OPA627

® OPA 627 OPA627 OPA637 OPA 627 Precision High-Speed Difet ® OPERATIONAL AMPLIFIERS FEATURES q VERY LOW NOISE: 4.5nV/√Hz at 10kHz q FAST SETTLING TIME: OPA627—550ns to 0.01% OPA637—450ns to 0.01% q LOW VOS: 100µV max q LOW DRIFT: 0.8µV/°C max q LOW IB: 5pA max q OPA627: Unity-Gain Stable q OPA637: Stable in Gain ≥ 5 APPLICATIONS q PRECISION INSTRUMENTATION q FAST DATA ACQUISITION q DAC OUTPUT AMPLIFIER q OPTOELECTRONICS q SONAR, ULTRASOUND q HIGH-IMPEDANCE SENSOR AMPS q HIGH-PERFORMANCE AUDIO CIRCUITRY q ACTIVE FILTERS High frequency complementary transistors allow increased circuit bandwidth, attaining dynamic performance not possible with previous precision FET op amps. The OPA627 is unity-gain stable. The OPA637 is stable in gains equal to or greater than five. DESCRIPTION The OPA627 and OPA637 Difet operational amplifiers provide a new level of performance in a precision FET op amp. When compared to the popular OPA111 op amp, the OPA627/637 has lower noise, lower offset voltage, and much higher speed. It is useful in a broad range of precision and high speed analog circuitry. The OPA627/637 is fabricated on a high-speed, dielectrically-isolated complementary NPN/PNP process. It operates over a wide range of power supply voltage— ±4.5V to ±18V. Laser-trimmed Difet input circuitry provides high accuracy and low-noise performance comparable with the best bipolar-input op amps. Trim 1 Difet fabrication achieves extremely low input bias currents without compromising input voltage noise performance. Low input bias current is maintained over a wide input common-mode voltage range with unique cascode circuitry. The OPA627/637 is available in plastic DIP, SOIC and metal TO-99 packages. Industrial and military temperature range models are available. 7 +VS 5 Trim Output 6 +In 3 –In 2 Difet ®, Burr-Brown Corp. –VS 4 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 ©1989 Burr-Brown Corporation PDS-998H Printed in U.S.A. March, 1998 SPECIFICATIONS ELECTRICAL At TA = +25°C, and VS = ±15V, unless otherwise noted. OPA627BM, BP, SM OPA637BM, BP, SM PARAMETER OFFSET VOLTAGE (1) Input Offset Voltage AP, BP, AU Grades Average Drift AP, BP, AU Grades Power Supply Rejection INPUT BIAS CURRENT (2) Input Bias Current Over Specified Temperature SM Grade Over Common-Mode Voltage Input Offset Current Over Specified Temperature SM Grade NOISE Input Voltage Noise Noise Density: f = 10Hz f = 100Hz f = 1kHz f = 10kHz Voltage Noise, BW = 0.1Hz to 10Hz Input Bias Current Noise Noise Density, f = 100Hz Current Noise, BW = 0.1Hz to 10Hz INPUT IMPEDANCE Differential Common-Mode INPUT VOLTAGE RANGE Common-Mode Input Range Over Specified Temperature Common-Mode Rejection OPEN-LOOP GAIN Open-Loop Voltage Gain Over Specified Temperature SM Grade FREQUENCY RESPONSE Slew Rate: OPA627 OPA637 Settling Time: OPA627 0.01% 0.1% OPA637 0.01% 0.1% Gain-Bandwidth Product: OPA627 OPA637 Total Harmonic Distortion + Noise POWER SUPPLY Specified Operating Voltage Operating Voltage Range Current OUTPUT Voltage Output