Ultra Fast FET-Input Operational Amplifier CORPORATION LH0032 / LH0032C FEATURES GENERAL DESCRIPTION • 500V/µs Slew Rate Bandwidth • 70MHz 12 Ω Input Impedance • 10 • As Low as 2mV Max Input Offset Voltage • FET Input Null with Single Pot • Offset • No Compensation for Gains Above 50 • Peak Output Current to 100mA The LH0032 is a FET input, high slew rate amplifier capable of driving up to 100mA current. With wide bandwidth, high slew rate, high input impedance and high current drive capability, LH0032 is an ideal choice for many applications that includes high speed integrator, video amplifier, summing amplifier, high speed D/A converters, etc. ORDERING INFORMATION Part Package LH0032G LH0032CG H12A (TO8-12 Lead) H12A (TO8-12 Lead) Temperature Range -55oC to +125oC -25oC to +85oC CONNECTION DIAGRAMS OUTPUT COMPENSATION NC BALANCE/ COMPENSATION 3 2 4 INV INPUT 12 + 5 11 OUT 10 6 NON-INV INPUT V+ 1 7 8 NC V- 9 NC NC Top View H12A CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-1076 LH0032 / LH0032C CORPORATION ABSOLUTE MAXIMUM RATINGS Supply Voltage, VS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±18V Input Voltage, VIN. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±VS Differential Input Voltage . . . . . . . . . . . . . . . . . . ±30V or± 2VS Power Dissipation, PD TA = 25oC. . . . . . . . . . . . . 1.5W, derate 100oC/W to 125oC TC = 25oC. . . . . . . . . . . . . 2.2W, derate 70oC/W to 125oC Operating Temperature Range, TA LH0032G . . . . . . . . . . . . . . . . . . . . . . . . . -55oC to +125oC LH0032CG . . . . . . . . . . . . . . . . . . . . . . . . . -25oC to +85oC Operating Junction Temperature, TJ . . . . . . . . . . . . . . 175oC Storage Temperature Range . . . . . . . . . . . . -65oC to +150oC Lead Temp. (Soldering, 10 seconds). . . . . . . . . . . . . . 300oC DC ELECTRICAL CHARACTERISTICS VS = ±15V, TMIN ≤ TA ≤ TMAX unless otherwise noted (Note 1) (TA = T j) LH0032 SYMBOL LH0032C PARAMETER UNITS MIN TYP MAX 2 15 MIN TYP MAX 5 10 2 15 20 mV 50 15 50 µV/ o C TEST CONDITIONS TA = TJ = 25oC (Note 3) VOS Input Offset Voltage ∆VOS/∆T Average Offset Voltage Drift IOS Input Offset Current 25 250 25 50 500 5 pA pA nA IB Input Bias Current 100 1 50 500 5 15 pA nA nA VINCM Input Voltage Range ±10 ±12 ±10 ±12 V Note 6 CMRR Common Mode Rejection Ratio 50 60 50 60 dB ∆VIN = ±10V 60 70 60 70 dB VO = ±10V, f = 1kHz RL = 1kΩ (Note 7) ±13 V RL = 1kΩ AVOL Open-Loop Voltage Gain 57 VO Output Voltage Swing IS Power Supply Current PSRR Power Supply Rejection Ratio ±10 57 ±13.5 18 50 60 ±10 20 20 50 60 22 (Note 4) VIN = 0 TJ = 25oC (Note 2) TA = 25oC (Note 3) TJ = 25oC (Note 2) TA = 25oC (Note 3) mA TA = 25oC, IO = 0 (Note 3) dB ∆VS = 10V (±5 to ±15V) TJ = 25oC CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-1076 LH0032 / LH0032C CORPORATION AC ELECTRICAL CHARACTERISTICS VS = ±15V, RL = 1kΩ, TJ = 25oC (Note 5) SYMBOL PARAMETER SR Slew Rate ts Settling Time to 1% of Final Value MIN TYP 350 500 MAX UNITS CONDITIONS V/µs AV = +1 ∆VIN = 20V 100 AV = -1 ts Settling Time to 0.1% of Final Value tR Small Signal Rise Time 8 20 tD Small Signal Delay Time 10 25 300 ns AV = +1, ∆VIN = 1V Note 1. LH0032G/CG are 100% production tested as specified at 25 oC, Specifications at temperature extremes are verified by testing, periodic characterization, or correlation. Note 2. Specification is at 25oC junction temperature due to requirements of high-speed automatic testing. Actual values