2024年6月15日发(作者：瑞文静)
SN54147, SN54148, SN54LS147, SN54LS148
SN74147, SN74148 (TIM9907), SN74LS147, SN74LS148
10ĆLINE TO 4ĆLINE AND 8ĆLINE TO 3ĆLINE PRIORITY ENCODERS
SDLS053B − OCTOBER 1976 − REVISED MAY 2004
D
D
’147, ’LS147
Encode 10-Line Decimal to 4-Line BCD
Applications Include:
− Keyboard Encoding
− Range Selection
D
D
’148, ’LS148
Encode 8 Data Lines to 3-Line Binary
(Octal)
Applications Include:
− n-Bit Encoding
− Code Converters and Generators
SN54147, J OR W PACKAGE
SN74147, D OR N PACKAGE
(TOP VIEW)
SN54148, J OR W PACKAGE
SN74148, D, N, OR NS PACKAGE
(TOP VIEW)
4
5
6
7
8
C
B
GND
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
V
CC
NC
D
3
2
1
9
A
4
5
6
7
EI
A2
A1
GND
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
V
CC
E0
GS
3
2
1
0
A0
FK PACKAGE
(TOP VIEW)
FK PACKAGE
(TOP VIEW)
54
N
C
V
C
C
N
C
6
7
NC
8
C
4
5
6
7
8
3212019
18
17
16
15
14
910111213
54
N
C
V
C
C
E
0
D
3
NC
2
1
6
7
NC
EI
A2
4
5
6
7
8
3212019
18
17
16
15
14
910111213
GS
3
NC
2
1
B
G
N
D
N
C
A
9
NC − No internal connection
TYPICAL
DATA
DELAY
10 ns
10 ns
15 ns
15 ns
TYPICAL
POWER
DISSIPATION
225 mW
190 mW
60 mW
60 mW
TYPE
’147
’148
’LS147
’LS148
NOTE:The SN54147, SN54LS147, SN54148, SN74147, SN74LS147, and SN74148 are obsolete and are no longer supplied.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
TexasInstruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
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.
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
•
A
1
G
N
D
N
C
A
0
0
Copyright 2004, Texas Instruments Incorporated
On products compliant to MILĆPRFĆ38535, all parameters are tested
unless otherwise noted. On all other products, production
processing does not necessarily include testing of all parameters.
1
SDLS053B − OCTOBER 1976 − REVISED MAY 2004
SN54147, SN54148, SN54LS147, SN54LS148
SN74147, SN74148 (TIM9907), SN74LS147, SN74LS148
10ĆLINE TO 4ĆLINE AND 8ĆLINE TO 3ĆLINE PRIORITY ENCODERS
description/ordering information
These TTL encoders feature priority decoding of the inputs to ensure that only the highest-order data line is
encoded. The ’147 and ’LS147 devices encode nine data lines to four-line (8-4-2-1) BCD. The implied decimal
zero condition requires no input condition, as zero is encoded when all nine data lines are at a high logic level.
The ’148 and ’LS148 devices encode eight data lines to three-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. For all types, data inputs and outputs are active at the low logic level. All inputs are buffered to represent
one normalized Series 54/74 or 54/74LS load, respectively.
ORDERING INFORMATION
T
A
PDIP − N
0°C to 70°CSOIC − D
SOP − NS
CDIP − J
−55°C to 125°C
CFP − W
LCCC − FK
PACKAGE
†
Tube
Tube
Tape and reel
Tape and reel
Tube
Tube
Tube
ORDERABLE
PART NUMBER
SN74LS148N
SN74LS148D
SN74LS148DR
SN74LS148NSR
SNJ54LS148J
SNJ54LS148W
SNJ54LS148FK
TOP-SIDE
MARKING
SN74LS148N
LS148
74LS148
SNJ54LS148J
SNJ54LS148W
SNJ54LS148FK
†
Package drawings, standard packing quantities, thermal data, symbolization, and PCB design guidelines are
available at /sc/package.
