® OPA603 OPA 603 OPA 603 High Speed, Current-Feedback, High Voltage OPERATIONAL AMPLIFIER FEATURES APPLICATIONS ● WIDE SUPPLY RANGE: ±4.5 to ±18V ● VIDEO AMPLIFIER ● BANDWIDTH: 100MHz, G = 1 to 10 ● SLEW RATE: 1000V/µs ● PULSE AMPLIFIER ● SONAR, ULTRASOUND BUFFERS ● FAST SETTLING TIME: 50ns to 0.1% ● HIGH OUTPUT CURRENT: ±150mA peak ● ATE PIN DRIVERS ● xDSL LINE DRIVER ● HIGH OUTPUT VOLTAGE: ±12V ● FAST DATA ACQUISTION ● WAVEFORM GENERATORS DESCRIPTION +VS The OPA603 is a high-speed current-feedback op amp with guaranteed specifications at both ±5V and ±15V power supplies. It can deliver full ±10V signals into 150Ω loads with up to 1000V/µs slew rate. This allows it to drive terminated 75Ω cables. With 150mA peak output current capability it is suitable for driving load capacitance or long lines at high speed. 7 In contrast with conventional op amps, the currentfeedback approach provides nearly constant bandwidth and settling time over a wide range of closedloop voltage gains. +In –In VO 3 2 6 The OPA603 is available in a plastic 8-pin DIP and SO-16 surface-mount packages, specified over the industrial temperature range. –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-1026E Printed in U.S.A. February, 1995 SPECIFICATIONS: VS = ±15V ELECTRICAL At TA = +25°C, and RL = 150Ω, unless otherwise noted. OPA603AP, AU PARAMETER CONDITIONS INPUT OFFSET VOLTAGE Initial vs Temperature vs Common-Mode Voltage vs Supply (tracking) Voltage vs Supply (non-tracking)(1) +INPUT BIAS CURRENT Initial vs Temperature vs Common-Mode vs Supply (tracking) vs Supply (non-tracking)(1) –INPUT BIAS CURRENT Initial vs Temperature vs Common-Mode vs Supply (tracking) vs Supply (non-tracking)(1) VCM = ±10V VS = ±12V to ±18V |VS| = 12V to 18V MIN TYP 50 80 55 8 60 85 60 VCM = ±10V VS = ±12V to ±18V |VS| = 12V to 18V 30 200 50 150 VCM = ±10V VS = ±12V to ±18V |VS| = 12V to 18V 300 200 300 1500 OUTPUT CHARACTERISTICS Voltage Peak Current Short-Circuit Current(2) Output Resistance, Open-Loop FREQUENCY RESPONSE Small-Signal Bandwidth(3) Gain Flatness, ±0.5dB Full-Power Bandwidth Differential Gain Differential Phase TIME DOMAIN RESPONSE Propagation Delay Rise and Fall Time Settling Time to 0.10% Slew Rate DISTORTION 2nd Harmonic Distortion 3rd Harmonic Distortion 5 mV µV/°C dB dB dB 5 µA nA/°C nA/V nA/V nA/V 500 100 300 600 500 2000 µA nA/°C nA/V nA/V nA/V 5 || 2 30 || 2 MΩ || pF Ω || pF VO = ±10V 300 440 1.8 kΩ pF RL = 150Ω ±10 ±12 150 250 70 V mA mA Ω 70 35 160 75 10 0.03 0.025 MHz MHz MHz % Degrees 10 10 50 1000 ns ns ns V/µs –65 –90 dBc dBc VO = 0V G = +2 VO = 20Vp-p f = 4.43MHz, VO = 1V f = 4.43MHz, VO = 1V G = +2 10V Step G = +2, RL = 100Ω, f = 10MHz VO = 0.2Vp-p VO = 0.2Vp-p POWER SUPPLY Specified Operating Voltage Operating Voltage Range Current –60 –70 ±4.5 TEMPERATURE RANGE Specification Storage THERMAL RESISTANCE, θJA UNITS 25 INPUT IMPEDANCE +Input –Input OPEN LOOP CHARACTERISTICS Transresistance Transcapacitance MAX ±15 ±21 –25 –40 Soldered to Printed Circuit 90 ±18 ±25 V V mA +85 +150 °C °C °C/W NOTES: (1) One power supply fixed at 15V; the other supply varied from 12V to 18V. (2) Observe power derating curve. (3) See bandwidth versus gain curve, Figure 5. 