at operating temperature will exceed the value at TJ = 25oC. When supply voltages are ±15V, no-load operating junction temperature may rise 40-60oC above ambient, and more under load conditions. Accordingly, VOS may change one to several mV, and I B and IOS will change significantly during warm-up. Refer to IB and I OS vs. temperature graph for expected values. Note 3. Measured in still air 7 minutes after application of power. Guaranteed thru correlated automatic pulse testing. Note 4. ∆VOS/∆T is the average value calculated from measurements at 25 oC and TMAX, specifications at temperature are verified by testing, periodic characterization, or correlation. Note 5. Not 100% production tested; verified by testing, periodic characterization, or correlation. Note 6. Guaranteed by CMRR test condition. Note 7. Guaranteed thru correlated pulse testing at T j = 25 oC. AUXILIARY CIRCUITS Offset Null Output Short Circuit Protection V+ V+ LM113 12 6 10k + 12 6 LH0032 4 5 + INPUTS 3 LH0032 5 - 2 11 - 11 62Ω 10 OUTPUT 10 V- V- CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-1076 LH0032 / LH0032C CORPORATION TYPICAL PERFORMANCE CHARACTERISTICS MAXIMUM POWER DISSIPATION 24 INFINITE HEAT SINK TA = -55˚C 22 SUPPLY CURRENT (mA) POWER DISSIPATION (W) 2.5 SUPPLY CURRENT vs. SUPPLY VOLTAGE 2.0 θJC = 70˚C/W 1.5 1.0 NO HEAT SINK θJA = 100˚C/W 0.5 20 TC = 25˚C 18 16 14 TA = +125˚C 12 0 10 0 25 50 75 100 125 150 5 10 15 TEMPERATURE (˚C) SUPPLY VOLTAGE (±V) INPUT VOLTAGE RANGE AND OUTPUT VOLTAGE vs. SUPPLY VOLTAGE BODE PLOT (UNCOMPENSATED) 20 80 VS = ±15V RL = 1k TC = 25˚C VOLTAGE GAIN (dB) 0 15 VOUT 10 VIN 5 45 60 PHASE 40 90 135 180 GAIN 20 225 PHASE (DEGREES) VINCM , VOUT (±V) 20 270 0 10k 0 10 5 20 100k 1M 10M SUPPLY VOLTAGE (±V) FREQUENCY (Hz) BODE PLOT (UNITY GAIN COMPENSATED) LARGE SIGNAL FREQUENCY RESPONSE 80 24 60 0 PHASE 40 45 90 GAIN 20 100M 26 VS = ±15V 135 PHASE (DEGREES) VOLTAGE GAIN (dB) 15 VOLTAGE GAIN (dB) 0 A V = +10 22 20 18 A V = +1 16 14 12 10 VS = ±15V RL = 1k TC = +25˚C 8 0 10k 100k 1M 10M FREQUENCY (Hz) 100M 6 10 100 1M 10M 100M FREQUENCY (Hz) CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-1076 LH0032 / LH0032C CORPORATION COMMON MODE REJECTION RATIO vs. FREQUENCY LARGE SIGNAL PULSE RESPONSE 90 VS = ±15V RL = 1k 80 +10 OUTPUT VOLTAGE (V) COMMON-MODE REJECTION RATIO (dB) TYPICAL PERFORMANCE CHARACTERISTICS (Continued) 70 60 50 40 30 20 VS = ±15V A V = +1 RL = 1k +5 0 -5 10 -10 0 10k 100k 1M 10M 100M 0 100 200 300 400 500 FREQUENCY (Hz) TIME (ns) LARGE SIGNAL PULSE RESPONSE NORMALIZED INPUT BIAS AND OFFSET CURRENT vs. JUNCTION TEMPERATURE 10 4 CURRENT – NORMALIZED TO CURRENT AT TJ = 25˚C OUTPUT VOLTAGE (V) 10 VS = ±15V A V = +10 RL = 1k 5 0 -5 10 3 10 2 101 -10 0 100 200 300 400 10 0 25 500 45 65 85 105 125 145 165 JUNCTION TEMPERATURE (˚C) TIME (ns) NORMALIZED INPUT BIAS CURRENT DURING WARM-UP CURRENT – NORMALIZED TO CURRENT AT TIME = 0 100 VS = ±15V TA = 25˚C 10 1 0 2 4 6 8 10 TIME FROM POWER TURN-ON (MINUTES) CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-1076 LH0032 / LH0032C CORPORATION TYPICAL APPLICATIONS Unity Gain Amplifier 10X Buffer Amplifier 5pF 8pF - 10pF V- V- 12 12 2k 6 INPUT 2 + INPUT 2 + 3 3 11 LH0032 5 6 OUTPUT 5 4 10 11 LH0032 - 10 OUTPUT 9k 100pF VV- 1k 100 100X Buffer Amplifier Non-Compensated Unity Gain Inverter V+ V+ 10k INPUT 6 12 + 11 LH0032 5 - + 10k 10 5 INPUT V- - 11 LH0032 270 10k 12 6 0.01 + OUTPUT 10 100 V+ High Speed Sample and