Semiconductor Components Industries, LLC, 2001
October, 2001 Rev. 7
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
VCC
Supply Voltage
4.75
5.0
5.25
V
TA
Operating Ambient
Temperature Range
0
25
70
C
IOH
Output Current High
0.4
mA
IOL
Output Current Low
8.0
mA
LOW
POWER
SCHOTTKY
SOIC
D SUFFIX
CASE 751B
PLASTIC
N SUFFIX
CASE 648
16
1
16
1
Device
Package
Shipping
ORDERING INFORMATION
SN74LS147N
16 Pin DIP
2000 Units/Box
SN74LS147D
SOIC16
38 Units/Rail
SN74LS147DR2
SOIC16
2500/Tape & Reel
SN74LS148N
16 Pin DIP
2000 Units/Box
SN74LS148D
SOIC16
38 Units/Rail
SN74LS148DR2
SOIC16
2500/Tape & Reel
http://onsemi.com
SN74LS147, SN74LS148
http://onsemi.com
2
SN74LS147
(TOP VIEW)
SN74LS148
(TOP VIEW)
4
5
6
7
8
C
B
GND
D
3
2
1
9
A
VCC NC
14
13
12
11
10
9
1
2
3
4
5
6
7
16
15
8
D
3
2
1
9
A
4
5
6
7
8
C
B
OUTPUT
INPUTS
OUTPUT
INPUTS
OUTPUTS
4
5
6
7
E1
A2
A1 GND
VCC EO GS
3
2
1
0
A0
14
13
12
11
10
9
1
2
3
4
5
6
7
16
15
8
EO
GS
3
2
1
0
A0
4
5
6
7
EI
A2
A1
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
X
X
X
X
X
X
X
L
L
H
H
L
X
X
X
X
X
X
X
L
H
L
H
H
H
X
X
X
X
X
X
L
H
H
H
L
L
L
X
X
X
X
X
L
H
H
H
H
L
L
H
X
X
X
X
L
H
H
H
H
H
L
H
L
X
X
X
L
H
H
H
H
H
H
L
H
H
X
X
L
H
H
H
H
H
H
H
H
L
L
X
L
H
H
H
H
H
H
H
H
H
L
H
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
H
H
H
H
H
H
H
H
H
H
H
H
L
L
X
X
X
X
X
X
X
L
L
L
L
L
H
L
X
X
X
X
X
X
L
H
L
L
H
L
H
L
X
X
X
X
X
L
H
H
L
H
L
L
H
L
X
X
X
X
L
H
H
H
L
H
H
L
H
L
X
X
X
L
H
H
H
H
H
L
L
L
H
L
X
X
L
H
H
H
H
H
H
L
H
L
H
L
X
L
H
H
H
H
H
H
H
H
L
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
SN74LS147, SN74LS148
http://onsemi.com
4
DC CHARACTERISTICS OVER OPERATING TEMPERATURE RANGE
(unless otherwise specified)
Limits
Symbol
Parameter
Min
Typ
Max
Unit
Test Conditions
VIH
Input HIGH Voltage
2.0
V
Guaranteed Input HIGH Voltage for
All Inputs
VIL
Input LOW Voltage
0.8
V
Guaranteed Input LOW Voltage for
All Inputs
VIK
Input Clamp Diode Voltage
0.65
1.5
V
VCC = MIN, IIN = 18 mA
VOH
Output HIGH Voltage
2.7
3.5
V
VCC = MIN, IOH = MAX, VIN = VIH
or VIL per Truth Table
VOL
Output LOW Voltage
0.25
0.4
V
IOL = 4.0 mA
VCC = VCC MIN,
VIN VIL or VIH
VOL
Output LOW Voltage
0.35
0.5
V
IOL = 8.0 mA
VIN = VIL or VIH
per Truth Table
IIH
Input HIGH Current
All Others
Inputs 17 (LS148)
20
40
A
VCC = MAX, VIN = 2.7 V
IIH
All Others
Inputs 17 (LS148)
0.1
0.2
mA
VCC = MAX, VIN = 7.0 V
IIL
Input LOW Current
All Others
Inputs 17 (LS148)
0.4
0.8
mA
VCC = MAX, VIN = 0.4 V
IOS
Short Circuit Current (Note 1)
20
100
mA
VCC = MAX
ICCH
Power Supply Current Output HIGH
17
mA
VCC = MAX, All Inputs = 4.5 V
ICCL
Output LOW
20
mA
VCC = MAX, Inputs 7 & E1 = GND
All Other Inputs = 4.5 V
Note 1: Not more than one output should be shorted at a time, nor for more than 1 second.
