© 2000 Fairchild Semiconductor Corporation DS006205 www.fairchildsemi.com
April 1984
Revised February 2000
DM74ALS157 • DM74ALS158 Quad 1-of-2 Line Data Selector/Multiplexer
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 da ta selection to the fo ur output gates. A separate strobe input is provided. A 4-bit word
is selected from one o f two sources and is route d to the
four outputs. The A LS157 presen ts true data whereas the
ALS158 presents inverted data to minimize propagation
delay time.
Features
■ Switching specifications at 50 pF
■ Switching specifications guaranteed over full tempera-
ture and V
CC
range
■ Advanced oxide-isolated, ion-implanted Schottky TTL
process
■ Functionally and pin for pin compatible with Schottky
and low power Schottky TTL counterpart
■ Improved AC performance over Schottky and low power
Schottky counterparts
■ Expand any data input point
■ Multiplex dual data buses
■ General four functions of two variables (one variable is
common)
■ Source programmable counters
Ordering Code:
Devices also availab le in Tape and Reel. Specify by appending th e s uffix let t er “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
HXXX L H
LLLX L H
LLHX H L
LHXL L H
LHXH H L