TECHNICAL DATA
1
Quad 2-Input Data Selector/Multiplexer
This monolitic data selector/multiplexer contains inverters and
drivers to supply full on-chip data selection to the four output 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 LS157 has the same
functions and pin connections as the LS257 but the latter is provided
with 3-state outputs.
Buffered Inputs and Outputs
Common Strobe/Select input for all 4 circuits
IN74LS157
ORDERING INFORMATION
IN74LS157N Plastic
IN74LS157D SOIC
T
A
=0
to 70
C for all
packages
FUNCTION TABLE
Inputs
Outputs
Output
Enable
Select
Y0-Y3
H
X
L
L
L
A0-A3
L
H
B0-B3
X=don't care
A0-A3,B0-B3=the levels of the respective
Data-Word Inputs
LOGIC DIAGRAM
PIN 16 =V
CC
PIN 8 = GND
PIN ASSIGNMENT
IN74LS157
2
MAXIMUM RATINGS
*
Symbol
Parameter
Value
Unit
V
CC
Supply Voltage
7.0
V
V
IN
Input Voltage
7.0
V
V
OUT
Output Voltage
5.5
V
Tstg
Storage Temperature Range
-65 to +150
C
*
Maximum Ratings are those values beyond which damage to the device may occur.
Functional operation should be restricted to the Recommended Operating Conditions.
RECOMMENDED OPERATING CONDITIONS
Symbol
Parameter
Min
Max
Unit
V
CC
Supply Voltage
4.75
5.25
V
V
IH
High Level Input Voltage
2.0
V
V
IL
Low Level Input Voltage
0.8
V
I
OH
High Level Output Current
-0.4
mA
I
OL
Low Level Output Current
8.0
mA
T
A
Ambient Temperature Range
0
+70
C
DC ELECTRICAL CHARACTERISTICS over full operating conditions
Guaranteed Limit
Symbol
Parameter
Test Conditions
Min
Max
Unit
V
IK
Input Clamp Voltage
V
CC
= min, I
IN
= -18 mA
-1.5
V
V
OH
High Level Output Voltage
V
CC
= min, I
OH
= -0.4 mA
2.7
V
V
OL
Low Level Output Voltage
V
CC
= min, I
OL
= 4 mA
0.4
V
V
CC
= min, I
OL
= 8 mA
0.5
I
IH
High Level Input Current
V
CC
= max
for pins 1,15
40
A
V
IN
= 2.7 V
A or B input
20
V
CC
= max
for pins 1,15
0.2
mA
V
IN
= 7.0 V
A or B input
0.1
I
IL
Low Level Input Current
V
CC
= max
for pins 1,15
-0.8
mA
V
IN
= 0.4 V
A or B input
-0.4
I
O
Output Short Circuit Current
V
CC
= max, V
O
= 0 V
(Note 1)
-20
-100
mA
I
CC
Supply Current
V
CC
= max (Note 2)
16
mA
Note 1: Not more than one output should be shorted at a time, and the duration should not exceed one second.
Note 2: I
CC
is measured with all outputs open, and 4.5 V applied to all inputs.
IN74LS157
3
AC ELECTRICAL CHARACTERISTICS
(T
A
=25
C, V
CC
= 5.0 V, C
L
= 15 pF, R
L
= 2 k
, t
r
=15
ns, t
f
= 6.0 ns)
Symbol
Parameter
Min
Max
Unit
t
PLH
Propagation Delay, Input A or B to Output Y
14
ns
t
PHL
Propagation Delay, Input A or B to Output Y
14
ns
t
PLH
Propagation Delay, Select to Output Y
23
ns
t
PHL
Propagation Delay, Select to Output Y
27
ns
t
PLH
Propagation Delay, Output Enable to Output Y
20
ns
t
PHL
Propagation Delay, Output Enable to Output Y
21
ns
Figure 1. Switching Waveforms
Figure 2. Switching Waveforms
NOTES A. C
L
includes probe and jig capacitance.
B. All diodes are 1N916 or 1N3064.
Figure 3. Test Circuit
PDF 
ZIP