The LSTTL / MSI SN54 / 74LS157 is a high speed Quad 2-Input Multiplexer.
Four bits of data from two sources can be selected using the common Select
and Enable inputs. The four buffered outputs present the selected data in the
true (non-inverted) form. The LS157 can also be used to generate any four
of the 16 different functions of two variables. The LS157 is fabricated with the
Schottky barrier diode process for high speed and is completely compatible
with all Motorola TTL families.
SN54/74LS157
•
•
•
•
•
•
QUAD 2-INPUT MULTIPLEXER
LOW POWER SCHOTTKY
Schottky Process for High Speed
Multifunction Capability
Non-Inverting Outputs
Input Clamp Diodes Limit High Speed Termination Effects
Special Circuitry Ensures Glitch Free Multiplexing
ESD > 3500 Volts
CONNECTION DIAGRAM DIP
(TOP VIEW)
VCC
16
E
15
I0c
14
I1c
13
Zc
12
I0d
11
I1d
10
Zd
9
NOTE:
The Flatpak version has
the same pinouts
(Connection Diagram) as
the Dual In-Line Package.
16
J SUFFIX
CERAMIC
CASE 620-09
1
1
S
2
I0a
3
I1d
4
Za
5
I0b
6
I1b
7
Zb
8
GND
16
1
N SUFFIX
PLASTIC
CASE 648-08
PIN NAMES
S
E
I0a – I0d
I1a – I1d
Za – Zd
Common Select Input
Enable (Active LOW) Input
Data Inputs from Source 0
Data Inputs from Source 1
Multiplexer Outputs (Note b)
LOADING
(Note a)
HIGH
1.0 U.L.
1.0 U.L.
0.5 U.L.
0.5 U.L.
10 U.L.
LOW
0.5 U.L.
0.5 U.L.
0.25 U.L.
0.25 U.L.
5 (2.5) U.L.
16
1
D SUFFIX
SOIC
CASE 751B-03
ORDERING INFORMATION
SN54LSXXXJ
SN74LSXXXN
SN74LSXXXD
Ceramic
Plastic
SOIC
NOTES:
a) 1 TTL Unit Load (U.L.) = 40
µA
HIGH/1.6 mA LOW.
b) The Output LOW drive factor is 2.5 U.L. for Military (54) and 5 U.L. for Commercial (74)
Temperature Ranges.
LOGIC DIAGRAM
I0a
2
3
I1a
5
I0b
6
I1b
14
I0c
13
I1c
11
I0d
10
I1d E S
15
1
LOGIC SYMBOL
15 2 3
5
6 14 13 11 10
E I0a I1a I0b I1b I0c I1c I0d I1d
1
S
Za
Zb
Zc
Zd
4
7
12
9
4
7
12
9
Za
Zb
VCC = PIN 16
GND = PIN 8
= PIN NUMBERS
Zd
VCC = PIN 16
GND = PIN 8
Zc
FAST AND LS TTL DATA
5-268
SN54/74LS157
FUNCTIONAL DESCRIPTION
The LS157 is a Quad 2-Input Multiplexer fabricated with the
Schottky barrier diode process for high speed. It selects four
bits of data from two sources under the control of a common
Select Input (S). The Enable Input (E) is active LOW. When E
is HIGH, all of the outputs (Z) are forced LOW regardless of all
other inputs.
The LS157 is the logic implementation of a 4-pole,
2-position switch where the position of the switch is deter-
mined by the logic levels supplied to the Select Input. The logic
equations for the outputs are:
Za = E
⋅
(I1a
⋅
S + I0a
⋅
S)
Zc = E
⋅
(I1c
⋅
S + I0c
⋅
S)
Zb = E
⋅
(I1b
⋅
S + I0b
⋅
S)
Zd = E
⋅
(I1d
⋅
S + I0d
⋅
S)
A common use of the LS157 is the moving of data from two
groups of registers to four common output busses. The partic-
ular register from which the data comes is determined by the
state of the Select Input. A less obvious use is as a function
generator. The LS157 can generate any four of the 16 different
functions of two variables with one variable common. This is
useful for implementing highly irregular logic.
