CD74HC4518, CD74HC4520,
CD74HCT4520
Data sheet acquired from Harris Semiconductor
SCHS216
November 1997
High Speed CMOS Logic
Dual Synchronous Counters
Description
The Harris CD74HC4518 is a dual BCD up-counter. The
Harris CD74HC4520 and CD74HCT4520 are dual binary
up-counters. Each device consists of two independent
internally synchronous 4-stage counters. The counter stages
are D-type 鏗俰p-鏗俹ps having interchangeable CLOCK and
ENABLE lines for incrementing on either the positive-going
or the negative-going transition of CLOCK. The counters are
cleared by high levels on the MASTER RESET lines. The
counter can be cascaded in the ripple mode by connecting
Q
3
to the ENABLE input of the subsequent counter while the
CLOCK input of the latter is held low.
Features
鈥?Positive or Negative Edge Triggering
[ /Title
(CD74
HC451
8,
CD74
HC452
0,
CD74
HCT45
20)
/Sub-
ject
鈥?Synchronous Internal Carry Propagation
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
CD74HC4518E
CD74HC4520E
CD74HCT4520E
CD74HC4520M
CD74HCT4520M
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
-55 to 125
PACKAGE
16 Ld PDIP
16 Ld PDIP
16 Ld PDIP
16 Ld SOIC
16 Ld SOIC
PKG.
NO.
E16.3
E16.3
E16.3
M16.15
M16.15
Pinout
CD74HC4518
CD74HC4520, CD74HCT4520
(PDIP, SOIC)
TOP VIEW
1CP 1
1E 2
1Q
0
3
1Q
1
4
1Q
2
5
1Q
3
6
1MR 7
GND 8
16 V
CC
15 2MR
14 2Q
3
13 2Q
2
12 2Q
1
11 2Q
0
10 2E
9 2CP
CAUTION: These devices are sensitive to electrostatic discharge. Users should follow proper IC Handling Procedures.
Copyright
漏
Harris Corporation 1997
File Number
1665.1
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