=10kΩ 6 8 mV overTemperature RL=10kΩ 8 13 mV VoltageOutputSwingfromRail, OPA2378 VO RL=10kΩ 6 10 mV overTemperature RL=10kΩ 8 15 mV VoltageOutputSwingfromRail RL=100kΩ 0.7 2 mV overTemperature RL=100kΩ 3 mV Short-CircuitCurrent ISC ±30 mA CapacitiveLoadDrive CLOAD SeeFigure18 pF Open-LoopOutputImpedance ZO SeeFigure23 Ω POWERSUPPLY SpecifiedVoltageRange VS 2.2 5.5 V QuiescentCurrent(perAmplifier) IQ IO=0mA,VS=+5.5V 125 150 μA overTemperature 165 μA TEMPERATURERANGE SpecifiedRange –40 +125 °C OperatingRange –55 +150 °C ThermalResistance θJA °C/W SOT23-5 200 °C/W SC70-5 250 °C/W SOT23-8 100 °C/W 4 SubmitDocumentationFeedback Copyright©2008–2009,TexasInstrumentsIncorporated ProductFolderLink(s):OPA378OPA2378

OPA378 OPA2378 www.ti.com SBOS417D–JANUARY2008–REVISEDOCTOBER2009 TYPICAL CHARACTERISTICS AtT =+25°C,R =10kΩ,V =+5.5VandV =V /2,unlessotherwisenoted. A L S OUT S INPUTCURRENTANDVOLTAGENOISE 0.1HzTO10HzNOISE SPECTRALDENSITYvsFREQUENCY 1k Continues with No 1/f (flicker) Noise )z H Current Noise Ö V/div ensity (nV/Öe (fA/)Hz 100 100n ge Noise Durrent Nois 10 Voltage Noise aC olt V 1 Time (1s/div) 1 10 100 1k 10k Frequency (Hz) Figure1. Figure2. OFFSETVOLTAGE PRODUCTIONDISTRIBUTION OFFSETVOLTAGEDRIFTDISTRIBUTION VS= 5.5V VS= 5.5V n n o o ati ati ul ul p p o o P P -50-45-40-35-30-25-20-15-10-505101520253035404550 00.010.020.030.040.050.060.070.080.090.100.110.120.130.140.150.160.170.180.190.200.210.220.230.240.25 Offset Voltage (mV) |Offset Voltage Drift| (mV/°C) Figure3. Figure4. Copyright©2008–2009,TexasInstrumentsIncorporated SubmitDocumentationFeedback 5 ProductFolderLink(s):OPA378OPA2378

OPA378 OPA2378 SBOS417D–JANUARY2008–REVISEDOCTOBER2009 www.ti.com TYPICAL CHARACTERISTICS (continued) AtT =+25°C,R =10kΩ,V =+5.5VandV =V /2,unlessotherwisenoted. A L S OUT S POWER-SUPPLYREJECTIONRATIO OFFSETVOLTAGEvsTEMPERATURE vsFREQUENCY 80 120 60 100 40 +PSRR V) m 80 Voltage ( 200 RR (dB) 60 -PSRR Offset -20 PS 40 -40 20 -60 -80 0 -75 -50 -25 0 25 50 75 100 125 150 1 10 100 1k 10k 100k 1M Temperature (°C) Frequency (Hz) Figure5. Figure6. OPEN-LOOPGAINANDPHASE OPEN-LOOPGAIN vsFREQUENCY vsTEMPERATURE 140 140 150 145 120 120 PPhhaassee 140 100 100 RL= 100kW 135 R = 10kW 80 80 L Gain (dB) 6400 6400 Phase ()° A(dB)OL 111322050 RL= 5kW Gain 115 20 20 110 0 0 105 -20 -20 100 0.1 1 10 100 1k 10k 100k 1M 10M -75 -50 -25 0 25 50 75 100 125 150 FFrreeqquueennccyy ((HHzz)) Temperature (°C) Figure7. Figure8. COMMON-MODEREJECTIONRATIO COMMON-MODEREJECTIONRATIOAND vsFREQUENCY POWER-SUPPLYREJECTIONRATIOvsTEMPERATURE 120 140 100 130 VCM= R5.R5V S B) 80 R (dB) 120 VS= 5.5V PSRR d R CMRR ( 6400 SRR, CM 111000 VCM= R2.R2V P S 20 90 0 80 10 100 1k 10k 100k 1M -75 -50 -25 0 25 50 75 100 125 150 Frequency (Hz) Temperature (°C) Figure9. Figure10. 6 SubmitDocumentationFeedback Copyright©2008–2009,TexasInstrumentsIncorporated ProductFolderLink(s):OPA378OPA2378

