Data sheet acquired from Harris Semiconductor
SCHS149
CD74HC147,
CD74HCT147
High Speed CMOS Logic
10-to-4 Line Priority Encoder
Description
The Harris CD74HC147and CD74HCT147 are high speed
silicon-gate CMOS devices and are pin-compatible with low
power Schottky TTL (LSTTL).
The CD74HC147 and CD74HCT147 9-input priority
encoders accept data from nine active LOW inputs (l
1
to l
9
)
and provide binary representation on the four active LOW
inputs (Y0 to 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 l
9
having the highest priority.
These devices provide the 10-line to 4-line priority encoding
function by use of the implied decimal 鈥渮ero鈥? The 鈥渮ero鈥?is
encoded when all nine data inputs are HIGH, forcing all four
outputs HIGH.
September 1997
[ /Title
(CD74
HC147
,
CD74
HCT14
7)
/Sub-
ject
(High
Speed
CMOS
Logic
10-to-4
Line
Prior-
ity
Encode
r)
/Autho
r ()
/Key-
words
(High
Speed
CMOS
Logic
10-to-4
Line
Prior-
ity
Encode
r, High
Speed
CMOS
Logic
10-to-4
Line
Prior-
ity
Features
鈥?Buffered Inputs and Outputs
鈥?Typical Propagation Delay: 13ns at V
CC
= 5V,
C
L
= 15pF, T
A
= 25
o
C
鈥?Fanout (Over Temperature Range)
- Standard Outputs . . . . . . . . . . . . . . . 10 LSTTL Loads
- Bus Driver Outputs . . . . . . . . . . . . . 15 LSTTL Loads
鈥?Wide Operating Temperature Range . . . -55
o
C to 125
o
C
鈥?Balanced Propagation Delay and Transition Times
鈥?Signi鏗乧ant Power Reduction Compared to LSTTL
Logic ICs
鈥?HC Types
- 2V to 6V Operation
- High Noise Immunity: N
IL
= 30%, N
IH
= 30% of V
CC
at V
CC
= 5V
鈥?HCT Types
- 4.5V to 5.5V Operation
- Direct LSTTL Input Logic Compatibility,
V
IL
= 0.8V (Max), V
IH
= 2V (Min)
- CMOS Input Compatibility, I
l
鈮?/div>
1碌A(chǔ) at V
OL
, V
OH
Ordering Information
PART NUMBER
CD74HC147E
CD74HCT147E
CD74HC147M
CD74HCT147M
NOTES:
1. When ordering, use the entire part number. Add the suf鏗亁 96 to
obtain the variant in the tape and reel.
2. Wafer or die for this part number is available which meets all elec-
trical specifications. Please contact your local sales office or
Harris customer service for ordering information.
TEMP. RANGE (
o
C)
-55 to 125
-55 to 125
-55 to 125
-55 to 125
PACKAGE
16 Ld PDIP
16 Ld PDIP
16 Ld SOIC
16 Ld SOIC
PKG.
NO.
E16.3
E16.3
M16.15
M16.15
Pinout
CD74HC147, CD74HCT147
(PDIP, SOIC)
TOP VIEW
I4 1
I5 2
I6 3
I7 4
I8 5
Y2 6
Y1 7
GND 8
16 V
CC
15 NC
14 Y3
13 I3
12 I2
11 I1
10 I9
9 Y0
CAUTION: These devices are sensitive to electrostatic discharge. Users should follow proper IC Handling Procedures.
Copyright
漏
Harris Corporation 1997
File Number
1773.1
1
1
2
3
4
5
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