® OPA OPA2604 260 OPA 4 260 4 www.burr-brown.com/databook/OPA2604.html Dual FET-Input, Low Distortion OPERATIONAL AMPLIFIER FEATURES APPLICATIONS ● LOW DISTORTION: 0.0003% at 1kHz ● LOW NOISE: 10nV/√Hz ● HIGH SLEW RATE: 25V/µs ● PROFESSIONAL AUDIO EQUIPMENT ● PCM DAC I/V CONVERTER ● SPECTRAL ANALYSIS EQUIPMENT ● WIDE GAIN-BANDWIDTH: 20MHz ● UNITY-GAIN STABLE ● ACTIVE FILTERS ● TRANSDUCER AMPLIFIER ● WIDE SUPPLY RANGE: VS = ±4.5 to ±24V ● DRIVES 600Ω LOADS ● DATA ACQUISITION (8) V+ DESCRIPTION The OPA2604 is a dual, FET-input operational amplifier 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. New circuit techniques and special laser trimming of dynamic circuit performance yield very low harmonic distortion. The result is an op amp with exceptional sound 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. (+) (3, 5) (–) (2, 6) Distortion Rejection Circuitry* (1, 7) VO Output Stage* 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 International Airport Industrial Park • Mailing Address: PO Box 11400, Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706 • Tel: (520) 746-1111 • Twx: 910-952-1111 Internet: http://www.burr-brown.com/ • FAXLine: (800) 548-6133 (US/Canada Only) • Cable: BBRCORP • Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132 ® © 1991 Burr-Brown Corporation SBOS006 1 PDS-1069E OPA2604 Printed in U.S.A. October, 1997 SPECIFICATIONS ELECTRICAL At TA = +25°C, VS = ±15V, unless otherwise noted. OPA2604AP, AU PARAMETER CONDITION OFFSET VOLTAGE Input Offset Voltage Average Drift Power Supply Rejection INPUT BIAS CURRENT(1) Input Bias Current Input Offset Current MIN TYP MAX UNITS ±5 70 ±1 ±8 80 mV µV/°C dB VS = ±5 to ±24V VCM = 0V VCM = 0V NOISE Input Voltage Noise Noise Density: f = 10Hz f = 100Hz f = 1kHz f = 10kHz Voltage Noise, BW = 20Hz to 20kHz Input Bias Current Noise Current Noise Density, f = 0.1Hz to 20kHz INPUT VOLTAGE RANGE Common-Mode Input Range Common-Mode Rejection VCM = ±12V ±12 80 INPUT IMPEDANCE Differential Common-Mode OPEN-LOOP GAIN Open-Loop Voltage Gain FREQUENCY RESPONSE Gain-Bandwidth Product Slew Rate Settling Time: 0.01% 0.1% Total Harmonic Distortion + Noise (THD+N) Channel Separation OUTPUT Voltage Output Current Output Short Circuit Current Output Resistance, Open-Loop POWER SUPPLY Specified Operating Voltage Operating Voltage Range Current, Total Both Amplifiers VO = ±10V, RL = 1kΩ 80 G = 100 20Vp-p, RL = 1kΩ G = –1, 10V Step 15 G = 1, f = 1kHz VO = 3.5Vrms, RL = 1kΩ f = 1kHz, RL = 1kΩ RL = 600Ω VO = ±12V ±11 ±4.5 IO = 0 TEMPERATURE RANGE Specification Storage Thermal Resistance(2), θJA 100 ±4 pA pA 25 15 11 10 1.5 nV/√Hz nV/√Hz nV/√Hz nV/√Hz µVp-p 6 fA/√Hz ±13 100 V dB 1012 || 8 1012 || 10 Ω || pF Ω || pF 100 dB 20 25 1.5 1 0.0003 MHz V/µs µs µs % 142 dB ±12 ±35 ±40 25 V mA mA Ω ±15 ±10.5 –25 –40 ±24 ±12 +85 +125 90 V V mA °C °C °C/W 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. ® OPA2604 2 PIN CONFIGURATION ABSOLUTE MAXIMUM RATINGS(1) Top View Power Supply Voltage ....................................................................... ±25V Input