Hold 100Ω V+ 2N2222 2N4391 VOUT + VIN 2N3907 10k V+ LH0032 100Ω 1N914 1k CS = 1000pF V- LOGIC CONTROL 1/2 DH0034 *Use polystyrene dielectric for minimum drift V- CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-1076 LH0032 / LH0032C CORPORATION TYPICAL APPLICATIONS (Continued) High Speed Current Mode MUX 3.8pF 4 5 V- R5 6 18µF 12 R1 2 AM9710 A1 5.1k R2 5 6 3 LH0032 6 1 2 - G1 A2 3 11 VOUT + 10 5.1k R3 11 G2 9 5 V- 7 A3 5.1k R4 G3 13 10 8 A4 5.1k G4 12 14 APPLICATION INFORMATION: Power Supply Decoupling The LH0032, like most high speed circuits, is sensitive to layout and stray capacitance. Power supplies should be bypassed as near to pins 10 and 12 as practicable with low inductance capacitors such as 0.01µF disc ceramics. Compensation components should also be located close to the appropriate pins to minimize stray reactances. Input Current Because the input devices are FETs, the input bias current may be expected to double for each 11oC junction temperature rise. This characteristic is plotted in the typical performance characteristics graphs. The device will self-heat due to internal power dissipation after application of power thus raising the FET junction temperature 40-60oC above free-air ambient temperature when supplies are ±15V. The device temperature will stabilize within 5-10 minutes after application of power, and the input bias currents measured at that time will be indicative of normal operating currents. An additional rise would occur as power is delivered to a load due to additional internal power dissipation. There is an additional effect on input bias current as the input voltage is changed. The effect, common to all FETs, is an avalanche-like increase in gate current as the FET gate-to-drain voltage is increased above a critical value depending on FET geometry and doping levels. This effect will be noted as the input voltage of the LH0032 is taken below ground potential when the supplies are ±15V. All of the effects described here may be minimized by operating the device with VS ≤ ±15V. These effects are indicated in the typical performance curves. Input Capacitance The input capacitance to the LH0032/LH0032C is typically 5pF and thus may form a significant time constant with high value resistors. For optimum performance, the input CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-1076 LH0032 / LH0032C CORPORATION In the non-inverting configuration, it may be advantageous to bootstrap the case and/or a guard conductor to the inverting input. This serves both to divert leakage currents away from the non-inverting input and to reduce the effective input capacitance. A unity gain follower so treated will have an input capacitance under a picofarad. Figure 1. LH0032 Frequency Compensation Circuit R2 0.01µF 12 CA 5 _ INPUT 4 11 LH0032 R1 OUTPUT 3 6 + 2 10 CC 0.01µF -15V Two compensation schemes may be used, depending on the designer’s specific needs. The first technique is shown in Figure 1. It offers the best 0.1% settling time for a ±10V square wave input. The compensation capacitors CC and CA should be selected from Figure 2 for various closed-loop gains. Figure 3 shows how the LH0032 frequency response is modified for different value compensation capacitors. Figure 2. Recommended Value of Compensation Capacitor vs Closed-Loop Gain for Optimum Settling Time 100 10 75 CC 5 50 CA 25 0 1 10 100 0 1000 COMPENSATION CAPACITANCE CA (pF) +15V R3 Compensation