AD797 (Rev. K) - Analog Devices

1 Ultralow Distortion, Ultralow Noise Op Amp Data Sheet AD797 . FEATURES GENERAL DESCRIPTION. Low noise The AD797 is a very low noise, low distortion operational amplifier nV/ Hz typical ( nV/ Hz maximum) input voltage ideal for use as a preamplifier. The low noise of nV/ Hz and noise at 1 kHz low total harmonic distortion of 120 dB in audio bandwidths 50 nV p-p input voltage noise, Hz to 10 Hz give the AD797 the wide dynamic range necessary for preamps Low distortion in microphones and mixing consoles. 120 dB total harmonic distortion at 20 kHz Furthermore, the AD797 has an excellent slew rate of 20 V/ s Excellent ac characteristics and a 110 MHz gain bandwidth, which makes it highly suitable 800 ns settling time to 16 bits (10 V step). for low frequency ultrasound applications.

2 110 MHz gain bandwidth (G = 1000). 8 MHz bandwidth (G = 10) The AD797 is also useful in infrared (IR) and sonar imaging 280 kHz full power bandwidth at 20 V p-p applications, where the widest dynamic range is necessary. The 20 V/ s slew rate low distortion and 16-bit settling time of the AD797 make it Excellent dc precision ideal for buffering the inputs to - ADCs or the outputs of 80 V maximum input offset voltage high resolution DACs, especially when the device is used in V/ C VOS drift critical applications such as seismic detection or in spectrum Specified for 5 V and 15 V power supplies analyzers. Key features such as a 50 mA output current drive High output drive current of 50 mA and the specified power supply voltage range of 5 V to 15 V. make the AD797 an excellent general-purpose amplifier.

3 APPLICATIONS 5. Professional audio preamplifiers IR, CCD, and sonar imaging systems INPUT VOLTAGE NOISE (nV/ Hz). 4. Spectrum analyzers Ultrasound preamplifiers 3. Seismic detectors - ADC/DAC buffers 2. 1. 0. 00846-002. 10 100 1k 10k 100k 1M 10M. FREQUENCY (Hz). Figure 1. AD797 Voltage Noise Spectral Density Table 1. Low Noise Op Amps Voltage Noise nV nV nV nV nV nV. Single AD797 AD8597 ADA4004-1 AD8675/ADA4075-2 OP27 AD8671. Dual AD8599 ADA4004-2 AD8676 OP270 AD8672. Quad ADA4004-4 OP470 AD8674. 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.

4 No One Technology Way, Box 9106, Norwood, MA 02062-9106, license is granted by implication or otherwise under any patent or patent rights of Analog Devices . Tel: 1992 2015 Analog Devices , Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. Technical Support AD797 Data Sheet TABLE OF CONTENTS. Features .. 1 Noise and Source Impedance Considerations .. 12. Applications .. 1 Low Frequency Noise .. 12. General Description .. 1 Wideband Noise .. 12. Revision History .. 2 Bypassing Considerations .. 13. 3 The Noninverting Configuration .. 13. Absolute Maximum 5 The Inverting Configuration .. 14. Pin Configuration .. 5 Driving Capacitive Loads .. 14. Thermal Resistance .. 5 Settling Time .. 14. ESD Caution .. 5 Distortion Reduction.

5 15. Typical Performance Characteristics .. 6 Outline Dimensions .. 18. Theory of Operation .. 11 Ordering Guide .. 19. REVISION HISTORY. 3/15 Rev. J to Rev. K 7/05 Rev. D to Rev. E. Changes to Figure 35 .. 12 Updated Figure 1 Caption ..1. Changes to Ordering Guide .. 19 Deleted Metallization Photo ..6. Changes to Equation 1 .. 12. 2/14 Rev. I to Rev. J Updated Outline Dimensions .. 19. Changes to Power Supply Rejection Parameter, Table 2 .. 3 Changes to Ordering Guide .. 20. 3/13 Rev. H to Rev. I 10/02 Rev. C to Rev. D. Added Figure 8 Deleted 8-Lead CERDIP Package (Q-8) .. Universal Edits to Specifications ..2. 6/10 Rev. G to Rev. H Edits to Absolute Maximum Ratings ..3. Added Table 1; Renumbered Sequentially .. 1 Edits to Ordering Guide ..3. Moved Figure 1 to Absolute Maximum Ratings Section; Edits to Table I.

6 9. Renumbered 5 Deleted Operational Amplifiers Graphic .. 15. Changes to Table 3 .. 5 Updated Outline Dimensions .. 15. Added Thermal Resistance Section and Table 4 .. 5. Moved Figure 3 to Typical Performance Characteristics Section .. 10. Change to Noise and Source Impedance Considerations Section .. 12. Changes to Ordering Guide .. 19. 9/08 Rev. F to Rev. G. Changes to Input Common-Mode Voltage Range Parameter, Table 1 .. 3. 1/08 Rev. E to Rev. F. Changes to Absolute Maximum Ratings .. 5. Change to Equation 1 .. 12. Changes to the Noninverting Configuration Section .. 13. Updated Outline Dimensions .. 19. Changes to Ordering Guide .. 20. Rev. K | Page 2 of 19. Data Sheet AD797 . SPECIFICATIONS. TA = 25 C and VS = 15 V dc, unless otherwise noted. Table 2. AD797A AD797B.

