运放使用手册

Printed in U.S.A.®OPA2604/databook/OPA2604.htmlDual FET-Input, Low DistortionOPERATIONAL AMPLIFIERFEATURESq LOW DISTORTION: 0.0003% at 1kHz q LOW NOISE: 10nV/ Hz q HIGH SLEW RATE: 25V/∝sq WIDE GAIN-BANDWIDTH: 20MHz q UNITY-GAIN STABLEq WIDE SUPPLY RANGE: V S = ±4.5 to ±24V q DRIVES 600& LOADSDESCRIPTIONThe OPA2604 is a dual, FET-input operational ampli- fier designed for enhanced AC performance. Very low distortion, low noise and wide bandwidth provide superior performance in high quality audio and other applications requiring excellent dynamic performance.APPLICATIONSq PROFESSIONAL AUDIO EQUIPMENT q PCM DAC I/V CONVERTERq SPECTRAL ANALYSIS EQUIPMENT q ACTIVE FILTERS q TRANSDUCER AMPLIFIER q DATA ACQUISITION(+)(3, 5)(8) V+New circuit techniques and special laser trimming of dynamic circuit performance yield very low harmonic distortion. The result is an op amp with exceptional (–) (2, 6)Distortion Rejection Circuitry*Output Stage*(1, 7)V Osound quality. The low-noise FET input of the OPA2604 provides wide dynamic range, even with high source impedance. Offset voltage is laser-trimmed to minimize the need for interstage coupling capacitors. The OPA2604 is available in 8-pin plastic mini-DIP and SO-8 surface-mount packages, specified for the –25︒C to +85︒C temperature range.(4) V –* Patents Granted: #5053718, 5019789®© 1991 Burr-Brown CorporationPDS-1069ESBOS006SPECIFICATIONSELECTRICALAt T A=+25︒C,V S=±15V,unless otherwise noted.NOTES:(1)Typical performance,measured fully warmed-up.(2)Soldered to circuit board—see text.The information provided herein is believed to be reliable;however,BURR-BROWN assumes no responsibility for inaccuracies or omissions.BURR-BROWN assumes no responsibility for the use of this information,and all use of such information shall be entirely at the user’s own risk.Prices and specifications are subject to change without notice.No patent rights or licenses to any of the circuits described herein are implied or granted to any third party.BURR-BROWN does not authorize or warrant any BURR-BROWN product for use in life support devices and/or systems.OPA26042PIN CONFIGURATIONTop ViewDIP/SOICABSOLUTEMAXIMUM RATINGS (1)Power Supply Voltage .......................................................................±25VInput Voltage ............................................................. (V –)–1V to (V+)+1V Output A–In A+In AV –12348765V+Output B–In B+In BOutput Short Circuit to Ground ...............................................ContinuousOperating Temperature ................................................. –40︒C to +100︒C Storage Temperature.....................................................–40︒C to +125︒CJunction Temperature .................................................................... +150︒C Lead Temperature (soldering, 10s) AP ......................................... +300︒C Lead Temperature (soldering, 3s) AU ..........................................+260︒CNOTE: (1) Stresses above these ratings may cause permanent damage.ORDERING INFORMATIONELECTROSTATICDISCHARGE SENSITIVITYAny integrated circuit can be damaged by ESD. Burr-Brown recommends that all integrated circuits be handled with ap- propriate precautions. Failure to observe proper handling and installation procedures can cause damage.ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric PACKAGING INFORMATION NOTE: (1) For detailed drawing and dimension table, please see end of data sheet, or Appendix C of Burr-Brown IC Data Book.changes could cause the device not to meet published speci- fications.®3OPA2604T H D +N (%)T H D +N (%)P h a s e S h i f t (D e g r e e s )I n p u t O f f s e t C u r r e n t (p A )I n p u t B i a s C u r r e n t (p A )I n p u t B i a s C u r r e n t (p A )I n p u t O f f s e t C u r r e n t (p A )C u r r e n t N o i s e (f A /H z )V o l t a g e G a i n (d B )V o l t a g e N o i s e (n V /H z )TYPICAL PERFORMANCE CURVESAt T A = +25︒C, V S = ±15V, unless otherwise noted.TOTAL HARMONIC DISTORTION + NOISEvs FREQUENCYTOTAL HARMONIC DISTORTION + NOISEvs OUTPUT VOLTAGE10.10.1See “Distortion Measurements”for description of test method.V O1k &0.01f = 1kHz0.01 0.0010.001Measurement BW = 80kHz0.0001 201001k 10k 20k Frequency (Hz)OPEN-LOOP GAIN/PHASE vs FREQUENCY0.00010.11 10 100Output Voltage (Vp-p)INPUT VOLTAGE AND CURRENT NOISESPECTRAL DENSITY vs FREQUENCY120 01k1k100 –45 80 60 40–90 10010020 0 –20 1101001k 10k 100k 1M 10M Frequency (Hz) –135–180 101 110110100 1k 10k 100k 1MFrequency (Hz)100nAINPUT BIAS AND INPUT OFFSET CURRENT10nAINPUT BIAS AND INPUT OFFSET CURRENTvs INPUT COMMON-MODE VOLTAGE1nA10nAInput1nA1nA Bias Current100100 10100Input10Offset Current1–75 –50–250255075100125Ambient Temperature (°C)10–151–10–5 0 5 10 15Common-Mode Voltage (V)®OPA2604 4C o m m o n -M o d e R e j e c t i o n (d B )I n p u t B i a s C u r r e n t (p A )A O L ,P S R ,C M R (dB )P S R ,C M R (d B )G a i n -B a n d w i d t h (M H z )G a i n -B a n d w i d t h (M H z )S l e w R a t e (V /µs )S l e w R a t e (V /µs )–252575TYPICAL PERFORMANCE CURVES (CONT)At T A = +25︒C, V S = ±15V, unless otherwise noted.1nAINPUTBIAS CURRENTvs TIME FROM POWER TURN-ON120COMMON-MODE REJECTION vs COMMON-MODE VOLTAGE110100 1001090180012345Time After Power Turn-On (min)–15–10–5 0 5 10 15Common-Mode Voltage (V)POWER SUPPLY AND COMMON-MODE120100REJECTION vs FREQUENCY120110A OL , PSR, AND CMR vs SUPPLY VOLTAGE80100609040200 80 702824 20 16 12 101001k 10k 100k 1M 10MFrequency (Hz)GAIN-BANDWIDTH AND SLEW RATEvs SUPPLY VOLTAGE282420 16 12510152025Supply Voltage (±V S ) GAIN-BANDWIDTH AND SLEW RATE vs TEMPERATURE510152025–75–50050100125Supply Voltage (±V S )Temperature (°C)5 OPA2604®C h a n n e l S e p a r a t i o n (d B )S e t t l i n g T i m e (µs )O u t p u t V o l t a g e (V p -p )S u p p l y C u r r e n t (m A )O u t p u t V o l t a g e (V )O u t p u t V o l t a g e (m V )S l e w R a t e (V /µs )TYPICAL PERFORMANCE CURVES (CONT)At T A = +25︒C, V S = ±15V, unless otherwise noted.5SETTLING TIME vs CLOSED-LOOP GAIN160CHANNEL SEPARATION vs FREQUENCY4140 31202110080 –1–10–100–1000101001k 10k 100k30Closed-Loop Gain (V/V)MAXIMUM OUTPUT VOLTAGE SWING vs FREQUENCY14 Frequency (Hz)SUPPLY CURRENT vs TEMPERATURE1220 10 10 8 0 6 10k 100k1M 10M –75–50–250255075100125+10Frequency (Hz)LARGE-SIGNAL TRANSIENT RESPONSE+100Ambient Temperature (°C)SMALL-SIGNAL TRANSIENT RESPONSE30FPOBleed to edge25201510–105 10Time (µs)–1001∝s 2∝sTime (µs)25®OPA2604 6S h o r t -C i r c u i t C u r r e n t (m A )P o w e r D i s s i p a t i o n (W )T o t a l P o w e r D i s s i p a t i o n (W )TYPICAL PERFORMANCE CURVES (CONT)At T A = +25︒C, V S = ±15V, unless otherwise noted.6050SHORT-CIRCUIT CURRENT vs TEMPERATURE10.9 0.8POWER DISSIPATION vs SUPPLY VOLTAGE0.7 0.6 400.5 0.4 30200.3 0.2 0.1 –75–50–250255075100125Ambient Temperature (°C)681012141618202224Supply Voltage, ±V S (V)MAXIMUM POWER DISSIPATION vs TEMPERATURE1.41.21.00.80.60.40.2255075100125150Ambient Temperature (°C)7 OPA2604®APPLICATIONS INFORMATIONThe OPA2604is unity-gain stable,making it easy to use in a wide range of circuitry.Applications with noisy or high impedance power supply lines may require decoupling ca-pacitors close to the device pins.In most cases1∝F tantalum capacitors are adequate.DISTORTION MEASUREMENTSThe distortion produced by the OPA2604is below the mea-surement limit of virtually all commercially available equip-ment.A special test circuit,however,can be used to extend the measurement capabilities.Op amp distortion can be considered an internal error source which can be referred to the input.Figure1shows a circuit which causes the op amp distortion to be101times greater than normally produced by the op amp.The addition of R3to the otherwise standard non-inverting amplifier configuration alters the feedback factor or noise gain of the circuit.The closed-loop gain is unchanged,but the feedback available for error correction is reduced by a factor of101.This extends the measurement limit,including the effects of the signal-source purity,by a factor of101.Note that the input signal and load applied to the op amp are the same as with conventional feedback without R3.Validity of this technique can be verified by duplicating measurements at high gain and/or high frequency where the distortion is within the measurement capability of the test equipment.Measurements for this data sheet were made with the Audio Precision System One which greatly simplifies such repetitive measurements.The measurement technique can,however,be performed with manual distortion measure-ment instruments.CAPACITIVE LOADSThe dynamic characteristics of the OPA2604have been optimized for commonly encountered gains,loads and oper-ating conditions.The combination of low closed-loop gain and capacitive load will decrease the phase margin and may lead to gain peaking or oscillations.Load capacitance reacts with the op amp’s open-loop output resistance to form an additional pole in the feedback loop.Figure2shows various circuits which preserve phase margin with capacitive load. Request Application Bulletin AB-028for details of analysis techniques and applications circuits.For the unity-gain buffer,Figure2a,stability is preserved by adding a phase-lead network,R C and C C.Voltage drop across R C will reduce output voltage swing with heavy loads.An alternate circuit,Figure2b,does not limit the output with low load impedance.It provides a small amount of positive feed-back to reduce the net feedback factor.Input impedance of this circuit falls at high frequency as op amp gain rolloff reduces the bootstrap action on the compensation network. Figures2c and2d show compensation techniques for noninverting amplifiers.Like the follower circuits,the circuit in Figure2d eliminates voltage drop due to load current,but at the penalty of somewhat reduced input impedance at