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. ® OPA603 2 SPECIFICATIONS: VS = ±5V ELECTRICAL At TA = +25°C, and RL= 75Ω, unless otherwise noted. OPA603AP, AU PARAMETER INPUT OFFSET VOLTAGE Initial vs Temperature vs Common-Mode vs Supply (tracking) vs Supply (non-tracking)(1) +INPUT BIAS CURRENT Initial vs Temperature vs Common-Mode vs Supply (tracking) vs Supply (non-tracking)(1) –INPUT BIAS CURRENT Initial vs Temperature vs Common-Mode vs Supply (tracking) vs Supply (non-tracking)(1) CONDITIONS VCM = ±3V VS = ±4V to ±6V |VS| = 4V to 6V MIN TYP 50 75 55 8 55 80 60 VCM = ±3V VS = ±4V to ±6V |VS| = 4V to 6V 30 350 100 200 VCM = ±3V VS = ±4V to ±6V |VS| = 4V to 6V 300 300 500 2500 OUTPUT CHARACTERISTICS Voltage Peak Current Short-Circuit Current(2) Output Resistance, Open-Loop FREQUENCY RESPONSE Small-Signal Bandwidth(3) Gain Flatness, ±0.5dB Full-Power Bandwidth Differential Gain Differential Phase TIME DOMAIN RESPONSE Propagation Delay Rise and Fall Time Settling Time to 0.10% Slew Rate DISTORTION 2nd Harmonic Distortion 3rd Harmonic Distortion 6 mV µV/°C dB dB dB 5 µA nA/°C nA/V nA/V nA/V 600 200 300 600 700 3000 µA nA/°C nA/V nA/V nA/V 3.3 || 2 30 || 2 MΩ || pF Ω || pF VO = ±2V 225 330 2.4 kΩ pF RL = 75Ω ±2 ±2.75 150 250 80 V mA mA Ω 140 65 20 0.03 0.025 MHz MHz MHz % Degrees 15 20 60 750 ns ns ns V/µs –67 –78 dBc dBc VO = 0V G = +2 f = 4.43MHz, VO = 1V, RL = 150Ω f = 4.43MHz, VO = 1V, RL = 150Ω G = +2, RL = 100Ω G = +2, RL = 100Ω, f = 10MHz VO = 0.2Vp-p VO = 0.2Vp-p POWER SUPPLY Specified Operating Voltage Operating Voltage Range Current ±4.5 TEMPERATURE RANGE Specification Storage THERMAL RESISTANCE, θJUNCTION-AMBIENT UNITS 25 INPUT IMPEDANCE +Input –Input OPEN LOOP CHARACTERISTICS Transresistance Transcapacitance MAX ±5 ±21 –25 –40 Soldered to Printed Circuit ±18 ±25 V V mA +85 +150 °C °C °C/W 90 NOTES: (1) One power supply fixed at 5V; the other supply varied from 4V to 6V. (2) Observe power derating curve. (3) See bandwidth versus gain curves, Figure 5. ® 3 OPA603 PIN CONFIGURATION PIN CONFIGURATION Top View Top View DIP NC 8 1 NC SO-16 NC 1 16 NC NC 2 15 NC –In 3 14 +VS NC 4 13 NC –In 2 7 +VS +In 5 12 VO +In 3 6 VO NC 6 11 NC NC –VS 7 10 NC NC 8 9 –VS 5 4 NC: No Internal Connection. Solder to ground plane for improved heat dissipation. NC: No Internal Connection. Solder to ground plane for improved heat dissipation. ABSOLUTE MAXIMUM RATINGS ELECTROSTATIC DISCHARGE SENSITIVITY Supply Voltage ................................................................................... ±18V Input Voltage Range ............................................................................ ±VS Differential Input Voltage ..................................................................... ±6V Power Dissipation ........................................................ See derating curve Operating Temperature ................................................................. +100°C Storage Temperature ..................................................................... +150°C Junction Temperature .................................................................... +150°C Lead Temperature (soldering, 10s) ............................................... +300°C (soldering SO-16 package, 3s) ...................... +260°C 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. PACKAGE/ORDERING INFORMATION PRODUCT PACKAGE PACKAGE DRAWING NUMBER(1) OPA603AP OPA603AU Plastic DIP SO-16 006 211 SPECIFIED TEMPERATURE RANGE –25°C to +85°C –25°C to +85°C NOTE: (1) For detailed drawing and dimension table, please see end of data sheet, or Appendix C of Burr-Brown IC Data Book. ® OPA603 NC 4 TYPICAL PERFORMANCE CURVES At TA = +25°C, unless otherwise noted. OUTPUT SWING vs TEMPERATURE OUTPUT SWING vs TEMPERATURE 14 3.1 RL = ∞ Positive Swing 13 Output Swing (V) Output Swing (V) VS = ±15V RL = ∞ RL = 150Ω 12 Negative Swing Positive Swing 2.9 RL = 75Ω 2.7 VS = ±5V 2.5 Negative Swing 11 2.3 10 2.1 –25 0 +25 +50 +75 +100 –25 0 +25 +50 +75 Temperature (°C) Temperature (°C) NONINVERTING INPUT BIAS CURRENT vs TEMPERATURE INVERTING INPUT BIAS CURRENT vs TEMPERATURE +5 +100 +30 +4 +20 +3 +10 VS = ±15V +1 IB – (µA) I B + (µA) +2 0 VS = ±5V –1 0 VS = ±15V –10 –2 –3 –20 VS = ±5V –4 –30 –5 –25 0 +25 +50 +75 +100 –25 0 Temperature (°C) IB – Common-Mode Rejection Ratio (A/V) COMMON-MODE REJECTION vs FREQUENCY Common-Mode Rejection (dB) 65 VS = ±15V VS = ±5V 55 45 35 10 100 1k 10k 100k +25 +50 +75 +100 Temperature (°C) 1M 10M IB – –8 –7 VS = ±15V –6 VS = ±5V 10 10 –5 10 –4 10 10 Frequency (Hz) COMMON-MODE REJECTION RATIO 10 100 1k 10k 100k 1M 10M Frequency (Hz) ® 5 OPA603 TYPICAL PERFORMANCE CURVES (CONT) At TA = +25°C, unless otherwise noted. POWER SUPPLY REJECTION vs FREQUENCY POWER SUPPLY REJECTION vs FREQUENCY 85 VS = ±15V Tracking Supplies Tracking Supplies Power Supply Rejection (dB) Power Supply Rejection (dB) 90 80 70 +VS 60 –VS 50 65 +VS –VS 55 45 35 40 100 10 1k 10k 100k 100 10 1M 1k IB – PSRR vs FREQUENCY Tracking Supplies –VS –6 10 100k 1M IB – PSRR vs FREQUENCY –7 IB – Power Supply Rejection Ratio (A/V) IB – Power Supply Rejection Ratio (A/V) –7 10 10k Frequency (Hz) Frequency (Hz) V S = ±15V +VS –5 10 –4 10 –3 10 Tracking Supplies –VS –6 10 V S = ±5V +VS –5 10 –4 10 –3 10 10 10 100 1k 10k 100k 10 1M 100 1k 10k 100k Frequency (Hz) Frequency (Hz) LARGE-SIGNAL HARMONIC DISTORTION vs FREQUENCY LARGE-SIGNAL HARMONIC DISTORTION vs FREQUENCY –30 1M –30 G = +2 V O = 2Vp-p RL = 100 Ω –40 Harmonic Distortion (dBc) Harmonic Distortion (dBc) VS = ±5V 75 2f –50 –60 3f –70 –80 VS = ±15V –90 G = +2V/V V O = 2Vp-p RL = 100Ω –40 –50 2f –60 3f –70 –80 VS = ±5V –90 –100 –100 10 1 100 1 Frequency (MHz) ® OPA603 10 Frequency (MHz) 6 100 TYPICAL PERFORMANCE CURVES (CONT) At TA = +25°C, unless otherwise noted. SMALL-SIGNAL HARMONIC DISTORTION vs FREQUENCY SMALL-SIGNAL HARMONIC DISTORTION vs FREQUENCY –30 VS = ±15V G = +2V/V V O = 0.5Vp-p RL = 100Ω –40 –50 Harmonic Distortion (dBc) Harmonic Distortion (dBc) –30 2f –60 –70 –80 3f –90 VS = ±5V G = +2V/V V O = 0.5Vp-p RL = 100Ω –40 –50 2f –60 –70 3f –80 –90 –100 1 10 –100 100 1 10 Frequency (MHz) 100 Frequency (MHz) 2-TONE, 3rd ORDER INTERMODULATION INTERCEPT MAXIMUM POWER DISSIPATION vs TEMPERATURE 40 Power Dissipation (W) Intercept Point (+dBm) 2.0 30 VS = ±15V 20 1.5 Safe 1.0 VS = ±5V 0.5 10 10 20 30 40 50 –25 0 Frequency (MHz) OPEN-LOOP TRANSIMPEDANCE vs TEMPERATURE +50 +75 +100 OPEN-LOOP OUTPUT RESISTANCE vs TEMPERATURE 500 125 Open-Loop Output Resistance (Ω ) Open-Loop Transimpedance (kΩ ) +25 Temperature (°C) V S = ±15V 400 VS = ±5V 300 200 100 V S = ±5V 75 V S = ±15V 50 25 –25 0 +25 +50 +75 +100 –25 Temperature (°C) 0 +25 +50 +75 +100 Temperature (°C) ® 7 OPA603 TYPICAL PERFORMANCE CURVES (CONT) At TA = +25°C, unless otherwise noted. INPUT NOISE vs FREQUENCY 3 10 3 10 INPUT NOISE vs FREQUENCY 3 2 10 Inverting Current 10 10 Voltage 2 Noise Voltage (nV/ Hz) 10 10 2 10 1 100 1k 10 1 100k 10k Noninverting NoninvertingCurrent Current 1 10 1 100 1k 10k LARGE-SIGNAL OUTPUT vs FREQUENCY LARGE-SIGNAL OUTPUT vs FREQUENCY 5 VS = ±15V VS = ±5V 20 Output Voltage (Vp-p) Output Voltage (Vp-p) 1 100k Frequency (Hz) 25 15 R L = 150Ω 10 4 3 R L = 75Ω 2 1 5 0 0 1k 10k 100k 1M 10M 100 100M 1k 10k 100k 1M 10M 100M Frequency (Hz) Frequency (Hz) OPEN-LOOP PHASE vs FREQUENCY OPEN-LOOP TRANSIMPEDANCE vs FREQUENCY 6 10 10 Phase Shift (Degrees) Transimpedance (Ω ) 0 VS = ±5V 5 VS = ±15V 4 10 3 10 2 VS = ±5V VS = ±15V –45 –90 –135 –180 10 100 1k 10k 100k 1M 10M 100M 1G 100 1k 10k 100k 1M Frequency (Hz) Frequency (Hz) ® OPA603 2 10 Voltage Voltage Frequency (Hz) 100 10 Inverting Current Noninverting Current 1 3 VS = ±5V Noise Current (pA/ Hz) Noise Voltage (nV/ Hz) VS = ±15V 10 8 10M 100M 1G Noise Current (pA/ Hz) 10 TYPICAL PERFORMANCE CURVES (CONT) 45 40 0 20 –45 0 10k 100k 1M 10M OPEN-LOOP OUTPUT IMPEDANCE 80 –90 100M 90 V S = ±5V 60 45 40 0 20 –45 –90 100M 0 10k Frequency (Hz) 100k 1M Open-Loop Output Z Phase (°) V S = ±15V 60 90 Open- Loop Output Z Magnitude (Ω ) OPEN-LOOP OUTPUT IMPEDANCE 80 Open-Loop Output Z Phase (°) Open- Loop Output Z Magnitude (Ω ) At TA = +25°C, unless otherwise noted. 10M Frequency (Hz) 0.05% ∆ Gain 0.0625° ∆θ 200 IRE Full Scale Measured with Rohde & Schwarz Differential Gain/Phase Meter. Rohde & Schwarz SPF2 Video Signal Generator VS = ±5V 75Ω 75Ω Rohde & Schwarz PVF Differential Gain/Phase Meter Scope Plotter 499Ω 5pF 499Ω FIGURE 1. Video Differential Gain/Phase Performance. ® 9 OPA603 SMALL-SIGNAL FREQUENCY RESPONSE LARGE SIGNAL PULSE RESPONSE 100pF 2.5k 2.5kΩ +6 Input 2.5k 2.5kΩ – VIN +3 Gain (dB) VO VIN VO + 150Ω 150Ω CL 50pF 0 0pF VS = ±15V CL = 20pF 10pF –3 Output NOTE: Feedback resistor value selected for reduced peaking. –6 100k 1M 10M 100M Frequency (Hz) FIGURE 2. Dynamic Response, Inverting Unity-Gain. SMALL-SIGNAL FREQUENCY RESPONSE LARGE SIGNAL PULSE RESPONSE VVININ +26 Input + VO VO – 150Ω 150Ω Gain (dB) +23 CL 100pF 3570Ω 3570Ω 402Ω 402Ω 50pF +20 V S = ±15V Output 0pF +17 +14 100k NOTE: Feedback resistor value selected for reduced peaking. 