OPA378 OPA2378 www.ti.com SBOS417D–JANUARY2008–REVISEDOCTOBER2009 TYPICAL CHARACTERISTICS (continued) AtT =+25°C,R =10kΩ,V =+5.5VandV =V /2,unlessotherwisenoted. A L S OUT S INPUTBIASCURRENT INPUTBIASCURRENT vsINPUTCOMMON-MODEVOLTAGE vsTEMPERATURE 400 2000 300 1500 -I B A) 200 A) 1000 Current (p 1000 Current (p 5000 Bias -100 Bias -500 Input --230000 +IB Input --11050000 -400 -2000 -0.5 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 -75 -50 -25 0 25 50 75 100 125 150 Input Common-Mode Voltage (V) Temperature (°C) Figure11. Figure12. QUIESCENTCURRENT QUIESCENTCURRENT vsSUPPLYVOLTAGE vsTEMPERATURE 200 200 175 175 A) A) m m ent ( 150 ent ( 150 urr urr C C ent 125 ent 125 esc esc ui ui Q 100 Q 100 75 75 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 -75 -50 -25 0 25 50 75 100 125 150 V (V) Temperature (°C) S Figure13. Figure14. OUTPUTVOLTAGESWING MAXIMUMOUTPUTVOLTAGE vsOUTPUTCURRENT vsFREQUENCY 3 6 V+ = +2.75 V = 5.5V 2 5 S +125°C +25°C -40°C Output Swing (V) -101 VS=±1.1 +125°C +25°C -40°C Output Voltage (V) 432 V = 2.2V +125°C +25°C -40°C S -2 1 V-=-2.75 -3 0 0 2 4 6 8 10 12 14 16 18 20 1k 10k 100k 1M 10M Output Current (mA) Frequency (Hz) Figure15. Figure16. Copyright©2008–2009,TexasInstrumentsIncorporated SubmitDocumentationFeedback 7 ProductFolderLink(s):OPA378OPA2378

OPA378 OPA2378 SBOS417D–JANUARY2008–REVISEDOCTOBER2009 www.ti.com TYPICAL CHARACTERISTICS (continued) AtT =+25°C,R =10kΩ,V =+5.5VandV =V /2,unlessotherwisenoted. A L S OUT S TOTALHARMONICDISTORTION+NOISE SMALL-SIGNALOVERSHOOT vsFREQUENCY vsLOADCAPACITANCE 1 60 50 0.1 N (%) 0.01 oot (%) 4300 D+ sh Gain = +1V/V,-1V/V H er R = 10kW T Ov 20 0.001 10 Gain =-1V/V R = 5kW 0.0001 0 10 100 1k 10k 1 10 100 1k Frequency (Hz) Load Capacitance (pF) Figure17. Figure18. POSITIVEOVER-VOLTAGERECOVERY NEGATIVEOVER-VOLTAGERECOVERY 10kW v 10kW Output v 1kW +2.5V V/di 0 1kW +2.5V V/di 0 OPA378 2 2 RL Output OPA378 -2.5V RL -2.5V v v Input V/di 0 V/di 0 1 Input 1 Time (10ms/div) Time (4ms/div) Figure19. Figure20. SMALL-SIGNALSTEPRESPONSE LARGE-SIGNALSTEPRESPONSE G = +1 VS=±2.75V v) di V/ V V m v) IN OUT e (10 1V/di ag e ( ut Volt Voltag p ut O Time (5ms/div) Time (20ms/div) Figure21. Figure22. 8 SubmitDocumentationFeedback Copyright©2008–2009,TexasInstrumentsIncorporated ProductFolderLink(s):OPA378OPA2378

