54AC161

Synchronous Presettable Binary Counter

General Description

The ’AC/’ACT161 are high-speed synchronous modulo-16

binary counters. They are synchronously presettable for ap-

plication in programmable dividers and have two types of

Count Enable inputs plus a Terminal Count output for versa-

tility in forming synchronous multistage counters. The ’AC/

’ACT161 has an asynchronous Master Reset input that over-

rides all other inputs and forces the outputs LOW.

Features

n Synchronous counting and loading

n High-speed synchronous expansion

n Typical count rate of 125 MHz

n Outputs source/sink 24 mA

n ’ACT161 has TTL-compatible inputs

n Standard Microcircuit Drawing (SMD)

— ’AC161: 5962-89561

— ’ACT161: 5962-91722

Logic Symbols

Pin Names

Description

CEP

Count Enable Parallel Input

CET

Count Enable Trickle Input

CP

Clock Pulse Input

MR

Asynchronous Master Reset Input

P

Parallel Data Inputs

PE

Parallel Enable Inputs

Q

Flip-Flop Outputs

TC

Terminal Count Output

DS100274-1

IEEE/IEC

DS100274-2

November 1998

© 1998 National Semiconductor Corporation

DS100274

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