54F 74F138 1-of-8 Decoder Demultiplexer
November 1994
54F 74F138
1-of-8 Decoder Demultiplexer
General Description
The ’F138 is a high-speed 1-of-8 decoder demultiplexer
This device is ideally suited for high-speed bipolar memory
chip select address decoding The multiple input enables
allow parallel expansion to a 1-of-24 decoder using just
three ’F138 devices or a 1-of-32 decoder using four ’F138
devices and one inverter
Features
Y
Y
Y
Y
Demultiplexing capability
Multiple input enable for easy expansion
Active LOW mutually exclusive outputs
Guaranteed 4000V minimum ESD protection
Commercial
74F138PC
Military
Package
Number
N16E
Package Description
16-Lead (0 300 Wide) Molded Dual-In-Line
16-Lead Ceramic Dual-In-Line
16-Lead (0 150 Wide) Molded Small Outline JEDEC
16-Lead (0 300 Wide) Molded Small Outline EIAJ
16-Lead Cerpack
20-Lead Ceramic Leadless Chip Carrier Type C
54F138DM (Note 2)
74F138SC (Note 1)
74F138SJ (Note 1)
54F138FM (Note 2)
54F138LM (Note 2)
J16A
M16A
M16D
W16A
E20A
Note 1
Devices also available in 13 reel Use suffix
e
SCX and SJX
Note 2
Military grade device with environmental and burn-in processing Use suffix
e
DMQB FMQB and LMQB
Logic Symbols
Connection Diagrams
Pin Assignment for DIP
SOIC and Flatpak
Pin Assignment
for LCC
TL F 9478–3
IEEE IEC
TL F 9478 – 1
TL F 9478 – 2
TL F 9478–6
TRI-STATE is a registered trademark of National Semiconductor Corporation
C
1995 National Semiconductor Corporation
TL F 9478
RRD-B30M75 Printed in U S A
Unit Loading Fan Out
54F 74F
Pin Names
Description
UL
HIGH LOW
10 10
10 10
10 10
50 33 3
Input I
IH
I
IL
Output I
OH
I
OL
20
mA
b
0 6 mA
20
mA
b
0 6 mA
20
mA
b
0 6 mA
b
1 mA 20 mA
A
0
– A
2
E
1
E
2
E
3
O
0
– O
7
Address Inputs
Enable Inputs (Active LOW)
Enable Input (Active HIGH)
Outputs (Active LOW)
Functional Description
The ’F138 high-speed 1-of-8 decoder demultiplexer ac-
cepts three binary weighted inputs (A
0
A
1
A
2
) and when
enabled provides eight mutually exclusive active LOW out-
puts (O
0
–O
7
) The ’F138 features three Enable inputs two
active LOW (E
1
E
2
) and one active HIGH (E
3
) All outputs
will be HIGH unless E
1
and E
2
are LOW and E
3
is HIGH
This multiple enable function allows easy parallel expansion
of the device to a 1-of-32 (5 lines to 32 lines) decoder with
just four ’F138 devices and one inverter (See
Figure 1
) The
’F138 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 appropriate
active HIGH or active LOW state
Truth Table
Inputs
E
1
H
X
X
L
L
L
L
L
L
L
L
E
2
X
H
X
L
L
L
L
L
L
L
L
E
3
X
X
L
H
H
H
H
H
H
H
H
A
0
X
X
X
L
H
L
H
L
H
L
H
A
1
X
X
X
L
L
H
H
L
L
H
H
A
2
X
X
X
L
L
L
L
H
H
H
H
O
0
H
H
H
L
H
H
H
H
H
H
H
O
1
H
H
H
H
L
H
H
H
H
H
H
O
2
H
H
H
H
H
L
H
H
H
H
H
Outputs
O
3
H
H
H
H
H
H
L
H
H
H
H
O
4
H
H
H
H
H
H
H
L
H
H
H
O
5
H
H
H
H
H
H
H
H
L
H
H
O
6
H
H
H
H
H
H
H
H
H
L
H
O
7
H
H
H
H
H
H
H
H
H
H
L
H
e
HIGH Voltage Level
L
e
LOW Voltage Level
X
e
Immaterial
2
Logic Diagram
TL F 9478 – 4
Please note that this diagram is provided only for the understanding of logic operations and should not be used to estimate propagation delays
3
Absolute Maximum Ratings
(Note 1)
If Military Aerospace specified devices are required
please contact the National Semiconductor Sales