OPA378 OPA2378 www.ti.com SBOS417D–JANUARY2008–REVISEDOCTOBER2009 TYPICAL CHARACTERISTICS (continued) AtT =+25°C,R =10kΩ,V =+5.5VandV =V /2,unlessotherwisenoted. A L S OUT S INPUTBIASCURRENTvs OPEN-LOOPOUTPUTIMPEDANCEvsFREQUENCY INPUTDIFFERENTIALVOLTAGE 10k 50 Normal Operating Range 40 (see theInput Differential 1k 30 Voltagesection in the W) A) Applications Information) nce ( 100 IO= 0A ment ( 2100 Output Impeda 101 IO= 400mA Input Bias Curr ---1230000 Over-Driven Condition Over-Driven Condition -40 I = 2mA 0.1 O -50 1 10 100 1k 10k 100k 1M -1V -800 -600 -400 -200 0 200 400 600 800 1V Frequency (Hz) Input Differential Voltage (mV) Figure23. Figure24. OPA2378CHANNELSEPARATION -160 -140 -120 %) -100 oot ( -80 h s ver -60 O -40 -20 0 1k 10k 100k 1M 10M 100M 1G Frequency (Hz) Figure25. Copyright©2008–2009,TexasInstrumentsIncorporated SubmitDocumentationFeedback 9 ProductFolderLink(s):OPA378OPA2378

OPA378 OPA2378 SBOS417D–JANUARY2008–REVISEDOCTOBER2009 www.ti.com APPLICATIONS INFORMATION The OPA378 and OPA2378 are unity-gain stable, precision operational amplifiers that are free from 50 V =±2.75V phase reversal. The use of proprietary Zerø-Drift 40 S 10 Typical Units Shown circuitry gives the benefit of low input offset voltage 30 over time and temperature as well as lowering the 1/f 20 noise component. This design provides the V) 10 optimization of gain, noise, and power, making the m ( 0 OPA378 series one of the best performers in this OS V -10 bandwidth range. As a result of the high PSRR, this deviceworkswellinapplicationsthatrundirectlyfrom -20 battery power without regulation. They are optimized -30 for low-voltage, single-supply operation. These -40 miniature, high-precision, low quiescent current -50 amplifiers offer high-impedance inputs that have a -3.0-2.5-2.0-1.5-1.0-0.5 0 0.5 1.0 1.5 2.0 2.5 3.0 common-mode range 100mV beyond the supplies, V (V) CM excellent CMRR, and a rail-to-rail output that swings within 10mV of the supplies. This design results in Figure26. OffsetVoltageversusCommon-Mode superior performance for driving analog-to-digital Voltage converters (ADCs) without degradation of differential linearity. Normally, input bias current is about 150pA; however, input voltages exceeding the power supplies can OPERATING VOLTAGE cause excessive current to flow into or out of the The OPA378 and OPA2378 can be used with single input pins. Momentary voltages greater than the or dual supplies from an operating range of V = power supply can be tolerated if the input current is S +2.2V (±1.1V) and up to V = +5.5V (±2.75V). This limitedto10mA.Thislimitationiseasilyaccomplished S device does not require symmetrical supplies, only a withaninputresistor,asFigure27shows. differential supply voltage of 2.2V to 5.5V. A power-supply rejection ratio of 1.5μV/V (typical) Current-limiting resistor ensures that the device functions with an unregulated required if input voltage battery source. Supply voltages higher than +7V can exceeds supply rails by ³0.5V. permanently damage the device; see the Absolute +5V Maximum Ratings table. Key parameters are assured I over the specified temperature range, T = –40°C to OVERLOAD A 10mA max +125°C. Parameters that vary over the supply voltage OPA378 V OUT or temperature range are shown in the Typical V IN Characteristicssectionofthisdatasheet. 5kW INPUT VOLTAGE Figure27. InputCurrentProtection The OPA378 and OPA2378 input common-mode voltage range extends 0.05V beyond the supply rails. The OPA378 achieves a common-mode rejection ratio of 112dB (typical) over the common-mode voltage range. Figure 26 shows the variation of offset voltage over the entire specified common-mode rangefor10typicalunits. 10 SubmitDocumentationFeedback Copyright©2008–2009,TexasInstrumentsIncorporated ProductFolderLink(s):OPA378OPA2378

