REV. A

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a

Ultralow Drift,

Dual BiFET Op Amp

AD647

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

Tel: 617/329-4700

Fax: 617/326-8703

FEATURES

Low Offset Voltage Drift

Matched Offset Voltage

Matched Offset Voltage Over Temperature

Matched Bias Currents

Crosstalk: –124 dB at 1 kHz

Low Bias Current: 35 pA max Warmed Up

Low Offset Voltage: 250

V max

Low Input Voltage Noise: 2

V p-p

High Open Loop Gain: 108 dB

Low Quiescent Current: 2.8 mA max

Low Total Harmonic Distortion

Standard Dual Amplifier Pinout

Available in Hermetic Metal Can Package, Hermetic

Surface Mount (20-Pin LCC) and Chip Form

MIL-STD-883B Processing Also Available

Single Version Available: AD547

PRODUCT HIGHLIGHTS

1. The AD647 is guaranteed and tested to tight matching speci-

fications to ensure high performance and to eliminate the se-

lection and matching of single devices.

2. Laser wafer drift trimming reduces offset voltage and offset

voltage drifts to 250

µV and 2.5 µV/°C max.

3. Voltage noise is guaranteed at 4

µV p-p max (0.1 Hz to

10 Hz) on K, L and S grades.

4. Bias current (35 pA K, L, S; 75 pA J) is specified after five

minutes of operation.

5. Total supply current is a low 2.8 mA max.

6. High open loop gain ensures high linearity in precision instru-

mentation amplifier applications.

7. The standard dual amplifier pinout permits the direct substi-

tution of the AD647 for lower performance devices.

8. The AD647 is available in chip form.

PRODUCT DESCRIPTION

The AD647 is an ultralow drift, dual JFET amplifier that com-

bines high performance and convenience in a single package.

The AD647 uses the most advanced ion-implantation and laser

wafer drift trimming technologies to achieve the highest perfor-

mance currently available in a dual JFET. Ion-implantation per-

mits the fabrication of matched JFETs on a monolithic bipolar

chip. Laser wafer drift trimming trims both the initial offset volt-

age and its drift with temperature to provide offsets as low as

100

µV (250 µV max) and drifts of 2.5 µV/°C max.

In addition to outstanding individual amplifier performance, the

AD647 offers guaranteed and tested matching performance on

critical parameters such as offset voltage, offset voltage drift and

bias currents.

The high level of performance makes the AD647 especially well

suited for high precision instrumentation amplifier applications

that previously would have required the costly selection and

matching of space wasting single amplifiers.

The AD647 is offered in four performance grades, three com-

mercial (the J, K and L) and one extended (the S). All are sup-

plied in hermetically sealed 8-pin TO-99 packages and are

available processed to MIL-STD-883B. The LCC version is

also available processed to MIL-STD-883B.