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March 2004

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HIGH SPEED:

s

LOW POWER DISSIPATION:

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HIGH NOISE IMMUNITY:

s

SYMMETRICAL OUTPUT IMPEDANCE:

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BALANCED PROPAGATION DELAYS:

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WIDE OPERATING VOLTAGE RANGE:

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PIN AND FUNCTION COMPATIBLE WITH

54 SERIES 191

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SPACE GRADE-1: ESA SCC QUALIFIED

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50 krad QUALIFIED, 100 krad AVAILABLE ON

REQUEST

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NO SEL UNDER HIGH LET HEAVY IONS

IRRADIATION

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DEVICE FULLY COMPLIANT WITH

SCC-9204-066

DESCRIPTION

The M54HC191 is an high speed CMOS 4-BIT

SYNCHRONOUS

UP/DOWN

COUNTER

State changes of the counter are synchronous

with the LOW-to-HIGH transition of the Clock

Pulse Input.

An asynchronous parallel load input overrides

counting and loads the data present on the DATA

inputs into the flip-flops, which makes it possible to

use the circuits as programmable counters. A

count enable input serves as the carry/borrow

input in multi-stage counters. Control input, Down/

Up, determines whether a circuit counts up or

down. A MAX/MIN output and a Ripple Clock

output provide overflow/underflow indication and

make possible a variety of methods for generating

carry/borrow

signals

in

multi-stage

counter

applications.

All inputs are equipped with protection circuits

against static discharge and transient excess

voltage.

M54HC191

RAD-HARD 4 BIT SYNCHRONOUS UP/DOWN COUNTERS

PIN CONNECTION

ORDER CODES

PACKAGE

FM

EM

DILC

M54HC191D

M54HC191D1

FPC

M54HC191K

M54HC191K1

DILC-16

FPC-16