OPA378 OPA2378 www.ti.com SBOS417D–JANUARY2008–REVISEDOCTOBER2009 INPUT DIFFERENTIAL VOLTAGE OPA378 operational amplifier family incorporates an internal input low-pass filter that reduces the amplifier The typical input bias current of the OPA378 during response to EMI. Both common-mode and normal operation is approximately 150pA. In differential-mode filtering are provided by the input over-driven conditions, the bias current can increase filter. The filter is designed for a cutoff frequency of significantly (see Figure 24). The most common approximately 25MHz (–3dB), with a roll-off of 20dB cause of an over-driven condition occurs when the op perdecade.Figure29showstheEMIfilter. amp is outside of the linear range of operation. When the output of the op amp is driven to one of the 0 supply rails the feedback loop requirements cannot be satisfied and a differential input voltage develops across the input pins. This differential input voltage -10 results in activation of parasitic diodes inside the front B) d end input chopping switches that combine with 1.5kΩ e ( s EMI filter resistors to create the equivalent circuit pon -20 showninFigure28. s e R er 1.5kW Clamp Filt -30 f = 25MHz with Parasitics +In C Over Temperature CORE -29dB at 800MHz -In -40 1.5kW 1k 10k 100k 1M 10M 100M 1G Frequency (Hz) Figure28. EquivalentInputCircuit Figure29. EMIFilter INTERNAL OFFSET CORRECTION GENERAL LAYOUT GUIDELINES TheOPA378andOPA2378familyofopampsusean auto-calibration technique with a time-continuous Attention to good layout practices is always 350kHz op amp in the signal path. This amplifier is recommended. Keep traces short and, when zero-corrected every 3μs using a proprietary possible, use a printed circuit board (PCB) ground technique. Upon power-up, the amplifier requires plane with surface-mount components placed as approximately 100μs to achieve specified V close to the device pins as possible. Place a 0.1μF OS accuracy. This architecture has no aliasing or flicker capacitor closely across the supply pins. These noise. guidelines should be applied throughout the analog circuittoimproveperformance. NOISE For lowest offset voltage and precision performance, The OPA378 series of op amps have excellent circuit layout and mechanical conditions should be distortion characteristics. Total harmonic distortion + optimized. Avoid temperature gradients that create noise is below 0.003% (G = +1, V = 3V , and f = thermoelectric (Seebeck) effects in the thermocouple O RMS 1kHz, with a 10kΩ load). Design of low-noise op amp junctions formed from connecting dissimilar circuits requires careful consideration of a variety of conductors. These thermally-generated potentials can possible noise contributors: noise from the signal be made to cancel by assuring they are equal on source, noise generated in the op amp, and noise both input terminals. Other layout and design from the feedback network resistors. The total noise considerationsinclude: of the circuit is the root-sum-square combination of all • Use low thermoelectric-coefficient conditions thenoisecomponents. (avoiddissimilarmetals). • Thermally isolate components from power EMI SUSCEPTIBILITY AND INPUT FILTERING suppliesorotherheatsources. Operational amplifiers vary in their susceptibility to • Shield op amp and input circuitry from air electromagnetic interference (EMI). If conducted EMI currents,suchascoolingfans. enters the operational amplifier, the dc offset Following these guidelines reduces the likelihood of observed at the amplifier output may shift from its junctions being at different temperatures, which can nominal value while the EMI is present. This shift is a cause thermoelectric voltages of 0.1μV/°C or higher, result of signal rectification associated with the dependingonmaterialsused. internalsemiconductorjunctions.Whilealloperational amplifier pin functions can be affected by EMI, the input pins are likely to be the most susceptible. The Copyright©2008–2009,TexasInstrumentsIncorporated SubmitDocumentationFeedback 11 ProductFolderLink(s):OPA378OPA2378

OPA378 OPA2378 SBOS417D–JANUARY2008–REVISEDOCTOBER2009 www.ti.com ELECTRICAL OVERSTRESS It is helpful to have a good understanding of this basic ESD circuitry and its relevance to an electrical Designers often ask questions about the capability of overstress event. Figure 30 shows the ESD circuits an operational amplifier to withstand electrical contained in the OPA378 (indicated by the dashed overstress. These questions tend to focus on the line area). The ESD protection circuitry involves deviceinputs,butmayinvolvethesupplyvoltagepins several current-steering diodes connected from the or even the output pin. Each of these different pin input and output pins and routed back to the internal functions have electrical stress limits determined by power-supply lines, where they meet at an absorption the voltage breakdown characteristics of the device internal to the operational amplifier. This particular semiconductor fabrication process and protection circuitry is intended to remain inactive specific circuits connected to the pin. Additionally, duringnormalcircuitoperation. internal electrostatic discharge (ESD) protection is built into these circuits to protect them from accidental ESD events both before and during productassembly. R F +V S +V ESD OPA378 V- ESD R I -In ESD Current- Steering Diodes Op-Amp Out +In Core Edge-Triggered ESD R I Absorption Circuit L D ESD V (1) IN ESD V+ -V -V S (1) V =+V +500mV. IN S Figure30. EquivalentInternalESDCircuitryandItsRelationtoaTypicalCircuitApplication 12 SubmitDocumentationFeedback Copyright©2008–2009,TexasInstrumentsIncorporated ProductFolderLink(s):OPA378OPA2378

