This decoder utilizes advanced silicon-gate CMOS technol-
ogy and is well suited to memory address decoding or data
routing applications The circuit features high noise immuni-
ty and low power consumption usually associated with
CMOS circuitry yet has speeds comparable to low power
Schottky TTL logic
The MM54HC138 MM74HC138 has 3 binary select inputs
(A B and C) If the device is enabled these inputs deter-
mine which one of the eight normally high outputs will go
low Two active low and one active high enables (G1 G2A
and G2B) are provided to ease the cascading of decoders
The decoder’s outputs can drive 10 low power Schottky TTL
equivalent loads and are functionally and pin equivalent to
the 54LS138 74LS138 All inputs are protected from dam-
age due to static discharge by diodes to V
CC
and ground
Features
Y
Y
Y
Y
Y
Typical propagation delay 20 ns
Wide power supply range 2V – 6V
Low quiescent current 80
mA
maximum (74HC Series)
Low input current 1
mA
maximum
Fanout of 10 LS-TTL loads
Connection and Logic Diagrams
Dual-In-Line Package
TL F 5120–1
Order Number MM54HC138
or MM74HC138
TL F 5120 – 2
Truth Table
Inputs
Enable
G1
X
L
H
H
H
H
H
H
H
H
G2
H
X
L
L
L
L
L
L
L
L
Select
C
X
X
L
L
L
L
H
H
H
H
B
X
X
L
L
H
H
L
L
H
H
A
X
X
L
H
L
H
L
H
L
H
Y0
H
H
L
H
H
H
H
H
H
H
Y1
H
H
H
L
H
H
H
H
H
H
Y2
H
H
H
H
L
H
H
H
H
H
Y3
H
H
H
H
H
L
H
H
H
H
Y4
H
H
H
H
H
H
L
H
H
H
Y5
H
H
H
H
H
H
H
L
H
H
Y6
H
H
H
H
H
H
H
H
L
H
Y7
H
H
H
H
H
H
H
H
H
L
Outputs
G2
e
G2A
a
G2B
H
e
high level L
e
low level X
e
don’t care
C
1995 National Semiconductor Corporation
TL F 5120
RRD-B30M105 Printed in U S A
2)
If Military Aerospace specified devices are required
please contact the National Semiconductor Sales
Office Distributors for availability and specifications
b
0 5 to
a
7 0V
Supply Voltage (V
CC
)
DC Input Voltage (V
IN
)
DC Output Voltage (V
OUT
)
Clamp Diode Current (I
IK
I
OK
)
DC Output Current per pin (I
OUT
)
b
1 5 to V
CC
a
1 5V
b
0 5 to V
CC
a
0 5V
g
20 mA
g
25 mA
Absolute Maximum Ratings
(Notes 1
Operating Conditions
Supply Voltage (V
CC
)
DC Input or Output Voltage
(V
IN
V
OUT
)
Operating Temp Range (T
A
)
MM74HC
MM54HC
Input Rise or Fall Times
V
CC
e
2 0V
(t
r
t
f
)
V
CC
e
4 5V
V
CC
e
6 0V
Min
2
0
Max
6
V
CC
Units
V
V
b
40
b
55
a
85
a
125
C
C
ns
ns
ns
g
50 mA
DC V
CC
or GND Current per pin (I
CC
)
b
65 C to
a
150 C
Storage Temperature Range (T
STG
)
Power Dissipation (P
D
)
(Note 3)
600 mW
S O Package only
500 mW
Lead Temp (T
L
) (Soldering 10 seconds)
260 C
1000
500
400
DC Electrical Characteristics
(Note 4)
Symbol
Parameter
Conditions
V
CC
2 0V
4 5V
6 0V
2 0V
4 5V
6 0V
V
IN
e
V
IH
or V
IL
l
I
OUT
l
s
20
mA
2 0V
4 5V
6 0V
4 5V
6 0V
2 0V
4 5V
6 0V
4 5V
6 0V
6 0V
6 0V
20
45
60
42
57
0
0
0
02
02
T
A
e
25 C
Typ
V
IH
Minimum High Level
Input Voltage
Maximum Low Level
Input Voltage
Minimum High Level
Output Voltage
15
3 15
42
05
1 35
18
19
44
59
3 98
5 48
01
01
01
0 26
0 26
g
0 1
74HC
T
A
eb
40 to 85 C
Guaranteed Limits
15
3 15
42
05
1 35
18
19
44
59
3 84
5 34
01
01
01
0 33
0 33
g
1 0
54HC
T
A
eb
55 to 125 C
Units
15
3 15
42
05
1 35
18
19
44
59
37
52
01
01
01
04
04
g
1 0
