Single-Phase PLL

Are you trying to make a homemade Grid Tie Inverter system?

It always depends on the response time and precision you are looking for.

If slow is OK, you can filter the AC and use a zero crossing with very little hysteresis to generate a nice square wave used for the phase comparator. Of course, the following filter will be very slow as it will only get valid phase info twice per cycle. It will have some phase jitter.

Good luck

Actually am working on single phase active filter and to provide syncrhonisation with grid i need single pha PLL efficent mehtod.

I want to write this PLL in my software only...