OPA378 OPA2378 www.ti.com SBOS417D–JANUARY2008–REVISEDOCTOBER2009 An ESD event produces a short duration, Another common question involves what happens to high-voltage pulse that is transformed into a short the amplifier if an input signal is applied to the input duration, high-current pulse as it discharges through while the power supplies +V and/or –V are at 0V. S S a semiconductor device. The ESD protection circuits Again,itdependsonthesupplycharacteristicwhileat are designed to provide a current path around the 0V, or at a level below the input signal amplitude. If operational amplifier core to prevent it from being the supplies appear as high impedance, then the damaged. The energy absorbed by the protection operational amplifier supply current may be supplied circuitryisthendissipatedasheat. by the input source via the current steering diodes. This state is not a normal bias condition; the amplifier When an ESD voltage develops across two or more most likely will not operate normally. If the supplies of the amplifier device pins, current flows through one are low impedance, then the current through the or more of the steering diodes. Depending on the steering diodes can become quite high. The current path that the current takes, the absorption device level depends on the ability of the input source to may activate. The absorption device has a trigger, or delivercurrent,andanyresistanceintheinputpath. threshold voltage, that is above the normal operating voltage of the OPA378 but below the device APPLICATION IDEAS breakdown voltage level. Once this threshold is exceeded, the absorption device quickly activates Figure 31 shows the basic configuration for a bridge and clamps the voltage across the supply rails to a amplifier. safelevel. A low-side current shunt monitor is shown in When the operational amplifier connects into a circuit Figure 32. R are optional resistors used to isolate N such as that illustrated in Figure 30, the ESD the ADS8325 from the noise of the digital two-wire protection components are intended to remain bus. Because the ADS8325 is a 16-bit converter, a inactive and not become involved in the application precise reference is essential for maximum accuracy. circuit operation. However, circumstances may arise If absolute accuracy is not required, and the 5V where an applied voltage exceeds the operating power supply is sufficiently stable, the REF3330 may voltage range of a given pin. Should this condition beomitted. occur, there is a risk that some of the internal ESD Figure 33 shows a high-side current monitor. The protection circuits may be biased on, and conduct load current develops a voltage drop across R . current. Any such current flow occurs through SHUNT The noninverting input monitors this voltage and is steering diode paths and rarely involves the duplicated on the inverting input. R then has the absorptiondevice. G same voltage drop as R . R can be sized to SHUNT G Figure 30 depicts a specific example where the input provide whatever current is most convenient to the voltage, V , exceeds the positive supply voltage designer based on design constraints. The current IN (+V ) by 300mV or more. Much of what happens in from R then flows through the MOSFET and to S G the circuit depends on the supply characteristics. If resistor R , creating a voltage that can be read. Note L +V can sink the current, one of the upper input thatR andR setthevoltagegainofthecircuit. S L G steering diodes conducts and directs current to +V . S The supply voltage for the op amp is derived from the Excessively high current levels can flow with zener diode. For the OPA378 V must be between increasingly higher V . As a result, the datasheet S IN 2.2V and 5.5V. Two possible methods to bias the specifications recommend that applications limit the zener are shown in the circuit of Figure 33: the inputcurrentto10mA. customary resistor bias and the current monitor. The If the supply is not capable of sinking the current, V current monitor biasing achieves the lowest possible IN may begin sourcing current to the operational voltage. Resistor R and the diode on the 1 amplifier, and then take over as the source of positive noninvertinginputprovideshort-circuitprotection. supply voltage. The danger in this case is that the voltage can rise to levels that exceed the operational V amplifier absolute maximum ratings. In extreme but EX R1 rare cases, the absorption device triggers on while +V and –V are applied. If this event happens, a +5V S S direct current path is established between the +V R R S R R and –VS supplies. The power dissipation of the OPA378 VOUT absorption device is quickly exceeded, and the extreme internal heating destroys the operational amplifier. R1 V REF Figure31. SingleOpAmpBridgeAmplifier Copyright©2008–2009,TexasInstrumentsIncorporated SubmitDocumentationFeedback 13 ProductFolderLink(s):OPA378OPA2378

