DM74ALS157 • DM74ALS158 Quad 1-of-2 Line Data Selector/Multiplexer
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-
ture and V
CC
range
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:
Order Number
DM74ALS157M
DM74ALS157SJ
DM74ALS157N
DM74ALS158N
Package Number
M16A
M16D
N16E
N16E
Package Description
16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150 Narrow
16-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.
Connection Diagram
Function Table
Inputs
Strobe Select
H
L
L
L
L
X
L
L
H
H
A
X
L
H
X
X
B
X
X
X
L
H
L
L
H
L
H
Output Y
DM74ALS157 DM74ALS158
H
H
L
H
L
H
=
HIGH Level
L
=
LOW Level
X
=
Don't Care
© 2000 Fairchild Semiconductor Corporation
DS006205
www.fairchildsemi.com
DM74ALS157 • DM74ALS158
Absolute Maximum Ratings
(Note 1)
Supply Voltage
Input Voltage
Operating Free Air Temperature Range
Storage Temperature Range
7V
7V
0°C to
+70°C
−65°C
to
+150°C
Note 1:
The “Absolute Maximum Ratings” are those values beyond which
the safety of the device cannot be guaranteed. The device should not be
operated at these limits. The parametric values defined in the Electrical
Characteristics tables are not guaranteed at the absolute maximum ratings.
The “Recommended Operating Conditions” table will define the conditions
for actual device operation.
Recommended Operating Conditions
Symbol
V
CC
V
IH
V
IL
I
OH
I
OL
T
A
Supply Voltage
HIGH Level Input Voltage
LOW Level Input Voltage
HIGH Level Output Current
LOW Level Output Current
Free Air Operating Temperature
0
Parameter
Min
4.5
2
0.8
−0.4
8
70
Nom
5
Max
5.5
Units
V
V
V
mA
mA
°C
Electrical Characteristics
over recommended operating free air temperature range. All typical values are measured at V
CC
=
5V, T
A
=
25°C.
Symbol
V
IK
V
OH
V
OL
I
I
I
IH
I
IL
I
O
I
CC
Parameter
Input Clamp Voltage
HIGH Level Output Voltage
LOW Level
Output Voltage
Input Current @ Maximum
Input Voltage
HIGH Level Input Current
LOW Level Input Current
Output Drive Current
Supply Current
V
CC
=
5.5V, V
IH
=
7V
V
CC
=
5.5V, V
IH
=
2.7V
V
CC
=
5.5V, V
IL
=
0.4V
V
CC
=
5.5V
V
CC
=
5.5V
All Inputs
=
4.5V
V
O
=
2.25V
DM74ALS157
DM74ALS158
−30
6
5
Conditions
V
CC
=
4.5V, I
I
= −18
mA
I
OH
= −0.4
mA, V
CC
=
4.5V to 5.5V
V
CC
=
4.5V
I
OL
=
4 mA
I
OL
=
8 mA
V
CC
−
2
0.25
0.35
0.4
0.5
0.1
20
−0.1
−112
11
10
Min
Typ
Max
−1.2
Units
V
V
V
V
mA
µA
mA
mA
mA
mA
Switching Characteristics
over recommended operating free air temperature range.
From (Input)
Symbol
Parameter
To (Output)
t
PLH
t
PHL
t
PLH
t
PHL
t
PLH
t
PHL
Propagation Delay Time
LOW-to-HIGH Level Output
Propagation Delay Time
HIGH-to-LOW Level Output
Propagation Delay Time
LOW-to-HIGH Level Output
Propagation Delay Time
HIGH-to-LOW Level Output
Propagation Delay Time
LOW-to-HIGH Level Output
Propagation Delay Time
HIGH-to-LOW Level Output
Select to Y
Strobe to Y
Data to Y
Conditions
V
CC
=
4.5V to 5.5V
C
L
=
50 pF
R
L
=
500Ω
DM74ALS157
Min
3
2
6
4
7
4
Max
14
12
20
13
24
14
DM74ALS158
Min
3
1
5
5
5
5
Max
15
8
18
18
19
18
Units
ns
ns
ns
ns
ns
ns
3
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