SN54HC42, SN74HC42
4-LINE TO 10-LINE DECODERS (1 of 10)
SCLS091B – DECEMBER 1982 – REVISED MAY 1997
SN54HC42 . . . J OR W PACKAGE
SN74HC42 . . . D OR N PACKAGE
(TOP VIEW)
Full Decoding of Input Logic
All Outputs Are High for Invalid BCD
Conditions
0
V
A
B
Also for Applications as 3-Line to 8-Line
Decoders
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
CC
1
2
Package Options Include Plastic
Small-Outline (D) and Ceramic Flat (W)
Packages, Ceramic Chip Carriers (FK), and
Standard Plastic (N) and Ceramic (J)
300-mil DIPs
3
C
D
9
4
5
6
8
GND
7
description
SN54HC42 . . . FK PACKAGE
(TOP VIEW)
These monolithic decimal decoders consist of
eight inverters and ten 4-input NAND gates. The
inverters are connected in pairs to make BCD
input data available for decoding by the NAND
gates. Full decoding of valid input logic ensures
that all inputs remain off for all invalid input
conditions.
3
2
1
20 19
18
B
2
3
4
5
6
7
8
C
17
16
15
14
NC
D
NC
4
The SN54HC42 is characterized for operation
over the full military temperature range of –55°C
to 125°C. The SN74HC42 is characterized for
operation from –40°C to 85°C.
9
5
9 10 11 12 13
NC – No internal connection
FUNCTION TABLE
INPUTS
OUTPUTS
NO.
D
L
C
B
L
A
L
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
L
L
L
H
L
H
H
L
H
H
H
L
H
H
H
H
L
H
H
H
H
H
L
H
H
H
H
H
H
L
H
H
H
H
H
H
H
L
H
H
H
H
H
H
H
H
L
H
H
H
H
H
H
H
H
H
L
L
L
H
L
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
L
L
H
H
L
H
H
H
H
H
H
H
H
H
H
H
H
H
H
L
L
H
L
H
H
H
H
H
H
H
H
H
H
H
H
H
L
H
H
H
H
L
H
H
H
H
H
H
H
H
H
H
H
H
L
L
H
L
H
H
H
H
H
H
H
H
H
H
H
L
H
H
L
H
H
H
H
H
H
H
H
H
H
L
H
L
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
L
L
H
L
H
H
H
H
H
H
H
L
H
H
L
H
H
H
H
H
H
L
H
L
H
H
H
H
Invalid
L
H
L
H
H
H
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
Copyright 1997, Texas Instruments Incorporated
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
1
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