Voltage ............................................................. (V–)–1V to (V+)+1V Output Short Circuit to Ground ............................................... Continuous Operating Temperature ................................................. –40°C to +100°C Storage Temperature ..................................................... –40°C to +125°C Junction Temperature .................................................................... +150°C Lead Temperature (soldering, 10s) AP ......................................... +300°C Lead Temperature (soldering, 3s) AU .......................................... +260°C DIP/SOIC Output A 1 8 V+ –In A 2 7 Output B +In A 3 6 –In B V– 4 5 +In B NOTE: (1) Stresses above these ratings may cause permanent damage. ORDERING INFORMATION PRODUCT OPA2604AP OPA2604AU ELECTROSTATIC DISCHARGE SENSITIVITY PACKAGE TEMP. RANGE 8-Pin Plastic DIP SO-8 Surface-Mount –25°C to +85°C –25°C to +85°C PACKAGING INFORMATION Any integrated circuit can be damaged by ESD. Burr-Brown recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. PACKAGE DRAWING PRODUCT OPA2604AP OPA2604AU 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 changes could cause the device not to meet published specifications. PACKAGE NUMBER(1) 8-Pin Plastic DIP SO-8 Surface-Mount 006 182 NOTE: (1) For detailed drawing and dimension table, please see end of data sheet, or Appendix C of Burr-Brown IC Data Book. ® 3 OPA2604 TYPICAL PERFORMANCE CURVES At TA = +25°C, VS = ±15V, unless otherwise noted. TOTAL HARMONIC DISTORTION + NOISE vs OUTPUT VOLTAGE TOTAL HARMONIC DISTORTION + NOISE vs FREQUENCY 1 THD + N (%) VO G = 100V/V 0.01 See “Distortion Measurements” for description of test method. 1kΩ 0.01 THD + N (%) VO = 3.5Vrms 1kΩ 0.1 0.1 Measurement BW = 80kHz See “Distortion Measurements” for description of test method. f = 1kHz Measurement BW = 80kHz 0.001 G = 10V/V 0.001 G = 1V/V 0.0001 20 100 1k 10k 0.0001 0.1 20k 1 10 100 Frequency (Hz) Output Voltage (Vp-p) OPEN-LOOP GAIN/PHASE vs FREQUENCY INPUT VOLTAGE AND CURRENT NOISE SPECTRAL DENSITY vs FREQUENCY 1k 1k 0 120 –90 60 40 –135 G 20 100 10 10 –180 0 Current Noise 1 –20 10 100 1k 10k 100k 1M 1 10M 10 100 100 1nA 10 100 Input Offset Current 1 10 0 25 50 75 100 Input Bias Current 1nA 100 10 100 Input Offset Current 10 –15 0.1 125 –10 –5 0 5 Common-Mode Voltage (V) Ambient Temperature (°C) ® OPA2604 Input Bias Current (pA) 1nA Input Offset Current (pA) Input Bias Current –25 1 1M 1nA 10nA 10nA 100nA –50 100k INPUT BIAS AND INPUT OFFSET CURRENT vs INPUT COMMON-MODE VOLTAGE INPUT BIAS AND INPUT OFFSET CURRENT vs TEMPERATURE 1 –75 10k Frequency (Hz) Frequency (Hz) 10nA 1k 4 10 1 15 Input Offset Current (pA) 1 Input Bias Current (pA) 100 Voltage Noise Current Noise (fA/ Hz) φ Voltage Noise (nV/ Hz) Voltage Gain (dB) –45 80 Phase Shift (Degrees) 100 TYPICAL PERFORMANCE CURVES (CONT) At TA = +25°C, VS = ±15V, unless otherwise noted. COMMON-MODE REJECTION vs COMMON-MODE VOLTAGE INPUT BIAS CURRENT vs TIME FROM POWER TURN-ON 120 1nA Common-Mode Rejection (dB) Input Bias Current (pA) VS = ±24VDC