REV. D

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a

AD96685/AD96687

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

Tel: 781/329-4700

www.analog.com

Fax: 781/326-8703

© Analog Devices, Inc., 2001

Ultrafast Comparators

AD96685 FUNCTIONAL BLOCK DIAGRAM

NONINVERTING

INPUT

INVERTING

INPUT

Q OUTPUT

Q OUTPUT

LATCH

ENABLE

AD96687 FUNCTIONAL BLOCK DIAGRAM

NONINVERTING

INPUT

INVERTING

INPUT

Q OUTPUT

Q OUTPUT

LE

LE

LATCH

ENABLE

NONINVERTING

INPUT

INVERTING

INPUT

Q OUTPUT

Q OUTPUT

LE

LE

LATCH

ENABLE

THE OUTPUTS ARE OPEN EMITTERS, REQUIRING EXTERNAL

PULL-DOWN RESISTORS.THESE RESISTORS MAY BE IN THE

RANGE OF 50 -200

CONNECTED TO –2.0V, OR 200 -2000

FEATURES

Fast: 2.5 ns Propagation Delay

Low Power: 118 mW per Comparator

Packages: DIP, SOIC, PLCC

Power Supplies: +5 V, –5.2 V

Logic Compatibility: ECL

50 ps Delay Dispersion

APPLICATIONS

High Speed Triggers

High Speed Line Receivers

Threshold Detectors

Window Comparators

Peak Detectors

GENERAL DESCRIPTION

The AD96685 and AD96687 are ultrafast voltage comparators.

The AD96685 is a single comparator with 2.5 ns propagation

delay; the AD96687 is an equally fast dual comparator. Both

devices feature 50 ps propagation delay dispersion which is a

particularly important characteristic of high-speed comparators.

It is a measure of the difference in propagation delay under

differing overdrive conditions.

A fast, high precision differential input stage permits consistent

propagation delay with a wide variety of signals in the common-

mode range from –2.5 V to +5 V. Outputs are complementary

digital signals fully compatible with ECL 10 K and 10 KH logic

families. The outputs provide sufficient drive current to directly

drive transmission lines terminated in 50

Ω to –2 V. A level

sensitive latch input which permits tracking, track-hold, or

sample-hold modes of operation is included.

The AD96685 is available in industrial –25

°C to +85°C range

in 16-pin SOIC.

The AD96687 is available in industrial range –25

°C to +85°C,

in 16-pin DIP, SOIC, and 20-lead PLCC.