TC74HC191AP/AF

2007-10-01

1

TOSHIBA CMOS Digital Integrated Circuit Silicon Monolithic

TC74HC191AP,TC74HC191AF

4-Bit Binary Up/Down Counter

The TC74HC191A are high speed CMOS 4-BIT UP/DOWN

COUNTERs fabricated with silicon gate C2MOS technology.

It achieves the high speed operation similar to equivalent

LSTTL while maintaining the CMOS low power dissipation.

The TC74HC191A is 4-bit binary up/down counter.

They have an asynchronous load input (LOAD) which is active

low.

The direction of counting is determined by the level of

DOWN/UP. When D/U is low, the counter counts up; when D/U is

high, it counts down. Counting occurs on the positive going

transition of the clock input.

Enable input (ENABLE) and two carry inputs (RIPPLE

CLOCK OUT, MAX/MIN) are provided to permit easy cascading

of the counters, which facilitates easy implementation of N-bit

counters without using external gates.

All inputs are equipped with protection circuits against static

discharge or transient excess voltage.

Features

• Output drive capability: 10 LSTTL loads

• Pin and function compatible with 74LS191

Pin Assignment

TC74HC191AP

TC74HC191AF

Weight

DIP16-P-300-2.54A

: 1.00 g (typ.)

SOP16-P-300-1.27A

: 0.18 g (typ.)