a
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
Ultrafast Comparators
AD96685/AD96687
AD96685 FUNCTIONAL BLOCK DIAGRAM
NONINVERTING
INPUT
INVERTING
INPUT
R
L
R
L
Q
OUTPUT
Q OUTPUT
LATCH
ENABLE
V
T
AD96687 FUNCTIONAL BLOCK DIAGRAM
NONINVERTING
INPUT
Q
OUTPUT
Q OUTPUT
INVERTING
INPUT
LE
LE
V
T
R
L
R
L
Q
OUTPUT
Q OUTPUT
R
L
R
L
LE
INVERTING
INPUT
LE
NONINVERTING
INPUT
LATCH
ENABLE
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
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.
REV. D
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties that
may result from its use. No license is granted by implication or otherwise
under any patent or patent rights of Analog Devices.
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
AD [ ANALOG DEVICES ]
