Datasheet

54LS42 DM54LS42 DM74LS42 BCD Decimal Decoders
General Description

Features

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

Y

ConnectionDiagram

Function Table

Y

Y
Y

Diode clamped inputs
Also for applications as 4-line-to-16-line decoders 3line-to-8-line decoders
All outputs are high for invalid input conditions
Alternate Military Aerospace device (54LS42) is available Contact a National Semiconductor Sales Office
Distributor for specifications

Dual-In-Line Package
No

BCD Inputs

Decimal Outputs

D

A0

1

2

L
L
L
L
L

L
L
L
L
H

L
L
H
H
L

L
H
L
H
L

L
H
H
H
H

H
L
H
H
H

HHHHHHHH
HHHHHHHH
LHHHHHHH
HLHHHHHH
HHLHHHHH

5
6
7
8
9

TL F 6365 – 1

B

0
1
2
3
4

Order Number 54LS42DMQB 54LS42FMQB
DM54LS42J DM54LS42W DM74LS42M or DM74LS42N
See NS Package Number J16A M16A N16E or W16A

C

3

L
L
L
H
H

H
H
H
L
L

LH
H
L
L

H
L
H
L
H

HH
HH
HH
HH
HH

HHHL
HHHH
HHHH
HHHH
HHHH

HHHH
LHHH
HLHH
HHLH
HHHL

I
N
V
A
L
I
D

H
H
H
H
H
H

L
L
H
H
H
H

H
H
L
L
H
H

L
H
L
H
L
H

HH
HH
HH
HH
HH
HH

H
H
H
H
H
H

H
H
H
H
H
H

H
H
H
H
H
H

4

H
H
H
H
H
H

5

H
H
H
H
H
H

6

7

H
H
H
H
H
H

8

H
H
HH
H
H

9

H
H
H
H
H
H

H e High Level
L e Low Level

Logic Diagram

TL F 6365 – 2
C1995 National Semiconductor Corporation

TL F 6365

RRD-B30M105 Printed in U S A

54LS42 DM54LS42 DM74LS42 BCD Decimal Decoders

June 1989

Absolute Maximum Ratings (Note)
Note The ‘‘Absolute Maximum Ratings’’ are those values
beyond which the safety of the device cannot beguaranteed 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

If Military Aerospace specified devices are required
please contact the National Semiconductor Sales
OfficeDistributors for availability and specifications
Supply Voltage
7V
Input Voltage
7V
Operating Free Air Temperature Range
b 55 C to a 125 C
DM54LS and 54LS
DM74LS
0 C to a 70 C
Storage Temperature Range

b 65 C to a 150 C

Recommended Operating Conditions
Symbol

DM54LS42

Parameter

DM74LS42

Units

Min

VIL

Free Air Operating Temperature

55

4 75

5

5 25

V08

V

b0 4

mA

8

mA

70

C

Low Level Output Current

TA

5

High Level Output Current

IOL

Max

Low Level Input Voltage

IOH

Nom

b0 4

High Level Input Voltage

Min

07

Supply Voltage

VIH

Max

45

VCC

Nom

Electrical Characteristics
Symbol

2

2

V

4
b 55

125

0

over recommended operating free air temperaturerange (unless otherwise noted)

Parameter

Min

Typ
(Note 1)

DM54

25

34

DM74

27

34

Conditions

Max

Units

b1 5

V

VI

Input Clamp Voltage

VCC e Min II e b18 mA

VOH

High Level Output
Voltage

VCC e Min IOH e Max
VIL e Max VIH e Min

Low Level Output
Voltage

VCC e Min IOL e Max
VIL e Max VIH e Min

DM54

0 25

04

DM74

0 35

05IOL e 4 mA VCC e Min

DM74

0 25

04

VOL

VCC e Max VI e 7V

V

II

Input Current
Input Voltage

IIH

High Level Input Current

VCC e Max VI e 2 7V

20

mA

IIL

Low Level Input Current

VCC e Max VI e 0 4V

b0 4

mA

IOS

Short Circuit
Output Current

VCC e Max
(Note 2)

Supply Current

VCC e Max (Note 3)

ICC

Max

V

01

DM54...