Over Specified Temperature Current Output Short-Circuit Current Output Impedance, Open-Loop TEMPERATURE RANGE Specification: AP, BP, AM, BM, AU SM Storage: AM, BM, SM AP, BP, AU θJ-A: AM, BM, SM AP, BP AU RL = 1kΩ VO = ±10V 1MHz –25 –55 –60 –40 200 100 160 ±11 ±10.5 106 112 106 100 40 100 CONDITIONS MIN TYP 40 100 0.4 0.8 120 1 MAX 100 250 0.8 2 100 5 1 50 5 1 50 OPA627AM, AP, AU OPA637AM, AP, AU MIN TYP 130 280 1.2 2.5 116 2 MAX 250 500 2 UNITS µV µV µV/° C µV/° C dB pA nA nA pA pA nA nA VS = ±4.5 to ±18V VCM = 0V VCM = 0V VCM = 0V VCM = ±10V VCM = 0V VCM = 0V 106 10 2 1 0.5 2 1 10 2 15 8 5.2 4.5 0.6 1.6 30 1013 || 8 1013 || 7 ±11.5 ±11 116 120 117 114 55 135 550 450 450 300 16 80 0.00003 ±15 ±7 ±12.3 ±11.5 ±45 +70/–55 55 40 20 8 6 1.6 2.5 60 20 10 5.6 4.8 0.8 2.5 48 * * * * 100 106 100 * * 110 116 110 nV/√Hz nV/√Hz nV/√Hz nV/√Hz µVp-p fA/√Hz fAp-p Ω || pF Ω || pF V V dB dB dB dB V/µs V/µs ns ns ns ns MHz MHz % V V mA VCM = ±10.5V VO = ±10V, RL = 1kΩ VO = ±10V, RL = 1kΩ VO = ±10V, RL = 1kΩ G G G G G G –1, 10V Step –4, 10V Step –1, 10V Step –1, 10V Step –4, 10V Step –4, 10V Step G=1 G = 10 G = +1, f = 1kHz = = = = = = * * * * * * * * * * * * ±4.5 ±18 ±7.5 * * * * * * * * * * * ±11.5 ±11 ±35 ±100 * * V mA mA Ω °C °C °C °C ° C/W ° C/W ° C/W +85 +125 +150 +125 * * * * * * * * * Specifications same as “B” grade. NOTES: (1) Offset voltage measured fully warmed-up. (2) High-speed test at TJ = +25°C. See Typical Performance Curves for warmed-up performance. 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. ® OPA627, 637 2 PIN CONFIGURATIONS Top View DIP/SOIC ABSOLUTE MAXIMUM RATINGS(1) Supply Voltage .................................................................................. ±18V Input Voltage Range .............................................. +VS + 2V to –VS – 2V Differential Input Range ....................................................... Total VS + 4V Power Dissipation ........................................................................ 1000mW Operating Temperature M Package .................................................................. –55°C to +125°C P, U Package ............................................................. –40°C to +125°C Storage Temperature M Package .................................................................. –65°C to +150°C P, U Package ............................................................. –40°C to +125°C Junction Temperature M Package .................................................................................. +175°C P, U Package ............................................................................. +150°C Lead Temperature (soldering, 10s) ............................................... +300°C SOlC (soldering, 3s) ................................................................... +260°C NOTE: (1) Stresses above these ratings may cause permanent damage. Offset Trim –In +In –VS 1 2 3 4 8 7 6 5 No Internal Connection +VS Output Offset Trim Top View No Internal Connection 8 Offset Trim 1 7 +VS TO-99 PACKAGE/ORDERING