VS = ±15VDC 100 VS = ±5VDC 10 1 2 3 4 100 90 80 –15 1 0 110 5 –10 POWER SUPPLY AND COMMON-MODE REJECTION vs FREQUENCY 0 5 10 15 AOL, PSR, AND CMR vs SUPPLY VOLTAGE 120 120 CMR 100 110 AOL, PSR, CMR (dB) PSR, CMR (dB) –5 Common-Mode Voltage (V) Time After Power Turn-On (min) 80 –PSR +PSR 60 40 CMR 100 AOL 90 80 20 PSR 0 10 70 100 1k 10k 100k 1M 10M 5 10 15 20 Frequency (Hz) Supply Voltage (±VS) GAIN-BANDWIDTH AND SLEW RATE vs SUPPLY VOLTAGE GAIN-BANDWIDTH AND SLEW RATE vs TEMPERATURE 28 25 28 33 30 29 Slew Rate 20 25 16 21 12 5 10 15 20 24 25 20 20 Gain-Bandwidth G = +100 16 15 12 17 25 –75 –50 –25 0 Slew Rate (V/µs) Gain-Bandwidth G = +100 Gain-Bandwidth (MHz) 24 Slew Rate (V/µs) Gain-Bandwidth (MHz) Slew Rate 25 50 75 100 10 125 Temperature (°C) Supply Voltage (±VS) ® 5 OPA2604 TYPICAL PERFORMANCE CURVES (CONT) At TA = +25°C, VS = ±15V, unless otherwise noted. SETTLING TIME vs CLOSED-LOOP GAIN CHANNEL SEPARATION vs FREQUENCY 5 160 VO = 10V Step RL = 1kΩ CL = 50pF RL = ∞ Channel Separation (dB) Settling Time (µs) 4 3 0.01% 2 0.1% 1 140 RL = 1kΩ 120 100 0 VO = 20Vp-p RL A B Measured Output 80 –1 –10 –100 –1000 10 100 1k Closed-Loop Gain (V/V) MAXIMUM OUTPUT VOLTAGE SWING vs FREQUENCY 14 Total for Both Op Amps Supply Current (mA) Output Voltage (Vp-p) VS = ±15V 20 10 0 VS = ±15VDC 12 VS = ±24VDC 10 VS = ±5VDC 8 6 10k 100k 1M 10M –75 Frequency (Hz) Output Voltage (mV) Output Voltage (V) +10 FPO Bleed to edge 0 5 0 25 50 75 +100 –100 0 10 Time (µs) 1µs Time (µs) 15 10 25 ® OPA2604 –25 SMALL-SIGNAL TRANSIENT RESPONSE –10 Slew Rate (V/µs) 20 –50 Ambient Temperature (°C) LARGE-SIGNAL TRANSIENT RESPONSE 25 100k SUPPLY CURRENT vs TEMPERATURE 30 30 10k Frequency (Hz) 6 2µs 100 125 TYPICAL PERFORMANCE CURVES (CONT) At TA = +25°C, VS = ±15V, unless otherwise noted. POWER DISSIPATION vs SUPPLY VOLTAGE SHORT-CIRCUIT CURRENT vs TEMPERATURE 1 Worst case sine wave RL = 600Ω (both channels) 0.9 Power Dissipation (W) ISC+ and ISC– 50 40 30 0.8 Typical high-level music RL = 600Ω (both channels) 0.7 0.6 0.5 0.4 No signal or no load 0.3 0.2 20 0.1 –75 –50 –25 0 25 50 75 100 125 6 8 10 Ambient Temperature (°C) 12 14 16 18 20 22 24 Supply Voltage, ±VS (V) MAXIMUM POWER DISSIPATION vs TEMPERATURE 1.4 Total Power Dissipation (W) Short-Circuit Current (mA) 60 θJ-A = 90°C/W Soldered to Circuit Board (see text) 1.2 1.0 0.8 0.6 Maximum Specified Operating Temperature 85°C 0.4 0.2 0 0 25 50 75 100 125 150 Ambient Temperature (°C) ® 7 OPA2604 APPLICATIONS INFORMATION The OPA2604 is 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 capacitors close to the device pins. In most cases 1µF tantalum capacitors are adequate. 