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Picoampere Input Current QuadBipolar Op AmpAD704OUTPUT 11 IN 3AD704 VS 4TOP VIEW IN 5–IN 623OUTPUT 714OUTPUT IN 313–IN VS 412 IN IN 511–VS–IN 610 INOUTPUT 79–IN8OUTPUT(Not to Scale)–IN1OUT1NCOUT4–IN421201914NC 5AD704 VS 6TOP VIEW(Not to Scale)9101112NCOUT3313–IN32 IN2 813 –VSTOP VIEW12 IN211 –IN310 OUTPUTNC NO CONNECTNC 7The AD704 is a quad, low power bipolar op amp that has thelow input bias current of a BiFET amplifier and offers a significantly lower IB drift over temperature. It uses superbeta bipolarinput transistors to achieve picoampere input bias current levels(similar to FET input amplifiers at room temperature), while itsIB typically increases only by 5 at 125 C (unlike a BiFET amp,for which IB doubles every 10 C, resulting in a 1000 increase at125 C). In addition, the AD704 achieves 150 μV offset voltage andthe low noise characteristics of a precision bipolar input op amp.14 INAD704Figure 2. 16-Lead SOIC (R) Package3 IN1 415 –IN4NC 8 (Not to Scale) 9 NCFigure 1. 14-Lead Plastic DIP (N)GENERAL DESCRIPTION18 IN417NC16–VS15NC14 IN3NC NO CONNECTFigure 3. 20-Terminal LCC(E-20-1) Package100TYPICAL IB (nA)10TYPICAL JFET AMP10.1AD7040.01–5525TEMPERATURE ( C)12500818-004The AD704 is an excellent choice for use in low frequency activefilters in 12- and 14-bit data acquisition systems, in precisioninstrumentation, and as a high quality integrator. The AD704 isinternally compensated for unity gain stability. The AD704J israted over the commercial temperature range of 0 C to 70 C.The AD704A is rated over the industrial temperature of 40 Cto 85 C. The AD704S is rated over the military temperaturerange of 55 C to 125 C, processed to MIL-STD-883B.4100818-003–IN 200818-001OUTPUT 1Industrial/process controlsWeigh scalesECG/EKG instrumentationLow frequency active filtersBecause it has only 1/20 the input bias current of an OP07, theAD704 does not require the commonly used balancing resistor.Furthermore, the current noise is 1/5 that of the OP07, whichmakes the AD704 usable with much higher source impedances.At 1/6 the supply current (per amplifier) of the OP07, theAD704 is better suited for today’s higher density circuit boardsand battery-powered applications.16 OUTPUT–IN 2–IN2APPLICATIONSCONNECTION DIAGRAMSOUT2High dc precision150 µV maximum offset voltage1.5 µV/ C maximum offset voltage drift270 pA maximum input bias current0.3 pA/ C typical IB driftLow noise: 0.5 µV p-pTypical noise: 0.1 Hz to 10 HzLow power: 600 µA maximum supply current per amplifierDual version: AD706Figure 4. Input Bias Current Over TemperatureTable 1. Low IB @ 125 7AD86691.3 to 5VAD8603AD8607AD8609Next GenerationN/AAD8622AD8624Rev. EInformation furnished by Analog Devices is believed to be accurate and reliable. However, noresponsibility is assumed by Analog Devices for its use, nor for any infringements of patents or otherrights