Ultralow Distortion, Wide Bandwidth
Voltage Feedback Op Amps
AD9631/AD9632
Data Sheet
FEATURES
PIN CONFIGURATION
Wide bandwidth
AD9631, G = +1
AD9632, G = +2
Small signal
AD9631/
1
2
3
4
8
7
6
5
NC
+V
NC
–INPUT
+INPUT
AD9632
S
OUTPUT
NC
TOP VIEW
(Not to Scale)
–V
S
AD9631, 320 MHz
AD9632, 250 MHz
Large signal (4 V p-p)
NOTES
1. NC = NO CONNECT.
Figure 1. 8-Lead PDIP (N) and SOIC (R) Packages
AD9631, 175 MHz
AD9632, 180 MHz
A proprietary design architecture has produced an amplifier
that combines many of the best characteristics of both current
feedback and voltage feedback amplifiers. The AD9631/AD9632
exhibit exceptionally fast and accurate pulse response (16 ns to
0.01%) as well as extremely wide small signal and large signal
bandwidth and ultralow distortion. The AD9631 achieves
−72 dBc at 20 MHz, 320 MHz small signal bandwidth, and
175 MHz large signal bandwidths.
Ultralow distortion (SFDR), low noise
−113 dBc typical @ 1 MHz
−95 dBc typical @ 5 MHz
−72 dBc typical @ 20 MHz
46 dBm third-order intercept @ 25 MHz
7.0 nV/√Hz spectral noise density
High speed
Slew rate: 1300 V/μs
These characteristics position the AD9631/AD9632 ideally for
driving flash as well as high resolution ADCs. Additionally, the
balanced high impedance inputs of the voltage feedback archi-
tecture allow maximum flexibility when designing active filters.
Settling time to 0.01%, 2 V step: 16 ns
3 V to 5 V supply operation
17 mA supply current
APPLICATIONS
The AD9631/AD9632 are offered in the industrial (−40°C to
+85°C) temperature range. They are available in PDIP and SOIC.
ADC input driver
Differential amplifiers
IF/RF amplifiers
Pulse amplifiers
Professional video
–30
V
= ±5V
S
R
= 500Ω
= 2V p-p
L
–40
–50
V
OUT
DAC current to voltage
Baseband and video communications
Pin diode receivers
–60
–70
–80
Active filters/integrators/log amps
–90
SECOND HARMONIC
GENERAL DESCRIPTION
–100
–110
–120
–130
The AD9631/AD9632 are very high speed and wide bandwidth
amplifiers. The AD9631 is unity gain stable. The AD9632 is
stable at gains of 2 or greater. Using a voltage feedback
architecture, the exceptional settling time, bandwidth, and low
distortion of the AD9631/AD9632 meet the requirements of
many applications that previously depended on current feed-
back amplifiers. Its classical op amp structure works much more
predictably in many designs.
THIRD HARMONIC
10k
100k
1M
10M
100M
FREQUENCY (Hz)
Figure 2. AD9631 Harmonic Distortion vs. Frequency, G = +1
Rev. D
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