Programmable Digital Timer circuit

Programmable Digital Timer circuit
A positive pulse on MASTER RESET resets the counters
and latch. The output goes high and remains high until the
number of pulses, selected by A and B, are counted. This
circuit is retriggerable and is as accurate as the input frequency.
If additional accuracy is desired, an external clock
can be used on pin 3. A setup time equal to the width of the
one-shot output is required immediately following initial
power up, during which time the output will be high.
f =1/(2.3 RtcCtc)
A = 0, B = 0 , COUNT = 8192
A = 0, B = 1 , COUNT = 1024
A = 1, B = 0 , COUNT = 256
A = 1, B = 1 , COUNT = 65535
t = COUNT / f

CD4541B
CMOS Programmable TimerHigh Voltage Types (20V Rating)
Description
CD4541B programmable timer consists of a 16-stage binary
counter, an oscillator that is controlled by external R-C components
(2 resistors and a capacitor), an automatic power-on
reset circuit, and output control logic. The counter increments
on positive-edge clock transitions and can also be reset via the
MASTER RESET input
Datasheet