of third parties that may result from its use. Specifications subject to change without notice. Nolicense is granted by implication or otherwise under any patent or patent rights of Analog Devices.Trademarks and registered trademarks are the property of their respective owners.One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.Tel: 781.329.4700www.analog.comFax: 781.461.3113 2001-2010 Analog Devices, Inc. All rights reserved.00818-002FEATURES
AD704TABLE OF CONTENTSFeatures . 1Absolute Maximum Ratings .5Applications . 1ESD Caution.5General Description . 1Typical Performance Characteristics .6Connection Diagrams . 1Theory of Operation . 11Revision History . 2Outline Dimensions . 13Specifications. 3Ordering Guide . 14REVISION HISTORY1/10—Rev. D to Rev. EUpdated Format . UniversalChanges to Features and General Description Section,Added Table 1, Renumbered Sequentially . 1Changes to Table 2 . 3Changes to Table 3 . 5Updated Outline Dimensions . 13Changes to Ordering Guide . 1412/09—Rev. C to Rev. DUpdated Outline Dimensions . 10Changes to Ordering Guide . 1011/01—Rev. B to Rev. CEdits to Features . 1Edits to Product Description . 1Edits to Absolute Maximum Ratings . 3Deleted Metalization Photograph . 3Edits to Ordering Guide . 4Rev. E Page 2 of 16
AD704SPECIFICATIONSTA 25 C, VCM 0 V, and VS 15 V dc, unless otherwise noted.Table 2.ParametersINPUT OFFSET VOLTAGEInitial OffsetOffsetvs. Temp, Average TCvs. Supply (PSRR)TMIN TMAXLong-Term StabilityINPUT BIAS CURRENT 1vs. Temp, Average TCTMIN TMAXINPUT OFFSET CURRENTvs. Temp, Average TCTMIN TMAXConditionsMinTMIN TMAXVS 2 V to 18 VVS 2.5 V to 18 V100100VCM 0 VVCM 13.5 VAD704J/ATyp501000.21321260.3100VCM 0 VVCM 13.5 V800.6100100VCM 0 VVCM 13.5 VTMIN TMAXCommon-Mode Rejection3TMIN TMAXPower Supply Rejection4INPUT VOLTAGE NOISEμVμVμV/ CdBdBμV/monthpApApA/ CpApA270300TMIN TMAXf 10 HzRLOAD 2 kΩRev. E Page 3 of 1630040094949494G 1TMIN TMAXVCM 13.5 VTMIN TMAX0.1 Hz to 10 Hzf 10 Hz0.1 Hz to 10 Hzf 10 Hzf 1 kHz250300250400500600Input Bias Current2INPUT CURRENT NOISE1502501.5300400TMIN TMAXFREQUENCY RESPONSE UNITY GAINCrossover FrequencySlew Rate, Unity GainSlew RateINPUT IMPEDANCEDifferentialCommon-ModeINPUT VOLTAGE RANGECommon-Mode VoltageCommon-Mode Rejection RatioUnit0.3VCM 0 VVCM 13.5 VMATCHING CHARACTERISTICSOffset VoltageCrosstalk5Max 13.510098pApApA/ s40 2300 2MΩ pFGΩ pF 141321283500.51715VdBdBpA p-pfA/ HzμV p-pnV/ HznV/ Hz22
AD704ParametersOPEN-LOOP GAINOUTPUT CHARACTERISTICSVoltage SwingCurrentCAPACITIVE LOADDrive CapabilityPOWER SUPPLYRated PerformanceOperating RangeQuiescent CurrentTRANSISTOR COUNTConditionsVO 12 VRLOAD 10 kΩTMIN TMAXVO 10 VRLOAD 2 kΩTMIN TMAXRLOAD 10 kΩTMIN TMAXShort 0001000V/mVV/mV 13 14 15mA10,000pFMaxVGain 1 15 2.0TMIN TMAXNumber of transistorsBias current specifications are guaranteed maximum at either input.Input bias current match is the maximum difference between corresponding inputs of all four amplifiers.3CMRR match is the difference of ΔVOS/ΔVCM between any two amplifiers, expressed in dB.4PSRR match is the difference between ΔVOS/ΔVSUPPLY for any two amplifiers, expressed in dB.5See Figure 5 for test circuit.12Rev. E Page 4 of 16Unit1.51.6180 182.42.6VVmAmA