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
mA
mA
V
IL
V
OH
V
IN
e
V
IH
or V
IL
l
I
OUT
l
s
4 0 mA
l
I
OUT
l
s
5 2 mA
V
OL
Maximum Low Level
Output Voltage
V
IN
e
V
IH
or V
IL
l
I
OUT
l
s
20
mA
V
IN
e
V
IH
or V
IL
l
I
OUT
l
s
4 0 mA
l
I
OUT
l
s
5 2 mA
I
IN
I
CC
Maximum Input
Current
Maximum Quiescent
Supply Current
V
IN
e
V
CC
or GND
V
IN
e
V
CC
or GND
I
OUT
e
0
mA
80
80
160
Note 1
Absolute Maximum Ratings are those values beyond which damage to the device may occur
Note 2
Unless otherwise specified all voltages are referenced to ground
Note 3
Power Dissipation temperature derating
plastic ‘‘N’’ package
b
12 mW C from 65 C to 85 C ceramic ‘‘J’’ package
b
12 mW C from 100 C to 125 C
Note 4
For a power supply of 5V
g
10% the worst case output voltages (V
OH
and V
OL
) occur for HC at 4 5V Thus the 4 5V values should be used when designing
with this supply Worst case V
IH
and V
IL
occur at V
CC
e
5 5V and 4 5V respectively (The V
IH
value at 5 5V is 3 85V ) The worst case leakage current (I
IN
I
CC
and
I
OZ
) occur for CMOS at the higher voltage and so the 6 0V values should be used
V
IL
limits are currently tested at 20% of V
CC
The above V
IL
specification (30% of V
CC
) will be implemented no later than Q1 CY’89
2
AC Electrical Characteristics
V
CC
e
5V
Symbol
t
PLH
t
PHL
t
PHL
t
PLH
t
PHL
Parameter
Maximum Propagation
Delay Binary Select to any Output
Maximum Propagation
Delay Binary Select to any Output
Maximum Propagation
Delay G1 to any Output
Maximum Propagation
Delay G2A or G2B to
Output
Maximum Propagation
Delay G2A or G2B to
Output
T
A
e
25 C C
L
e
15 pF t
r
e
t
f
e
6 ns
Typ
18
28
18
23
Guaranteed
Limit
25
35
25
30
Units
ns
ns
ns
ns
Conditions
t
PLH
18
25
ns
AC Electrical Characteristics
C
L
e
50 pF
Symbol
Parameter
Conditions
V
CC
t
r
e
t
f
e
6 ns (unless otherwise specified)
T
A
e
25 C
Typ
74HC
T
A
eb
40 to 85 C
54HC
T
A
eb
55 to 125 C
Units
Guaranteed Limits
150
30
26
200
40
34
150
30
26
175
35
30
150
30
26
75
15
13
10
189
38
32
252
50
43
189
38
32
221
44
37
189
38
32
95
19
16
10
224
45
38
298
60
51
224
45
38
261
52
44
224
45
38
110
22
19
10
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
pF
pF
t
PLH
Maximum Propagation
Delay Binary Select to
any Output Low to High
Maximum Propagation
Delay Binary Select to any
Output High to Low
Maximum Propagation
Delay G1 to any
Output
Maximum Propagation
Delay G2A or G2B to
Output
Maximum Propagation
Delay G2A or G2B to
Output
Output Rise and
Fall Time
Maximum Input
Capacitance
Power Dissipation
Capacitance
(Note 5)
2 0V
4 5V
6 0V
2 0V
4 5V
6 0V
2 0V
4 5V
6 0V
2 0V
4 5V
6 0V
2 0V
4 5V
6 0V
2 0V
4 5V
6 0V
75
15
13
100
20
17
75
15
13
82
28
22
75
15
13
30
8
7
3
75
t
PHL
t
PHL
t
PLH
t
PHL
t
PLH
t
TLH
t
THL
C
IN
C
PD
Note 5
C
PD
determines the no load dynamic power consumption P
D
e
C
PD
V
CC2
f
a
I
CC
V
CC
and the no load dynamic current consumption I
S
e
C
PD
V
CC
f
a
I
CC
3
MM54HC138 MM74HC138 3-to-8 Line Decoder
Physical Dimensions
inches (millimeters)
Order Number MM54HC138J or MM74HC138J
NS Package Number J16A
Order Number MM74HC138N
NS Package Number N16E
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