HCF4521B Datasheet, PDF (1/12 Pages) STMicroelectronics – 24 STAGE FREQUENCY DIVIDER

®
HCF4521B
24 STAGE FREQUENCY DIVIDER
s VERY LOW QUIESCENT CURRENT
s HIGH NOISE IMMUNITY
s VOLTAGE SUPPLY RANGE 3V TO 18V
s ALL STAGES ARE RESETTABLE
s RESET DISABLES THE RC OSCILLATORFOR
LOW STANDBY POWER DRAIN
s RC AND CRYSTAL OSCILLATOR OUTPUT
ARE CAPABLE OF DRIVING EXTERNAL
LOADS
DESCRIPTION
The HCF4521B is a monolithic integrated circuit,
available in 16-lead dual-in-line plastic package
and plastic micro packages.
The HCF4521B have a chain of 24 flip-flops with
an input circuit that allows three modes of
operation. The input circuit functions as a crystal
or an RC oscillator or as an input buffer for an
external oscillator. Each flip-flop performs a
divide-by-two function giving a total count of 2²⁴ =
16,777,216. The count advances on the negative
going edge of the clock. Access is available to the
final seven stages giving the device added
flexibility.
EY
(Plastic Package)
M1
(Micro Package)
ORDER CODES :
HCF4521BEY
HCF4521BM1
PIN CONNECTION
February 1999
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