OPA378 OPA2378 SBOS417D–JANUARY2008–REVISEDOCTOBER2009 www.ti.com 3V +5V REF3330 Load R R 1 2 4.99kW 49.9kW R V 60R0SW 716.5kW 5R6NW ILOAD R1WSHUNT OPA378 C 1 R3 R4 1.2nF ADS1100 RN I2C 4.99kW 48.7kW 56W Stray Ground-Loop Resistance R7 (PGA Gain = 4) 1.18kW FS = 3.0V NOTE:1%resistorsprovideadequatecommon-moderejectionatsmallground-looperrors. Figure32. Low-SideCurrentMonitor R G RRSSHHUUNNTT zenRe1r((21)) V+ CBYPASS MOSFET rated to 10kW OPA378 stand-off supply voltage such as BSS84 for up to 50V. +5V V+ Two zener biasing methods are shown.(3) Output Load R BIAS R L (1) Zenerratedforopampsupplycapability(thatis,5.1VfortheOPA378). (2) Current-limitingresistor. (3) ChoosezenerbiasingresistorordualNMOSFETs(2N7002,NTZD511ON,SM6K2T110). Figure33. High-SideCurrentMonitor 14 SubmitDocumentationFeedback Copyright©2008–2009,TexasInstrumentsIncorporated ProductFolderLink(s):OPA378OPA2378

OPA378 OPA2378 www.ti.com SBOS417D–JANUARY2008–REVISEDOCTOBER2009 3.3V +5V REF3333 + 0.1mF R8 150kW R 1 6.04kW R +5V 5 31.6kW 10mF D1 00..11mmFF R2 R7 2.94kW 549W - - + + OPA378 V R O 6 K-Type 200W Thermocouple R R Zero Adj. 4 3 40.7mV/°C 6.04kW 60.4W Figure34. TemperatureMeasurement 100kW 1MW 60kW -VIn1 INA152 OPA378 2 5 3V NTC R2 1MW Thermistor OPA378 6 R V 1 O R 2 Figure35. ThermistorMeasurement 3 1 OPA378 V 2 +In V = (1 + 2R/R) (V -V) O 2 1 2 1 Figure36. PrecisionInstrumentationAmplifier Copyright©2008–2009,TexasInstrumentsIncorporated SubmitDocumentationFeedback 15 ProductFolderLink(s):OPA378OPA2378

OPA378 OPA2378 SBOS417D–JANUARY2008–REVISEDOCTOBER2009 www.ti.com +V f = 150Hz S LPF C 4 R1 1/2 1.06nF 100kW OPA2378 RA R G = 1kV/V 14 R TOT 1MW +V 1070kW +VS S R6 3 7 GINA= 5 R12 +VS R2 1/2 100kW 6 5kW 100kW OPA2378 INA321(1) 2 1 LL 4 C OPA378 VOUT R8 5 1m3F R13 GOPA= 200 +V 100kW 318kW S +V dc ac S R3 1/2 100kW OPA2378 1/2 LA Wilson OPA2378 V CENTRAL C1 (RA + LA + LL)/3 47pF f = 0.5Hz HPF (provides ac signal coupling) 1/2 V S R 5 390kW +V R4 +VS 20Rk9W 1S/2 VBWS= = + 02..57HVz t oto + 155.50VHz 100kW 1/2 OPA2378 RL OPA2378 Inverted +V V S CM R 10 1MW 1/2 V S C2 R11 0.64mF 1MW f = 0.5Hz O (1) Otherinstrumentationamplifierscanbeused,suchastheINA326,whichhaslowernoisebuthigherquiescentcurrent. Figure37. Single-Supply,VeryLowPowerECGCircuit 16 SubmitDocumentationFeedback Copyright©2008–2009,TexasInstrumentsIncorporated ProductFolderLink(s):OPA378OPA2378

OPA378 OPA2378 www.ti.com SBOS417D–JANUARY2008–REVISEDOCTOBER2009 C 7 C 110pF 4 Digital Stethoscope 600pF Microphone Output R 5 R 100kW 3 100kW C2 R2 +5V 10Cm5F 10Rk4W +5V 10mF 10kW OPA378 C 1 OPA378 Electret Out 33pF C Microphone 6 Gnd C 470nF Elewmithent 2.2kW 1m3F Internal FET Mic Mic VBIAS1 VBIAS2 Bias Output Figure38. DigitalStethoscopeCircuit Copyright©2008–2009,TexasInstrumentsIncorporated SubmitDocumentationFeedback 17 ProductFolderLink(s):OPA378OPA2378