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. Figure 2 shows various circuits which preserve phase margin with capacitive load. Request Application Bulletin AB-028 for details of analysis techniques and applications circuits. DISTORTION MEASUREMENTS The distortion produced by the OPA2604 is below the measurement limit of virtually all commercially available equipment. A special test circuit, however, can be used to extend the measurement capabilities. For the unity-gain buffer, Figure 2a, stability is preserved by adding a phase-lead network, RC and CC. Voltage drop across RC will reduce output voltage swing with heavy loads. An alternate circuit, Figure 2b, does not limit the output with low load impedance. It provides a small amount of positive feedback 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. Op amp distortion can be considered an internal error source which can be referred to the input. Figure 1 shows a circuit which causes the op amp distortion to be 101 times greater than normally produced by the op amp. The addition of R3 to 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 of 101. This extends the measurement limit, including the effects of the signal-source purity, by a factor of 101. Note that the input signal and load applied to the op amp are the same as with conventional feedback without R3. Figures 2c and 2d show compensation techniques for noninverting amplifiers. Like the follower circuits, the circuit in Figure 2d eliminates voltage drop due to load current, but at the penalty of somewhat reduced input impedance at high frequency. Figures 2e and 2f show input lead compensation networks for inverting and difference amplifier configurations. NOISE PERFORMANCE Op 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 bipolarinput op amps such as the OPA27 and OPA37 provide 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. 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 measurement instruments. CAPACITIVE LOADS The dynamic characteristics of the OPA2604 have been optimized for commonly encountered gains, loads and operating conditions. The combination of low closed-loop gain R1 R2 SIG. DIST. GAIN GAIN 1 R3 2 VO = 10Vp-p (3.5Vrms) OPA2604 Generator Output R2 R3 ∞ 5kΩ 50Ω 10 101 500Ω 5kΩ 500Ω 100 101 50Ω 5kΩ ∞ Analyzer Input Audio Precision System One Analyzer* RL 1kΩ * Measurement BW = 80kHz FIGURE 1. Distortion Test Circuit. ® OPA2604 R1 101 1 8 IBM PC or Compatible (a) (b) CC 820pF 1 1 2 eo eo OPA2604 ei 750Ω CL 5000pF CC 0.47µF CL 5000pF CC = 2 OPA2604 RC R2 RC 2kΩ 10Ω ei 120 X 10–12 CL RC = CC = R2 4CL X 1010 – 1 CL X 103 RC (c) (d) R1 R2 R1 R2 10kΩ 10kΩ CC 2kΩ 2kΩ RC 20Ω 24pF 1 CC 0.22µF RC 2 eo OPA2604 ei 2 eo ei 25Ω CL 5000pF 50 CL R2 CC = 1 OPA2604 RC = CC = CL 5000pF R2 2CL X 1010 – (1 + R2/R1) C L X 103 RC (e) (f) R2 R1 R2 2kΩ 2kΩ e1 2kΩ R1 ei 1 2kΩ RC 20Ω 2 1 eo OPA2604 CC 0.22µF RC 20Ω CL 5000pF CC 0.22µF 2 eo OPA2604 R3 R4 2kΩ 2kΩ CL 5000pF e2 RC = R2 2CL X 1010 – (1 + R2/R1) RC = CC = CL X 103 RC CC = R2 2C L X 1010 – (1 + R2/R1) C L X 103 RC NOTE: Design equations and component values are approximate. User adjustment is required for optimum performance. FIGURE 2. Driving Large Capacitive Loads. ® 9 OPA2604 Copper leadframe construction used in the OPA2604 improves 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. POWER DISSIPATION The OPA2604 is capable of driving 600Ω 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 Supply 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. OUTPUT CURRENT LIMIT Output current is limited by internal circuitry to approximately ±40mA at 25°C. The limit current decreases with increasing temperature as shown in the typical curves. R4 22kΩ C3 R1 R2 100pF R3 VIN 1 2.7kΩ 22kΩ C1 3000pF 10kΩ 2 VO OPA2604 C2 2000pF fp = 20kHz FIGURE 3. Three-Pole Low-Pass Filter. 