OPA2227-EP www.ti.com SBOS594A–MARCH2012–REVISEDNOVEMBER2012 HIGH PRECISION, LOW NOISE OPERATIONAL AMPLIFIER CheckforSamples:OPA2227-EP FEATURES 1 • LowNoise:3nV/√Hz SUPPORTS DEFENSE, AEROSPACE, AND MEDICAL APPLICATIONS • WideBandwidth:8MHz,2.3V/μs • SettlingTime:5μs • ControlledBaseline • HighCMRR:138dB(Typical) • OneAssemblyandTestSite • HighOpen-LoopGain:160dB(Typical) • OneFabricationSite • LowInputBiasCurrent:10nAMaximumat • AvailableinMilitary(–55°Cto125°C) 25°C TemperatureRange (1) • LowOffsetVoltage:100μVMaximumat25°C • ExtendedProductLifeCycle • WideSupplyRange:±2.5Vto±18V • ExtendedProduct-ChangeNotification • ProductTraceability APPLICATIONS D PACKAGE • DataAcquisition (TOPVIEW) • TelecomEquipment • GeophysicalAnalysis OutA 1 8 V+ A • VibrationAnalysis –InA 2 7 Out B • SpectralAnalysis +InA 3 B 6 –In B • ProfessionalAudioEquipment V– 4 5 +In B • ActiveFilters • PowerSupplyControl (1) Additionaltemperaturerangesavailable-contactfactory DESCRIPTION The OPA2227 operational amplifier combines low noise and wide bandwidth with high precision to make it the idealchoiceforapplicationsrequiringbothacandprecisiondcperformance. TheOPA2227isunity-gainstableandfeatureshighslewrate(2.3V/μs)andwidebandwidth(8MHz). The OPA2227 operational amplifier is ideal for professional audio equipment. In addition, low quiescent current andlowcostmakethemidealforportableapplicationsrequiringhighprecision. The OPA2227 operational amplifier is a pin-for-pin replacement for the industry standard OP-27 with substantial improvements across the board. The dual and quad versions are available for space savings and perchannel costreduction. TheOPA2227isavailableinanSOIC-8package.Operationisspecifiedfrom–55°Cto125°C. 1 Pleasebeawarethatanimportantnoticeconcerningavailability,standardwarranty,anduseincriticalapplicationsof TexasInstrumentssemiconductorproductsanddisclaimerstheretoappearsattheendofthisdatasheet. PRODUCTIONDATAinformationiscurrentasofpublicationdate. Copyright©2012,TexasInstrumentsIncorporated Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarilyincludetestingofallparameters.

OPA2227-EP SBOS594A–MARCH2012–REVISEDNOVEMBER2012 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. ORDERINGINFORMATION(1) ORDERABLEPART T PACKAGE TOP-SIDEMARKING VIDNUMBER TRANSPORTMEDIA A NUMBER –55°Cto OPA2227MDREP V62/12610-01XE TapeandReel,large SOIC-8–D 2227EP 125°C OPA2227MDEP V62/12610-01XE-T Tube (1) Forthemostcurrentpackageandorderinginformation,seethePackageOptionAddendumattheendofthisdocument,orseetheTI websiteatwww.ti.com. ABSOLUTE MAXIMUM RATINGS(1) overoperatingfree-airtemperaturerange(unlessotherwisenoted) VALUE UNIT Supplyvoltage ±18 V Signalinputterminals Voltage (V–)–0.7to(V+)+0.7 V Current 20 mA Outputshort-circuit(toground)(2) Continuous Operatingtemperature -55to125 °C Storagetemperature -65to150 °C Junctiontemperature 150 °C Leadtemperature(soldering,10s) 300 °C (1) Stressesbeyondthoselistedunder"absolutemaximumratings"maycausepermanentdamagetothedevice.Thesearestressratings only,andfunctionaloperationofthedeviceattheseoranyotherconditionsbeyondthoseindicatedunder"recommendedoperating conditions"isnotimplied.Exposuretoabsolute-maximum-ratedconditionsforextendedperiodsmayaffectdevicereliability. (2) Onechannelperpackage. THERMAL INFORMATION OPA2227 THERMALMETRIC(1) D UNITS 8PINS θ Junction-to-ambientthermalresistance(2) 91.9 JA θ Junction-to-case(top)thermalresistance(3) 39.9 JCtop θ Junction-to-boardthermalresistance(4) 40.6 JB °C/W ψ Junction-to-topcharacterizationparameter(5) 3.9 JT ψ Junction-to-boardcharacterizationparameter(6) 39.6 JB θ Junction-to-case(bottom)thermalresistance(7) N/A JCbot (1) Formoreinformationabouttraditionalandnewthermalmetrics,seetheICPackageThermalMetricsapplicationreport,SPRA953. (2) Thejunction-to-ambientthermalresistanceundernaturalconvectionisobtainedinasimulationonaJEDEC-standard,high-Kboard,as specifiedinJESD51-7,inanenvironmentdescribedinJESD51-2a. (3) Thejunction-to-case(top)thermalresistanceisobtainedbysimulatingacoldplatetestonthepackagetop.NospecificJEDEC- standardtestexists,butaclosedescriptioncanbefoundintheANSISEMIstandardG30-88. (4) Thejunction-to-boardthermalresistanceisobtainedbysimulatinginanenvironmentwitharingcoldplatefixturetocontrolthePCB temperature,asdescribedinJESD51-8. (5) Thejunction-to-topcharacterizationparameter,ψ ,estimatesthejunctiontemperatureofadeviceinarealsystemandisextracted JT fromthesimulationdataforobtainingθ ,usingaproceduredescribedinJESD51-2a(sections6and7). JA (6) Thejunction-to-boardcharacterizationparameter,ψ ,estimatesthejunctiontemperatureofadeviceinarealsystemandisextracted JB fromthesimulationdataforobtainingθ ,usingaproceduredescribedinJESD51-2a(sections6and7). JA (7) Thejunction-to-case(bottom)thermalresistanceisobtainedbysimulatingacoldplatetestontheexposed(power)pad.Nospecific JEDECstandardtestexists,butaclosedescriptioncanbefoundintheANSISEMIstandardG30-88. Spacer 2 SubmitDocumentationFeedback Copyright©2012,TexasInstrumentsIncorporated ProductFolderLinks:OPA2227-EP