INFORMATION PRODUCT OPA627AP OPA627BP OPA627AU OPA627AM OPA627BM OPA627SM OPA637AP OPA637BP OPA637AU OPA637AM OPA637BM OPA637SM PACKAGE Plastic DIP Plastic DIP SOIC TO-99 Metal TO-99 Metal TO-99 Metal Plastic DIP Plastic DIP SOIC TO-99 Metal TO-99 Metal TO-99 Metal PACKAGE DRAWING NUMBER(1) 006 006 182 001 001 001 006 006 182 001 001 001 TEMPERATURE RANGE –25°C to +85°C –25°C to +85°C –25°C to +85°C –25°C to +85°C –25°C to +85°C –55°C to +125°C –25°C to +85°C –25°C to +85°C –25°C to +85°C –25°C to +85°C –25°C to +85°C –55°C to +125°C –In 2 6 Output 3 +In 4 –VS Case connected to –VS. 5 Offset Trim NOTE: (1) For detailed drawing and dimension table, please see end of data sheet, or Appendix C of Burr-Brown IC Data Book. ELECTROSTATIC DISCHARGE SENSITIVITY This 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. 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 its published specifications. ® 3 OPA627, 637 TYPICAL PERFORMANCE CURVES At TA = +25 °C, and VS = ±15V, unless otherwise noted. INPUT VOLTAGE NOISE SPECTRAL DENSITY 1k 100 TOTAL INPUT VOLTAGE NOISE vs BANDWIDTH p-p Voltage Noise (nV/ √ Hz) Input Voltage Noise (µV) 10 100 Noise Bandwidth: 0.1Hz to indicated frequency. 1 10 0.1 RMS 1 1 10 100 1k 10k 100k 1M 10M Frequency (Hz) 0.01 1 10 100 1k 10k 100k 1M 10M Bandwidth (Hz) VOLTAGE NOISE vs SOURCE RESISTANCE 1k – OPEN-LOOP GAIN vs FREQUENCY 140 120 Voltage Gain (dB) Voltage Noise (nV/ √ Hz) + 100 RS 100 80 60 40 20 OPA627 OPA637 OPA627 + Resistor 10 Comparison with OPA27 Bipolar Op Amp + Resistor Spot Noise at 10kHz 1M 10M 100M Resistor Noise Only 1 100 1k 10k 100k Source Resistance ( Ω) 0 –20 1 10 100 1k 10k 100k 1M 10M 100M Frequency (Hz) OPA627 GAIN/PHASE vs FREQUENCY 30 –90 OPA637 GAIN/PHASE vs FREQUENCY 30 –90 Phase (Degrees) 10 Gain 0 75° Phase Margin Phase –150 Phase 10 Gain –150 –180 0 –180 –10 1 10 Frequency (MHz) –210 100 –10 1 10 Frequency (MHz) 100 –210 ® OPA627, 637 4 Phase (Degrees) 20 Gain (dB) –120 20 Gain (dB) –120 TYPICAL PERFORMANCE CURVES (CONT) At TA = +25°C, and VS = ±15V, unless otherwise noted. OPEN-LOOP GAIN vs TEMPERATURE 125 100 OPEN-LOOP OUTPUT IMPEDANCE vs FREQUENCY 120 Voltage Gain (dB) Output Resistance (Ω) 80 60 115 40 110 20 105 –75 0 –50 –25 0 25 50 75 100 125 2 20 200 2k 20k 200k 2M 20M Temperature (°C) Frequency (Hz) COMMON-MODE REJECTION vs FREQUENCY 140 COMMON-MODE REJECTION vs INPUT COMMON MODE VOLTAGE 130 Common-Mode Rejection Ratio (dB) 120 100 80 60 40 20 0 1 10 100 1k 10k OPA627 OPA637 Common-Mode Rejection (dB) 120 110 100 90 100k 1M 10M 80 –15 –10 –5 0 5 10 15 Frequency (Hz) Common-Mode Voltage (V) POWER-SUPPLY REJECTION vs FREQUENCY 140 Power-Supply Rejection (dB) 125 POWER-SUPPLY REJECTION AND COMMON-MODE REJECTION vs TEMPERATURE 120 100 80 60 40 20 0 1 10 100 1k 10k 100k 1M 10M Frequency (Hz) 105 –75 –50 PSR –VS PSRR 627 and 637 CMR and PSR (dB) 120 115 CMR +VS PSRR 627 637 110 –25 0 25 50 75 100 125 Temperature (°C) ® 5 OPA627, 637 TYPICAL PERFORMANCE CURVES At TA = +25 °C, and VS = ±15V, unless otherwise noted. (CONT) SUPPLY