TECHNICAL DATA
IN74LS157
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
ORDERING INFORMATION
IN74LS157N Plastic
IN74LS157D SOIC
T
A
=0° to 70° C for all
packages
PIN ASSIGNMENT
LOGIC DIAGRAM
FUNCTION TABLE
Inputs
PIN 16 =V
CC
PIN 8 = GND
Output
Enable
H
L
L
Select
X
L
H
Outputs
Y0-Y3
L
A0-A3
B0-B3
X=don’t care
A0-A3,B0-B3=the levels of the respective
Data-Word Inputs
1
IN74LS157
MAXIMUM RATINGS
*
Symbol
V
CC
V
IN
V
OUT
Tstg
*
Parameter
Supply Voltage
Input Voltage
Output Voltage
Storage Temperature Range
Value
7.0
7.0
5.5
-65 to +150
Unit
V
V
V
°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
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
Ambient Temperature Range
0
Parameter
Min
4.75
2.0
0.8
-0.4
8.0
+70
Max
5.25
Unit
V
V
V
mA
mA
°C
DC ELECTRICAL CHARACTERISTICS
over full operating conditions
Guaranteed Limit
Symbol
V
IK
V
OH
V
OL
I
IH
Parameter
Input Clamp Voltage
High Level Output Voltage
Low Level Output Voltage
High Level Input Current
Test Conditions
V
CC
= min, I
IN
= -18 mA
V
CC
= min, I
OH
= -0.4 mA
V
CC
= min, I
OL
= 4 mA
V
CC
= min, I
OL
= 8 mA
V
CC
= max
V
IN
= 2.7 V
V
CC
= max
V
IN
= 7.0 V
I
IL
I
O
I
CC
Low Level Input Current
Output Short Circuit Current
Supply Current
V
CC
= max
V
IN
= 0.4 V
for pins 1,15
A or B input
for pins 1,15
A or B input
for pins 1,15
A or B input
-20
2.7
0.4
0.5
40
20
0.2
0.1
-0.8
-0.4
-100
16
mA
mA
mA
mA
µA
Min
Max
-1.5
Unit
V
V
V
V
CC
= max, V
O
= 0 V
(Note 1)
V
CC
= max (Note 2)
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.
2
IN74LS157
AC ELECTRICAL CHARACTERISTICS
(T
A
=25°C, V
CC
= 5.0 V, C
L
= 15 pF, R
L
= 2 kΩ, t
r
=15
ns, t
f
= 6.0 ns)
Symbol
t
PLH
t
PHL
t
PLH
t
PHL
t
PLH
t
PHL
Parameter
Propagation Delay, Input A or B to Output Y
Propagation Delay, Input A or B to Output Y
Propagation Delay, Select to Output Y
Propagation Delay, Select to Output Y
Propagation Delay, Output Enable to Output Y
Propagation Delay, Output Enable to Output Y
Min
Max
14
14
23
27
20
21
Unit
ns
ns
ns
ns
ns
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
3
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