Semiconductor Components Industries, LLC, 2001
October, 2001 – Rev. 7 1Publication 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
TAOperating 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 SOIC–16 38 Units/Rail
SN74LS147DR2 SOIC–16 2500/Tape & Reel
SN74LS148N 16 Pin DIP 2000 Units/Box
SN74LS148D SOIC–16 38 Units/Rail
SN74LS148DR2 SOIC–16 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
D3219AVCC NC
14 13 12 11 10 9
123456 7
16 15
8
D321 9
A4
567 8C 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
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
XXXXXXXXLLHHL
XXXXXXXLHLHHH
XXXXXXLHHHLLL
XXXXXLHHHHLLH
XXXXLHHHHHLHL
XXXLHHHHHHLHH
XXLHHHHHHHHLL
XLHHHHHHHHHLH
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
LHHHHHHHH H HHH L
LXXXXXXXL L LLL H
LXXXXXXLH L LHL H
LXXXXXLHH L HL L H
LXXXXLHHH L HH L H
LXXXLHHHH H LLL H
LXXLHHHHH H LHL H
LXLHHHHHH 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
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 VGuaranteed 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
Out
p
ut 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
I
IH
Input HIGH Current
All Others
Inputs 1–7 (LS148) 20
40 µA VCC = MAX, VIN = 2.7 V
IIH
All Others
Inputs 1–7 (LS148) 0.1
0.2 mA VCC = MAX, VIN = 7.0 V
IIL Input LOW Current
All Others
Inputs 1–7 (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 C
L
= 15 pF,
tPLH
Any
Any
Out-of-phase 21 33
ns
CL
=
15
F
,
RL = 2.0 kΩ
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 kΩ
tPHL 0 thru 7 GS
In hase
output 9.0 21 ns
R
L =
2
.
0
kΩ
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
p
hase
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 648–08
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
FC
S
HGD
J
L
M
16 PL
SEATING
18
916
K
PLANE
–T–
M
A
M
0.25 (0.010) T
DIM MIN MAX MIN MAX
MILLIMETERSINCHES
A0.740 0.770 18.80 19.55
B0.250 0.270 6.35 6.85
C0.145 0.175 3.69 4.44
D0.015 0.021 0.39 0.53
F0.040 0.70 1.02 1.77
G0.100 BSC 2.54 BSC
H0.050 BSC 1.27 BSC
J0.008 0.015 0.21 0.38
K0.110 0.130 2.80 3.30
L0.295 0.305 7.50 7.74
M0 10 0 10
S0.020 0.040 0.51 1.01
SN74LS147, SN74LS148
http://onsemi.com
7
PACKAGE DIMENSIONS
D SUFFIX
PLASTIC SOIC PACKAGE
CASE 751B–05
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.
18
16 9
SEATING
PLANE
F
J
M
RX 45
G
8 PLP
–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
INCHESMILLIMETERS
A9.80 10.00 0.386 0.393
B3.80 4.00 0.150 0.157
C1.35 1.75 0.054 0.068
D0.35 0.49 0.014 0.019
F0.40 1.25 0.016 0.049
G1.27 BSC 0.050 BSC
J0.19 0.25 0.008 0.009
K0.10 0.25 0.004 0.009
M0 7 0 7
P5.80 6.20 0.229 0.244
R0.25 0.50 0.010 0.019
SN74LS147, SN74LS148
http://onsemi.com
8
ON Semiconductor and are trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes
without further notice to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular
purpose, nor does SCILLC assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability,
including without limitation special, consequential or incidental damages. “Typical” parameters which may be provided in SCILLC data sheets and/or
specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including “Typicals” must be
validated for each customer application by customer’s technical experts. SCILLC does not convey any license under its patent rights nor the rights of others.
SCILLC products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body , or other applications
intended to support or sustain life, or for any other application in which the failure of the SCILLC product could create a situation where personal injury or
death may occur. Should Buyer purchase or use SCILLC products for any such unintended or unauthorized application, Buyer shall indemnify and hold
SCILLC and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable
attorney fees arising out of, directly or indirectly , any claim of personal injury or death associated with such unintended or unauthori zed use, even if such claim
alleges that SCILLC was negligent regarding the design or manufacture of the part. SCILLC is an Equal Opportunity/Affirmative Action Employer.
PUBLICATION ORDERING INFORMATION
JAPAN: ON Semiconductor, Japan Customer Focus Center
4–32–1 Nishi–Gotanda, Shinagawa–ku, Tokyo, Japan 141–0031
Phone: 81–3–5740–2700
Email: r14525@onsemi.com
ON Semiconductor Website: http://onsemi.com
For additional information, please contact your local
Sales Representative.
SN74LS147/D
Literature Fulfillment:
Literature Distribution Center for ON Semiconductor
P.O. Box 5163, Denver, Colorado 80217 USA
Phone: 303–675–2175 or 800–344–3860 Toll Free USA/Canada
Fax: 303–675–2176 or 800–344–3867 Toll Free USA/Canada
Email: ONlit@hibbertco.com
N. American Technical Support: 800–282–9855 Toll Free USA/Canada