OPA2227-EP www.ti.com SBOS594A–MARCH2012–REVISEDNOVEMBER2012 ELECTRICAL CHARACTERISTICS AtT =25°C,V =±5Vto±15V,R =10kΩ(unlessotherwisenoted). A S L PARAMETER TESTCONDITIONS MIN TYP MAX UNIT OFFSETVOLTAGE Inputoffsetvoltage(VOS) ±5 ±100 µV vsTemperature,TA=-55°Cto125°C ±10 ±250 µV vsTemperature(dVOS/dT),TA=-55°Cto125°C ±0.1 µV/°C vsPowersupply(PSRR)TA=-55°Cto125°C VS=±2.5Vto±18V ±0.5 ±2.1 µV/V vsTime 0.2 µV/mo dc 0.2 µV/V Channelseparation(dual) f=1kHz,RL=5kΩ 110 dB INPUTBIASCURRENT Inputbiascurrent(IB) ±2.5 ±10 nA TA=-55°Cto125°C SeeTypicalCharacteristics Inputoffsetcurrent(IOS) ±2.5 ±10 nA TA=-55°Cto125°C SeeTypicalCharacteristics NOISE Inputvoltagenoise,f=0.1Hzto10Hz 90 nVp-p 15 nVrms Inputvoltagenoisedensity(en) f=10Hz 3.5 nV/√Hz f=100Hz 3 nV/√Hz f=1kHz 3 nV/√Hz Currentnoisedensity(in),f=1kHz 0.4 pA/√Hz INPUTVOLTAGERANGE Common-modevoltagerange(VCM) (V-)+2 (V+)–2 V TA=-55°Cto125°C Common-moderejection(CMRR) VCM=(V–)+2Vto(V+)–2V 120 138 dB TA=-55°Cto125°C 108 138 dB INPUTIMPEDANCE Differential Open-loopvoltagegain(AOL) 107||12 Ω||pF Common-mode VCM=(V–)+2Vto(V+)–2V 109||3 Ω||pF OPEN-LOOPGAIN Open-loopvoltagegain(AOL) VO=(V–)+2Vto(V+)–2V,RL=10kΩ 132 160 TA=-55°Cto125°C 112 160 dB VO=(V–)+3.5Vto(V+)–3.5V,RL=600Ω 132 160 TA=-55°Cto125°C 112 160 FREQUENCYRESPONSE Gainbandwidthproduct(GBW) 8 MHz Slewrate(SR) 2.3 V/µs Settlingtime: 0.1% G=1,10-VStep,CL=100pF 5 µs 0.01% G=1,10-VStep,CL=100pF 5.6 µs Overloadrecoverytime VINxG=VS 1.3 µs Totalharmonicdistortion+noise(THD+N) f=1kHz,G=1,VO=3.5Vrms 0.00005 % OUTPUT Voltageoutput TA=-55°Cto125°C RL=10kΩ (V-)+2 (V+)–2 V TA=-55°Cto125°C RL=600Ω (V-)+3.5 (V+)–3.5 Short-circuitcurrent(ISC) ±45 mA Capacitiveloaddrive(CLOAD) SeeTypicalCharacteristics POWERSUPPLY Specifiedvoltagerange(VS) ±5 ±15 V Operatingvoltagerange ±2.5 ±18 V Quiescentcurrent(peramplifier)(IQ) IO=0A ±3.7 ±3.95 Copyright©2012,TexasInstrumentsIncorporated SubmitDocumentationFeedback 3 ProductFolderLinks:OPA2227-EP