CURRENT vs TEMPERATURE 8 100 OUTPUT CURRENT LIMIT vs TEMPERATURE 80 Supply Current (mA) +IL at VO = 0V +IL at VO = +10V Output Current (mA) 7.5 60 7 40 –IL at VO = 0V 20 –IL at VO = –10V 6.5 6 –75 –50 –25 0 25 50 75 100 125 Temperature (°C) 0 –75 –50 –25 0 25 50 75 100 125 Temperature (°C) OPA627 GAIN-BANDWIDTH AND SLEW RATE vs TEMPERATURE 24 60 120 OPA637 GAIN-BANDWIDTH AND SLEW RATE vs TEMPERATURE 160 Slew Rate Gain-Bandwidth (MHz) Gain-Bandwidth (MHz) Slew Rate 16 55 Slew Rate (V/µs) 80 GBW 60 120 12 GBW 100 8 –75 50 –50 –25 0 25 50 75 100 125 Temperature (°C) 40 –75 –50 –25 0 25 50 75 100 125 Temperature (°C) 80 OPA627 TOTAL HARMONIC DISTORTION + NOISE vs FREQUENCY 0.1 VI G = +1 + – VO = ±10V 600 Ω VI G = +10 + – 100pF 549 Ω VO = ±10V 5kΩ 600 Ω OPA637 TOTAL HARMONIC DISTORTION + NOISE vs FREQUENCY 1 VI G = +10 + – VO = ±10V 5k Ω 600Ω G = +50 VI + – VO = ±10V 5k Ω 600Ω 0.01 100pF 0.1 549Ω 100pF 102 Ω 100pF THD+N (%) 0.001 Measurement BW: 80kHz G = +10 THD+N (%) 0.01 G = +50 Measurement BW: 80kHz 0.001 0.0001 G = +1 0.00001 20 100 1k Frequency (Hz) 10k 20k 0.0001 20 100 1k Frequency (Hz) G = +10 10k 20k ® OPA627, 637 6 Slew Rate (V/µs) 20 100 140 TYPICAL PERFORMANCE CURVES At TA = +25°C, and VS = ±15V, unless otherwise noted. (CONT) INPUT BIAS AND OFFSET CURRENT vs JUNCTION TEMPERATURE 10k 20 INPUT BIAS CURRENT vs POWER SUPPLY VOLTAGE NOTE: Measured fully warmed-up. 15 TO-99 10 Plastic DIP, SOIC 100 IB IOS 10 Input Bias Current (pA) 1k Input Current (pA) 1 5 TO-99 with 0807HS Heat Sink 0.1 –50 –25 0 25 50 75 100 125 150 Junction Temperature (°C) 0 ±4 ±6 ±8 ±10 ±12 ±14 ±16 ±18 Supply Voltage (±VS) INPUT BIAS CURRENT vs COMMON-MODE VOLTAGE 1.2 Input Bias Current Multiplier Offset Voltage Change (µV) INPUT OFFSET VOLTAGE WARM-UP vs TIME 50 1.1 Beyond Linear Common-Mode Range 25 1 0 0.9 Beyond Linear Common-Mode Range –25 0.8 –15 –10 –5 0 5 Common-Mode Voltage (V) 10 15 –50 0 1 2 3 4 5 6 Time From Power Turn-On (Min) MAX OUTPUT VOLTAGE vs FREQUENCY 30 SETTLING TIME vs CLOSED-LOOP GAIN 100 Output Voltage (Vp-p) Error Band: ±0.01% Settling Time (µs) 20 10 OPA627 OPA637 10 OPA627 1 OPA637 0 100k 1M Frequency (Hz) 10M 100M 0.1 –1 –10 –100 –1000 Closed-Loop Gain (V/V) ® 7 OPA627, 637 TYPICAL PERFORMANCE CURVES At TA = +25 °C, and VS = ±15V, unless otherwise noted. (CONT) SETTLING TIME vs ERROR BAND 1500 RI – SETTLING TIME vs LOAD CAPACITANCE 3 CF +5V RF 2kΩ –5V + Settling Time (ns) 1000 Settling Time (µs) OPA627 RI 2kΩ RF 2kΩ CF 6pF OPA637 500Ω 2kΩ 4pF 2 Error Band: ±0.01% OPA637 G = –4 500 OPA637 G = –4 0 0.001 OPA627 G = –1 1 OPA627 G = –1 0 0.01 0.1 Error Band (%) 1 10 0 150 200 300 400 500 Load Capacitance (pF) APPLICATIONS INFORMATION The OPA627 is unity-gain stable. The OPA637 may be used to achieve higher speed and bandwidth in circuits with noise gain greater than five. Noise gain refers to the closed-loop gain of a circuit as if the non-inverting op amp input were being driven. For example, the OPA637 may be used in a non-inverting amplifier with gain greater than five, or an