OP177

PIN CONNECTIONS REV.CInformation furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices.aUltraprecision Operational AmplifierOP177FEATURESUltralow Offset Voltage:T A = 25؇C: 25 ␮V MaxOutstanding Offset Voltage Drift: 0.1 ␮V/؇C Max Excellent Open-Loop Gain and Gain Linearity:12 V/␮V Typ CMRR: 130 dB Min PSRR: 115 dB MinLow Supply Current: 2.0 mA MaxFits Industry Standard Precision Op Amp Sockets (OP07/OP77)GENERAL DESCRIPTIONThe OP177 features the highest precision performance of any op amp currently available. Offset voltage of the OP177 is only 25 µV max at room temperature. The ultralow V OS of the OP177 combines with its exceptional offset voltage drift(TCV OS ) of 0.1 µV/°C max to eliminate the need for external V OS adjustment and increases system accuracy over temperature.The OP177’s open-loop gain of 12 V/µV is maintained over the full ±10 V output range. CMRR of 130 dB min, PSRR of 120 dB min, and maximum supply current of 2 mA are just a few examples of the excellent performance of this operational amplifier. The OP177’s combination of outstanding specifications ensures accurate performance in high closed-loop gain applications.This low noise bipolar input op amp is also a cost effective alternative to chopper-stabilized amplifiers. The OP177 provides chopper-type performance without the usual problems of high noise, low frequency chopper spikes, large physical size, limited common-mode input voltage range, and bulky external storage capacitors.The OP177 is offered in the –40°C to +85°C extended industrial temperature ranges. This product is available in 8-pin epoxy DIPs, as well as the space saving 8-pin Small-Outline (SO).V+V–R2A AND R2B ARE ELECTRONICALLY ADJUSTED ON CHIP AT FACTORY.Figure 1.Simplified SchematicEpoxy Mini-DIP(P Suffix)8-Pin SO (S-Suffix)V OS TRIM –IN +IN V OS TRIMV+OUT NCV –One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.Tel: 781/ Fax: 781/326-8703© Analog Devices, Inc., 2002OP177REV. C–2–OP177F OP177GParameter Symbol Conditions Min Typ Max Min Typ Max Unit INPUT OFFSETVOLTAGE V OS10252060µV LONG-TERMINPUT OFFSETVoltage Stability∆V OS/Time0.30.4µV/Mo INPUT OFFSET1CURRENT I OS0.3 1.50.3 2.8nA INPUT BIASCURRENT I B–0.2 1.22–0.2 1.2 2.8nA INPUT NOISEVOLTAGE e n f o = 1 Hz to 100 Hz2118150118150nV rms INPUT NOISECURRENT i n f o = 1 Hz to 100 Hz23838pA rms INPUTRESISTANCEDifferential-Mode3R IN264518.545MΩINPUTRESISTANCECOMMON-MODE R INCM200200GΩINPUT VOLTAGERANGE4IVR±13±14±13±14V COMMON-MODEREJECTIONRATIO CMRR V CM = ±13 V130140115140dB POWER SUPPLYREJECTIONRATIO PSRR V S = ±3 V to ±18 V115125110120dB LARGE SIGNALVOLTAGE GAIN A VO R LՆ 2 kΩ,50001200020006000V/mVV O = 610 V5OUTPUTVOLTAGESWING V O R LՆ 10 kΩ±13.5±14.0±13.5±14.0VR LՆ 2 kΩ±12.5±13.0±12.5±13.0VR LՆ 1 kΩ±12.0±12.5±12.0±12.5V SLEW RATE2SR R LՆ 2 kΩ0.10.30.10.3V/µs CLOSED-LOOPBANDWIDTH2BW A VCL = 10.40.60.40.6MHz OPEN-LOOPOUTPUTRESISTANCE R O6060ΩELECTRICAL CHARACTERISTICS(@ V S = ؎15 V, T A = 25؇C, unless otherwise noted.)OP177REV. C –3–POWERCONSUMPTIONP DV S = ±15 V,No Load 50605060mW Vs = ±3 V,No Load 3.54.53.54.5mWSUPPLY CURRENT I SYV S = ±15 V,No Load1.62 1.62mAOFFSETADJUSTMENT RANGER P = 20 k Ω±3±3mVNOTES 1Long-Term Input Offset Voltage Stability refers to the averaged trend line of V OS versus time over extended periods after the first 30 days of operation. Excluding the initial hour of operation, changes in V OS during the first 30 operating days are typically less than 2.0 µV.2Sample tested.3Guaranteed by design.4Guaranteed by CMRR test condition.5To ensure high open-loop gain throughout the ±10 V output range, A VO is tested at –10 V ≤ V O ≤ 0 V, 0 V ≤ V O ≤ +10 V, and –10 V ≤V O ≤ +10 V.Specifications subject to change without notice.OP177–SPECIFICATIONSREV. C–4–ELECTRICAL CHARACTERISTICSOP177F OP177GParameterSymbol ConditionsMin Typ Max Min Typ Max UnitINPUT OFFSET VOLTAGE V OS 154020100µV AVERAGE INPUT OFFSETVOLTAGE DRIFT 1TCV OS 0.10.30.7 1.2µV/°C INPUT OFFSET CURRENT I OS 0.5 2.20.5 4.5nA AVERAGE INPUT OFFSET CURRENT DRIFT 2TCI OS 1.540 1.585pA/°C INPUT BIAS CURRENT I B –0.22.44 2.4±6nA AVERAGE INPUT BIAS CURRENT DRIFT 2TCI B 8401560pA/°C INPUT VOLTAGE RANGE 3IVR ±13±13.5±13±13.5V