OPA2227-EP SBOS594A–MARCH2012–REVISEDNOVEMBER2012 www.ti.com ELECTRICAL CHARACTERISTICS (continued) AtT =25°C,V =±5Vto±15V,R =10kΩ(unlessotherwisenoted). A S L PARAMETER TESTCONDITIONS MIN TYP MAX UNIT TA=-55°Cto125°C IO=0A ±4.30 mA TEMPERATURERANGE Specifiedtemperaturerange –55 125 °C Operatingtemperaturerange –55 125 °C Storagetemperaturerange –65 150 °C xxx 1000000 s) 100000 ur o H e ( Lif d e at m sti 10000 E 1000 125 130 135 140 145 150 ContinuousTJ(°C) A. Seedatasheetforabsolutemaximumandminimumrecommendedoperatingconditions. B. Silicon operating life design goal is 10 years at 105°C junction temperature (does not include package interconnect life). Figure1. OPA2227-EPWirebondLifeDeratingChart 4 SubmitDocumentationFeedback Copyright©2012,TexasInstrumentsIncorporated ProductFolderLinks:OPA2227-EP

OPA2227-EP www.ti.com SBOS594A–MARCH2012–REVISEDNOVEMBER2012 TYPICAL CHARACTERISTICS AtT =25°C,R =10kΩ,V =±15V(unlessotherwisenoted). A L S OPEN-LOOPGAIN/PHASE vs FREQUENCY POWER SUPPLYAND COMMON-MODE 180 0 REJECTION RATIO vs FREQUENCY 140 160 –20 140 –40 120 G +CMRR 120 –60 A(dB)OL 1086000 φ –––81100200 Phase°) ( CMRR (dB) 18000 +PSRR 40 –140 RR, 60 –PSRR S 20 –160 P 40 0 –180 -20 –20 –200 0.01 0.10 1 10 100 1k 10k 100k 1M 10M 100M –0 0.1 1 10 100 1k 10k 100k 1M Frequency (Hz) Frequency (Hz) INPUTVOLTAGEANDCURRENTNOISE TOTALHARMONIC DISTORTION + NOISE SPECTRALDENSITYvsFREQUENCY vs FREQUENCY 100k 0.01 V = 3.5Vrms OUT 10k Hz)Hz) √Noise (nV/√Noise (fA/ 1k Current Noise +Noise (%) 0.001 Voltage Current 10100 THD 0.0001 G = 1, RL= 10kΩ Voltage Noise 1 0.00001 0.1 1 10 100 1k 10k 20 100 1k 10k 20k Frequency (Hz) Frequency (Hz) INPUTNOISEVOLTAGEvsTIME CHANNELSEPARATION vs FREQUENCY 140 B) 120 d n ( o v ati 100 di ar 50nV/ el Sep 80 nn Dual and quad devices. G = 1, all channels. a h Quad measured ChannelAto D, or B to C; C 60 other combinations yield similiar or improved rejection. 40 1s/div 10 100 1k 10k 100k 1M Frequency (Hz) Copyright©2012,TexasInstrumentsIncorporated SubmitDocumentationFeedback 5 ProductFolderLinks:OPA2227-EP