1M CL = 20pF 10pF 10M 100M Frequency (Hz) FIGURE 3. Dynamic Response, Gain = +10. APPLICATIONS INFORMATION With control of the open-loop characteristics of the op amp, dynamic behavior can be tailored to an application’s requirements. Lower feedback resistance gives wider bandwidth, more frequency-response peaking and more pulse response overshoot. The higher open-loop gain resulting from lower feedback network resistors also yields lower distortion. Higher feedback network resistance gives an over-damped response with little or no peaking and overshoot. This may be beneficial when driving capacitive loads. Feedback network impedance can also be varied to optimize dynamic performance. To achieve wider bandwidth, use a feedback resistor value somewhat lower than indicated in Figure 4. For most circuit configurations, the OPA603 current-feedback op amp can be treated like a conventional op amp. As with a conventional op amp, the feedback network connected to the inverting input controls the closed-loop gain. But with a current-feedback op amp, the impedance of the feedback network also controls the open-loop gain and frequency response. Feedback resistor values can be selected to provide a nearly constant closed-loop bandwidth over a very wide range of gain. This is in contrast to a conventional op amp where circuit bandwidth is inversely proportional to the closedloop gain, sharply limiting bandwidth at high gain. EXTENDING BANDWIDTH For gains less than approximately 20, bandwidth can be extended by adding a capacitor, CF, in parallel with a lower value for RF. The optimum feedback resistor value in this case is far lower than those shown in Figure 1. For ±15V operation, select RF with the following equation: Figures 4a and 4b show appropriate feedback resistor values versus closed-loop gain for maximum bandwidth with minimal peaking. The dual vertical axes of these curves also show the resulting bandwidth. Note that the bandwidth remains nearly constant as gain is increased. ® OPA603 10 RF (Ω) = 30 • (30 – G) for VS = ±15V For example, for a gain of 10, use RF = 600Ω. Optimum values differ slightly for ±5V operation: RF (Ω) = 30 • (23 – G) for VS = ±5V 30 Voltage Gain (dB) 20 CF will range from 1pF to 10pF depending on the selected gain, load, and circuit layout. Adjust CF to optimize bandwidth and minimize peaking. Figure 5 shows bandwidth which can be acheived using this technique. Typical values for this capacitor range from 1pF to 10pF depending on closed-loop gain and load characteristics. Too large a value of CF can cause instability. 45 1.5k RF RI 37.5 – 750 + G= –1 3k RF 45 2k – + 37.5 1k RI G=1+ 1 POWER DISSIPATION RF RI 30 10 1G Power supplies should be bypassed with good high-frequency capacitors positioned close to the op amp pins. In most cases, a 0.01µF ceramic capacitor in parallel with a 2.2µF solid tantalum capacitor at each power supply pin is adequate. The OPA603 can deliver high load current—up to 150mA peak. Applications with low impedance or capacitive loads demand large current transients from the power supplies. It is the power supply bypass capacitors which must supply these current transients. Larger bypass capacitors such as 10µF solid tantalum capacitors may improve performance in these applications. Feedback Resistor (Ω) Closed-Loop Bandwidth (MHz) 52.5 10M 100M Frequency (Hz) With any high-speed, wide-bandwidth circuitry, careful circuit layout will ensure best performance. Make short, direct circuit