AD797_V01 AD | Alldatasheet

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Ultralow Distortion, Ultralow Noise Op Amp Data Sheet AD797 Rev. K Document Feedback Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. Tel: 781.329.4700 ©1992–2015 Analog Devices, Inc. All rights reserved. Technical Support www.analog.com

FEATURES

0.9 nV/√Hz typical (1.2 nV/√Hz maximum) input voltage noise at 1 kHz 50 nV p-p input voltage noise, 0.1 Hz to 10 Hz Low distortion −120 dB total harmonic distortion at 20 kHz Excellent ac characteristics 800 ns settling time to 16 bits (10 V step)

110 MHz gain bandwidth (G = 1000)

8 MHz bandwidth (G = 10)

280 kHz full power bandwidth at 20 V p-p

20 V/μs slew rate

80 μV maximum input offset voltage 1.0 μV/°C V OS drift Specified for ±5 V and ±15 V power supplies High output drive current of 50 mA

APPLICATIONS

Professional audio preamplifiers IR, CCD, and sonar imaging systems Spectrum analyzers Ultrasound preamplifiers Seismic detectors Σ-Δ ADC/DAC buffers GENERAL DESCRIPTION The AD797 is a very low noise, low distortion operational amplifier ideal for use as a preamplifier. The low noise of 0.9 nV/√Hz and low total harmonic distortion of −120 dB in audio bandwidths give the AD797 the wide dynamic range necessary for preamps in microphones and mixing consoles. Furthermore, the AD797 has an excellent slew rate of 20 V/μs and a 110 MHz gain bandwidth, which makes it highly suitable for low frequency ultrasound applications. The AD797 is also useful in infrared (IR) and sonar imaging applications, where the widest dynamic range is necessary. The low distortion and 16-bit settling time of the AD797 make it ideal for buffering the inputs to Σ-Δ ADCs or the outputs of high resolution DACs, especially when the device is used in critical applications such as seismic detection or in spectrum analyzers. Key features such as a 50 mA output current drive and the specified power supply voltage range of ±5 V to ±15 V make the AD797 an excellent general-purpose amplifier. 00846-002 10M 100 1M100k10k1k FREQUENCY (Hz) INPUT VOLTAGE NOISE (nV/√Hz) Figure 1. AD797 Voltage Noise Spectral Density Table 1. Low Noise Op Amps

Rev. K | Page 2 of 19 TABLE OF CONTENTS

REVISION HISTORY

3/15—Rev. J to Rev. K 2/14—Rev. I to Rev. J 3/13—Rev. H to Rev. I 6/10—Rev. G to Rev. H Moved Figure 1 to Absolute Maximum Ratings Section; Moved Figure 3 to Typical Performance Characteristics Change to Noise and Source Impedance Considerations 9/08—Rev. F to Rev. G Changes to Input Common-Mode Voltage Range Parameter, 1/08—Rev. E to Rev. F 7/05—Rev. D to Rev. E 10/02—Rev. C to Rev. D

Rev. K | Page 3 of 19 SPECIFICATIONS TA = 25°C and VS = ±15 V dc, unless otherwise noted. Table 2. AD797A AD797B Parameter Conditions Supply Voltage (V) Min Typ Max Min Typ Max Unit INPUT OFFSET VOLTAGE ±5 V, ±15 V 25 80 10 40 μV T MIN to TMAX 50 125/180 30 60 μV Offset Voltage Drift ±5 V, ±15 V 0.2 1.0 0.2 0.6 μV/°C INPUT BIAS CURRENT ±5 V, ±15 V 0.25 1.5 0.25 0.9 μA T MIN to TMAX 0.5 3.0 0.25 2.0 μA INPUT OFFSET CURRENT ±5 V, ±15 V 100 400 80 200 nA T MIN to TMAX 120 600/700 120 300 nA OPEN-LOOP GAIN VOUT = ±10 V ±15 V 1 20 2 20 V/μV R LOAD = 2 kΩ 1 6 2 10 V/μV T MIN to TMAX 1 15 2 15 V/μV R LOAD = 600 Ω 1 5 2 7 V/μV T MIN to TMAX 14,000 20,000 14,000 20,000 V/V At 20 kHz1 DYNAMIC PERFORMANCE Gain Bandwidth Product G = 1000 ±15 V 110 110 MHz G = 10002 15 V 450 450 MHz –3 dB Bandwidth G = 10 ±15 V 8 8 MHz Full Power Bandwidth1 VOUT = 20 V p-p, RLOAD = 1 kΩ ±15 V 280 280 kHz Slew Rate RLOAD = 1 kΩ ±15 V 12.5 20 12.5 20 V/μs Settling Time to 0.0015% 10 V step ±15 V 800 1200 800 1200 ns COMMON-MODE REJECTION V CM = CMVR ±5 V, ±15 V 114 130 120 130 dB T MIN to TMAX 110 120 114 120 dB POWER SUPPLY REJECTION V S = ±5 V to ±18 V 114 130 120 130 dB T MIN to TMAX 110 120 114 120 dB INPUT VOLTAGE NOISE f = 0.1 Hz to 10 Hz ±15 V 50 50 nV p-p f = 10 Hz ±15 V 1.7 1.7 2.5 nV/√Hz f = 1 kHz ±15 V 0.9 1.2 0.9 1.2 nV/√Hz f = 10 Hz to 1 MHz ±15 V 1.0 1.3 1.0 1.2 μV rms INPUT CURRENT NOISE f = 1 kHz ±15 V 2.0 2.0 pA/√Hz INPUT COMMON-MODE VOLTAGE RANGE OUTPUT VOLTAGE SWING R LOAD = 2 kΩ ±15 V ±12 ±13 ±12 ±13 V R LOAD = 600 Ω ±15 V ±11 ±13 ±11 ±13 V R LOAD = 600 Ω ±5 V ±2.5 ±3 ±2.5 ±3 V Short-Circuit Current ±5 V, ±15 V 80 80 mA Output Current3 ±5 V, ±15 V 30 50 30 50 mA TOTAL HARMONIC DISTORTION RLOAD = 1 kΩ, CN = 50 pF, f = 250 kHz, 3 V rms RLOAD = 1 kΩ, f = 20 kHz, 3 V rms ±15 V −120 −110 −120 −110 dB