AD704ABSOLUTE MAXIMUM RATINGSTable 3.–80Rating 18 VAMP4AMP2–1000 C to 70 C 40 C to 85 C300 C–16010Specification is for the device in free air:14-lead plastic package: θJA 150 C/W.16-lead SOIC package: θJA 100 C/W.20-terminal LCC package: θJA 150 C/W.2The input pins of this amplifier are protected by back-to-back diodes. If thedifferential voltage exceeds 0.7 volts, external series protection resistorsshould be added to limit the input current to less than 25 mA.ESD CAUTION9kΩ VSOUTPUT1µF0.1µF1µFAD704PIN 4COMAD7042.5kΩINPUT SIGNAL10.1µF–VS1kΩAD704PIN 11NOTES1. ALL FOUR AMPLIFIERS ARE CONNECTED AS SHOWN.00818-0051THE SIGNAL INPUT (SUCH THAT THE AMPLIFIER’S OUTPUT IS AT MAXIMUMAMPLITUDE WITHOUT CLIPPING OR SLEW LIMITING) IS APPLIED TO ONEAMPLIFIER AT A TIME. THE OUTPUTS OF THE OTHER THREE AMPLIFIERS ARETHEN MEASURED FOR CROSSTALK.1001kFREQUENCY (Hz)10kFigure 6. Crosstalk vs. FrequencyStresses above those listed under Absolute Maximum Ratingsmay cause permanent damage to the device. This is a stressrating only; functional operation of the device at these or anyother conditions above those indicated in the operationalsection of this specification is not implied. Exposure to absolutemaximum rating conditions for extended periods may affectdevice reliability.1/4–120–14011kΩAMP3Figure 5. Crosstalk Test CircuitRev. E Page 5 of 16100k00818-006 VS 0.7 VIndefinite 65 C to 125 CCROSSTALK (dB)ParameterSupply VoltageInternal Power Dissipation (25 C)1Input VoltageDifferential Input Voltage2Output Short-Circuit Duration (Single Input)Storage Temperature RangeOperating Temperature RangeAD704JAD704ALead Temperature (Soldering, 10 sec)
AD704TYPICAL PERFORMANCE CHARACTERISTICSTA 25 C, VS 15 V dc, unless otherwise noted. VSUNITS (%)4030200–80–40040INPUT OFFSET VOLTAGE (µV)80–1.0–1.5 1.5 1.0 0.5–VS00818-00710–0.5Figure 7. Typical Distribution of Input Offset Voltage0510SUPPLY VOLTAGE (V)1500818-010INPUT COMMON-MODE VOLTAGE LIMIT –V(REFERRED TO SUPPLY VOLTAGES)5020Figure 10. Input Common-Mode Voltage Range vs. Supply Voltage355030OUTPUT VOLTAGE (V p-p)UNITS (%)4030202520151010–160–80080INPUT BIAS CURRENT (pA)16001k00818-0080Figure 8. Typical Distribution of Input Bias Current10k100kFREQUENCY (Hz)1M00818-0115Figure 11. Large Signal Frequency Response501003020100–120–60060INPUT OFFSET CURRENT (pA)1201010.11k00818-009UNITS (%)40Figure 9. Typical Distribution of Input Offset Current10k100k1MSOURCE RESISTANCE (Ω)10MFigure 12. Offset Voltage Drift vs. Source ResistanceRev. E Page 6 of 16100M00818-012OUTPUT VOLTAGE DRIFT (µV/ C)SOURCE RESISTANCE MAY BE EITHERBALANCED OR UNBALANCED.