COMPENSATION CAPACITANCE CC (pF) capacitance to the inverting input should be compensated by a small capacitor across the feedback resistor. The value is strongly dependent on layout and closed loop gain, but will typically be in the neighborhood of several picofarads. CLOSED LOOP GAIN Figure 3. The Effect of Various Compensation Capacitors on LH0032 Open Loop Frequency Response A VOL 60 40 C C = 0pF C C = 1pF 0 C C = 5pF C C = 10pF -45 20 C C = 5pF C C = 10pF 0 VS = ±15V RL = 1k TA = 25˚C -20 10k 100k -90 PHASE C C = 1pF C C = 0pF 1M 10M -135 -180 100M 10V PHASE SHIFT (DEGREES) VOLTAGE GAIN (dB) 80 Figure 4. LH0032 Unity Gain Non-Inverting Large Signal Pulse Response: TA = 25oC, CC = 10pF, CA = 100pF 10V 100nS FREQUENCY (Hz) CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-1076 LH0032 / LH0032C CORPORATION Although this approach offers the shortest settling time, the falling edge exhibits overshoot up to 30% lasting 200 to 300ns. Figure 4 shows the typical pulse response. If obtaining minimum ringing at the falling edge is the primary objective, a slight modification to the above is recommended. It is based on the same circuit as that of Figure 1. The values of the unity gain compensation capacitors CC and CA should be modified to 5pF and 1000pF, respectively. Figure 5 shows the suitable capacitance to use for various closed-loop gains. The resulting unity gain pulse response 5 1000 4 3 CC 2 500 CA 1 0 1 10 100 0 1000 COMPENSATION CAPACITANCE CA (pF) COMPENSATION CAPACITANCE CC (pF) Figure 5. Recommended Value of Compensation Capacitor vs Closed-Loop Gain for Optimum Slew Rate waveform is shown in Figure 6. The settling time to 1% final value is actually superior to the first method of compensation. However, the LH0032 suffers slow settling thereafter to 0.1% accuracy at the falling edge, and nearly four times as much at the rising edge, compared to the previous scheme. Note, however, that the falling edge ringing is considerably reduced. Furthermore, the slew rate is consistently superior using this compensation because of the smaller value of Miller capacitance CC required. The second compensation scheme works well with both inverting or non-inverting modes. Figure 7 shows the circuit schematic, in which a 270ohm resistor and a 0.01µF capacitor are shunted across the inputs of the device. This lag compensation introduces a zero in the loop modifying the response such that adequate phase margin is preserved at unity gain crossover frequency. Note that the circuit requires no additional compensation. Heat Sinking While the LH0032 is specified for operation without any explicit heat sink, internal power dissipation does cause a significant temperature rise. Improved bias current performance can thus be obtained by limiting this temperature rise with a small heat sink such as the Thermalloy No. 2241 or equivalent. The case of the device has no internal connection, so it may be electrically connected to the sink if this is advantageous. However, that this will affect the stray capacitance to all pins and may thus require adjustment of circuit compensation values. CLOSED LOOP GAIN Figure 6. LH0032 Unity Gain Non-Inverting Large Signal Pulse Response: CC = 5pF, CA = 1000pF Figure 7. LH0032 Non-Compensated Unity Gain Compensation +15V 10V 1k 1k INPUT 0.01µF 5 _ LH0032 270 1k 12 11 OUTPUT 6 + 10 0.01µF 0.01µF 10V 50nS -15V CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-1076