interconnections and avoid stray wiring capacitance— especially at the inverting input pin. A component-side ground plane will help ensure low ground impedance. Do not place the ground plane under or near the inputs and feedback network. BANDWIDTH AND FEEDBACK RESISTOR vs NONINVERTING GAIN 4k RF RI CIRCUIT LAYOUT Voltage Gain (V/V) (4a) 60 G=1+ FIGURE 5. Bandwidth Results with Added Capacitor CF. 0 –100 –10 RF 1M –RF RI 30 CF 0 –20 Feedback Resistor (Ω) Closed-Loop Bandwidth (MHz) 2.25k G = 2, RF = 820 Ω, CF ≈ 3pF RI 3k 52.5 G = 10, RF = 560 Ω, C F ≈ 3pF –10 BANDWIDTH AND FEEDBACK RESISTOR vs INVERTING GAIN 60 10 VOLTAGE GAIN vs FREQUENCY G = 20, RF = 220 Ω, C F ≈ 8pF High output current causes increased internal power dissipation in the OPA603. Copper leadframe construction maximizes 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. Solder the unused pins, (1, 5 and 8) to a top-side ground plane for improved power dissipation. Limit the load and signal conditions depending on maximum ambient temperature to assure operation within the power derating curve. 0 100 Voltage Gain (V/V) (4b) FIGURE 4. Feedback Resistor Selection Curves. UNITY-GAIN OPERATION As Figure 4b indicates, the OPA603 can be operated in unity gain. A feedback resistor (approximately 2.8kΩ) sets the appropriate open-loop characteristics and resistor RI is omitted. Just as with gains greater than one, the value of the feedback resistor (and capacitor if used) can be optimized for the desired dynamic response and load characteristics. The OPA603 may be operated at reduced power supply voltage to minimize power dissipation. Detailed specifications are provided for both ±15V and ±5V operation. Care should be exercised not to exceed the maximum differential input voltage rating of ±6V. Large input voltage steps which exceed the device’s slew rate of 1000V/µs can apply excessive differential input voltage. ® 11 OPA603 APPLICATIONS CIRCUITS R +15V VO OPA603 1590Ω C C 100pF 100pF VIN VIN 1590Ω R 100kΩ VO OPA603 5pF 10kΩ RF 2-pole Butterworth HP f –3dB = 1MHz 1 f–3dB = 2π RC RG –15V FIGURE 6. Offset Voltage Adjustment. 511Ω 866Ω G = 1.6 FIGURE 9. High-Pass Filter — 1MHz. R G = 10 VIN VIN VO OPA603 C 110Ω 100pF C 100pF 1kΩ 110Ω R VO OPA603 220Ω 2R 5pF 1kΩ 511Ω 110Ω 261Ω (a) Varying inverting input Z changes dynamic response. G = 70 f C = 10MHz 1kΩ 100Ω MFE2000 VIN fC = 22dB G = –10 1 2 2 π RC VO OPA603 fC 1/2f C 2f C 1MΩ FIGURE 10. Bandpass Filter — 10MHz. VB : 0V - Max Bandwidth –V - Reduced Bandwidth R2 (b) FIGURE 7. Controlling Dynamic Performance. A1 VI C VO OPA603 R L ≥ 150Ω for ±10V Out 100pF VIN R R 159Ω 159Ω R1 C 100pF 2-pole Butterworth LP f –3dB = 10MHz 1 f –3dB = 2π RC R3 VO OPA603 5pF R4 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. See Application Bulletin AB-007 for details. 511Ω 866Ω (1) G = 1.6 NOTE: (1) Minimize capacitance at this node. FIGURE 8. Low-Pass Filter — 10MHz. GAIN (V/V) A1 OP AMP R1 (Ω) R2 (kΩ) R3 (Ω) R4 (kΩ) –3dB (MHz) SLEW RATE (V/µs) 100 1000 OPA627 OPA637 50.5(1) 49.9 4.99 4.99 20 12 1 1 15 11 700 500 NOTE: (1) Closest 1/2% value. FIGURE 11. Precision-Input Composite Amplifier. ® OPA603 12