OPA378 OPA2378 SBOS417D–JANUARY2008–REVISEDOCTOBER2009 www.ti.com REVISION HISTORY NOTE:Pagenumbersforpreviousrevisionsmaydifferfrompagenumbersinthecurrentversion. ChangesfromRevisionC(June2009)toRevisionD Page • ChangedOPA2378orderablestatustoproductiondata;updatedreferencesthroughoutdocument ................................. 1 • ChangedfirstsentenceofDescriptionsection ..................................................................................................................... 1 • Deletedfootnote2fromPackageInformationtable ............................................................................................................. 2 • AddedOPA2378parameterstotheOffsetVoltagesectionoftheElectricalCharacteristicstable...................................... 3 • Deletedfootnote1fromElectricalCharacteristicstable ....................................................................................................... 3 • AddedOPA378totheOffsetVoltage,InputOffsetVoltageandvsPowerSupplyparametersoftheElectrical Characteristicstable ............................................................................................................................................................. 3 • AddedtypicalspecificationtotheOPA378OffsetVoltage,OverTemperatureparameteroftheElectrical Characteristicstable ............................................................................................................................................................. 3 • AddedOffsetVoltage,ChannelSeparationparametertotheElectricalCharacteristicstable ............................................. 3 • AddedOPA2378parameterstotheInputBiasCurrentsectionoftheElectricalCharacteristicstable ............................... 3 • AddedOPA378totheInputBiasCurrent,InputBiasCurrentandInputOffsetCurrentparametersoftheElectrical Characteristicstable ............................................................................................................................................................. 3 • AddedtypicalspecificationtotheInputBiasCurrent,InputOffsetCurrent,OPA378parameteroftheElectrical Characteristicstable ............................................................................................................................................................. 3 • AddedOPA378totheOutput,VoltageOutputSwingfromRailparameteroftheElectricalCharacteristics ...................... 4 • AddedtypicalspecificationtotheOPA378Output,OverTemperatureparameteroftheElectricalCharacteristics table ...................................................................................................................................................................................... 4 • AddedtheOPA2378Output,VoltageOutputSwingfromRailandOverTemperatureparameterstotheElectrical Characteristicstable ............................................................................................................................................................. 4 • UpdatedFigure18 ................................................................................................................................................................ 8 • AddedFigure25 ................................................................................................................................................................... 9 • UpdatedFigure32 .............................................................................................................................................................. 14 • UpdatedFigure33andchangedfootnote3 ....................................................................................................................... 14 18 SubmitDocumentationFeedback Copyright©2008–2009,TexasInstrumentsIncorporated ProductFolderLink(s):OPA378OPA2378

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) OPA2378AIDCNR ACTIVE SOT-23 DCN 8 3000 Green (RoHS NIPDAU Level-2-260C-1 YEAR -40 to 125 OCAI & no Sb/Br) OPA2378AIDCNT ACTIVE SOT-23 DCN 8 250 Green (RoHS NIPDAU Level-2-260C-1 YEAR -40 to 125 OCAI & no Sb/Br) OPA378AIDBVR ACTIVE SOT-23 DBV 5 3000 Green (RoHS NIPDAU Level-2-260C-1 YEAR -40 to 125 OAZI & no Sb/Br) OPA378AIDBVT ACTIVE SOT-23 DBV 5 250 Green (RoHS NIPDAU Level-2-260C-1 YEAR -40 to 125 OAZI & no Sb/Br) OPA378AIDCKR ACTIVE SC70 DCK 5 3000 Green (RoHS NIPDAU Level-2-260C-1 YEAR -40 to 125 BTS & no Sb/Br) OPA378AIDCKT ACTIVE SC70 DCK 5 250 Green (RoHS NIPDAU Level-2-260C-1 YEAR -40 to 125 BTS & 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. Addendum-Page 1