OPA2227-EP SBOS594A–MARCH2012–REVISEDNOVEMBER2012 www.ti.com TYPICAL CHARACTERISTICS (continued) AtT =25°C,R =10kΩ,V =±15V(unlessotherwisenoted). A L S VOLTAGENOISEDISTRIBUTION(10Hz) WARM-UPOFFSETVOLTAGE DRIFT 24 10 8 V) 6 µ s (%) 16 nge ( 4 nit ha 2 U C Percent of 8 et Voltage ––024 s Off –6 –8 0 –10 0 50 100 150 200 250 300 0 3.16 3.25 3.34 3.43 3.51 3.60 3.69 3.78 Time from Power SupplyTurn-On (s) Noise (nV/√Hz) AOL,CMRR,PSRRvsTEMPERATURE INPUTBIAS CURRENTvsTEMPERATURE 160 40 A OL 150 30 CMRR 140 MRR, PSRR (dB) 111113200000 PSRR Bias Current (nA) −1120000 A, COL 9800 Input −−3200 70 −40 60 −50 –75 –50 –25 0 25 50 75 100 125 −60 −40 −20 0 20 40 60 80 100 120 140 Temperature (°C) Temperature (°C) INPUTOFFSETCURRENTvsTEMPERATURE SHORT-CIRCUITCURRENTvsTEMPERATURE 6 60 5 50 nA) 4 mA) et Current ( 23 uit Current ( 4300 +ISC –ISC Offs 1 Circ 20 put 0 ort- n h I S 10 −1 −2 0 −60 −40 −20 0 20 40 60 80 100 120 140 –75 –50 –25 0 25 50 75 100 125 Temperature (°C) Temperature (°C) 6 SubmitDocumentationFeedback Copyright©2012,TexasInstrumentsIncorporated ProductFolderLinks:OPA2227-EP

OPA2227-EP www.ti.com SBOS594A–MARCH2012–REVISEDNOVEMBER2012 TYPICAL CHARACTERISTICS (continued) AtT =25°C,R =10kΩ,V =±15V(unlessotherwisenoted). A L S QUIESCENTCURRENTvsTEMPERATURE QUIESCENTCURRENTvs SUPPLY VOLTAGE 5.0 3.8 ±18V ent Current (mA) 443...505 ±±±±±21115.052V5VVVV ent Current (mA) 333...642 esc esc ui ui Q 3.0 Q 3.0 2.5 2.8 –60 –40 –20 0 20 40 60 80 100 120 140 0 2 4 6 8 10 12 14 16 18 20 Temperature (°C) Supply Voltage (±V) CHANGE IN INPUTBIAS CURRENT SLEWRATEvsTEMPERATURE vs POWER SUPPLYVOLTAGE 3.0 2.0 Curveshowsnormalizedchangeinbiascurrent 1.5 2.5 withrespecttoVS=±10V.TypicalIBmayrange Positive Slew Rate Negative Slew Rate 1.0 from–2nAto +2nAat VS= ±10V. V) 2.0 V/ 0.5 µate ( 1.5 (nA)B 0 w R ∆I –0.5 Sle 1.0 –1.0 0.5 RLOAD= 2kΩ C = 100pF –1.5 LOAD 0 –2.0 –75 –50 –25 0 25 50 75 100 125 0 5 10 15 20 25 30 35 40 Temperature (°C) Supply Voltage (V) CHANGEININPUTBIASCURRENT SETTLINGTIMEvsCLOSED-LOOPGAIN vsCOMMON-MODEVOLTAGE 100 1.5 V =±15V, 10V Step Curveshowsnormalizedchangeinbiascurrent S C = 1500pF withrespecttoV =0V.TypicalI mayrange L 1.0 from–2nAto +2nCAMat V = 0V. B RL= 2kΩ CM s) µ 0.5 e ( (nA)B 0 VS=±15V ngTim 10 0.01% 0.1% ∆I ettli –0.5 S V =±5V S –1.0 1 –1.5 ±1 ±10 ±100 –15 –10 –5 0 5 10 15 Gain (V/V) Common-Mode Voltage (V) Copyright©2012,TexasInstrumentsIncorporated SubmitDocumentationFeedback 7 ProductFolderLinks:OPA2227-EP