COMMON-MODE REJECTION RATIO CMRR V CM = ±13 V 120140110140dB POWER SUPPLY REJECTION RATIO PSSR V S = ±3 V to ±18 V 110120106115dB LARGE-SIGNAL VOLTAGE GAIN 4A VOR L Ն 2 k Ω, V O = 10 V 2000600010004000V/mV OUTPUT VOLTAGE SWING V O R L Ն 2/k Ω±12±13±12±13V POWER CONSUMPTION P D V S = ±15 V, No Load 607560 75mW SUPPLY CURRENTI SYV S = ±15 V, No Load202.522.5mANOTES 1OP177TCV OS is sample tested.2Guaranteed by endpoint limits.3Guaranteed by CMRR test condition.4To ensure high open-loop gain throughout the ±10 V output range, A VO is tested at –10 V ≤ V O ≤ 0 V, 0 V ≤ V O ≤ +10 V, and –10 V ≤V O ≤ +10 V.Specifications subject to change without notice.V OFigure 2.Typical Offset Voltage Test Circuit–+Figure 3.Optional Offset Nulling Circuit(@ V S = ؎15 V, –40؇C ≤ T A ≤ 85؇C, unless otherwise noted.)OP177REV. C –5–ABSOLUTE MAXIMUM RATINGS Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±22 V Internal Power Dissipation 1 . . . . . . . . . . . . . . . . . . .500 mW Differential Input Voltage . . . . . . . . . . . . . . . . . . . . . . ±30 V Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±22 V Output Short-Circuit Duration . . . . . . . . . . . . . . . . Indefinite Storage Temperature RangeS, P Package . . . . . . . . . . . . . . . . . . . . . . . –65°C to +125°C Operating Temperature RangeOP177F, OP177G . . . . . . . . . . . . . . . . . . –40°C to +85°C Lead Temperature Range (Soldering, 60 sec) . . . . . . . 300°C DICE Junction Temperature (T J) . . . . . . . . –65°C to +150°C Package Type ␪JA 2␪JC Unit 8-Pin Plastic DIP (P)10343°C/W 8-Pin SO (S)15843°C/WNOTES 1For supply voltages less than ±22 V, the absolute maximum input voltage is equal to the supply voltage.2␪JA is specified for worst-case mounting conditions, i.e., ␪JA is specified for device in socket for P-DIP; ␪JA is specified for device soldered to printed circuit board for SO package.ORDERING GUIDETemperature Package Package Model Range Description Option OP177FP –40°C to +85°C 8-Pin Plastic DIP N-8OP177GP –40°C to +85°C 8-Pin Plastic DIP N-8OP177FS –40°C to +85°C 8-Pin SO SO-8OP177GS–40°C to +85°C8-Pin SOSO-8Figure 4. Burn-In CircuitOP177–Typical Performance CharacteristicsREV. C–6–TPC 2.Power Consumption vs.Power Supply TPC 5.Open-Loop Gainvs. Temperature TPC 8.Input Offset Currentvs. Temperature TPC 3.Warm-Up V OS Drift(Normalized) Z PackageTPC 6.Open-Loop Gain vs.Power Supply VoltageTPC 9.Closed-Loop Responsefor Various Gain ConfigurationsTPC 1.Gain Linearity (InputVoltage vs. Output Voltage)TPC 4.Offset Voltage ChangeDue to Thermal Shock TPC 7.Input Bias Current vs. TemperatureOP177REV. C–7–TPC 11.CMRR vs. Frequency TPC 14.Input Wideband Noise vs. Bandwidth (0.1 Hz toFrequency Indicated)TPC 12.PSRR vs. FrequencyTPC 15.Maximum Output Swingvs. FrequencyTPC 10.Open-LoopFrequency ResponseTPC 13.Total Input NoiseVoltage vs. FrequencyTPC 16.Maximum Output Voltagevs. Load Resistance TPC 17.Output Short-Circuit Current vs. TimeOP177REV. C–8–APPLICATION INFORMATION Gain LinearityThe actual open-loop gain of most monolithic op amps varies at different output voltages. This nonlinearity causes errors in high closed-loop gain circuits.It is important to know that the manufacturer’s A VO specifi-cation is only a part of the solution, since all automated testers use endpoint testing and, therefore, show only the average gain.For example, Figure 5 shows a typical precision op amp with a respectable open-loop gain of 650 V/mV. However, the gain is not constant through the output voltage range, causing nonlinear errors. An ideal op amp would show a horizontalscope trace.Figure 5.Typical Precision Op AmpFigure 6. Output Gain Linearity TraceXV IN = ؎Figure 7.Open-Loop Gain Linearity Test CircuitFigure 6 shows the OP177’s output gain linearity trace with its truly impressive average A VO of 12000 V/mV. The output trace is virtually horizontal at all points, assuring extremely high gain accuracy. ADI also performs additional testing to ensure consistent high open-loop gain at various output voltages.Figure 7 is a simple open-loop gain test circuit for your own evaluation.THERMOCOUPLE AMPLIFIER WITH COLD-JUNCTION COMPENSATIONAn example of a precision