PACKAGE OPTION ADDENDUM www.ti.com 6-Feb-2020 (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 10-Jul-2018 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) OPA2378AIDCNR SOT-23 DCN 8 3000 179.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3 OPA2378AIDCNT SOT-23 DCN 8 250 179.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3 OPA378AIDBVR SOT-23 DBV 5 3000 178.0 8.4 3.3 3.2 1.4 4.0 8.0 Q3 OPA378AIDBVT SOT-23 DBV 5 250 178.0 8.4 3.3 3.2 1.4 4.0 8.0 Q3 OPA378AIDCKR SC70 DCK 5 3000 178.0 9.0 2.4 2.5 1.2 4.0 8.0 Q3 OPA378AIDCKR SC70 DCK 5 3000 179.0 8.4 2.2 2.5 1.2 4.0 8.0 Q3 OPA378AIDCKT SC70 DCK 5 250 178.0 9.0 2.4 2.5 1.2 4.0 8.0 Q3 OPA378AIDCKT SC70 DCK 5 250 179.0 8.4 2.2 2.5 1.2 4.0 8.0 Q3 PackMaterials-Page1

PACKAGE MATERIALS INFORMATION www.ti.com 10-Jul-2018 *Alldimensionsarenominal Device PackageType PackageDrawing Pins SPQ Length(mm) Width(mm) Height(mm) OPA2378AIDCNR SOT-23 DCN 8 3000 195.0 200.0 45.0 OPA2378AIDCNT SOT-23 DCN 8 250 195.0 200.0 45.0 OPA378AIDBVR SOT-23 DBV 5 3000 445.0 220.0 345.0 OPA378AIDBVT SOT-23 DBV 5 250 445.0 220.0 345.0 OPA378AIDCKR SC70 DCK 5 3000 180.0 180.0 18.0 OPA378AIDCKR SC70 DCK 5 3000 195.0 200.0 45.0 OPA378AIDCKT SC70 DCK 5 250 180.0 180.0 18.0 OPA378AIDCKT SC70 DCK 5 250 195.0 200.0 45.0 PackMaterials-Page2

None

None

None

None

PACKAGE OUTLINE DBV0005A SOT-23 - 1.45 mm max height SCALE 4.000 SMALL OUTLINE TRANSISTOR C 3.0 2.6 0.1 C 1.75 1.45 1.45 B A 0.90 PIN 1 INDEX AREA 1 5 2X 0.95 3.05 2.75 1.9 1.9 2 4 3 0.5 5X 0.3 0.15 0.2 C A B (1.1) TYP 0.00 0.25 GAGE PLANE 0.22 TYP 0.08 8 TYP 0.6 0 0.3 TYP SEATING PLANE 4214839/E 09/2019 NOTES: 1. All linear dimensions are in millimeters. Any dimensions in parenthesis are for reference only. Dimensioning and tolerancing per ASME Y14.5M. 2. This drawing is subject to change without notice. 3. Refernce JEDEC MO-178. 4. Body dimensions do not include mold flash, protrusions, or gate burrs. Mold flash, protrusions, or gate burrs shall not exceed 0.15 mm per side. www.ti.com

EXAMPLE BOARD LAYOUT DBV0005A SOT-23 - 1.45 mm max height SMALL OUTLINE TRANSISTOR PKG 5X (1.1) 1 5 5X (0.6) SYMM (1.9) 2 2X (0.95) 3 4 (R0.05) TYP (2.6) LAND PATTERN EXAMPLE EXPOSED METAL SHOWN SCALE:15X SOLDER MASK SOLDER MASK METAL UNDER METAL OPENING OPENING SOLDER MASK EXPOSED METAL EXPOSED METAL 0.07 MAX 0.07 MIN ARROUND ARROUND NON SOLDER MASK SOLDER MASK DEFINED DEFINED (PREFERRED) SOLDER MASK DETAILS 4214839/E 09/2019 NOTES: (continued) 5. Publication IPC-7351 may have alternate designs. 6. Solder mask tolerances between and around signal pads can vary based on board fabrication site. www.ti.com

EXAMPLE STENCIL DESIGN DBV0005A SOT-23 - 1.45 mm max height SMALL OUTLINE TRANSISTOR PKG 5X (1.1) 1 5 5X (0.6) SYMM 2 (1.9) 2X(0.95) 3 4 (R0.05) TYP (2.6) SOLDER PASTE EXAMPLE BASED ON 0.125 mm THICK STENCIL SCALE:15X 4214839/E 09/2019 NOTES: (continued) 7. Laser cutting apertures with trapezoidal walls and rounded corners may offer better paste release. IPC-7525 may have alternate design recommendations. 8. Board assembly site may have different recommendations for stencil design. www.ti.com

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