Phase Locked Loop

[Charles Linquis]

I didn't see the attachment at first.

A few years ago, I "wrote" a PLL implementation that I used for a heart rate monitor. It does a good job of pulling out the hear beat rate in the presece of noise.

If I get any time at all in the next few days, I'll see if it looks suitable for your application.

[amgen]

if sensing zero crossing with an interrupt, how about keep checking that the xing pin or voltage sense pin stays at changed condition for .5 milli sec or 1 milli sec before starting timing firing counter. That should filter noise spikes and you only loose a few percent of phase control at top end due to delay from checking ?

don
amgen