AD7041k50VOLTAGE NOISE (nV/ Hz)40UNITS (%)302010010–0.8–0.400.4INPUT OFFSET VOLTAGE DRIFT (µV/ C)100818-01300.811001kFREQUENCY (Hz)Figure 16. Input Noise Voltage Spectral DensityFigure 13. Typical Distribution of Input Offset Voltage Drift1k4CURRENT NOISE (fA/ Hz)321100100Ω1010kΩ20MΩ00123WARM-UP TIME (Minutes)4511101001kFREQUENCY (Hz)00818-017VOUT00818-014CHANGE IN OFFSET VOLTAGE (µV)1000818-01610Figure 17. Input Noise Current Spectral DensityFigure 14. Change in Input Offset Voltage vs. Warm-Up Time120POSITIVE IB800.5µV6040NEGATIVE IB0–15–10–505COMMON-MODE VOLTAGE (V)101505TIME (Seconds)Figure 18. 0.1 Hz to 10 Hz Noise VoltageFigure 15. Input Bias Current vs. Common-Mode VoltageRev. E Page 7 of 161000818-0182000818-015INPUT BIAS CURRENT (pA)100
AD70410MOPEN-LOOP VOLTAGE GAINQUIESCENT CURRENT (µA)500450400 125 C 25 C350–55 C 25 C 125 C1M–55 C510SUPPLY VOLTAGE ( V)1520100k1Figure 19. Quiescent Supply Current vs. Supply Voltage (per Amplifier)10LOAD RESISTANCE (kΩ)00818-022000818-019200100Figure 22. Open-Loop Gain vs. Load Resistance Over Temperature160140012030OPEN-LOOP VOLTAGE GAIN UENCY (Hz)10k100k1M–200.0100818-0201Figure 20. Common-Mode Rejection vs. Frequency1001k10kFREQUENCY (Hz)100k1M10MOUTPUT VOLTAGE SWING –V(REFERRED TO SUPPLY VOLTAGES)RL 10kΩ120–PSR1008060 PSR401101001kFREQUENCY (Hz)10k100k1M–0.5–1.0–1.5 1.5 1.0 0.5–VS00818-021PSR (dB)10 VSVS 15VTA 25 C140200.11Figure 23. Open-Loop Gain and Phase vs. Frequency1801600.100818-02302000.1PHASE0510SUPPLY VOLTAGE ( V)15Figure 24. Output Voltage Swing vs. Supply VoltageFigure 21. Power Supply Rejection vs. FrequencyRev. E Page 8 of 162000818-024CMR (dB)10060100PHASE SHIFT (Degrees)VS 15V
AD704IOUT 1mA5µs100100 AV –1000 90101AV 10.1100% 0.0100818-028CLOSED-LOOP OUTPUT IMPEDANCE (Ω)1k1101001kFREQUENCY (Hz)10k100k00818-02520mV0.001Figure 28. Unity Gain Follower Small Signal Pulse Response RF 0 Ω,CL 100 pFFigure 25. Closed-Loop Output Impedance vs. FrequencyRF5µs VS0.1µF100 E INPUT–VS00818-029100% 20mVFigure 26. Unity Gain Follower (for Large Signal Applications, Resistor RFLimits the Current Through the Input Protection Diodes)Figure 29. Unity Gain Follower Small Signal Pulse Response RF 0 Ω,CL 1000 pF10kΩ VS0.1µF 90VIN10kΩ1/4AD704SQUAREWAVE INPUTRL2.5kΩVOUTCL0.1µF–VS10 2V 50µs 00818-0270% Figure 27. Unity Gain Follower Large Signal Pulse Response RF 10 kΩ,CL 1000 pFRev. E Page 9 of 16Figure 30. Unity Gain Inverter Connection00818-030100
AD704 100 0% 00818-031 Figure 33. Unity Gain Inverter Small Signal Pulse Response, CL 1000 pF5µs 9020mV00818-032100% 20mVFigure 31. Unity Gain Inverter Large Signal Pulse Response, CL 1000 pF100 10100% 909000818-033100 5µs50µs2VFigure 32. Unity Gain Inverter Small Signal Pulse Response, CL 100 pFRev. E Page 10 of 16