inverting amplifier of gain greater than four. When choosing between the OPA627 or OPA637, it is important to consider the high frequency noise gain of your circuit configuration. Circuits with a feedback capacitor (Figure 1) place the op amp in unity noise-gain at high frequency. These applications must use the OPA627 for proper stability. An exception is the circuit in Figure 2, where a small feedback capacitance is used to compensate for the input capacitance at the op amp’s inverting input. In this case, the closed-loop noise gain remains constant with frequency, so if the closed-loop gain is equal to five or greater, the OPA637 may be used. – + OPA627 Buffer RI RF < 4RI – + Non-Inverting Amp G 1 For Approximate Butterworth Response: 2 RO CL RF >> RO CF = RF f–3dB = 1 2π √ RF RO CF CL FIGURE 6. Driving Large Capacitive Loads. OPA627, 637 10 INPUT PROTECTION The inputs of the OPA627/637 are protected for voltages between +VS + 2V and –VS – 2V. If the input voltage can exceed these limits, the amplifier should be protected. The diode clamps shown in Figure 7a will prevent the input voltage from exceeding one forward diode voltage drop beyond the power supplies—well within the safe limits. If the input source can deliver current in excess of the maximum forward current of the protection diodes, use a series resistor, RS, to limit the current. Be aware that adding resistance to the input will increase noise. The 4nV/√Hz theoretical thermal noise of a 1kΩ resistor will add to the 4.5nV/√Hz noise of the OPA627/637 (by the square-root of the sum of the squares), producing a total noise of 6nV/√Hz. Resistors below 100Ω add negligible noise. Leakage current in the protection diodes can increase the total input bias current of the circuit. The specified maximum leakage current for commonly used diodes such as the 1N4148 is approximately 25nA—more than a thousand times larger than the input bias current of the OPA627/637. Leakage current of these diodes is typically much lower and may be adequate in many applications. Light falling on the junction of the protection diodes can dramatically increase leakage current, so common glass-packaged diodes should be shielded from ambient light. Very low leakage can be achieved by using a diode-connected FET as shown. The 2N4117A is specified at 1pA and its metal case shields the junction from light. Sometimes input protection is required on I/V converters of inverting amplifiers (Figure 7b). Although in normal operation, the voltage at the summing junction will be near zero (equal to the offset voltage of the amplifier), large input transients may cause this node to exceed 2V beyond the power supplies. In this case, the summing junction should be protected with diode clamps connected to ground. Even with the low voltage present at the summing junction, common signal diodes may have excessive leakage current. Since the reverse voltage on these diodes is clamped, a diode-connected signal transistor can be used as an inexpensive low leakage diode (Figure 