TL F 6391
54LS138DM54LS138DM74LS138
54LS139DM54LS139DM74LS139
DecodersDemultiplexers
June 1989
54LS138 DM54LS138 DM74LS138
54LS139 DM54LS139 DM74LS139
Decoders Demultiplexers
General Description
These Schottky-clamped circuits are designed to be used in
high-performance memory-decoding or data-routing appli-
cations requiring very short propagation delay times In
high-performance memory systems these decoders can be
used to minimize the effects of system decoding When
used with high-speed memories the delay times of these
decoders are usually less than the typical access time of the
memory This means that the effective system delay intro-
duced by the decoder is negligible
The LS138 decodes one-of-eight lines based upon the con-
ditions at the three binary select inputs and the three enable
inputs Two active-low and one active-high enable inputs
reduce the need for external gates or inverters when ex-
panding A 24-line decoder can be implemented with no ex-
ternal inverters and a 32-line decoder requires only one
inverter An enable input can be used as a data input for
demultiplexing applications
The LS139 comprises two separate two-line-to-four-line de-
coders in a single package The active-low enable input can
be used as a data line in demultiplexing applications
All of these decoders demultiplexers feature fully buffered
inputs presenting only one normalized load to its driving
circuit
All inputs are clamped with high-performance
Schottky diodes to suppress line-ringing and simplify system
design
Features
Y
Designed specifically for high speed
Memory decoders
Data transmission systems
Y
LS138 3-to-8-line decoders incorporates 3 enable in-
puts to simplify cascading and or data reception
Y
LS139 contains two fully independent 2-to-4-line decod-
ers demultiplexers
Y
Schottky clamped for high performance
Y
Typical propagation delay (3 levels of logic)
LS138
21 ns
LS139
21 ns
Y
Typical power dissipation
LS138
32 mW
LS139
34 mW
Y
Alternate
Military Aerospace
devices
(54LS138
54LS139) are available Contact a National Semicon-
ductor Sales Office Distributor for specifications
Connection Diagrams
Dual-in-Line Package
TL F 6391 1
Order Number 54LS138DMQB 54LS138FMQB
54LS138LMQB DM54LS138J DM54LS138W
DM74LS138M or DM74LS138N
See NS Package Number E20A J16A
M16A N16E or W16A
Dual-in-Line Package
TL F 6391 2
Order Number 54LS139DMQB 54LS139FMQB
54LS139LMQB DM54LS139J DM54LS139W
DM74LS139M or DM74LS139N
See NS Package Number E20A J16A
M16A N16E or W16A
C1995 National Semiconductor Corporation
RRD-B30M105 Printed in U S A
Absolute Maximum Ratings
(Note)
If Military Aerospace specified devices are required
please contact the National Semiconductor Sales
Office Distributors for availability and specifications
Supply Voltage
7V
Input Voltage
7V
Operating Free Air Temperature Range
DM54LS and 54LS
b
55 C to
a
125 C
DM74LS
0 C to
a
70 C
Storage Temperature Range
b
65 C to
a
150 C
Note
The ``Absolute Maximum Ratings'' are those values
beyond which the safety of the device cannot be guaran-
teed The device should not be operated at these limits The
parametric values defined in the ``Electrical Characteristics''
