pansion to a 1-of-24 decoder using just three LS138 devices or to a 1-of-32
decoder using four LS138s and one inverter. The LS138 is fabricated with the
Schottky barrier diode process for high speed and is completely compatible
with all Motorola TTL families.
SN54/74LS138
1-OF-8 DECODER/
DEMULTIPLEXER
LOW POWER SCHOTTKY
•
•
•
•
•
Demultiplexing Capability
Multiple Input Enable for Easy Expansion
Typical Power Dissipation of 32 mW
Active Low Mutually Exclusive Outputs
Input Clamp Diodes Limit High Speed Termination Effects
CONNECTION DIAGRAM DIP
(TOP VIEW)
VCC
16
O0
15
O1
14
O2
13
O3
12
O4
11
O5
10
O6
9
NOTE:
The Flatpak version
has the same pinouts
(Connection Diagram) as
the Dual In-Line Package.
16
1
J SUFFIX
CERAMIC
CASE 620-09
16
1
N SUFFIX
PLASTIC
CASE 648-08
1
A0
2
A1
3
A2
4
E1
5
E2
6
E3
7
O7
8
GND
PIN NAMES
A0 – A2
E1, E2
E3
O0 – O7
Address Inputs
Enable (Active LOW) Inputs
Enable (Active HIGH) Input
Active LOW Outputs (Note b)
LOADING
(Note a)
HIGH
0.5 U.L.
0.5 U.L.
0.5 U.L.
10 U.L.
LOW
0.25 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
A2
3
2
A1
1
A0
4
E1 E2 E3
5
6
LOGIC SYMBOL
VCC = PIN 16
GND = PIN 8
= PIN NUMBERS
1 2 3
456
12 3
A0 A1 A2
E
O0 O1 O2 O3 O4 O5 O6 O7
15 14 13 12 11 10 9
VCC = PIN 16
GND = PIN 8
7
9
10
11
12
13
14
15
7
O7
O6
O5
O4
O3
O2
O1
O0
FAST AND LS TTL DATA
5-230
SN54/74LS138
FUNCTIONAL DESCRIPTION
The LS138 is a high speed 1-of-8 Decoder/Demultiplexer
fabricated with the low power Schottky barrier diode process.
The decoder accepts three binary weighted inputs (A0, A1, A2)
and when enabled provides eight mutually exclusive active
LOW Outputs (O0 – O7). The LS138 features three Enable in-
puts, two active LOW (E1, E2) and one active HIGH (E3). All
outputs will be HIGH unless E1 and E2 are LOW and E3 is
HIGH. This multiple enable function allows easy parallel ex-
pansion of the device to a 1-of-32 (5 lines to 32 lines) decoder
with just four LS138s and one inverter. (See Figure a.)
The LS138 can be used as an 8-output demultiplexer by
using one of the active LOW Enable inputs as the data input
and the other Enable inputs as strobes. The Enable inputs
which are not used must be permanently tied to their appropri-
ate active HIGH or active LOW state.
TRUTH TABLE
INPUTS
E1
H
X
X
L
L
L
L
L
L
L
L
E2
X
H
X
L
L
L
L
L
L
L
L
E3
X
X
L
H
H
H
H
H
H
H
H
A0
X
X
X
L
H
L
H
L
H
L
H
A1
X
X
X
L
L
H
H
L
L
H
H
A2
X
X
X
L
L
L
L
H
H
H
H
O0
H
H
H
L
H
H
H
H
H
H
H
O1
H
H
H
H
L
H
H
H
H
H
H
O2
H
H
H
H
H
L
H
H
H
H
H
OUTPUTS
O3
H
H
H
H
H
H
L
H
H
H
H
O4
H
H
H
H
H
H
H
L
H
H
H
O5
H
H
H
H
H
H
H
H
L
H
H
O6
H
H
H
H
H
H
H
H
H
L
H
O7
H
H
H
H
H
H
H
H
H
H
L
H = HIGH Voltage Level
L = LOW Voltage Level
X = Don’t Care
A0
A1
A2
LS04
A3
A4
H
123
A0 A1 A2
E
A0 A1 A2
123
E
A0 A1 A2
123
E
A0 A1 A2
123
E
LS138
O0 O1 O2 O3 O4 O5 O6 O7
LS138
O0 O1 O2 O3 O4 O5 O6 O7
LS138
O0 O1 O2 O3 O4 O5 O6 O7
LS138
O0 O1 O2 O3 O4 O5 O6 O7
O0
O31
Figure a
FAST AND LS TTL DATA
5-231
SN54/74LS138
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
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
Input LOW Current
Short Circuit Current (Note 1)
Power Supply Current
– 20
0.35
0.5
20
0.1
– 0.4
–100
10
V
µA
mA
mA
mA
mA
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
IIH
IIL
IOS
ICC
VCC = MAX, VIN = 2.7 V
VCC = MAX, VIN = 7.0 V
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)
Symbol
tPLH
tPHL
tPLH
tPHL
tPLH
tPHL
tPLH
tPHL
Parameter
Propagation Delay
Address to Output
Propagation Delay
Address to Output
Propagation Delay E1 or E2
Enable to Output
Propagation Delay E3
Enable to Output
Levels of
Delay
2
2
3
3
2
2
3
3
Limits
Min
Typ
13
27
18
26
12
21
17
25
Max
20
41
27
39
18
32
26
38
Unit
ns
ns
ns
ns
Test Conditions
VCC = 5.0 V
CL = 15 pF
AC WAVEFORMS
V
IN
1.3 V
1.3 V
V
IN
1.3 V
1.3 V
t
PHL
V
OUT
t
PLH
t
PHL
V
OUT
t
PLH
1.3 V
1.3 V
1.3 V
1.3 V
Figure 1
Figure 2
FAST AND LS TTL DATA
5-232
-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
5-233
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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
not convey any license under its patent rights nor the rights of others. Motorola products are not designed, intended, or authorized for use as components in
systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of
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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.
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are registered trademarks of Motorola, Inc. Motorola, Inc. is an Equal Opportunity/Affirmative Action Employer.
Literature Distribution Centers:
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