SN74LS139

http://onsemi.com

3

LOGIC DIAGRAM

GND = PIN 8

= PIN NUMBERS

12

11

6

7

4

5

10

9

1

2

3

15

14

13

FUNCTIONAL DESCRIPTION

The LS139 is a high speed dual 1-of-4 decoder/

demultiplexer fabricated with the Schottky barrier diode

process. The device has two independent decoders, each of

provide four mutually exclusive active LOW outputs

When E is HIGH all outputs are forced HIGH. The enable

can be used as the data input for a 4-output demultiplexer

application.

Each half of the LS139 generates all four minterms of two

variables. These four minterms are useful in some

applications, replacing multiple gate functions as shown in

Fig. a, and thereby reducing the number of packages

required in a logic network.

TRUTH TABLE

INPUTS

OUTPUTS

E

H

X

X

H

H

H

H

L

LL

L

HHH

L

HL

H

LH

H

L

LH

H

HLH

L

HH

H

HH

L

H = HIGH Voltage Level

L = LOW Voltage Level

X = Don’t Care

Figure a

E

E

E

E

E

E

E

E