REV. C

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a

60 MHz, 2000 V/ s

Monolithic Op Amp

AD844

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.

Tel: 617/329-4700

Fax: 617/326-8703

CONNECTION DIAGRAMS

FEATURES

Wide Bandwidth: 60 MHz at Gain of –1

Very High Output Slew Rate: Up to 2000 V/ s

Fast Settling: 100 ns to 0.1% (10 V Step)

Differential Gain Error: 0.03% at 4.4 MHz

Differential Phase Error: 0.15 at 4.4 MHz

High Output Drive:

50 mA into 50

Ω Load

Low Offset Voltage: 150

V max (B Grade)

Low Quiescent Current: 6.5 mA

Available in Tape and Reel in Accordance with

EIA-481A Standard

APPLICATIONS

Flash ADC Input Amplifiers

High Speed Current DAC Interfaces

Video Buffers and Cable Drivers

Pulse Amplifiers

PRODUCT DESCRIPTION

The AD844 is a high speed monolithic operational amplifier fab-

ricated using Analog Devices’ junction isolated complementary

bipolar (CB) process. It combines high bandwidth and very fast

large signal response with excellent dc performance. Although

optimized for use in current to voltage applications and as an

inverting mode amplifier, it is also suitable for use in many non-

inverting applications.

The AD844 can be used in place of traditional op amps, but its

current feedback architecture results in much better ac perfor-

mance, high linearity and an exceptionally clean pulse response.

This type of op amp provides a closed-loop bandwidth which is

determined primarily by the feedback resistor and is almost in-

dependent of the closed-loop gain. The AD844 is free from the

slew rate limitations inherent in traditional op amps and other

current-feedback op amps. Peak output rate of change can be

over 2000 V/

µs for a full 20 V output step. Settling time is typi-

cally 100 ns to 0.1%, and essentially independent of gain. The

AD844 can drive 50

Ω loads to ±2.5 V with low distortion and

is short circuit protected to 80 mA.

The AD844 is available in four performance grades and three

package options. In the 16-pin SOIC (R) package, the AD844J

is specified for the commercial temperature range of 0

°C to

+70

°C. The AD844A and AD844B are specified for the indus-

trial temperature range of –40

°C to +85°C and are available in

the cerdip (Q) package. The AD844A is also available in an 8-pin

plastic mini-DIP (N). The AD844S is specified over the military

temperature range of –55

°C to +125°C. It is available in the

8-pin cerdip (Q) package. “A” and “S” grade chips and devices

processed to MIL-STD-883B, REV. C are also available.

PRODUCT HIGHLIGHTS

1. The AD844 is a versatile, low cost component providing an

excellent combination of ac and dc performance. It may be

used as an alternative to the EL2020 and CLC400/1.

2. It is essentially free from slew rate limitations. Rise and fall

times are essentially independent of output level.

3. The AD844 can be operated from

±4.5 V to ±18 V power

supplies and is capable of driving loads down to 50

Ω, as

well as driving very large capacitive loads using an external

network.

4. The offset voltage and input bias currents of the AD844 are

1

µV/°C and bias current drift is typically 9 nA/°C.

5. The AD844 exhibits excellent differential gain and differen-

tial phase characteristics, making it suitable for a variety of

video applications with bandwidths up to 60 MHz.

6. The AD844 combines low distortion, low noise and low drift

with wide bandwidth, making it outstanding as an input am-

plifier for flash A/D converters.

16-Pin SOIC

(R) Package

8-Pin Plastic (N),

and Cerdip (Q) Packages