TRUTH TABLE
ENABLE
E
H
L
L
L
L
H = HIGH Voltage Level
L = LOW Voltage Level
X = Don’t Care
SELECT
INPUT
S
X
H
H
L
L
INPUTS
I0
X
X
X
L
H
I1
X
L
H
X
X
OUTPUT
Z
L
L
H
L
H
GUARANTEED OPERATING RANGES
Symbol
VCC
TA
IOH
IOL
Supply Voltage
Operating Ambient Temperature Range
Output Current — High
Output Current — Low
Parameter
54
74
54
74
54, 74
54
74
Min
4.5
4.75
– 55
0
Typ
5.0
5.0
25
25
Max
5.5
5.25
125
70
– 0.4
4.0
8.0
Unit
V
°C
mA
mA
FAST AND LS TTL DATA
5-269
SN54/74LS157
DC CHARACTERISTICS OVER OPERATING TEMPERATURE RANGE
(unless otherwise specified)
Limits
Symbol
VIH
VIL
VIK
VOH
Parameter
Input HIGH Voltage
Input LOW Voltage
Input Clamp Diode Voltage
Output HIGH Voltage
54
74
54, 74
VOL
Output LOW Voltage
74
Input HIGH Current
I0, I1
E, S
I0, I1
E, S
IIL
IOS
ICC
Input LOW Current
I0, I1
E, S
Short Circuit Current (Note 1)
Power Supply Current
– 20
0.35
0.5
20
40
0.1
0.2
– 0.4
– 0.8
– 100
16
V
µA
2.5
2.7
54
74
– 0.65
3.5
3.5
0.25
0.4
Min
2.0
0.7
0.8
– 1.5
V
V
V
V
Typ
Max
Unit
V
V
Test Conditions
Guaranteed Input HIGH Voltage for
All Inputs
Guaranteed Input LOW Voltage for
All Inputs
VCC = MIN, IIN = – 18 mA
VCC = MIN, IOH = MAX, VIN = VIH
or VIL per Truth Table
IOL = 4.0 mA
IOL = 8.0 mA
VCC = VCC MIN,
VIN = VIL or VIH
per Truth Table
VCC = MAX, VIN = 2.7 V
IIH
mA
VCC = MAX, VIN = 7.0 V
mA
mA
mA
VCC = MAX, VIN = 0.4 V
VCC = MAX
VCC = MAX
Note 1: Not more than one output should be shorted at a time, nor for more than 1 second.
AC CHARACTERISTICS
(TA = 25°C)
Limits
Symbol
tPLH
tPHL
tPLH
tPHL
tPLH
tPHL
Parameter
Propagation Delay
Data to Output
Propagation Delay
Enable to Output
Propagation Delay
Select to Output
Min
Typ
9.0
9.0
13
14
15
18
Max
14
14
20
21
23
27
Unit
ns
ns
ns
Figure 2
Figure 1
Figure 2
VCC = 5.0 V
CL = 15 pF
Test Conditions
AC WAVEFORMS
V
IN
1.3 V
1.3 V
V
IN
1.3 V
1.3 V
t
PHL
t
PLH
t
PHL
t
PLH
V
OUT
1.3 V
1.3 V
V
OUT
1.3 V
1.3 V
Figure 1
Figure 2
FAST AND LS TTL DATA
5-270
-A-
Case 751B-03 D Suffix
16-Pin Plastic
SO-16
NOTES:
1.
DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.
2.
3.
CONTROLLING DIMENSION: MILLIMETER.
DIMENSION A AND B DO NOT INCLUDE MOLD
PROTRUSION.
4.
MAXIMUM MOLD PROTRUSION 0.15 (0.006)
PER SIDE.
5.
751B 01 IS OBSOLETE, NEW STANDARD
751B 03.
