TLF5324

November 1995

MM54HC195MM74HC195

4-Bit Parallel Shift Register

General Description

The MM54HC195MM74HC195 is a high speed 4-bit SHIFT

REGISTER utilizes advanced silicon-gate CMOS technolo-

gy to achieve the low power consumption and high noise

immunity of standard CMOS integrated circuits along with

the ability to drive 10 LS-TTL loads at LS type speeds

This shift register features parallel inputs parallel outputs J-

K serial inputs SHIFTLOAD control input and a direct

overriding CLEAR This shift register can operate in two

Parallel loading is accomplished by applying the four bits of

data and taking the SHIFTLOAD control input low The

data is loaded into the associated flip flops and appears at

the outputs after the positive transition of the clock input

During parallel loading serial data flow is inhibited Serial

shifting occurs synchronously when the SHIFTLOAD con-

trol input is high Serial data for this mode is entered at the

J-K inputs These inputs allow the first stage to perform as a

J-K or TOGGLE flip flop as shown in the truth table

The 54HC74HC logic family is functionally as well as pin-

out compatible with the standard 54LS74LS logic family

All inputs are protected from damage due to static dis-

Features

Y

Typical operating frequency 45 MHz

Y

Typical propagation delay 16 ns (clock to Q)

Y

Wide operating supply voltage range 2 – 6V

Y

Low input current 1 mA maximum

Y

Low quiescent current 80 mA maximum (74HC Series)

Y

Fanout of 10 LS-TTL loads

Connection Diagram

Dual-In-Line Package

TLF5324 – 1

Top View

Order Number MM54HC195 or MM74HC195

Function Table

Inputs

Outputs

Clear Shift

Clock

Serial

Parallel

Load

J

K

ABCD

LX

X

X

X

X X X X

L

L

L

L

H

HL

u

XX

a b c d

a

b

c

d

d

HH

L

X

X

HH

u

LH

HH

u

LL

X X X X

L

HH

u

HH

X X X X

H

HH

u

HL

or D respectively

respectively before the indicated steady-state input condi-

tions were established

before the most-recent transition of the clock

C1995 National Semiconductor Corporation

RRD-B30M115Printed in U S A