Rev. K | Page 4 of 19 AD797A AD797B Parameter Conditions Supply Voltage (V) Min Typ Max Min Typ Max Unit INPUT CHARACTERISTICS Input Resistance Differential 7.5 7.5 kΩ Common Mode 100 100 MΩ Input Capacitance Differential4 20 20 pF Common Mode 5 5 pF OUTPUT RESISTANCE A V = 1, f = 1 kHz 3 3 mΩ POWER SUPPLY Operating Range ±5 ±18 ±5 ±18 V Quiescent Current ±5 V, ±15 V 8.2 10.5 8.2 10.5 mA 1 Full power bandwidth = slew rate/2π VPEAK. 2 Specified using external decompensation capacitor. 3 Output current for |VS − VOUT| > 4 V, AOL > 200 kΩ. 4 Differential input capacitance consists of 1.5 pF package capacitance and 18.5 pF from the input differential pair.

current should be limited to less than 25 mA by series protection resistors. Note, however, that this degrades the low noise performance of the device. Figure 2. 8-Lead Plastic Dual In-Line Package [PDIP] and board (PCB) with zero airflow for the PDIP package. Table 4. Thermal Resistance

USE CIRCUIT BOARD WITH GROUND PLANE. Figure 44. Settling Time Test Circuit

450 MHz at G = 1000, and distortion can be held to −100 dB at

connecting a capacitor from Pin 8 to ground (see C1 in Figure 45). compensation capacitance and therefore a larger bandwidth. recommended. At a gain of 1000, the bandwidth is 450 kHz. AD797 with distortion cancellation and decompensation. Figure 45. Recommended Connections for Distortion Cancellation Table 8. Recommended External Compensation for Figure 46. Total Harmonic Distortion (THD) vs. Frequency at 3 V rms

combination of low noise and low gain is difficult to achieve.

1 MHz for a 2 V p-p output level and drops rapidly to better

than −70 dBc at an output level of 200 mV p-p. *USE THE POWER SUPPLY BYPASSING SHOWN IN FIGURE 35. Figure 51. An Ultrasound Preamplifier Circuit bandwidth, as shown by Figure 53. *USE THE POWER SUPPLY BYPASSING SHOWN IN FIGURE 35. Figure 52. Amorphous Detector Preamp Figure 53. Total Integrated Voltage Noise and VOUT desired output with extremely low THD and IMD. *USE THE POWER SUPPLY BYPASSING SHOWN IN FIGURE 35. Figure 54. A Professional Audio DAC Buffer Figure 55. Offset Null Configuration

Rev. K | Page 19 of 19 ORDERING GUIDE Model1 Temperature Range Package Description Package Option AD797ANZ −40°C to +85°C 8-Lead Plastic Dual In-Line Package [PDIP] N-8 AD797AR −40°C to +85°C 8-Lead Standard Small Outline Package [SOIC_N] R-8 AD797AR-REEL7 −40°C to +85°C 8-Lead Standard Small Outline Package [SOIC_N] R-8 AD797ARZ −40°C to +85°C 8-Lead Standard Small Outline Package [SOIC_N] R-8 AD797ARZ-REEL −40°C to +85°C 8-Lead Standard Small Outline Package [SOIC_N] R-8 AD797ARZ-REEL7 −40°C to +85°C 8-Lead Standard Small Outline Package [SOIC_N] R-8 AD797BRZ −40°C to +85°C 8-Lead Standard Small Outline Package [SOIC_N] R-8 AD797BRZ-REEL −40°C to +85°C 8-Lead Standard Small Outline Package [SOIC_N] R-8 AD797BRZ-REEL7 −40°C to +85°C 8-Lead Standard Small Outline Package [SOIC_N] R-8 1 Z = RoHS Compliant Part. ©1992–2015 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the prop erty of their respective owners. D00846-0-3/15(K)