detect if a pulse train has an irregular pulse intervals

[pankaj jha]

Hi
I have a pulse train. I have to detect whether the pulses are coming at regular intervals or irregular intervals (just yes or no).

Can anyone suggest a simple analog circuit based solution for the same??

 

[betwixt]

It depends on how big the pulses are and the maximimum/minimum intervals between them. Probably the simplest method would be a PLL, you can use the lock detection to see if the frequency has shifted.

Brian.

 

[d123]

Hi.

The 555 timer can be configured as a missing pulse detector, it appears in quite a few of the datasheets in the "typical applications" section.

 

[chuckey]

The spec. is a bit vague. Are you talking about a constant width pulse but with irregular spaces between them? A constant on/off period for the pulses but of different repetition rate. Or the inverse of the first one, constant space , variable ones. Or pulses just missing in a constant pulse train. Also what sort of errors? .01% of the pulses missing ?, 30%?
Frank

 

[D.A.(Tony)Stewart]

Start with specs.
Normal pulse interval range.
Abnormal interval min/max

Then use dual precision one-shot IC to detect missing or extra pulses with 2 circuits.
Setup pulse on each one shot for min & max tolerance.
If pulse input occurs during active state of non-retriggerable 1shot for MIN pulse interval then "extra pulse." from AND function
Use retrigerable 1shot for MAX interval and if it times out then " missing pulse"

 

[D.A.(Tony)Stewart]

or did you want to measure the interval deviation?
then use a PLL and monitor the phase detector.