7b). +VS – D + D Optional RS –VS (a) OPA627 D: IN4148 — 25nA Leakage 2N4117A — 1pA Leakage Siliconix = VO IIN – VO D D + OPA627 D: 2N3904 = (b) NC FIGURE 7. Input Protection Circuits. LARGE SIGNAL RESPONSE SMALL SIGNAL RESPONSE (A) (B) FPO When used as a unity-gain buffer, large common-mode input voltage steps produce transient variations in input-stage currents. This causes the rising edge to be slower and falling edges to be faster than nominal slew rates observed in higher-gain circuits. – + OPA627 G=1 FIGURE 8. OPA627 Dynamic Performance, G = +1. ® 11 OPA627, 637 LARGE SIGNAL RESPONSE +10 VOUT (V) VOUT (V) +10 0 (C) 0 (D) –10 –10 6pF(1) When driven with a very fast input step (left), common-mode transients cause a slight variation in input stage currents which will reduce output slew rate. If the input step slew rate is reduced (right), output slew rate will increase slightly. NOTE: (1) Optimum value will depend on circuit board layout and stray capacitance at the inverting input. 2kΩ – 2kΩ + OPA627 G = –1 VOUT FIGURE 9. OPA627 Dynamic Performance, G = –1. OPA637 LARGE SIGNAL RESPONSE OPA637 SMALL SIGNAL RESPONSE +10 VOUT (mV) VOUT (V) +100 0 (E) 0 (F) FPO –100 –10 4pF(1) 2kΩ – + 500Ω NOTE: (1) Optimum value will depend on circuit board layout and capacitance at inverting input. G=5 OPA637 VOUT FIGURE 10. OPA637 Dynamic Response, G = 5. ® OPA627, 637 12 RI / Error Out 2kΩ CF OPA627 RI , R 1 CF Error Band (0.01%) 2kΩ 6pF ±0.5mV OPA637 500Ω 4pF ±0.2mV HP50822835 2kΩ +15V High Quality Pulse Generator RI – 51Ω ±5V Out + NOTE: CF is selected for best settling time performance depending on test fixture layout. Once optimum value is determined, a fixed capacitor may be used. –15V FIGURE 11. Settling Time and Slew Rate Test Circuit. Gain = 100 CMRR ≈ 116dB Bandwidth ≈ 1MHz 2 25kΩ INA105 Differential Amplifier 3 – +In + RF 5kΩ OPA637 Differential Voltage Gain = 1 + 2RF /RG 25kΩ 1 25kΩ 5 –In + – OPA637 RF 5kΩ Input Common-Mode Range = ±5V RG 101Ω 3pF – + 25kΩ 6 Output FIGURE 12. High Speed Instrumentation Amplifier, Gain = 100. Gain = 1000 CMRR ≈ 116dB Bandwidth ≈ 400kHz 2 10kΩ INA106 Differential Amplifier 3 – RF 5kΩ OPA637 10kΩ 1 100kΩ 5 –In + – OPA637 RF 5kΩ Input Common-Mode Range = ±10V RG 101Ω 3pF – + 100kΩ 6 Output +In + Differential Voltage Gain = (1 + 2RF /RG) • 10 FIGURE 13. High Speed Instrumentation Amplifier, Gain = 1000. This composite amplifier uses the OPA603 current-feedback op amp to provide extended bandwidth and slew rate at high closed-loop gain. The feedback loop is closed around the composite amp, preserving the precision input characteristics of the OPA627/637. Use separate power supply bypass capacitors for each op amp. R2 – A1 VI + + *Minimize capacitance at this node. VO – OPA603 R1 R3 * RL ≥ 150Ω for ±10V Out GAIN (V/V) 100 1000 A1 OP AMP OPA627 OPA637 R1 (Ω ) 50.5(1) 49.9 R2 (kΩ) 4.99 4.99 R3 (Ω ) 20 12 R4 (kΩ ) 1 1 –3dB (MHz) 15 11 SLEW RATE (V/µs) 700 500 R4 NOTE: (1) Closest 1/2% value. FIGURE 14. Composite Amplifier for Wide Bandwidth. ® 13 OPA627, 637