16
9
-B-
1
8
P
8 PL
0.25 (0.010)
M
B
M
R X 45°
G
-T-
D
16 PL
0.25 (0.010)
M
C
SEATING
PLANE
K
T
B
S
M
F
J
A
S
DIM
A
B
C
D
F
G
J
K
M
P
R
MILLIMETERS
MIN
MAX
9.80
3.80
1.35
0.35
0.40
10.00
4.00
1.75
0.49
1.25
INCHES
MIN
MAX
0.386
0.150
0.054
0.014
0.016
0.393
0.157
0.068
0.019
0.049
1.27 BSC
0.19
0.10
0
0.25
0.25
7
0.050 BSC
0.008
0.004
0
0.009
0.009
7
°
°
°
°
5.80
0.25
6.20
0.50
0.229
0.010
0.244
0.019
Case 648-08 N Suffix
16-Pin Plastic
-A-
16
9
NOTES:
1.
DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.
2.
3.
CONTROLLING DIMENSION: INCH.
DIMENSION L" TO CENTER OF LEADS WHEN
FORMED PARALLEL.
4.
DIMENSION B" DOES NOT INCLUDE MOLD
FLASH.
5.
6.
ROUNDED CORNERS OPTIONAL.
648 01 THRU 07 OBSOLETE, NEW STANDARD
648 08.
B
1
8
F
S
C
-T-
K
SEATING
PLANE
L
H
G
D
16 PL
0.25 (0.010)
M
J
M
T
A
M
DIM
A
B
C
D
F
G
H
J
K
L
M
S
MILLIMETERS
MIN
MAX
18.80
6.35
3.69
0.39
1.02
19.55
6.85
4.44
0.53
1.77
INCHES
MIN
MAX
0.740
0.250
0.145
0.015
0.040
0.770
0.270
0.175
0.021
0.070
2.54 BSC
1.27 BSC
0.21
2.80
7.50
0
0.38
3.30
7.74
10
0.100 BSC
0.050 BSC
0.008
0.110
0.295
0
0.015
0.130
0.305
10
°
°
°
°
0.51
1.01
0.020
0.040
-A-
16
9
Case 620-09 J Suffix
16-Pin Ceramic Dual In-Line
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.
2. CONTROLLING DIMENSION: INCH.
-B-
1
8
3. DIMENSION L TO CENTER OF LEAD WHEN
FORMED PARALLEL.
4. DIM F MAY NARROW TO 0.76 (0.030) WHERE
THE LEAD ENTERS THE CERAMIC BODY.
C
L
5. 620 01 THRU 08 OBSOLETE, NEW STANDARD
620 09.
-T-
SEATING
PLANE
K
E
F
D
16 PL
0.25 (0.010)
M
N
G
T
A
S
M
J
16 PL
0.25 (0.010)
M
T
B
S
DIM
A
B
C
D
E
F
G
J
K
L
M
N
MILLIMETERS
MIN
MAX
19.05
6.10
19.55
7.36
4.19
0.39
0.53
INCHES
MIN
MAX
0.750
0.240
0.770
0.290
0.165
0.015
0.021
1.27 BSC
1.40
1.77
0.050 BSC
0.055
0.070
2.54 BSC
0.23
0.27
5.08
7.62 BSC
0
0.100 BSC
0.009
0.011
0.200
0.300 BSC
0
°
15
°
°
15
°
0.39
0.88
0.015
0.035
FAST AND LS TTL DATA
5-271
Motorola reserves the right to make changes without further notice to any products herein. Motorola makes no warranty, representation or guarantee regarding
the suitability of its products for any particular purpose, nor does Motorola assume any liability arising out of the application or use of any product or circuit,
and specifically disclaims any and all liability, including without limitation consequential or incidental damages. “Typical” parameters can and do vary in different
applications. All operating parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. Motorola does
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against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death
associated with such unintended or unauthorized use, even if such claim alleges that Motorola was negligent regarding the design or manufacture of the part.
Motorola and
are registered trademarks of Motorola, Inc. Motorola, Inc. is an Equal Opportunity/Affirmative Action Employer.
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