Philips 74HCT147N, 74HCT147U, 74HC147U, 74HC147N, 74HC147DB Datasheet

DATA SH EET
Product specification File under Integrated Circuits, IC06
December 1990
INTEGRATED CIRCUITS
74HC/HCT147
10-to-4 line priority encoder
For a complete data sheet, please also download:
The IC06 74HC/HCT/HCU/HCMOS Logic Package Outlines
December 1990 2
Philips Semiconductors Product specification
10-to-4 line priority encoder 74HC/HCT147
FEATURES
Encodes 10-line decimal to 4-line BCD
Useful for 10-position switch encoding
Used in code converters and generators
Output capability: standard
ICCcategory: MSI
GENERAL DESCRIPTION
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.
The 74HC/HCT147 9-input priority encoders accept data from nine active LOW inputs (A0to A8) and provide a binary representation on the four active LOW outputs (Y0to Y3). A priority is assigned to each input so that when two or more inputs are simultaneously active, the input with the highest priority is represented on the output, with input line A8having 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.
QUICK REFERENCE DATA
GND = 0 V; T
amb
= 25 °C; tr= tf= 6 ns
Notes
1. C
PD
is used to determine the dynamic power dissipation (PDin µW):
PD= CPD× V
CC
2
× fi+∑(CV
CC
2
× fo) where: fi= input frequency in MHz fo= output frequency in MHz (CV
CC
2
× fo) = sum of outputs CL= output load capacitance in pF VCC= supply voltage in V
2. For HC the condition is VI= GND to V
CC
For HCT the condition is VI= GND to VCC− 1.5 V
ORDERING INFORMATION
See
“74HC/HCT/HCU/HCMOS Logic Package Information”
.
SYMBOL PARAMETER CONDITIONS
TYPICAL
UNIT
HC HCT
t
PHL
/ t
PLH
propagation delay Anto Y
n
CL= 15 pF; VCC= 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
December 1990 3
Philips Semiconductors Product specification
10-to-4 line priority encoder 74HC/HCT147
PIN DESCRIPTION
PIN NO. SYMBOL NAME AND FUNCTION
8 GND ground (0 V) 9, 7, 6, 14
Y0to Y3BCD address outputs (active LOW)
11, 12, 13, 1, 2, 3, 4, 5, 10
A0to A8decimal 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.
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