OPA2227-EP SBOS594A–MARCH2012–REVISEDNOVEMBER2012 www.ti.com TYPICAL CHARACTERISTICS (continued) AtT =25°C,R =10kΩ,V =±15V(unlessotherwisenoted). A L S OUTPUTVOLTAGESWINGvsOUTPUTCURRENT MAXIMUM OUTPUTVOLTAGE vs FREQUENCY 15 V+ 30 14 (V+)–1V V = ±15V S 13 (V+)–2V 25 V) –40°C e Swing ( 111120 125°C85°2C5°C –55°C (V+)–3V ge (Vp-p) 20 oltag –10 –55°C Volta 15 ut V –11 125°C 85°C put 10 VS= ±5V utp –12 –40°C (V–) +3V Out O –13 25°C (V–) +2V 5 –14 (V–) +1V –15 V– 0 0 10 20 30 40 50 60 1k 10k 100k 1M 10M Output Current (mA) Frequency (Hz) SMALL-SIGNALOVERSHOOT LARGE-SIGNALSTEPRESPONSE vsLOADCAPACITANCE G=–1,C =1500pF L 70 60 Gain = +10 50 %) oot ( 40 div ersh 30 2V/ v O 20 Gain =–1 Gain =–10 Gain = +1 10 0 1 10 100 1k 10k 100k 5µs/div Load Capacitance(pF) SMALL-SIGNALSTEPRESPONSE SMALL-SIGNALSTEPRESPONSE G=+1,CL=1000pF G=+1,CL=5pF v v di di V/ V/ m m 5 5 2 2 400ns/div 400ns/div 8 SubmitDocumentationFeedback Copyright©2012,TexasInstrumentsIncorporated ProductFolderLinks:OPA2227-EP

OPA2227-EP www.ti.com SBOS594A–MARCH2012–REVISEDNOVEMBER2012 APPLICATION INFORMATION Basic Connection The OPA2227 is a precision operational amplifier with very low noise. It is unity-gain stable with a slew rate of 2.3 V/μs and 8-MHz bandwidth. Applications with noisy or high impedance power supplies may require decouplingcapacitorsclosetothedevicepins.Inmostcases,0.1-μFcapacitorsareadequate. Offset Voltage and Drift The OPA2227 has very low offset voltage and drift. To achieve highest dc precision, circuit layout and mechanical conditions should be optimized. Connections of dissimilar metals can generate thermal potentials at the op amp inputs which can degrade the offset voltage and drift. These thermocouple effects can exceed the inherent drift of the amplifier and ultimately degrade its performance. The thermal potentials can be made to cancelbyassuringthattheyareequalatbothinputterminals.Inaddition: • Keepthermalmassoftheconnectionsmadetothetwoinputterminalssimilar. • Locateheatsourcesasfaraspossiblefromthecriticalinputcircuitry. • Shieldoperationalamplifierandinputcircuitryfromaircurrentssuchasthosecreatedbycoolingfans. Operating Voltage OPA2227 operational amplifier operates from ±2.5-V to ±18-V supplies with excellent performance. Unlike most operational amplifiers which are specified at only one supply voltage, the OPA2227 is specified for real-world applications; a single set of specifications applies over the ±5-V to ±15-V supply range. Specifications are assured for applications between ±5-V and ±15-V power supplies. Some applications do not require equal positive and negative output voltage swing. Power supply voltages do not need to be equal. The OPA2227 can operate with as little as 5 V between the supplies and with up to 36 V between the supplies. For example, the positive supply could be set to 25 V with the negative supply at –5 V or vice-versa. In addition, key parameters are assured over the specified temperature range, –55°C to 125°C. Parameters which vary significantly with operatingvoltageortemperatureareshownintheTypicalPerformanceCurves. Offset Voltage Adjustment The OPA2227 is laser-trimmed for very low offset and drift so most applications will not require external adjustment. Input Protection Back-to-back diodes (see Figure 2) are used for input protection on the OPA2227. Exceeding the turn-on threshold of these diodes, as in a pulse condition, can cause current to flow through the input protection diodes due to the amplifier’s finite slew rate. Without external current-limiting resistors, the input devices can be destroyed. Sources of high input current can cause subtle damage to the amplifier. Although the unit may still be functional,importantparameterssuchasinputoffsetvoltage,drift,andnoisemayshift. R F 500Ω – OPA2227 Output + Input Figure2. PulsedOperation When using the OPA2227 as a unity-gain buffer (follower), the input current should be limited to 20 mA. This can be accomplished by inserting a feedback resistor or a resistor in series with the source. Sufficient resistor size canbecalculated: R =V /20mA-R (1) X S SOURCE Copyright©2012,TexasInstrumentsIncorporated SubmitDocumentationFeedback 9 ProductFolderLinks:OPA2227-EP