table 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
Parameter
DM54LS138
DM74LS138
Units
Min
Nom
Max
Min
Nom
Max
V
CC
Supply Voltage
4 5
5
5 5
4 75
5
5 25
V
V
IH
High Level Input Voltage
2
2
V
V
IL
Low Level Input Voltage
0 7
0 8
V
I
OH
High Level Output Current
b
0 4
b
0 4
mA
I
OL
Low Level Output Current
4
8
mA
T
A
Free Air Operating Temperature
b
55
125
0
70
C
'LS138 Electrical Characteristics
over recommended operating free air temperature range (unless otherwise noted)
Symbol
Parameter
Conditions
Min
Typ
Max
Units
(Note 1)
V
I
Input Clamp Voltage
V
CC
e
Min I
I
e b
18 mA
b
1 5
V
V
OH
High Level Output
V
CC
e
Min I
OH
e
Max
DM54
2 5
3 4
V
Voltage
V
IL
e
Max V
IH
e
Min
DM74
2 7
3 4
V
OL
Low Level Output
V
CC
e
Min I
OL
e
Max
DM54
0 25
0 4
Voltage
V
IL
e
Max V
IH
e
Min
DM74
0 35
0 5
V
I
OL
e
4 mA V
CC
e
Min
DM74
0 25
0 4
I
I
Input Current
Max
V
CC
e
Max V
I
e
7V
0 1
mA
Input Voltage
I
IH
High Level Input Current
V
CC
e
Max V
I
e
2 7V
20
m
A
I
IL
Low Level Input Current
V
CC
e
Max V
I
e
0 4V
b
0 36
mA
I
OS
Short Circuit
V
CC
e
Max
DM54
b
20
b
100
mA
Output Current
(Note 2)
DM74
b
20
b
100
I
CC
Supply Current
V
CC
e
Max (Note 3)
6 3
10
mA
Note 1
All typicals are at V
CC
e
5V T
A
e
25 C
Note 2
Not more than one output should be shorted at a time and the duration should not exceed one second
Note 3
I
CC
is measured with all outputs enabled and open
2
'LS138 Switching Characteristics
at V
CC
e
5V and T
A
e
25 C (See Section 1 for Test Waveforms and Output Load)
From (Input)
Levels
R
L
e
2 kX
Symbol
Parameter
To (Output)
of Delay
C
L
e
15 pF
C
L
e
50 pF
Units
Min
Max
Min
Max
t
PLH
Propagation Delay Time
Select to
2
18
27
ns
Low to High Level Output
Output
t
PHL
Propagation Delay Time
Select to
2
27
40
ns
High to Low Level Output
Output
t
PLH
Propagation Delay Time
Select to
3
18
27
ns
Low to High Level Output
Output
t
PHL
Propagation Delay Time
Select to
3
27
40
ns
High to Low Level Output
Output
t
PLH
Propagation Delay Time
Enable to
2
18
27
ns
Low to High Level Output
Output
t
PHL
Propagation Delay Time
Enable to
2
24
40
ns
High to Low Level Output
Output
t
PLH
Propagation Delay Time
Enable to
3
18
27
ns
Low to High Level Output
Output
t
PHL
Propagation Delay Time
Enable to
3
28
40
ns
High to Low Level Output
Output
Recommended Operating Conditions
Symbol
Parameter
DM54LS139
DM74LS139
Units
Min
Nom
Max
Min
Nom
Max
V
CC
Supply Voltage
4 5
5
5 5
4 75
5
5 25
V
V
IH
High Level Input Voltage
2
2
V
V
IL
Low Level Input Voltage
0 7
0 8
V
I
OH
High Level Output Current
b
0 4
b
0 4
mA
I
OL
Low Level Output Current
4
8
mA
T
A
Free Air Operating Temperature
b
55
125
0
70
C
3
'LS139 Electrical Characteristics
over recommended operating free air temperature range (unless otherwise noted)
Symbol
Parameter
Conditions
Min
Typ
Max
Units
(Note 1)
V
I
Input Clamp Voltage
V
CC
e
Min I
I
e b
18 mA
b
1 5
V
V
OH
High Level Output
V
CC
e
Min I
OH
e
Max
DM54
2 5
3 4
V
Voltage
V
IL
e
Max V
IH
e
Min
DM74
2 7
3 4
V
OL
Low Level Output
V
CC
e
Min I
OL
e
Max
DM54
0 25
0 4
Voltage
V
IL
e
Max V
IH
e
Min
DM74
0 35
0 5
V
I
OL
e
4 mA V
CC
e
Min
DM74
0 25
0 4
I
I
Input Current
Max
V
CC
e
Max V
I
e
7V
0 1
mA
Input Voltage
I
IH
High Level Input Current
