HCF4521B

24 STAGE FREQUENCY DIVIDER

®

February 1999

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 OSCILLATOR FOR

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 2

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.

PIN CONNECTION

M1

(Micro Package)

EY

(Plastic Package)

ORDER CODES :

HCF4521BEY

HCF4521BM1

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