Office Distributors for availability and specifications
Storage Temperature
Ambient Temperature under Bias
Junction Temperature under Bias
Plastic
V
CC
Pin Potential to
Ground Pin
b
65 C to
a
150 C
b
55 C to
a
125 C
b
55 C to
a
175 C
b
55 C to
a
150 C
b
0 5V to
a
7 0V
Recommended Operating
Conditions
Free Air Ambient Temperature
Military
Commercial
Supply Voltage
Military
Commercial
b
55 C to
a
125 C
0 C to
a
70 C
a
4 5V to
a
5 5V
a
4 5V to
a
5 5V
b
0 5V to
a
7 0V
Input Voltage (Note 2)
b
30 mA to
a
5 0 mA
Input Current (Note 2)
Voltage Applied to Output
in HIGH State (with V
CC
e
0V)
b
0 5V to V
CC
Standard Output
b
0 5V to
a
5 5V
TRI-STATE Output
Current Applied to Output
in LOW State (Max)
twice the rated I
OL
(mA)
ESD Last Passing Voltage (Min)
4000V
Note 1
Absolute maximum ratings are values beyond which the device may
be damaged or have its useful life impaired Functional operation under
these conditions is not implied
Note 2
Either voltage limit or current limit is sufficient to protect inputs
DC Electrical Characteristics
Symbol
V
IH
V
IL
V
CD
V
OH
Parameter
Min
Input HIGH Voltage
Input LOW Voltage
Input Clamp Diode Voltage
Output HIGH
Voltage
Output LOW
Voltage
Input HIGH
Current
Input HIGH Current
Breakdown Test
Output HIGH
Leakage Current
Input Leakage
Test
Output Leakage
Circuit Current
Input LOW Current
Output Short-Circuit Current
Power Supply Current
Power Supply Current
b
60
54F 74F
Typ
Max
Units
V
08
b
1 2
V
CC
Conditions
Recognized as a HIGH Signal
Recognized as a LOW Signal
20
V
V
V
Min
Min
I
IN
e b
18 mA
I
OH
e b
1 mA
I
OH
e b
1 mA
I
OH
e b
1 mA
I
OL
e
20 mA
I
OL
e
20 mA
V
IN
e
2 7V
V
IN
e
7 0V
V
OUT
e
V
CC
I
ID
e
1 9
mA
All Other Pins Grounded
V
IOD
e
150 mV
All Other Pins Grounded
V
IN
e
0 5V
V
OUT
e
0V
V
O
e
HIGH
V
O
e
LOW
54F 10% V
CC
74F 10% V
CC
74F 5% V
CC
54F 10% V
CC
74F 10% V
CC
54F
74F
54F
74F
54F
74F
74F
74F
25
25
27
05
05
20 0
50
100
70
250
50
4 75
3 75
b
0 6
b
150
V
OL
I
IH
I
BVI
I
CEX
V
ID
I
OD
I
IL
I
OS
I
CCH
I
CCL
V
mA
mA
mA
V
mA
mA
mA
mA
mA
Min
Max
Max
Max
00
00
Max
Max
Max
Max
13
13
20
20
4
AC Electrical Characteristics
74F
Symbol
Parameter
Min
t
PLH
t
PHL
t
PLH
t
PHL
t
PLH
t
PHL
Propagation Delay
A
n
to O
n
Propagation Delay
E
1
or E
2
to O
n
Propagation Delay
E
3
to O
n
35
40
35
30
40
35
T
A
e a
25 C
V
CC
e a
5 0V
C
L
e
50 pF
Typ
56
61
54
53
62
56
Max
75
80
70
70
80
75
54F
T
A
V
CC
e
Mil
C
L
e
50 pF
Min
30
40
30
30
35
35
Max
12 0
95
11 0
80
12 5
85
74F
T
A
V
CC
e
Com
C
L
e
50 pF
Min
35
40
35
30
40
35
Max
85
90
80
75
90
85
ns
ns
ns
Units
Fig
No
F
–3
F
–4
F
–4
TL F 9478 – 5
FIGURE 1 Expansion to 1-of-32 Decoding
Ordering Information
The device number is used to form part of a simplified purchasing code where the package type and temperature range are
defined as follows
74F
Temperature Range Family
74F
e
Commercial
54F
e
Military
Device Type
Package Code
P
e
Plastic DIP
D
e
Ceramic DIP
F
e
Flatpak
L
e
Leadless Chip Carrier (LCC)
S
e
Small Outline SOIC JEDEC
SJ
e
Small Outline SOIC EIAJ
138
S
C
X
Special Variations
QB
e
Military grade device with
environmental and burn-in
processing
X
e
Devices shipped in 13 reel
Temperature Range
C
e
Commercial (0 C to
a
70 C)
M
e
Military (
b
55 C to
a
125 C)
5
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