SN74LS147, SN74LS148
http://onsemi.com
5
AC CHARACTERISTICS
(VCC = 5.0 V, TA = 25
C)
SN74LS147
From
To
Limits
Symbol
From
(Input)
To
(Output)
Waveform
Min
Typ
Max
Unit
Test Conditions
tPLH
Any
Any
In-phase
12
18
ns
tPHL
Any
Any
In hase
output
12
18
ns
CL = 15 pF,
tPLH
Any
Any
Out-of-phase
21
33
ns
CL = 15 F,
RL = 2.0 k
tPHL
Any
Any
Out of hase
output
15
23
ns
SN74LS148
From
To
Limits
Symbol
From
(Input)
To
(Output)
Waveform
Min
Typ
Max
Unit
Test Conditions
tPLH
1 thru 7
A0 A1 or A2
In-phase
14
18
ns
tPHL
1 thru 7
A0, A1, or A2
In hase
output
15
25
ns
tPLH
1 thru 7
A0 A1 or A2
Out-of-phase
20
36
ns
tPHL
1 thru 7
A0, A1, or A2
Out of hase
output
16
29
ns
tPLH
0 thru 7
EO
Out-of-phase
7.0
18
ns
tPHL
0 thru 7
EO
Out of hase
output
25
40
ns
tPLH
0 thru 7
GS
In-phase
35
55
ns
CL = 15 pF,
RL = 2.0 k
tPHL
0 thru 7
GS
In hase
output
9.0
21
ns
RL = 2.0 k
tPLH
EI
A0 A1 or A2
In-phase
16
25
ns
tPHL
EI
A0, A1, or A2
In hase
output
12
25
ns
tPLH
EI
GS
In-phase
12
17
ns
tPHL
EI
GS
In hase
output
14
36
ns
tPLH
In phase
12
21
tPHL
EI
EO
In-phase
output
28
30
40
45
ns
(LS148)
SN74LS147, SN74LS148
http://onsemi.com
6
PACKAGE DIMENSIONS
N SUFFIX
PLASTIC PACKAGE
CASE 64808
ISSUE R
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.
2. CONTROLLING DIMENSION: INCH.
3. DIMENSION L TO CENTER OF LEADS WHEN
FORMED PARALLEL.
4. DIMENSION B DOES NOT INCLUDE MOLD FLASH.
5. ROUNDED CORNERS OPTIONAL.
A
B
F
C
S
H
G
D
J
L
M
16 PL
SEATING
1
8
9
16
K
PLANE
T
M
A
M
0.25 (0.010)
T
DIM
MIN
MAX
MIN
MAX
MILLIMETERS
INCHES
A
0.740
0.770
18.80
19.55
B
0.250
0.270
6.35
6.85
C
0.145
0.175
3.69
4.44
D
0.015
0.021
0.39
0.53
F
0.040
0.70
1.02
1.77
G
0.100 BSC
2.54 BSC
H
0.050 BSC
1.27 BSC
J
0.008
0.015
0.21
0.38
K
0.110
0.130
2.80
3.30
L
0.295
0.305
7.50
7.74
M
0
10
0
10
S
0.020
0.040
0.51
1.01
_
_
_
_
SN74LS147, SN74LS148
http://onsemi.com
7
PACKAGE DIMENSIONS
D SUFFIX
PLASTIC SOIC PACKAGE
CASE 751B05
ISSUE J
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.
2. CONTROLLING DIMENSION: MILLIMETER.
3. DIMENSIONS A AND B DO NOT INCLUDE
MOLD PROTRUSION.
4. MAXIMUM MOLD PROTRUSION 0.15 (0.006)
PER SIDE.
5. DIMENSION D DOES NOT INCLUDE DAMBAR
PROTRUSION. ALLOWABLE DAMBAR
PROTRUSION SHALL BE 0.127 (0.005) TOTAL
IN EXCESS OF THE D DIMENSION AT
MAXIMUM MATERIAL CONDITION.
1
8
16
9
SEATING
PLANE
F
J
M
R
X 45
_
G
8 PL
P
B
A
M
0.25 (0.010)
B
S
T
D
K
C
16 PL
S
B
M
0.25 (0.010)
A
S
T
DIM
MIN
MAX
MIN
MAX
INCHES
MILLIMETERS
A
9.80
10.00
0.386
0.393
B
3.80
4.00
0.150
0.157
C
1.35
1.75
0.054
0.068
D
0.35
0.49
0.014
0.019
F
0.40
1.25
0.016
0.049
G
1.27 BSC
0.050 BSC
J
0.19
0.25
0.008
0.009
K
0.10
0.25
0.004
0.009
M
0
7
0
7
P
5.80
6.20
0.229
0.244
R
0.25
0.50
0.010
0.019
_
_
_
_
SN74LS147, SN74LS148
http://onsemi.com
8
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SN74LS147/D
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