74HC_HCT147_CNV_2.pdf

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10-to-4 line priority encoder
INTEGRATED CIRCUITS
DATA SHEET
For a complete data sheet, please also download:
·
The IC06 74HC/HCT/HCU/HCMOS Logic Family Specifications
·
The IC06 74HC/HCT/HCU/HCMOS Logic Package Information
·
The IC06 74HC/HCT/HCU/HCMOS Logic Package Outlines
74HC/HCT147
10-to-4 line priority encoder
Product specification
File under Integrated Circuits, IC06
December 1990
21700842.006.png
Philips Semiconductors
Product specification
10-to-4 line priority encoder
74HC/HCT147
FEATURES
GENERAL DESCRIPTION
·
Encodes 10-line decimal to 4-line BCD
The 74HC/HCT147 are high-speed Si-gate CMOS devices
and are pin compatible with low power Schottky TTL
(LSTTL). They are specified in compliance with JEDEC
standard no. 7A.
·
Useful for 10-position switch encoding
·
Used in code converters and generators
·
Output capability: standard
The 74HC/HCT147 9-input pri o rity en coders accept data
from nine active LOW inputs (A 0 to A 8 ) and provide a
bin ary re presentation on the four active LOW outputs
(Y 0 to Y 3 ). A priority is assigned to each input so that when
two or more inputs are simultaneously active, the input
with the h ig hest priority is represented on the output, with
input line A 8 having the highest priority.
The devices provide the 10-line to 4-line priority encoding
function by use of the implied decimal “zero”. The “zero” is
encoded when all nine data inputs are HIGH, forcing all
four outputs HIGH.
·
I CC category: MSI
QUICK REFERENCE DATA
GND = 0 V; T amb = 25
°
C; t r = t f = 6 ns
TYPICAL
SYMBOL
PARAMETER
CONDITIONS
UNIT
HC
HCT
t PHL / t PLH
propagation delay A n to Y n
C L = 15 pF; V CC = 5 V 15
17
ns
C I
input capacitance
3.5
3.5
pF
C PD
power dissipation capacitance per package notes 1 and 2
30
33
pF
Notes
1. C PD is used to determine the dynamic power dissipation (P D in
m
W):
P D = C PD ´ V CC 2
´ f i +å (C L ´ V CC 2
´ f o ) where:
´ f o ) = sum of outputs
C L = output load capacitance in pF
V CC = supply voltage in V
2. For HC the condition is V I = GND to V CC
For HCT the condition is V I = GND to V CC -
f i = input frequency in MHz
f o = output frequency in MHz
å (C L ´ V CC 2
1.5 V
ORDERING INFORMATION
See “74HC/HCT/HCU/HCMOS Logic Package Information” .
December 1990
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Philips Semiconductors
Product specification
10-to-4 line priority encoder
74HC/HCT147
PIN DESCRIPTION
PIN NO.
SYMBOL NAME AND FUNCTION
8
G ND
ground (0 V)
9, 7, 6, 14
Y 0 to Y 3
BCD address outputs (active LOW)
11, 12, 13, 1, 2, 3, 4, 5, 10
A 0 to A 8
decimal data inputs (active LOW)
15
n.c.
not connected
16
V CC
positive supply voltage
Fig.1 Pin configuration.
Fig.2 Logic symbol.
Fig.3 IEC logic symbol.
December 1990
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Philips Semiconductors
Product specification
10-to-4 line priority encoder
74HC/HCT147
Fig.4 Functional diagram.
FUNCTION TABLE
INPUTS
OUTPUTS
A 0
A 1
A 2
A 3
A 4
A 5
A 6
A 7
A 8
Y 3
Y 2
Y 1
Y 0
H
H
H
H
H
H
H
H
H
H
H
H
H
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
L
X
X
L
H
X
L
H
H
L
H
H
H
L
L
H
H
H
H
L
L
H
H
L
L
L
H
L
H
X
X
X
X
X
X
X
L
X
X
L
H
X
L
H
H
L
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
L
L
H
H
H
H
L
L
L
H
L
H
L
H
H
H
H
H
H
H
H
H
H
H
L
Notes
1. H = HIGH voltage level
L = LOW voltage level
X = don’t care
December 1990
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Philips Semiconductors
Product specification
10-to-4 line priority encoder
74HC/HCT147
Fig.5 Logic diagram.
December 1990
5
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