SN54HC148, SN74HC148
8-LINE TO 3-LINE PRIORITY ENCODERS
SCLS109D – MARCH 1984 – REVISED MAY 1997
SN54HC148 . . . J OR W PACKAGE
SN74HC148 . . . D OR N PACKAGE
(TOP VIEW)
Encode Eight Data Lines to 3-Line Binary
(Octal)
Applications Include:
– n-Bit Encoding
– Code Converters and Generators
4
5
V
CC
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
EO
GS
3
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
6
7
EI
2
A2
A1
GND
1
0
A0
description
The ’HC148 feature priority decoding of the inputs
to ensure that only the highest-order data line is
encoded. These devices encode eight data lines
to 3-line (4-2-1) binary (octal). Cascading circuitry
(enable input EI and enable output EO) has been
provided to allow octal expansion without the
needforexternalcircuitry. Datainputsandoutputs
are active at the low logic level.
SN54HC148 . . . FK PACKAGE
(TOP VIEW)
3
2
1
20 19
18
GS
3
6
7
4
5
6
7
8
17
16
15
14
NC
2
NC
EI
The SN54HC148 is characterized for operation
over the full military temperature range of –55°C
to 125°C. The SN74HC148 is characterized for
operation from –40°C to 85°C.
1
A2
9 10 11 12 13
NC – No internal connection
FUNCTION TABLE
INPUTS
OUTPUTS
EI
H
L
0
X
H
X
X
X
X
X
X
1
X
H
X
X
X
X
X
X
2
X
H
X
X
X
X
X
L
3
X
H
X
X
X
X
L
4
X
H
X
X
X
L
5
X
H
X
X
L
6
X
H
X
L
7
X
H
L
A2
H
H
L
A1
H
H
L
A0
H
H
L
GS
H
H
L
EO
H
L
L
H
H
H
H
H
H
L
H
H
H
H
H
L
L
H
L
L
L
H
H
H
H
L
H
H
L
L
L
H
H
H
L
H
L
L
L
H
H
H
H
L
L
H
L
H
L
L
L
X
L
L
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
L
L
L
H
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
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265