© 2000 Fairchild Semiconductor Corporation

DS006205

www.fairchildsemi.com

April 1984

Revised February 2000

DM74ALS157 • DM74ALS158

Quad 1-of-2 Line Data Selector/Multiplexer

General Description

These data selectors/multiplexers contain inverters and

drivers to supply full on-chip data selection to the four out-

put gates. A separate strobe input is provided. A 4-bit word

is selected from one of two sources and is routed to the

four outputs. The ALS157 presents true data whereas the

ALS158 presents inverted data to minimize propagation

delay time.

Features

s Switching specifications at 50 pF

s Switching specifications guaranteed over full tempera-

s Advanced oxide-isolated, ion-implanted Schottky TTL

process

s Functionally and pin for pin compatible with Schottky

and low power Schottky TTL counterpart

s Improved AC performance over Schottky and low power

Schottky counterparts

s Expand any data input point

s Multiplex dual data buses

s General four functions of two variables (one variable is

common)

s Source programmable counters

Ordering Code:

Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.

Connection Diagram

Function Table

H

= HIGH Level

L

= LOW Level

X

= Don't Care

Order Number

Package Number

Package Description

DM74ALS157M

M16A

16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150 Narrow

DM74ALS157SJ

M16D

16-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide

DM74ALS157N

N16E

16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide

DM74ALS158N

N16E

16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide

Inputs

Output Y

Strobe Select

A

B

DM74ALS157 DM74ALS158

HX

X

X

L

H

LL

L

X

L

H

LL

H

X

H

L

LH

X

L

L

H

LH

X

H

H

L