MOTOROLA SN74LS147D, SN74LS147DR2, SN74LS147N, SN74LS148D, SN74LS148DR2 Datasheet
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Semiconductor Components Industries, LLC, 1999
December, 1999 – Rev. 6
1 Publication Order Number:
SN74LS147/D
SN74LS147 SN74LS148
10-Line-to-4-Line
and 8-Line-to-3-Line
Priority Encoders
The SN74LS147 and the SN74LS148 are Priority Encoders. They
provide priority decoding of the inputs to ensure that only the highest
order data line is encoded. Both devices have data inputs and outputs
which are active at the low logic level.
The LS147 encodes nine data lines to four-line (8-4-2-1) BCD. The
implied decimal zero condition does not require an input condition
because zero is encoded when all nine data lines are at a high logic
level.
The LS148 encodes eight data lines to three-line (4-2-1) binary
(octal). By providing cascading circuitry (Enable Input EI and Enable
Output EO) octal expansion is allowed without needing external
circuitry.
GUARANTEED OPERATING RANGES
Symbol Parameter Min Typ Max Unit
V
CC
Supply Voltage 4.75 5.0 5.25 V
T
A
Operating Ambient
T emperature Range
0 25 70 °C
I
OH
Output Current – High –0.4 mA
I
OL
Output Current – Low 8.0 mA
LOW
POWER
SCHOTTKY
Device Package Shipping
ORDERING INFORMATION
SN74LS147N 16 Pin DIP 2000 Units/Box
SN74LS147D 16 Pin
SOIC
D SUFFIX
CASE 751B
http://onsemi.com
2500/Tape & Reel
PLASTIC
N SUFFIX
CASE 648
16
1
16
1
SN74LS148N 16 Pin DIP
SN74LS148D 16 Pin
2000 Units/Box
2500/Tape & Reel
SN74LS147 SN74LS148
http://onsemi.com
2
SN74LS147
(TOP VIEW)
SN74LS148
(TOP VIEW)
4 5 6 7 8 C B GND
D3219AVCCNC
14 13 12 11 10 9
123456
7
16 15
8
D321 9
A4
5678CB
OUTPUT INPUTS OUTPUT
INPUTS OUTPUTS
4 5 6 7 E1 A2 A1 GND
V
CC
EO GS 3 2 1 0 A0
14 13 12 11 10 9
123456
7
16 15
8
EO GS 3 2 1 0
A04
56 7EIA2A1
OUTPUTS
INPUTS OUTPUT
INPUTS OUTPUTS
SN74LS147 SN74LS148
http://onsemi.com
3
SN74LS147
FUNCTION TABLE
INPUTS OUTPUTS
1 2 3 4 5 6 7 8 9 D C B A
H H H H H H H H H H H H H
X XXXXXXXLLHHL
X XXXXXXLHLHHH
X XXXXXLHHHLLL
X XXXXLHHHHLLH
X XXXLHHHHHLHL
X XXLHHHHHHLHH
X XLHHHHHHHHLL
X LHHHHHHHHHLH
L H H H H H H H H H H H L
SN74LS148
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 HHHHHHHH H HHH L
L XXXXXXXL L LL L H
L XXXXXXLH L LH L H
L XXXXXLHH L HL L H
L XXXXLHHH L HH L H
L XXXLHHHH H LLL H
L XXLHHHHH H LHL H
L XLHHHHHH H HL L H
L L H H H H H H H H H H L H
H = HIGH Logic Level, L = LOW Logic Level, X = Irrelevant
FUNCTIONAL BLOCK DIAGRAMS
SN74LS147 SN74LS148
1
2
3
4
5
6
7
8
9
(11)
(12)
(13)
(1)
(2)
(3)
(4)
(5)
(10)
(9)
(7)
(6)
(14)
A
B
C
D
0
1
2
3
4
5
6
7
EI
(10)
(11)
(12)
(13)
(1)
(2)
(3)
(4)
(5)
(15)
EO
(14)
GS
(8)
A0
(7)
A1
(6)
A2
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