FUNCTION TABLE − ’147, ’LS147
INPUTS
1
H
X
X
X
X
X
X
X
X
L
2
H
X
X
X
X
X
X
X
L
H
3
H
X
X
X
X
X
X
L
H
H
4
H
X
X
X
X
X
L
H
H
H
5
H
X
X
X
X
L
H
H
H
H
6
H
X
X
X
L
H
H
H
H
H
7
H
X
X
L
H
H
H
H
H
H
8
H
X
L
H
H
H
H
H
H
H
9
H
L
H
H
H
H
H
H
H
H
D
H
L
L
H
H
H
H
H
H
H
OUTPUTS
C
H
H
H
L
L
L
L
H
H
H
B
H
H
H
L
L
H
H
L
L
H
A
H
L
H
L
H
L
H
L
H
L
H = high logic level, L = low logic level, X = irrelevant
2
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
•
2024年6月15日发(作者：瑞文静)
SN54147, SN54148, SN54LS147, SN54LS148
SN74147, SN74148 (TIM9907), SN74LS147, SN74LS148
10ĆLINE TO 4ĆLINE AND 8ĆLINE TO 3ĆLINE PRIORITY ENCODERS
SDLS053B − OCTOBER 1976 − REVISED MAY 2004
D
D
’147, ’LS147
Encode 10-Line Decimal to 4-Line BCD
Applications Include:
− Keyboard Encoding
− Range Selection
D
D
’148, ’LS148
Encode 8 Data Lines to 3-Line Binary
(Octal)
Applications Include:
− n-Bit Encoding
− Code Converters and Generators
SN54147, J OR W PACKAGE
SN74147, D OR N PACKAGE
(TOP VIEW)
SN54148, J OR W PACKAGE
SN74148, D, N, OR NS PACKAGE
(TOP VIEW)
4
5
6
7
8
C
B
GND
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
V
CC
NC
D
3
2
1
9
A
4
5
6
7
EI
A2
A1
GND
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
V
CC
E0
GS
3
2
1
0
A0
FK PACKAGE
(TOP VIEW)
FK PACKAGE
(TOP VIEW)
54
N
C
V
C
C
N
C
6
7
NC
8
C
4
5
6
7
8
3212019
18
17
16
15
14
910111213
54
N
C
V
C
C
E
0
D
3
NC
2
1
6
7
NC
EI
A2
4
5
6
7
8
3212019
18
17
16
15
14
910111213
GS
3
NC
2
1
B
G
N
D
N
C
A
9
NC − No internal connection
TYPICAL
DATA
DELAY
10 ns
10 ns
15 ns
15 ns
TYPICAL
POWER
DISSIPATION
225 mW
190 mW
60 mW
60 mW
TYPE
’147
’148
’LS147
’LS148
NOTE:The SN54147, SN54LS147, SN54148, SN74147, SN74LS147, and SN74148 are obsolete and are no longer supplied.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
TexasInstruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
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.
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
•
A
1
G
N
D
N
C
A
0
0
Copyright 2004, Texas Instruments Incorporated
On products compliant to MILĆPRFĆ38535, all parameters are tested
unless otherwise noted. On all other products, production
processing does not necessarily include testing of all parameters.
1
SDLS053B − OCTOBER 1976 − REVISED MAY 2004
SN54147, SN54148, SN54LS147, SN54LS148
SN74147, SN74148 (TIM9907), SN74LS147, SN74LS148
10ĆLINE TO 4ĆLINE AND 8ĆLINE TO 3ĆLINE PRIORITY ENCODERS
description/ordering information
These TTL encoders feature priority decoding of the inputs to ensure that only the highest-order data line is
encoded. The ’147 and ’LS147 devices encode nine data lines to four-line (8-4-2-1) BCD. The implied decimal
zero condition requires no input condition, as zero is encoded when all nine data lines are at a high logic level.
The ’148 and ’LS148 devices encode eight data lines to three-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. For all types, data inputs and outputs are active at the low logic level. All inputs are buffered to represent
one normalized Series 54/74 or 54/74LS load, respectively.
ORDERING INFORMATION
T
A
PDIP − N
0°C to 70°CSOIC − D
SOP − NS
CDIP − J
−55°C to 125°C
CFP − W
LCCC − FK
PACKAGE
†
Tube
Tube
Tape and reel
Tape and reel
Tube
Tube
Tube
ORDERABLE
PART NUMBER
SN74LS148N
SN74LS148D
SN74LS148DR
SN74LS148NSR
SNJ54LS148J
SNJ54LS148W
SNJ54LS148FK
TOP-SIDE
MARKING
SN74LS148N
LS148
74LS148
SNJ54LS148J
SNJ54LS148W
SNJ54LS148FK
†
Package drawings, standard packing quantities, thermal data, symbolization, and PCB design guidelines are
available at /sc/package.
FUNCTION TABLE − ’147, ’LS147
INPUTS
1
H
X
X
X
X
X
X
X
X
L
2
H
X
X
X
X
X
X
X
L
H
3
H
X
X
X
X
X
X
L
H
H
4
H
X
X
X
X
X
L
H
H
H
5
H
X
X
X
X
L
H
H
H
H
6
H
X
X
X
L
H
H
H
H
H
7
H
X
X
L
H
H
H
H
H
H
8
H
X
L
H
H
H
H
H
H
H
9
H
L
H
H
H
H
H
H
H
H
D
H
L
L
H
H
H
H
H
H
H
OUTPUTS
C
H
H
H
L
L
L
L
H
H
H
B
H
H
H
L
L
H
H
L
L
H
A
H
L
H
L
H
L
H
L
H
L
H = high logic level, L = low logic level, X = irrelevant
2
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
•