OPA2227-EP SBOS594A–MARCH2012–REVISEDNOVEMBER2012 www.ti.com where R is either in series with the source or inserted in the feedback path. For example, for a 10-V pulse X (V = 10 V), total loop resistance must be 500 Ω. If the source impedance is large enough to sufficiently limit the S current on its own, no additional resistors are needed. The size of any external resistors must be carefully chosen since they will increase noise. See the Noise Performance section of this data sheet for further informationonnoisecalculation.Figure2showsanexampleimplementingacurrentlimitingfeedbackresistor. Input Bias Current Cancellation TheinputbiascurrentoftheOPA2227isinternallycompensatedwithanequalandoppositecancellationcurrent. Theresultinginputbiascurrentisthedifferencebetweenwithinputbiascurrentandthecancellationcurrent.The residualinputbiascurrentcanbepositiveornegative. When the bias current is cancelled in this manner, the input bias current and input offset current are approximately equal. A resistor added to cancel the effect of the input bias current (as shown in Figure 3) may actuallyincreaseoffsetandnoiseandisthereforenotrecommended. Conventional OpAmp Configuration R 2 R 1 OpAmp RB= R2|| R1 External Cancellation Resistor Figure3. InputBiasCurrentCancellation Noise Performance Figure 4 shows total circuit noise for varying source impedances with the operational amplifier in a unity-gain configuration(nofeedbackresistornetwork,thereforenoadditionalnoisecontributions).Twodifferentoperational amplifiers are shown with total circuit noise calculated. The OPA2227 has very low voltage noise, making it ideal for low source impedances (less than 20 kΩ). A similar precision operational amplifier, the OPA277, has somewhat higher voltage noise but lower current noise. It provides excellent noise performance at moderate source impedance (10 kΩ to 100 kΩ). Above 100 kΩ, a FET-input op amp such as the OPA132 (very low current noise) may provide improved performance. The equation is shown for the calculation of the total circuit noise. Note that e = voltage noise, i = current noise, R = source impedance, k = Boltzmann’s constant = n n S 1.38x10–23J/KandTistemperatureinK.Formoredetailsoncalculatingnoise,see “BasicNoiseCalculations.” VOLTAGE NOISE SPECTRALDENSITY vs SOURCE RESISTANCE 1.00+03 0 E y, sit EO OPA2227 e Noise Spectral Den√Typical at 1k (V/Hz) 11..0000EE++0021 RSOPA2227 Resistor Noise g Resistor Noise a otl V E 2=e2+(i R)2+4kTR O n n S S 1.00E+00 100 1k 10k 100k 1M Source Resistance, R (Ω) S Figure4. NoisePerformanceoftheOPA2227inUnity-GainBufferConfiguration 10 SubmitDocumentationFeedback Copyright©2012,TexasInstrumentsIncorporated ProductFolderLinks:OPA2227-EP

OPA2227-EP www.ti.com SBOS594A–MARCH2012–REVISEDNOVEMBER2012 BasicNoiseCalculations Design of low noise operational amplifier circuits requires careful consideration of a variety of possible noise contributors: noise from the signal source, noise generated in the operational amplifier, and noise from the feedback network resistors. The total noise of the circuit is the root-sum-square combination of all noise components. The resistive portion of the source impedance produces thermal noise proportional to the square root of the resistance. This function is shown plotted in Figure 4. Since the source impedance is usually fixed, select the operationalamplifierandthefeedbackresistorstominimizetheircontributiontothetotalnoise. Figure 4 shows total noise for varying source impedances with the operational amplifier in a unity-gain configuration (no feedback resistor network and therefore no additional noise contributions). The operational amplifier itself contributes both a voltage noise component and a current noise component. The voltage noise is commonly modeled as a time-varying component of the offset voltage. The current noise is modeled as the time- varying component of the input bias current and reacts with the source resistance to create a voltage component of noise. Consequently, the lowest noise operational amplifier for a given application depends on the source impedance. For low source impedance, current noise is negligible and voltage noise generally dominates. For highsourceimpedance,currentnoisemaydominate. Figure 5 shows both inverting and noninverting operational amplifier circuit configurations with gain. In circuit configurations with gain, the feedback network resistors also contribute noise. The current noise of the operational amplifier reacts with the feedback resistors to create additional noise components. The feedback resistorvaluescangenerallybechosentomakethesenoisesourcesnegligible.Theequationsfortotalnoiseare shownforbothconfigurations. Copyright©2012,TexasInstrumentsIncorporated SubmitDocumentationFeedback 11 ProductFolderLinks:OPA2227-EP

OPA2227-EP SBOS594A–MARCH2012–REVISEDNOVEMBER2012 www.ti.com Noise in Noninverting Gain Configuration R 2 R 1 E O R S V S Noise in Inverting Gain Configuration R 2 R 1 E R O S V S Foropampsat1kHz,e =3nV/√Hzandi =0.4pA/√Hz. n n Figure5. NoiseCalculationinGainConfigurations 12 SubmitDocumentationFeedback Copyright©2012,TexasInstrumentsIncorporated ProductFolderLinks:OPA2227-EP

