July 1998
54AC169 • 54ACT169
4-Stage Synchronous Bidirectional Counter
n Synchronous counting and loading
n Built-In lookahead carry capability
The ’AC/’ACT169 is fully synchronous 4-stage up/down
n Presettable for programmable operation
General Description
counter. The ’AC/’ACT169 is a modulo-16 binary counter. It
features a preset capability for programmable operation,
carry lookahead for easy cascading and a U/D input to con-
n Outputs source/sink 24 mA
n ’ACT has TTL-compatible inputs
n Standard Microcircuit Drawing (SMD)
5962-91603
trol the direction of counting. All state changes, whether in
counting or parallel loading, are initiated by the
LOW-to-HIGH transition of the Clock.
Features
n ICC reduced by 50%
Logic Symbols
Pin
Names
CEP
CET
CP
Description
Count Enable Parallel Input
Count Enable Trickle Input
Clock Pulse Input
P0–P3
PE
Parallel Data Inputs
Parallel Enable Input
Up-Down Count Control Input
Flip-Flop Outputs
U/D
Q0–Q3
TC
DS100276-1
Terminal Count Output
IEEE/IEC
DS100276-2
™
FACT is a trademark of Fairchild Semiconductor Corporation.
© 1998 National Semiconductor Corporation
DS100276
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