a
Ultralow Distortion, Wide
Bandwidth Voltage Feedback Op Amps
AD9631/AD9632
FUNCTIONAL BLOCK DIAGRAM
8-Pin Plastic Mini-DIP (N), Cerdip (Q),
and SO (R) Packages
FEATURES
Wide Bandwidth
AD9631, G = +1 AD9632, G = +2
Small Signal
320 MHz
250 MHz
Large Signal (4 V p-p) 175 MHz
180 MHz
Ultralow Distortion (SFDR), Low Noise
–113 dBc typ @ 1 MHz
–95 dBc typ @ 5 MHz
–72 dBc typ @ 20 MHz
+46 dBm 3rd Order Intercept @ 25 MHz
7.0 nV/√Hz Spectral Noise Density
High Speed
Slew Rate 1300 V/µs
Settling 16 ns to 0.01%, 2 V Step
±3
V to
±5
V Supply Operation
17 mA Supply Current
APPLICATIONS
ADC Input Driver
Differential Amplifiers
IF/RF Amplifiers
Pulse Amplifiers
Professional Video
DAC Current to Voltage
Baseband and Video Communications
Pin Diode Receivers
Active Filters/Integrators/Log Amps
PRODUCT DESCRIPTION
HARMONIC DISTORTION – dBc
NC
–INPUT
+INPUT
–V
S
1
2
3
4
8
7
6
NC
+V
S
OUTPUT
NC
AD9631/32
(Top View)
NC = NO CONNECT
5
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.
The AD9631 is offered in industrial (–40°C to +85°C) and mili-
tary (–55°C to +125°C) temperature ranges and the AD9632 in
industrial. Industrial versions are available in plastic DIP and
SOIC; MIL versions are packaged in cerdip.
–30
V
O
= 2V p–p
V
S
=
±5V
R
L
= 500Ω
–50
The AD9631 and AD9632 are very high speed and wide band-
width amplifiers. They are an improved performance alternative
to the AD9621 and AD9622. The AD9631 is unity gain stable.
The AD9632 is stable at gains of two or greater. Utilizing a
voltage feedback architecture, the AD9631/AD9632’s excep-
tional settling time, bandwidth, and low distortion meet the
requirements of many applications which previously depended
on current feedback amplifiers. Its classical op amp structure
works much more predictably in many designs.
A proprietary design architecture has produced an amplifier that
combines many of the best characteristics of both current feed-
back and voltage feedback amplifiers. The AD9631 and
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 and 320 MHz small signal and
175 MHz large signal bandwidths.
–70
2ND HARMONIC
–90
3RD HARMONIC
–110
–130
10k
100k
1M
FREQUENCY – Hz
10M
100M
Figure 1. AD9631 Harmonic Distortion vs. Frequency,
G = +1
REV. A
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
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norwood. MA 02062-9106, U.S.A.
Tel: 617/329-4700
Fax: 617/326-8703
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