REV. 0

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a

250 MHz, General Purpose

Voltage Feedback Op Amps

AD8047/AD8048

The AD8047 and AD8048’s low distortion and cap load drive

make the AD8047/AD8048 ideal for buffering high speed

ADCs. They are suitable for 12 bit/10 MSPS or 8 bit/60 MSPS

ADCs. Additionally, the balanced high impedance inputs of the

voltage feedback architecture allow maximum flexibility when

designing active filters.

The AD8047 and AD8048 are offered in industrial (–40

°C to

+85

°C) temperature ranges and are available in 8-pin plastic

DIP and SOIC packages.

5ns

1V

Figure 1. AD8047 Large Signal Transient Response,

FEATURES

Wide Bandwidth

AD8047, G = +1 AD8048, G = +2

Small Signal

250 MHz

260 MHz

Large Signal (2 V p-p)

130 MHz

160 MHz

5.8 mA Typical Supply Current

Low Distortion, (SFDR) Low Noise

–66 dBc typ @ 5 MHz

–54 dBc typ @ 20 MHz

5.2 nV/

√Hz (AD8047), 3.8 nV/√Hz (AD8048) Noise

Drives 50 pF Capacitive Load

High Speed

Slew Rate 750 V/

µs (AD8047), 1000 V/µs (AD8048)

Settling 30 ns to 0.01%, 2 V Step

±3 V to ±6 V Supply Operation

APPLICATIONS

Low Power ADC Input Driver

Differential Amplifiers

IF/RF Amplifiers

Pulse Amplifiers

Professional Video

DAC Current to Voltage Conversion

Baseband and Video Communications

Pin Diode Receivers

Active Filters/Integrators

PRODUCT DESCRIPTION

The AD8047 and AD8048 are very high speed and wide band-

width amplifiers. The AD8047 is unity gain stable. The

AD8048 is stable at gains of two or greater. The AD8047 and

AD8048, which utilize a voltage feedback architecture, meet the

requirements of many applications that previously depended on

current feedback amplifiers.

A proprietary circuit has produced an amplifier that combines

many of the best characteristics of both current feedback and

voltage feedback amplifiers. For the power (6.6 mA max) the

AD8047 and AD8048 exhibit fast and accurate pulse response

(30 ns to 0.01%) as well as extremely wide small signal and

large signal bandwidth and low distortion. The AD8047

achieves –54 dBc distortion at 20 MHz and 250 MHz small sig-

nal and 130 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

AD8047/48

NC

–INPUT

+INPUT

–V

S

NC

+V

S

OUTPUT

NC

(Top View)

NC = NO CONNECT

© Analog Devices, Inc., 1995

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Tel: 617/329-4700

Fax: 617/326-8703