OPA2227-EP www.ti.com SBOS594A–MARCH2012–REVISEDNOVEMBER2012 Figure 6 shows the 0.1-Hz to 10-Hz bandpass filter used to test the noise of the OPA2227. The filter circuit was designed using Texas Instruments’ FilterPro software (available at www.ti.com). Figure 7 shows the configuration oftheOPA2227fornoisetesting. R1 R2 R8 R11 2MΩ 2MΩ 402kΩ 178kΩ 1RkΩ3 9.0R94kΩ 22Cn4F 10Cn6F R R R R 6 7 9 10 40.2kΩ 97.6kΩ 178kΩ 226kΩ 2 6 C C 1 7 1µ1F 1µ2F U1 C 3 U2 C 5 U2 VOUT 3 5 0.47µF 0.47µF (OPA2227) (OPA2227) (OPA2227) Input from Device R 5 Under 634kΩ Test Figure6. 0.1-Hzto10-HzBandpassFilterUsedtoTestWidebandNoiseoftheOPA2227 22pF 100kΩ 10Ω 2 1 3 OPA2227 VOUT Device Under Test Figure7. NoiseTestCircuit Copyright©2012,TexasInstrumentsIncorporated SubmitDocumentationFeedback 13 ProductFolderLinks:OPA2227-EP

OPA2227-EP SBOS594A–MARCH2012–REVISEDNOVEMBER2012 www.ti.com 1.1kΩ 1.43kΩ 2.2nF dc Gain = 1 330pF 1.1kΩ 1.65kΩ 2 V IN 1.43kΩ 1.91kΩ 1 6 OPA2227 33nF 2.21kΩ 3 7 OPA2227 V 68nF OUT 5 10nF f = 13.86kHz f = 20.33kHz f = 7.2kHz N N Q = 1.186 Q = 4.519 Figure8. Three-Pole,20-kHzLowPass,0.5-dBChebyshevFilter 0.1µF 100Ω 100kΩ 2 1 Output OPA2227 3 NOTE: Use metal film resistors Dexter 1M and plastic film capacitor. Circuit Thermopile must be well shielded to achieve Detector low noise. Responsivity≈2.5 x 104V/W Output Noise≈30µVrms, 0.1Hz to 10Hz Figure9. Long-WavelengthInfraredDetectorAmplifier 14 SubmitDocumentationFeedback Copyright©2012,TexasInstrumentsIncorporated ProductFolderLinks:OPA2227-EP

OPA2227-EP www.ti.com SBOS594A–MARCH2012–REVISEDNOVEMBER2012 +15V 0.1µF 1kΩ 1kΩ Audio In 1/2 OPA2227 200Ω To 200Ω Headphone 1/2 OPA2227 This application uses two op amps in parallel for higher output current drive. 0.1µF –15V Figure10. HeadphoneAmplifier Copyright©2012,TexasInstrumentsIncorporated SubmitDocumentationFeedback 15 ProductFolderLinks:OPA2227-EP

OPA2227-EP SBOS594A–MARCH2012–REVISEDNOVEMBER2012 www.ti.com BassTone Control R R 2 R 1 50kΩ 3 7.5kΩ 7.5kΩ 3 CW 1 2 R 10 100kΩ MidrangeTone Control C 1 940pF R R 5 R 4 50kΩ 6 2.7kΩ 2.7kΩ 3 CW 1 V IN 2 C 2 0.0047µF TrebleTone Control R R 8 R 7 50kΩ 9 7.5kΩ 7.5kΩ R 3 CW 1 11 100kΩ 2 C 3 680pF 2 1 3 OPA2227 VOUT Figure11. Three-BandActiveToneControl(Bass,MidrangeandTreble) 16 SubmitDocumentationFeedback Copyright©2012,TexasInstrumentsIncorporated ProductFolderLinks:OPA2227-EP