circuit is a thermocouple amplifier that must amplify very low level signals accurately without introducing linearity and offset errors to the circuit. In this circuit, an S-type thermocouple, which has a Seebeck coef-ficient of 10.3 µV/°C, produces 10.3 mV of output voltage at a temperature of 1000°C. The amplifier gain is set at 973.16.Thus, it will produce an output voltage of 10.024 V. Extended temperature ranges to beyond 1500°C can be accomplished by reducing the amplifier gain. The circuit uses a low-cost diode to sense the temperature at the terminating junctions and, in turn,compensates for any ambient temperature change. The OP177,with its high open-loop gain, plus low offset voltage and drift combines to yield a very precision temperature sensing circuit.Circuit values for other thermocouple types are shown in Table I.Table I.Thermo-Seebeckcouple Type Coefficient R1R2R7R9K 39.2 µV/°C 110 Ω 5.76 k Ω102 k Ω269 k ΩJ 50.2 µV/°C 100 Ω 4.02 k Ω80.6 k Ω200 k ΩS10.3 µV/°C100 Ω20.5 k Ω392 k Ω 1.07 M ΩOUTANALOG GROUNDFigure 8.Thermocouple Amplifier with Cold Junction CompensationPRECISION HIGH GAIN DIFFERENTIAL AMPLIFIERThe high gain, gain linearity, CMRR, and low TCV OS of the OP177 make it possible to obtain performance not previously available in single stage, very high gain amplifier applications.See Figure 9.For best CMR, R 1R 2 must equalR 3R 4. In this example, with a 10 mV differential signal, the maximum errors are as listed in Table II.OP177REV. C–9–Figure 9.Precision High Gain Differential Amplifier Table II.High Gain Differential Amp PerformanceTypeAmountCommon-Mode Voltage0.1%/V Gain Linearity, Worst Case0.02%TCVOS0.0003%/°CTCIOS0.008%/°CISOLATING LARGE CAPACITIVE LOADSThe circuit in Figure 10 reduces maximum slew rate but allows driving capacitive loads of any size without instability. Becausethe 100Ωresistor is inside the feedback loop, its effect onoutput impedance is reduced to insignificance by the high open-loop gain of the OP177.Figure 10.Isolating Capacitive LoadsFigure 11.Bilateral Current SourceFigure 12.Precision Absolute Value AmplifierOP177REV. C–10–BILATERAL CURRENT SOURCEThe current sources shown in Figure 11 will supply both positive and negative current into a grounded load.Note that Z O =R 5R 4R 2+1R 5+R 4R 2–R 3R 1and that for Z O to be infinite,R 5+R 4R 2must =R 3R 1PRECISION ABSOLUTE VALUE AMPLIFIERThe high gain and low TCV OS assure accurate operation with inputs from microvolts to volts. In this circuit, the signal always appears as a common-mode signal to the op amps. See Figure 12.PRECISION POSITIVE PEAK DETECTORIn Figure 13, the C H must be of polystyrene, Teflon,* orpolyethylene to minimize dielectric absorption and leakage. The droop rate is determined by the size of C H and the bias current of the OP41.PRECISION THRESHOLD DETECTOR/AMPLIFIERIn Figure 14, when V IN < V TH , amplifier output swings nega-tive, reverse biasing diode D 1. V OUT = V TH if R L = ∞. When V IN≥ V TH, the loop closes,V OUT =V TH +V IN –V TH ()1+R F R SC C is selected to smooth the response of the loop.*Teflon is a registered trademark of DuPont.Figure 13.Precision Positive Peak DetectorFigure 14.Precision Threshold Detector/AmplifierOP177REV. C –11–OUTLINE DIMENSIONSDimensions shown in inches and (mm).8-Pin Plastic DIP(N-8)BSC8-Pin SO (SO-08)0.0098 (0.25)0.0075 (0.19)0.0160 (0.41)0.0138 (0.35)(1.27)BSCRevision HistoryLocationPage01/30—Data Sheet changed from REV. B to REV. C.Edits to FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1Edits to GENERAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1Edits to PIN CONNECTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1Edits to ELECTRICAL CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2, 3Global deletion of references to OP177E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3, 4, 10Edits to ABSOLUTE MAXIMUM RATINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5Edits to PACKAGE TYPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5Edits to ORDERING GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5Edit to OUTLINE DIMENSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11)C(2/2--982C.A.S.UNIDETNIRP –12–。