Dear Teng,
I would like to understand little more on the below points.
1. as you said the R21 and R22 will influence the system configuration how far? What would be the output regulation if I use direct feedback instead of opto-coupler.
My circuit does not need isolation.
2. What is the purpose of ZCD and DRV pin connected to Vcc circuit.
Thanks in advance.
Warm regards,
Sakthivishnu
