AD797_08 Datasheet, PDF (1/20 Pages) Analog Devices – Ultralow Distortion, Ultralow Noise Op Amp

FEATURES
Low noise
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
Excellent dc precision
80 μV maximum input offset voltage
1.0 μV/°C VOS 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
5
4
3
2
1
0
10
100
1k
10k
100k
1M
10M
FREQUENCY (Hz)
Figure 2. AD797 Voltage Noise Spectral Density
Ultralow Distortion,
Ultralow Noise Op Amp
AD797
PIN CONFIGURATION
OFFSET NULL 1
–IN 2
+IN 3
–V_S 4
DECOMPENSATION
AND DISTORTION
AD797 ⁸ NEUTRALIZATION
7 +V_S
6 OUTPUT
5 OFFSET NULL
TOP VIEW
Figure 1. 8-Lead Plastic Dual In-Line Package [PDIP] and
8-Lead Standard Small Outline Package [SOIC]
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 at
audio bandwidths give the AD797 the wide dynamic range
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
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.
–90
–100
0.001
–110
0.0003
–120
–130
100
300
MEASUREMENT
LIMIT
0.0001
1k
3k
10k 30k
FREQUENCY (Hz)
100k 300k
Figure 3. THD vs. Frequency
Rev. F
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