TLF5373

January 1988

MM54HC4511MM74HC4511

BCD-to-7 Segment LatchDecoderDriver

General Description

This high speed latchdecoderdriver utilizes advanced sili-

con-gate CMOS technology It has the high noise immunity

and low power consumption of standard CMOS integrated

circuits as well as the ability to drive 10 LS-TTL loads The

circuit provides the functions of a 4-bit storage latch an

8421 BCD-to-seven segment decoder and an output drive

capability Lamp test (LT) blanking (Bl) and latch enable

(LE) inputs are used to test the display to turn-off or pulse

modulate the brightness of the display and to store a BCD

code respectively It can be used with seven-segment light

emitting diodes (LED) incandescent fluorescent gas dis-

charge or liquid crystal readouts either directly or indirectly

Applications include instrument (eg

counter DVM etc)

display driver computercalculator display driver cockpit

display driver and various clock watch and timer uses

The 54HC74HC logic family is speed function and pinout

compatible with the standard 54LS74LS logic family All

inputs are protected from damage due to static discharge by

Features

Y

Latch storage of input data

Y

Blanking input

Y

Lamp test input

Y

Low power consumption characteristics of CMOS

devices

Y

Wide operating voltage range 2 to 6 volts

Y

Low input current 1 mA maximum

Y

Low quiescent current 80 mA maximum over full tem-

perature range (74 Series)

Connection Diagram

Dual-In-Line Package

TLF5373 – 1

Order Number MM54HC4511 or MM74HC4511

Truth Table

INPUTS

OUTPUTS

LE BI LT D C B A a b c d e

f

g DISPLAY

x

x

L

xxxx HHHHHHH

8

x

L

H

xxxx LLLLLLL

L

H

H

LLLL HHHHHH L

0

L

H

H

LLL H L H H LLLL

1

L

H

H

L LHLH HLH H LH

2

L

H

H

L L HHHHHH L L H

3

L

H

H

L H L L L HH L L HH

4

L

H

H

L H L HH L H H L HH

5

L

H

H

L HH L L L HHHHH

6

L

H

H

L HHHHHH L L L L

7

L

H

H

H L L L HHHHHHH

8

L

H

H

H L L HHHH L L HH

9

L

H

H

H L H LLLLLLLL

L

H

H

H L H H LLLLLLL

L

H

H

H H LLLLLLLLL

L

H

H

H H L H LLLLLLL

L

H

H

H H H LLLLLLLL

L

H

H

HHHH LLLLLLL

H

H

H

xxxx

e

Depends upon the BCD code applied during the 0 to 1 transition of LE

C1995 National Semiconductor Corporation

RRD-B30M105Printed in U S A