60 MHz 2000 V/μs

Monolithic Op Amp

AD844

Rev. F

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FEATURES

Wide bandwidth

60 MHz at gain of −1

33 MHz at gain of −10

Slew rate: 2000 V/μs

Fast settling: 100 ns to 0.1% (10 V step)

Differential gain error: 0.03% at 4.4 MHz

Differential phase error: 0.16° at 4.4 MHz

Low offset voltage: 150 μV maximum (B Grade)

Low quiescent current: 6.5 mA

Available in tape and reel in accordance with

EIA-481-A standard

APPLICATIONS

Flash ADC input amplifiers

High speed current DAC interfaces

Video buffers and cable drivers

Pulse amplifiers

FUNCTIONAL BLOCK DIAGRAMS

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AD844

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Figure 1. 8-Lead PDIP (N) and 8-Lead CERDIP (Q) Packages

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NC = NO CONNECT

AD844

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Figure 2. 16-Lead SOIC (R) Package

GENERAL DESCRIPTION

The AD844 is a high speed monolithic operational amplifier

fabricated using the Analog Devices, Inc., junction isolated

complementary bipolar (CB) process. It combines high band-

width 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 noninverting 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 that is

determined primarily by the feedback resistor and is almost

independent 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

typically 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-lead SOIC (RW) package, the AD844J

is specified for the commercial temperature range of 0°C to 70°C.

The AD844A and AD844B are specified for the industrial

temperature range of −40°C to +85°C and are available in the

CERDIP (Q) package. The AD844A is also available in an 8-lead

PDIP (N). The AD844S is specified over the military temperature

range of −55°C to +125°C. It is available in the 8-lead 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.

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

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

5.

The AD844 exhibits excellent differential gain and

differential 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 amplifier for flash analog-to-digital converters (ADCs).