AD704THEORY OF OPERATIONGAIN TRIM(500kΩ POT)OPTIONALAC CMRR TRIMR52.4kΩR36.34kΩR447.5kΩDCCMRRTRIM(5kΩ POT) VSCtRGC14C21Q1 ω R16.34kΩR249.9kΩQ2 R6 C1C2ω R6 FR8 C3C4R8 R90.1µF1/4C34C41R91MΩAD704C4–VIN–VS VIN1/4OUTPUTAD704R10, 2MΩR11, 2MΩC5, 0.01µFC6, 0.01µFOPTIONAL BALANCE RESISTOR NETWORKSCAN BE REPLACED WITH A SHORT.00818-034NOTESR2 2R21. INSTRUMENTATION AMPLIFIER GAIN 1 (FOR R1 R3, R2 R4 R5).R1 RG2. CAPACITORS C2 AND C4 ARE SOUTHERN ELECTRONICS MPCC, POLYCARBONATE, 5%, 50V.3. ALL RESISTORS METAL FILM, 1%.Figure 34. Gain-of-10 Instrumentation Amplifier with Post FilteringR2 R4 R5 49.9 kΩ49.9 kΩR1 R3 0.9 G 1RG (Max Value ofTrim Potentiometer)166 kΩ16.6 kΩ1.66 kΩ80TYPICAL MONOLITHIC IN AMP6040WITHOUT CAPACITOR Ct110100FREQUENCY (Hz)1k10kFigure 35. Common-Mode Rejection vs. Frequency with and WithoutCapacitor Ct12 π ( R3) 5 10 5R1 and R36.34 kΩ526 Ω56.2 Ω1000Table 4. Resistance Values for Various GainsCircuitGain (G)101001000CIRCUIT TRIMMEDUSING CAPACITOR Ct1202099.8 kΩ0.06 GMax Value of RG Ct GAIN 10, 0.2V p-p COMMON-MODE INPUT14000818-035The instrumentation amplifier circuit offers many performancebenefits, including BiFET level input bias currents, low inputoffset voltage drift, and only 1.2 mA quiescent current. It operatesfor gains that are G 2 and, at lower gains, it benefits from nooutput amplifier offset and no noise contribution as encounteredin a 3-op-amp design. Good low frequency CMRR is achievedeven without the optional ac CMRR trim (see Figure 35). Table 4provides resistance values for three common circuit gains. Forother gains, use the following equations:160COMMON-MODE REJECTION (dB)The instrumentation amplifier with post filtering (see Figure 34)combines two applications that benefit greatly from the AD704.This circuit achieves low power and dc precision over temperaturewith a minimum of components.Bandwidth( 3 dB), Hz50 k5k0.5 kRev. E Page 11 of 16
AD704180120OFFSET VOLTAGEOF FILTER CIRCUIT (RTI) (µV)WITHOUT OPTIONALBALANCE RESISTOR, R3600WITH OPTIONALBALANCE RESISTOR, R3–60–120–180–4004080TEMPERATURE ( C)12000818-036The 1 Hz, four-pole active filter offers dc precision with aminimum of components and cost. The low current noise,IOS, and IB allow the use of 1 MΩ resistors without sacrificingthe 1 μV/ C drift of the AD704. This means that lower capacitorvalues can be used, reducing cost and space. Furthermore,because the AD704’s IB is as low as its IOS, over most of the MILtemperature range, most applications do not require the use ofthe normal balancing resistor (with its stability capacitor).Adding the optional balancing resistor enhances performance athigh temperatures, as shown in Figure 36. Table 5 givescapacitor values for several common low pass responses.Figure 36. VOS vs. Temperature Performance of the 1 Hz Filter CircuitTable 5. 1 Hz, Four-Pole Low-Pass Filter Recommended Component Values1Desired Low PassResponseBesselButterworth0.1 dB Chebychev0.2 dB Chebychev0.5 dB Chebychev1.0 dB Chebychev1Section 1Frequency 6460.7050.785Section 2Frequency 2.943.56C1 ( µF)0.1160.1720.3040.3410.4160.508C2 (µF)0.1070.1470.1980.2040.2090.206C3 (µF)0.1600.4160.7330.8231.001.23Specified values are for a 3 dB point of 1.0 Hz. For other frequencies, simply scale the C1 through C4 capacitors directly; that is, for a 3 Hz Bessel response,C1 0.0387 μF, C2 0.0357 μF, C3 0.0533 μF, and C4 0.0205 μF.Rev. E Page 12 of 16C4 (µF)0.06160.06090.03850.03470.02900.0242