high frequency.Figures2e and2f show input lead compensation networks for inverting and difference amplifier configurations.NOISE PERFORMANCEOp amp noise is described by two parameters—noise voltage and noise current.The voltage noise determines the noise performance with low source impedance.Low noise bipolar-input op amps such as the OPA27and OPA37provide very low voltage noise.But if source impedance is greater than a few thousand ohms,the current noise of bipolar-input op amps react with the source impedance and will dominate.At a few thousand ohms source impedance and above,the OPA2604 will generally provide lower noise.FIGURE1.Distortion Test Circuit.®OPA2604*Measurement BW=80kHz8R 2 C L(a)C C(b)820pF1 21 2R COPA2604e o e iOPA2604750&e oC CC LC L0.47µF 5000pF5000pFR 2R CC C =120 X 10–12 C Le i2k &R C =10&R 24C L X 1010 – 1C C =C L X 10C(c)(d)R 110k &R 210k & C C24pFR 12k &R C20&R 22k &e i1 2OPA2604R C25&e oe iC C 0.22µF 1 2OPA2604e oC C = 50C L5000pFR C =R 22C L X 1010 – (1 + R 2/R 1)C L5000pFC CC L X 103C(e)(f)R 22k &e 1R 12k &R 22k &e iR 12k &R C20& C C 0.22µF1 2OPA2604e oC L5000pFe 2R C 20&C C 0.22µF R 31 2OPA2604R 4e oC L5000pFR C =R 22C L X 1010 – (1 + R 2/R 1)C C =C L X 103C2k & 2k &R C =R 22C L X 1010 – (1 + R 2/R 1)C CC L X 10CNOTE: Design equations and component values are approximate. User adjustment is required for optimum performance.FIGURE 2. Driving Large Capacitive Loads.®9 OPA2604POWER DISSIPATIONThe OPA2604is capable of driving600&loads with power supply voltages up to±24V.Internal power dissipation is increased when operating at high power supply voltage.The typical performance curve,Power Dissipation vs Power Sup-ply Voltage,shows quiescent dissipation(no signal or no load)as well as dissipation with a worst case continuous sine wave.Continuous high-level music signals typically produce dissipation significantly less than worst case sine waves.Copper leadframe construction used in the OPA2604im-proves heat dissipation compared to conventional plastic packages.To achieve best heat dissipation,solder the device directly to the circuit board and use wide circuit board traces. OUTPUT CURRENT LIMITOutput current is limited by internal circuitry to approxi-mately±40mA at25︒C.The limit current decreases with increasing temperature as shown in the typical curves.f p=20kHzFIGURE3.Three-Pole Low-Pass Filter.12R1R5OPA2604V O V IN6.04k&R24.02k&2k&C31000pF12 OPA2604R24.02k&C112OPA2604Low-pass3-pole Butterworthf–3dB=40kHz 1000pFR45.36k&See Application Bulletin AB-026 C2for information on GIC filters. 1000pFFIGURE4.Three-Pole Generalized Immittance Converter(GIC)Low-Pass Filter.®OPA260410C1*I-Out DAC R1C22k&2200pF12C OUT12OPA2604*C1=~R22.94k&C OUT2 R1f cR321k&OPA2604C3470pFLow-pass2-pole Butterworthf–3dB=20kHzV OR1=Feedback resistance=2k&f c=Crossover frequency=8MHzFIGURE5.DAC I/V Amplifier and Low-Pass Filter.FIGURE6.Differential Amplifier with Low-Pass Filter.®11OPA2604* Provides input bias current return path.FIGURE 7. High Impedance Amplifier.filter.FIGURE 8. Digital Audio DAC I-V Amplifier.FIGURE 9. Using the Dual OPA2604 Op Amp to Double the Output Current to a Load.