PACKAGE OPTION ADDENDUM www.ti.com 11-Apr-2013 PACKAGING INFORMATION Orderable Device Status Package Type Package Pins Package Eco Plan Lead/Ball Finish MSL Peak Temp Op Temp (°C) Top-Side Markings Samples (1) Drawing Qty (2) (3) (4) OPA2227MDREP ACTIVE SOIC D 8 2500 Green (RoHS CU NIPDAU Level-3-260C-168 HR -55 to 125 2227EP & no Sb/Br) V62/12610-01XE ACTIVE SOIC D 8 2500 Green (RoHS CU NIPDAU Level-3-260C-168 HR -55 to 125 2227EP & 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) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. TBD: The Pb-Free/Green conversion plan has not been defined. Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes. Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above. Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material) (3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. (4) Multiple Top-Side Markings will be inside parentheses. Only one Top-Side 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 Top-Side Marking for that device. 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. OTHER QUALIFIED VERSIONS OF OPA2227-EP : Addendum-Page 1

PACKAGE OPTION ADDENDUM www.ti.com 11-Apr-2013 •Catalog: OPA2227 NOTE: Qualified Version Definitions: •Catalog - TI's standard catalog product Addendum-Page 2

PACKAGE MATERIALS INFORMATION www.ti.com 25-Feb-2013 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) OPA2227MDREP SOIC D 8 2500 330.0 12.4 6.4 5.2 2.1 8.0 12.0 Q1 PackMaterials-Page1

PACKAGE MATERIALS INFORMATION www.ti.com 25-Feb-2013 *Alldimensionsarenominal Device PackageType PackageDrawing Pins SPQ Length(mm) Width(mm) Height(mm) OPA2227MDREP SOIC D 8 2500 367.0 367.0 35.0 PackMaterials-Page2

PACKAGE OUTLINE D0008A SOIC - 1.75 mm max height SCALE 2.800 SMALL OUTLINE INTEGRATED CIRCUIT C SEATING PLANE .228-.244 TYP [5.80-6.19] .004 [0.1] C A PIN 1 ID AREA 6X .050 [1.27] 8 1 2X .189-.197 [4.81-5.00] .150 NOTE 3 [3.81] 4X (0 -15 ) 4 5 8X .012-.020 B .150-.157 [0.31-0.51] .069 MAX [3.81-3.98] .010 [0.25] C A B [1.75] NOTE 4 .005-.010 TYP [0.13-0.25] 4X (0 -15 ) SEE DETAIL A .010 [0.25] .004-.010 0 - 8 [0.11-0.25] .016-.050 [0.41-1.27] DETAIL A (.041) TYPICAL [1.04] 4214825/C 02/2019 NOTES: 1. Linear dimensions are in inches [millimeters]. Dimensions in parenthesis are for reference only. Controlling dimensions are in inches. Dimensioning and tolerancing per ASME Y14.5M. 2. This drawing is subject to change without notice. 3. This dimension does not include mold flash, protrusions, or gate burrs. Mold flash, protrusions, or gate burrs shall not exceed .006 [0.15] per side. 4. This dimension does not include interlead flash. 5. Reference JEDEC registration MS-012, variation AA. www.ti.com

EXAMPLE BOARD LAYOUT D0008A SOIC - 1.75 mm max height SMALL OUTLINE INTEGRATED CIRCUIT 8X (.061 ) [1.55] SYMM SEE DETAILS 1 8 8X (.024) [0.6] SYMM (R.002 ) TYP [0.05] 5 4 6X (.050 ) [1.27] (.213) [5.4] LAND PATTERN EXAMPLE EXPOSED METAL SHOWN SCALE:8X SOLDER MASK SOLDER MASK METAL OPENING OPENING METAL UNDER SOLDER MASK EXPOSED METAL EXPOSED METAL .0028 MAX .0028 MIN [0.07] [0.07] ALL AROUND ALL AROUND NON SOLDER MASK SOLDER MASK DEFINED DEFINED SOLDER MASK DETAILS 4214825/C 02/2019 NOTES: (continued) 6. Publication IPC-7351 may have alternate designs. 7. Solder mask tolerances between and around signal pads can vary based on board fabrication site. www.ti.com

EXAMPLE STENCIL DESIGN D0008A SOIC - 1.75 mm max height SMALL OUTLINE INTEGRATED CIRCUIT 8X (.061 ) [1.55] SYMM 1 8 8X (.024) [0.6] SYMM (R.002 ) TYP [0.05] 5 4 6X (.050 ) [1.27] (.213) [5.4] SOLDER PASTE EXAMPLE BASED ON .005 INCH [0.125 MM] THICK STENCIL SCALE:8X 4214825/C 02/2019 NOTES: (continued) 8. Laser cutting apertures with trapezoidal walls and rounded corners may offer better paste release. IPC-7525 may have alternate design recommendations. 9. Board assembly site may have different recommendations for stencil design. www.ti.com

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