74HC148
器件描述：8-LINE TO 3-LINE PRIORITY ENCODERS
器件厂商：TI [Texas Instruments]
厂商主页：http://www.ti.com/
文件大小：127.38KB，共8页
Sponsor by e络盟器件资料摘要：
SN54HC148, SN74HC148
8-LINE TO 3-LINE PRIORITY ENCODERS
SCLS109D – MARCH 1984 – REVISED MAY 1997
1POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
C0068 Encode Eight Data Lines to 3-Line Binary
(Octal)
C0068 Applications Include:
– n-Bit Encoding
– Code Converters and Generators
C0068 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
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
need for external circuitry. Data inputs and outputs
are active at the low logic level.
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.
FUNCTION TABLE
INPUTS OUTPUTS
EI 0 1 2 3 4 5 6 7 A2 A1 A0 GS EO
H X X X X X X X X H H H H H
L H HHHHHHHHHHHL
L X XXXXXXLLLLLH
L X XXXXXLHLLHLH
L X XXXXLHHLHLLH
L X XXXLHHHLHHLH
L X XXLHHHHHLLLH
L X XLHHHHHHLHLH
L X LHHHHHHHHLLH
L L H H H H H H H H H H L 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.
3212019
910111213
4
5
6
7
8
18
17
16
15
14
GS
3
NC
2
1
6
7
NC
EI
A2
5 4 NC
A0
0
V EO
A1
GND
NC
SN54HC148 . . . FK PACKAGE
(TOP VIEW)
CC
NC – No internal connection
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
4
5
6
7
EI
A2
A1
GND
V
CC
EO
GS
3
2
1
0
A0
SN54HC148 ...J OR W PACKAGE
SN74HC148 . . . D OR N PACKAGE
(TOP VIEW)
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.
8-LINE TO 3-LINE PRIORITY ENCODERS
SCLS109D – MARCH 1984 – REVISED MAY 1997
1POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
C0068 Encode Eight Data Lines to 3-Line Binary
(Octal)
C0068 Applications Include:
– n-Bit Encoding
– Code Converters and Generators
C0068 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
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
need for external circuitry. Data inputs and outputs
are active at the low logic level.
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.
FUNCTION TABLE
INPUTS OUTPUTS
EI 0 1 2 3 4 5 6 7 A2 A1 A0 GS EO
H X X X X X X X X H H H H H
L H HHHHHHHHHHHL
L X XXXXXXLLLLLH
L X XXXXXLHLLHLH
L X XXXXLHHLHLLH
L X XXXLHHHLHHLH
L X XXLHHHHHLLLH
L X XLHHHHHHLHLH
L X LHHHHHHHHLLH
L L H H H H H H H H H H L 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.
3212019
910111213
4
5
6
7
8
18
17
16
15
14
GS
3
NC
2
1
6
7
NC
EI
A2
5 4 NC
A0
0
V EO
A1
GND
NC
SN54HC148 . . . FK PACKAGE
(TOP VIEW)
CC
NC – No internal connection
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
4
5
6
7
EI
A2
A1
GND
V
CC
EO
GS
3
2
1
0
A0
SN54HC148 ...J OR W PACKAGE
SN74HC148 . . . D OR N PACKAGE
(TOP VIEW)
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.