Ultralow Distortion,
Ultralow Noise Op Amp
a
AD797*
FEATURES
Low Noise
CO NNECTIO N D IAGRAM
8-P in P lastic Mini-D IP (N),
Cerdip (Q) and SO IC (R) P ackages
0.9 nV/ √Hz typ (1.2 nV/ √Hz m ax) Input Voltage
Noise at 1 kHz
50 nV p-p Input Voltage Noise, 0.1 Hz to 10 Hz
Low Distortion
DECOMPENSATION &
DISTORTION
NEUTRALIZATION
–120 dB Total Harm onic Distortion at 20 kHz
Excellent AC Characteristics
800 ns Settling Tim e to 16 Bits (10 V Step)
110 MHz Gain Bandw idth (G = 1000)
8 MHz Bandw idth (G = 10)
1
2
3
4
8
7
6
5
OFFSET NULL
AD797
+V
S
–IN
+IN
OUTPUT
–V
S
OFFSET NULL
280 kHz Full Pow er Bandw idth at 20 V p-p
20 V/ s Slew Rate
TOP VIEW
Excellent DC Precision
80 V m ax Input Offset Voltage
1.0 V/ ؇C VOS Drift
Specified for ؎5 V and ؎15 V Pow er Supplies
High Output Drive Current of 50 m A
necessary for preamps in microphones and mixing consoles.
Furthermore, the AD797’s excellent slew rate of 20 V/µs and
110 MHz gain bandwidth make it highly suitable for low fre-
quency ultrasound applications.
APPLICATIONS
Professional Audio Pream plifiers
IR, CCD, and Sonar Im aging System s
Spectrum Analyzers
Ultrasound Pream plifiers
Seism ic Detectors
⌺⌬ ADC/ DAC Buffers
T he AD797 is also useful in IR and Sonar Imaging applications
where the widest dynamic range is necessary. T he low distor-
tion and 16-bit settling time of the AD797 make it ideal for
buffering the inputs to Σ∆ ADCs or the outputs of high resolu-
tion DACs especially when they are used in critical applications
such as seismic detection and spectrum analyzers. Key features
such as a 50 mA output current drive and the specified power
supply voltage range of ±5 to ±15 volts make the AD797 an
excellent general purpose amplifier.
P RO D UCT D ESCRIP TIO N
T he AD797 is a very low noise, low distortion operational
amplifier ideal for use as a preamplifier. T he low noise of
0.9 nV/√Hz and low total harmonic distortion of –120 dB at
audio bandwidths give the AD797 the wide dynamic range
5
4
3
2
1
0
–90
–100
–110
–120
0.001
0.0003
0.0001
MEASUREMENT
LIMIT
–130
10
100
1k
10k
100k
1M
10M
100
300
1k
3k
10k
30k
100k
300k
FREQUENCY – Hz
FREQUENCY – Hz
THD vs. Frequency
AD797 Voltage Noise Spectral Density
*P atent pending.
REV. C
Inform ation furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assum ed by Analog Devices for its
use, nor for any infringem ents of patents or other rights of third parties
which m ay result from its use. No license is granted by im plication or
otherwise under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norw ood, MA 02062-9106, U.S.A.
Tel: 617/ 329-4700 Fax: 617/ 326-8703