Ultralow Noise, a High Speed, BiFET Op Amp AD745 FEATURES CONNECTION DIAGRAM ULTRALOW NOISE PERFORMANCE 16-Lead SOIC (R) Package 2.9 nV/ Hz at 10 kHz 0.38 V p-p, 0.1 Hz to 10 Hz 6.9 fA/ Hz Current Noise at 1 kHz EXCELLENT AC PERFORMANCE 12.5 V/ s Slew Rate 20 MHz Gain Bandwidth Product THD = 0.0002% 1 kHz Internally Compensated for Gains of +5 (or 4) or Greater EXCELLENT DC PERFORMANCE 0.5 mV Max Offset Voltage 250 pA Max Input Bias Current 2000 V/mV Min Open Loop Gain Available in Tape and Reel in Accordance with EIA-481A Standard APPLICATIONS amplifier for high-speed applications demanding low noise and Sonar high dc precision. Furthermore, the AD745 does not exhibit an Photodiode and IR Detector Amplifiers output phase reversal. Accelerometers The AD745 also has excellent dc performance with 250 pA Low Noise Preamplifiers maximum input bias current and 0.5 mV maximum offset voltage. High Performance Audio The internal compensation of the AD745 is optimized for higher gains, providing a much higher bandwidth and a faster slew PRODUCT DESCRIPTION rate. This makes the AD745 especially useful as a preamplifier The AD745 is an ultralow noise, high-speed, FET input opera- where low level signals require an amplifier that provides both tional amplifier. It offers both the ultralow voltage noise and high amplification and wide bandwidth at these higher gains. high speed generally associated with bipolar input op amps and The AD745 is available in two performance grades. The AD745J the very low input currents of FET input devices. Its 20 MHz and AD745K are rated over the commercial temperature range bandwidth and 12.5 V/ s slew rate makes the AD745 an ideal of 0C to 70C, and are available in the 16-lead SOIC package. 1000 120 120 R SOURCE 100 100 OP37 AND E RESISTOR PHASE O 80 80 R SOURCE 100 60 60 GAIN AD745 AND RESISTOR AD745 AND OR RESISTOR 40 40 OP37 AND RESISTOR 10 20 20 0 0 RESISTOR NOISE ONLY 20 20 1 100 1k 10k 100k 1M 10M 100 1k 10k 100k 1M 10M 100M SOURCE RESISTANCE FREQUENCY Hz Figure 1. Figure 2. REV. D Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. use, nor for any infringements of patents or other rights of third parties that Tel: 781/329-4700 www.analog.com may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Fax: 781/326-8703 Analog Devices, Inc., 2002 INPUT NOISE VOLTAGE nV/ Hz OPEN-LOOP GAIN dB PHASE MARGIN DegreesAD745SPECIFICATIONS ( +25 C and 15 V dc, unless otherwise noted.) AD745 ELECTRICAL CHARACTERISTICS Model AD745J AD745K Conditions Min Typ Max Min Typ Max Unit 1 INPUT OFFSET VOLTAGE Initial Offset 0.25 1.0 0.1 0.5 mV Initial Offset T to T 1.5 1.0 mV MIN MAX vs. Temp. T to T 22 V/C MIN MAX 2 vs. Supply (PSRR) 12 V to 18 V 90 96 100 106 dB vs. Supply (PSRR) T to T 88 98 105 dB MIN MAX 3 INPUT BIAS CURRENT Either Input V = 0 V 150 400 150 250 pA CM Either Input T V = 0 V 8.8 5.5 nA MAX CM Either Input V = +10 V 250 600 250 400 pA CM Either Input, V = 5 V V = 0 V 30 200 30 125 pA S CM INPUT OFFSET CURRENT V = 0 V 40 150 30 75 pA CM Offset Current T V = 0 V 2.2 1.1 nA MAX CM FREQUENCY RESPONSE Gain BW, Small Signal G = 4 20 20 MHz Full Power Response V = 20 V p-p 120 120 kHz O Slew Rate G = 4 12.5 12.5 V/ s Settling Time to 0.01% 5 5 s Total Harmonic f = 1 kHz 4 Distortion G = 4 0.0002 0.0002 % INPUT IMPEDANCE 10 10 Differential 1 10 20 1 10 20 pF 11 11 Common Mode 3 10 18 3 10 18 pF INPUT VOLTAGE RANGE 5 Differential 20 20 V Common-Mode Voltage +13.3, 10.7 +13.3, 10.7 V 6 Over Max Operating Range 10 +12 10 +12 V Common-Mode Rejection Ratio V = 10 V 80 95 90 102 dB CM T to T 78 88 dB MIN MAX INPUT VOLTAGE NOISE 0.1 to 10 Hz 0.38 0.38 1.0 V p-p f = 10 Hz 5.5 5.5 10.0 nV/Hz f = 100 Hz 3.6 3.6 6.0 nV/Hz f = 1 kHz 3.2 5.0 3.2 5.0 nV/Hz f = 10 kHz 2.9 4.0 2.9 4.0 nV/Hz INPUT CURRENT NOISE f = 1 kHz 6.9 6.9 fA/Hz OPEN LOOP GAIN V = 10 V O R 2 k 1000 4000 2000 4000 V/mV LOAD T to T 800 1800 V/mV MIN MAX R = 600 1200 1200 V/mV LOAD OUTPUT CHARACTERISTICS Voltage R 600 +13, 12 +13, 12 V LOAD R 600 +13.6, 12.6 +13.6, 12.6 V LOAD T to T +12, 10 +12, 10 V MIN MAX R 2 k 12 +13.8, 13.1 +13.8, 13.1 V LOAD Current Short Circuit 20 40 20 40 mA POWER SUPPLY Rated Performance 15 15 V Operating Range 4.8 18 4.8 18 V Quiescent Current 8 10.0 8 10.0 mA TRANSISTOR COUNT of Transistors 50 50 NOTES 1 Input offset voltage specifications are guaranteed after five minutes of operations at T = 25C. A 2 Test conditions: +V = 15 V, V = 12 V to 18 V and +V = 12 V to +18 V, V = 15 V. S S S S 3 Bias current specifications are guaranteed maximum at either input after five minutes of operation at T = 25C. For higher temperature, the current doubles every 10C. A 4 Gain = 4, R = 2 k , C = 10 pF. L L 5 Defined as voltage between inputs, such that neither exceeds 10 V from common. 6 The AD745 does not exhibit an output phase reversal when the negative common-mode limit is exceeded. All min and max specifications are guaranteed. Specifications subject to change without notice. 2 REV. D