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REV. A

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a

Ultralow Distortion, Wide

Bandwidth Voltage Feedback Op Amps

AD9631/AD9632

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

–130

100k

100M

10M

1M

10k

–70

–50

–110

–90

FREQUENCY – Hz

2ND HARMONIC

3RD HARMONIC

Figure 1. AD9631 Harmonic Distortion vs. Frequency,

G = +1

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

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.

FUNCTIONAL BLOCK DIAGRAM

8-Pin Plastic Mini-DIP (N), Cerdip (Q),

and SO (R) Packages

1

2

3

4

8

7

6

5

AD9631/32

NC

–INPUT

+INPUT

NC

OUTPUT

NC

(Top View)

NC = NO CONNECT