7 Supply Parameter Conditions Voltage (V) Min Typ Max Min Typ Max Unit INPUT OFFSET VOLTAGE 5 V, 15 V 25 80 10 40 V. TMIN to TMAX 50 125/180 30 60 V. Offset Voltage Drift 5 V, 15 V V/ C. INPUT BIAS CURRENT 5 V, 15 V A. TMIN to TMAX A. INPUT OFFSET CURRENT 5 V, 15 V 100 400 80 200 nA. TMIN to TMAX 120 600/700 120 300 nA. OPEN-LOOP GAIN VOUT = 10 V 15 V 1 20 2 20 V/ V. RLOAD = 2 k 1 6 2 10 V/ V. TMIN to TMAX 1 15 2 15 V/ V. RLOAD = 600 1 5 2 7 V/ V. TMIN 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, 15 V 280 280 kHz RLOAD = 1 k . slew Rate RLOAD = 1 k 15 V 20 20 V/ s Settling Time to 10 V step 15 V 800 1200 800 1200 ns COMMON-MODE REJECTION VCM = CMVR 5 V, 15 V 114 130 120 130 dB.

8 TMIN to TMAX 110 120 114 120 dB. POWER SUPPLY REJECTION VS = 5 V to 18 V 114 130 120 130 dB. TMIN to TMAX 110 120 114 120 dB. INPUT VOLTAGE NOISE f = Hz to 10 Hz 15 V 50 50 nV p-p f = 10 Hz 15 V nV/ Hz f = 1 kHz 15 V nV/ Hz f = 10 Hz to 1 MHz 15 V V rms INPUT CURRENT NOISE f = 1 kHz 15 V pA/ Hz INPUT COMMON-MODE 15 V 11 12 11 12 V. VOLTAGE RANGE. 5 V 3 3 V. OUTPUT VOLTAGE SWING RLOAD = 2 k 15 V 12 13 12 13 V. RLOAD = 600 15 V 11 13 11 13 V. RLOAD = 600 5 V 3 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 RLOAD = 1 k , CN = 50 pF, 15 V 98 90 98 90 dB. DISTORTION f = 250 kHz, 3 V rms RLOAD = 1 k , 15 V 120 110 120 110 dB. f = 20 kHz, 3 V rms Rev. K | Page 3 of 19. AD797 Data Sheet AD797A AD797B. Supply Parameter Conditions Voltage (V) Min Typ Max Min Typ Max Unit INPUT CHARACTERISTICS.

9 Input Resistance Differential k . Common Mode 100 100 M . Input Capacitance Differential4 20 20 pF. Common Mode 5 5 pF. OUTPUT RESISTANCE AV = 1, f = 1 kHz 3 3 m . POWER SUPPLY. Operating Range 5 18 5 18 V. Quiescent Current 5 V, 15 V mA. 1. Full power bandwidth = slew rate/2 VPEAK. 2. Specified using external decompensation capacitor. 3. Output current for |VS VOUT| > 4 V, AOL > 200 k . 4. Differential input capacitance consists of pF package capacitance and pF from the input differential pair. Rev. K | Page 4 of 19. Data Sheet AD797 . ABSOLUTE MAXIMUM RATINGS. PIN CONFIGURATION. Table 3. DECOMPENSATION. AND DISTORTION. Parameter Ratings OFFSET NULL 1 AD797 8 NEUTRALIZATION. Supply Voltage 18 V IN 2 7 +VS. +IN 3 6 OUTPUT. Input Voltage VS. 00846-001. VS 4 5 OFFSET NULL.

10 Differential Input Voltage1 V TOP VIEW. Output Short-Circuit Duration Indefinite within Figure 2. 8-Lead Plastic Dual In-Line Package [PDIP] and maximum internal 8-Lead Standard Small Outline Package [SOIC]. power dissipation THERMAL RESISTANCE. Storage Temperature Range 65 C to +125 C. (N, R Suffix) JA is specified for the device soldered on a 4-layer JEDEC. Operating Temperature Range 40 C to +85 C standard printed circuit board (PCB) with zero airflow for the Lead Temperature (Soldering 60 sec) 300 C SOIC package, and a 2-layer JEDEC standard printed circuit board (PCB) with zero airflow for the PDIP package. 1. The AD797 inputs are protected by back-to-back diodes. To achieve low noise, internal current-limiting resistors are not incorporated into the design Table 4.