Electronic Device And Electronic Circuit

Data of electronic device , PCB Design and electronic circuit

Web basicelectronic.blogspot.com

Thursday, July 06, 2006

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

CMOS Programmable TimerHigh Voltage Types (20V Rating)
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