REV. A

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© Analog Devices, Inc., 2001

Dual 9 MHz Precision

Operational Amplifier

PIN CONNECTIONS

8-Lead Narrow-Body SO (S-Suffix)

TOP VIEW

(Not to Scale)

OP285

–IN A

+IN A

V–

OUT A

V+

–IN B

+IN B

OUT B

8

7

6

5

1

2

3

4

8-Lead Epoxy DIP (P-Suffix)

8

7

6

5

V+

–IN B

+IN B

OUT B

1

2

3

4

–IN A

+IN A

V–

OUT A

+

–

+

–

OP285

The combination of low noise, speed and accuracy can be used

to build high speed instrumentation systems. Circuits such as

instrumentation amplifiers, ramp generators, bi-quad filters and

dc-coupled audio systems are all practical with the OP285. For

applications that require long term stability, the OP285 has a

guaranteed maximum long term drift specification.

The OP285 is specified over the XIND—extended industrial—

(–40

°C to +85°C) temperature range. OP285s are available in

8-pin plastic DIP and SOIC-8 surface mount packages.

FEATURES

Low Offset Voltage: 250

V

Low Noise: 6 nV/

√ Hz

Low Distortion: 0.0006%

High Slew Rate: 22 V/ s

Wide Bandwidth: 9 MHz

Low Supply Current: 5 mA

Low Offset Current: 2 nA

Unity-Gain Stable

SO-8 Package

APPLICATIONS

High Performance Audio

Active Filters

Fast Amplifiers

Integrators

GENERAL DESCRIPTION

The OP285 is a precision high-speed amplifier featuring the

Butler Amplifier front-end. This new front-end design com-

bines the accuracy and low noise performance of bipolar

transistors with the speed of JFETs. This yields an amplifier

with high slew rates, low offset and good noise performance

at low supply currents. Bias currents are also low compared

to bipolar designs.

The OP285 offers the slew rate and low power of a JFET

amplifier combined with the precision, low noise and low

drift of a bipolar amplifier. Input offset voltage is laser-trimmed

and guaranteed less than 250

µV. This makes the OP285 useful

in dc-coupled or summing applications without the need for

special selections or the added noise of additional offset

adjustment circuitry. Slew rates of 22 V/

µs and a bandwidth

of 9 MHz make the OP285 one of the most accurate medium

speed amplifiers available.

*Patents pending