1 R1 R5 2 OPA2604 VIN 6.04kΩ 2kΩ R2 4.02kΩ C3 1000pF R2 4.02kΩ 1 Low-pass 3-pole Butterworth f–3dB = 40kHz 2 OPA2604 1 2 OPA2604 C1 1000pF R4 5.36kΩ See Application Bulletin AB-026 for information on GIC filters. C2 1000pF FIGURE 4. Three-Pole Generalized Immittance Converter (GIC) Low-Pass Filter. ® OPA2604 10 VO C1* I-Out DAC R1 C2 2200pF 2kΩ 1 R2 R3 2.94kΩ 21kΩ 2 1 2 VO OPA2604 OPA2604 COUT C3 470pF ~ * C1 = COUT Low-pass 2-pole Butterworth f–3dB = 20kHz 2π R1 fc R1 = Feedback resistance = 2kΩ fc = Crossover frequency = 8MHz FIGURE 5. DAC I/V Amplifier and Low-Pass Filter. 1 7.87kΩ 10kΩ 2 10kΩ OPA2604 – 1 VIN 100pF 2 OPA2604 VO G=1 + 1 7.87kΩ 100kHz Input Filter 2 OPA2604 10kΩ 10kΩ FIGURE 6. Differential Amplifier with Low-Pass Filter. ® 11 OPA2604 100Ω 1 COUT * C1 ≈ 10kΩ Rf = Internal feedback resistance = 1.5kΩ fc = Crossover frequency = 8MHz G = 101 (40dB) 2 2π Rf fc 10 OPA2604 5 PCM63 20-bit 6 D/A 9 Converter Piezoelectric Transducer 1MΩ* C1* 1 2 OPA2604 * Provides input bias current return path. FIGURE 7. High Impedance Amplifier. FIGURE 8. Digital Audio DAC I-V Amplifier. 1/2 OPA2604 A2 I2 R4 1/2 OPA2604 R3 51Ω 51Ω A1 VIN IL = I1 + I2 i1 R2 VOUT Load R1 VOUT = VIN (1 + R2/R1) FIGURE 9. Using the Dual OPA2604 Op Amp to Double the Output Current to a Load. ® OPA2604 VO = ±3Vp To low-pass filter. 12 IMPORTANT NOTICE Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue any product or service without notice, and advise customers to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgment, including those pertaining to warranty, patent infringement, and limitation of liability. TI warrants performance of its semiconductor products to the specifications applicable at the time of sale in accordance with TI’s standard warranty. Testing and other quality control techniques are utilized to the extent TI deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily performed, except those mandated by government requirements. Customers are responsible for their applications using TI components. In order to minimize risks associated with the customer’s applications, adequate design and operating safeguards must be provided by the customer to minimize inherent or procedural hazards. TI assumes no liability for applications assistance or customer product design. TI does not warrant or represent that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other intellectual property right of TI covering or relating to any combination, machine, or process in which such semiconductor products or services might be or are used. TI’s publication of information regarding any third party’s products or services does not constitute TI’s approval, warranty or endorsement thereof. Copyright 2000, Texas Instruments Incorporated