®OPA2604 12PACKAGE OPTION ADDENDUM 6-Dec-2006 PACKAGING INFORMATIONOrderable Device Status(1)PackageType PackageDrawingPins Package Eco Plan(2)Lead/Ball Finish MSL Peak Temp(3)QtyOPA2604AP ACTIVE PDIP P850Green(RoHS&no Sb/Br) OPA2604APG4ACTIVE PDIP P850Green(RoHS&no Sb/Br) OPA2604AU ACTIVE SOIC D8100Green(RoHS&no Sb/Br) OPA2604AU/2K5ACTIVE SOIC D82500Pb-Free(RoHS) OPA2604AU/2K5E4ACTIVE SOIC D82500Pb-Free(RoHS) OPA2604AUE4ACTIVE SOIC D8100Green(RoHS&no Sb/Br) OPA2604AUG4ACTIVE SOIC D8100Green(RoHS&CU NIPDAU N/A for Pkg Type CU NIPDAU N/A for Pkg Type CU NIPDAU Level-3-260C-168HR CU NIPDAU Level-3-260C-168HR CU NIPDAU Level-3-260C-168HR CU NIPDAU Level-3-260C-168HR CU NIPDAU Level-3-260C-168HRno 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/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 requirementsfor all6substances,including the requirement that lead not exceed0.1%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 either1)lead-based flip-chip solder bumps used between the die and package,or2)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 exceed0.1%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.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 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8 单电源型
在正、负两电源下工作的运算放大器为普通的运 算放大器，而只用单电源工作的运算放大器为单电源 型，通常它自0V起也能放大信号。
1.2 集成运放的选择及使用
1．运放的选择
当采用集成运放设计电子电路时，应该首先理 解设计说明书和产品说明书介绍的运算放大器的参 数的含义，了解其参数是否满足电路的要求，然后 对电路作必要的修改，找出所选运放的外部接线图 进行连接。若有相同类型的集成运放，应选择失调 电压小、调零效果好、补偿电容小、输出幅度合适 又不产生失真的运放，同时还要考虑信号源的性质 、负载的性质、环境条件影响等其他因素。
2．运放使用注意事项
(1)运放的调零
调零的作用是实现运放零输入-零输出的要 求，运放调零有两种方法，一种是通过运放本身 的调零端子外加调零电位器调零；另一种是通过 给运放的输入端加偏移电压调零。
(2)自激的消除
自激振荡是运放工作时产生的一种现象，如 果电路出现自激现象，应该判断是哪种原因造成 的，尽量增加地线的面积，在运放供电脚附近， 一般是在附近增加高频退耦电容，采用高频屏蔽 等方法消除自激，减小干扰。
3．高速型
高速型运放是指输出端能对输入端信号的变化做 出快速反应，一般通过转换速率来描述其性能，
4．低功耗型
通常运算放大器的静态功耗在50mW以上。如果在 电源电压±15V时，最大功耗低于6mW；或是工作在 低电源电压（如1.5~4V）时，具有较低的静态功耗并 能保持良好的电气性能，这类运放为低功耗型运放。
5．高压型
普通运放的工作电压为V，而工作电压在V以上的 运算放大器为高电压型，这种运放的动态范围较宽。
6．低输入偏流型
运算放大器的输入偏流为零时是理想情况。
7．可编程序型

电子设计制作大赛中的基本概念、基本知识与基本方法汇编电信学院尹建新一、运算放大器的使用²运算放大器的基本结构²运算放大器输入端的偏置²运算放大器的单电源使用²运放输出摆幅与电源电压²运算放大器的开环使用与闭环使用²运算放大器的自激²运算放大器的主要指标二、振荡器的基本概念（待续）三、滤波器（有源滤波器）的带外特性（待续）四、工频干扰（待续）五、管子发烫问题的分析（待续）六、数量级概念（待续）七、集成稳压器的内阻与电源去耦（待续）一、运算放大器的使用运算放大器是使用得最为广泛的模拟集成电路，由其构成的放大器、加法器、比较器、恒流源、振荡器、脉冲处理电路、微积分电路、有源滤波器、施密特触发器等等，不仅在电子设计制作比赛中，而且在工程应用上频频出现。

但一般教材往往重在介绍其典型应用电路，而对于集成运放器件本身的使用（无论是开环使用与闭环使用）很少予以注重，故此处进行专题讲解。

1．运算放大器的基本结构所有的运算放大器都可以分为输入级、中间级和输出级构成，如图1所示：图1整个运放的增益主要由输入级提供，而输出级只是一种互补推挽形式的跟随器，以提供一定的电流输出。

虽然从使用的角度出发，我们并没有必要去了解运放内部的具体电路形式（而且不同型号的运放其内部电路形式也不相同），但是，其输入级和输出级是需要和外电路相连的，所以我们有必要了解运放的输入级和输出级的电路特点，以对其正确的外部使用提供依据。

无一例外地，运放的输入级必定是差分放大器的电路形式（或者是双极型管，或者是场效应管），而输出级必定是互补推挽形式的射极跟随器（或者是场效应管的源极跟随器）。

之所以运放的输入级必定是差分放大器，是因为运算放大器本质上是一种直接耦合的高增益放大器，所以必然会带来直接耦合放大器的必然难题——“零点漂移”问题，而差分放大器的优越的共模抑制能力就成为运放输入级电路形式的首选。

• OPA656的偏置电流，FET输入高速放大器
10
输入端口相关的指标 –偏置电流影响仿真
• OPA691的偏置电流在uA级别，双极型输入
• OPA656的偏置电流在nA级别，FET输入
11
输入端口相关的指标 – 输入电压范围
• 手册中的截图，关键字（input voltage, range, ）
16
输出端口相关的指标 –输出电压范围
• 手册中的截图，关键字（output swing）
• 在单电源供电的场合更需要注意，因为单电源供电电压低，并且小信 号输出时接近GND电源轨。在单电源供电中选择轨到轨（rail to rail） 更方便使用。
• 轨到轨运放OPA354
• 非轨到轨运放LM324
• OPA335的噪声特性
• 可以看出对与低频小信号OPA335的噪声性能更好
15
输出端口相关的指标 –输出的驱动能力
• 手册中的截图，关键字（current，output)
• 输出驱动能力是表示运放带负载的能力，作为最后一级时常常要考虑 其驱动能力。 • BUF634的驱动带宽30M或180M，注意手册中的continuous, 表示可以 承受均值电流250mA。 • THS3092也是一款常用的驱动级运放。
R1 1k
2
6
4
R2 1k
VF1 +
7
+
VG1
3
+
U1 OPA227
V1 1.25
V2 5
R5 1k
2
+
VG3
364R来自 1kVF3 + U3 OPA350
7
+
V5 1.25