V
CC
e
Max V
I
e
2 7V
20
m
A
I
IL
Low Level Input Current
V
CC
e
Max V
I
e
0 4V
b
0 36
mA
I
OS
Short Circuit
V
CC
e
Max
DM54
b
20
b
100
mA
Output Current
(Note 2)
DM74
b
20
b
100
I
CC
Supply Current
V
CC
e
Max (Note 3)
6 8
11
mA
Note 1
All typicals are at V
CC
e
5V T
A
e
25 C
Note 2
Not more than one output should be shorted at a time and the duration should not exceed one second
Note 3
I
CC
is measured with all outputs enabled and open
'LS139 Switching Characteristics
at V
CC
e
5V and T
A
e
25 C (See Section 1 for Test Waveforms and Output Load)
From (Input)
R
L
e
2 kX
Symbol
Parameter
To (Output)
C
L
e
15 pF
C
L
e
50 pF
Units
Min
Max
Min
Max
t
PLH
Propagation Delay Time
Select to
18
27
ns
Low to High Level Output
Output
t
PHL
Propagation Delay Time
Select to
27
40
ns
High to Low Level Output
Output
t
PLH
Propagation Delay Time
Enable to
18
27
ns
Low to High Level Output
Output
t
PHL
Propagation Delay Time
Enable to
24
40
ns
High to Low Level Output
Output
Function Tables
LS138
Inputs
Outputs
Enable
Select
G1 G2
C B A YO Y1 Y2 Y3 Y4 Y5 Y6 Y7
X
H
X
X
X
H
H
H
H
H
H
H
H
L
X
X
X
X
H
H
H
H
H
H
H
H
H
L
L
L
L
L
H
H
H
H
H
H
H
H
L
L
L
H
H
L
H
H
H
H
H
H
H
L
L
H
L
H
H
L
H
H
H
H
H
H
L
L
H H
H
H
H
L
H
H
H
H
H
L
H
L
L
H
H
H
H
L
H
H
H
H
L
H
L
H
H
H
H
H
H
L
H
H
H
L
H H
L
H
H
H
H
H
H
L
H
H
L
H H H
H
H
H
H
H
H
H
L
G2
e
G2A
a
G2B
H
e
High Level L
e
Low Level X
e
Don't Care
LS139
Inputs
Outputs
Enable
Select
G
B
A
Y0
Y1
Y2
Y3
H
X
X
H
H
H
H
L
L
L
L
H
H
H
L
L
H
H
L
H
H
L
H
L
H
H
L
H
L
H
H
H
H
H
L
H
e
High Level L
e
Low Level X
e
Don't Care
4
Logic Diagrams
LS138
TL F 6391 3
LS139
TL F 6391 4
5
Physical Dimensions
inches (millimeters)
Ceramic Leadless Chip Carrier Package (E)
Order Number 54LS138LMQB or 54LS139LMQB
NS Package Number E20A
16-Lead Ceramic Dual-In-Line Package (J)
Order Number 54LS138DMQB 54LS139DMQB DM54LS138J or DM54LS139J
NS Package Number J16A
6
Physical Dimensions
inches (millimeters) (Continued)
16-Lead Small Outline Molded Package (M)
Order Number DM74LS138M or DM74LS139M
NS Packge Number M16A
16-Lead Molded Dual-In-Line Package (N)
Order Number DM74LS138N or DM74LS139N
NS Package Number N16E
7
54LS138DM54LS138DM74LS138
54LS139DM54LS139DM74LS139
DecodersDemultiplexers
Physical Dimensions
inches (millimeters) (Continued)
16-Lead Ceramic Flat Package (W)
Order Number 54LS138FMQB 54LS139FMQB DM54LS138W or DM54LS139W
NS Package Number W16A
LIFE SUPPORT POLICY
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DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONAL
SEMICONDUCTOR CORPORATION As used herein
1 Life support devices or systems are devices or
2 A critical component is any component of a life
systems which (a) are intended for surgical implant
support device or system whose failure to perform can
into the body or (b) support or sustain life and whose
be reasonably expected to cause the failure of the life
failure to perform when properly used in accordance
support device or system or to affect its safety or
with instructions for use provided in the labeling can
effectiveness
be reasonably expected to result in a significant injury
to the user
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