AD704OUTLINE DIMENSIONS0.775 (19.69)0.750 (19.05)0.735 (18.67)14810.280 (7.11)0.250 (6.35)0.240 (6.10)70.325 (8.26)0.310 (7.87)0.300 (7.62)0.100 (2.54)BSC0.060 (1.52)MAX0.210 (5.33)MAX0.015(0.38)MIN0.150 (3.81)0.130 (3.30)0.110 (2.79)SEATINGPLANE0.022 (0.56)0.018 (0.46)0.014 (0.36)0.195 (4.95)0.130 (3.30)0.115 (2.92)0.015 (0.38)GAUGEPLANE0.014 (0.36)0.010 (0.25)0.008 (0.20)0.430 (10.92)MAX0.005 (0.13)MIN0.070 (1.78)0.050 (1.27)0.045 (1.14)070606-ACOMPLIANT TO JEDEC STANDARDS MS-001CONTROLLING DIMENSIONS ARE IN INCHES; MILLIMETER DIMENSIONS(IN PARENTHESES) ARE ROUNDED-OFF INCH EQUIVALENTS FORREFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN.CORNER LEADS MAY BE CONFIGURED AS WHOLE OR HALF LEADS.Figure 37. 14-Lead Plastic Dual In-Line Package [PDIP]Narrow Body (N-14)Dimensions shown in inches and (millimeters)10.50 (0.4134)10.10 (0.3976)9167.60 (0.2992)7.40 (0.2913)81.27 (0.0500)BSC0.30 (0.0118)0.10 (0.0039)COPLANARITY0.100.51 (0.0201)0.31 (0.0122)10.65 (0.4193)10.00 (0.3937)0.75 (0.0295)0.25 (0.0098)2.65 (0.1043)2.35 (0.0925)SEATINGPLANE45 8 0 0.33 (0.0130)0.20 (0.0079)COMPLIANT TO JEDEC STANDARDS MS-013- AACONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS(IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FORREFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN.Figure 38. 16-Lead Standard Small Outline Package [SOIC W]Wide Body (RW-16)Dimensions shown in millimeters and (inches)Rev. E Page 13 of 161.27 (0.0500)0.40 (0.0157)032707-B1
AD7040.200 (5.08)REF0.100 (2.54) REF0.015 (0.38)MIN0.075 (1.91)REF0.095 (2.41)0.075 (1.90)19180.358 (9.09)0.342 (8.69)SQ0.358(9.09)MAXSQ0.088 (2.24)0.054 (1.37)0.011 (0.28)0.007 (0.18)R TYP0.075 (1.91)REF0.055 (1.40)0.045 (1.14)32040.028 (0.71)0.022 (0.56)1BOTTOMVIEW0.050 (1.27)BSC81413945 TYP0.150 (3.81)BSCCONTROLLING DIMENSIONS ARE IN INCHES; MILLIMETER DIMENSIONS(IN PARENTHESES) ARE ROUNDED-OFF INCH EQUIVALENTS FORREFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN.022106-A0.100 (2.54)0.064 (1.63)Figure 39. 20-Terminal Ceramic Leadless Chip Carrier [LCC](E-20-1)Dimensions shown in inches and (millimeters)ORDERING ture Range 40 C to 85 C 40 C to 85 C 40 C to 85 C 40 C to 85 C0 C to 70 C0 C to 70 C0 C to 70 C0 C to 70 C0 C to 70 C0 C to 70 C 55 C to 125 CPackage Description16-Lead SOIC W16-Lead SOIC W16-Lead SOIC W16-Lead SOIC W14-Lead PDIP14-Lead PDIP16-Lead SOIC W16-Lead SOIC W16-Lead SOIC W16-Lead SOIC W20-Terminal LCCZ RoHS Compliant Part.Rev. E Page 14 of 16Package OptionRW -16RW -16RW -16RW -16N-14N-14RW -16RW -16RW -16RW -16E-20-1
AD704NOTESRev. E Page 15 of 16
AD704NOTES 2001-2010 Analog Devices, Inc. All rights reserved. Trademarks andregistered trademarks are the property of their respective owners.D00818-0-1/10(E)Rev. E Page 16 of 16
Mouser ElectronicsAuthorized DistributorClick to View Pricing, Inventory, Delivery & Lifecycle Information:Analog Devices Inc.:AD704ARZ-16 AD704JNZ AD704AR-16 AD704AR-16-REEL AD704ARZ-16-REEL AD704JRZ-16 AD704JRZ-16REEL AD704SE/883B
The AD704 is a quad, low power bipolar op amp that has the low input bias current of a BiFET amplifier and offers a signifi-cantly lower I. B. drift over temperature. It uses superbeta bipolar input transistors to achieve picoampere input bias current levels (similar to
