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TL/F/6365
54LS42/DM54LS42/DM74LS42 BCD/Decimal Decoders
June 1989
54LS42/DM54LS42/DM74LS42 BCD/Decimal Decoders
General Description
These BCD-to-decimal decoders consist of eight inverters
and ten, four-input NAND gates. The inverters are connected in pairs to make BCD input data available for decoding
by the NAND gates. Full decoding of input logic ensures
that all outputs remain off for all invalid (10 –15) input conditions.
Features
Y
Diode clamped inputs
Y
Also for applications as 4-line-to-16-line decoders; 3line-to-8-line decoders
Y
All outputs are high for invalid input conditions
Y
Alternate Military/Aerospace device (54LS42) is available. Contact a National Semiconductor Sales Office/
Distributor for specifications.
Connection Diagram
Dual-In-Line Package
TL/F/6365– 1
Order Number 54LS42DMQB, 54LS42FMQB,
DM54LS42J, DM54LS42W, DM74LS42M or DM74LS42N
See NS Package Number J16A, M16A, N16E or W16A
Function Table
No.
BCD Inputs Decimal Outputs
DCBA0123456789
0 L L L L LHHHHHHHHH
1 L L L HHL HHHHHHHH
2 L LHL HHL HHHHHHH
3 L LHHHHHL HHHHHH
4 LH L L HHHHL HHHHH
5 LH LHHHHHHL HHHH
6 LHHLHHHHHHLHHH
7 LHHHHHHHHHH LHH
8 H L L L HHHHHHHHL H
9 H L LHHHHHHHHHHL
I
HL HLHHHHHHHHHH
N
HL HHHHHHHHHHHH
V
HHL LHHHHHHHHHH
A
HHL HHHHHHHHHHH
L
HHHL HHHHHHHHHH
I
HHHHHHHHHHHHHH
D
HeHigh Level
L
e
Low Level
Logic Diagram
TL/F/6365– 2
C
1995 National Semiconductor Corporation RRD-B30M105/Printed in U. S. A.
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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§Ctoa125§C
DM74LS 0
§
Ctoa70§C
Storage Temperature Range
b
65§Ctoa150§C
Note:
The ‘‘Absolute Maximum Ratings’’ are those values
beyond which the safety of the device cannot be guaranteed. 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
DM54LS42 DM74LS42
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
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
eb
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 mA
I
IL
Low Level Input Current V
CC
e
Max, V
I
e
0.4V
b
0.4 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) 7 13 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 open and all inputs grounded.
2
Page 3
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
2kX
Symbol Parameter
To (Output)
C
L
e
15 pF C
L
e
50 pF Units
Min Max Min Max
t
PHL
Propagation Delay Time A, B, C, or D (2 Levels
25 30 ns
High to Low Level Output of Logic) to Output
t
PHL
Propagation Delay Time A, B, C, or D (3 Levels
30 35 ns
High to Low Level Output of Logic) to Output
t
PLH
Propagation Delay Time A, B, C, or D (2 Levels
25 30 ns
Low to High Level Output of Logic) to Output
t
PLH
Propagation Delay Time A, B, C, or D (3 Levels
30 35 ns
Low to High Level Output of Logic) to Output
3
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Physical Dimensions inches (millimeters)
16-Lead Ceramic Dual-In-Line Package (J)
Order Number 54LS42DMQB or DM54LS42J
NS Package Number J16A
4
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Physical Dimensions inches (millimeters) (Continued)
16-Lead Small Outline Molded Package (M)
Order Number DM74LS42M
NS Package Number M16A
16-Lead Molded Dual-In-Line Package (N)
Order Number DM74LS42N
NS Package Number N16E
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54LS42/DM54LS42/DM74LS42 BCD/Decimal Decoders
Physical Dimensions inches (millimeters) (Continued)
16-Lead Ceramic Flat Package (W)
Order Number 54LS42FMQB or DM54LS42W
NS Package Number W16A
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