Offline fly back converter design using NCP1250

[Balaji1998]

I used NCP1250 for my Fly-back converter design, similar like this when in without load its turning on and when I connect 1.2A load its going to hiccup mode (Designed for 2A). Even I used less load then recommended. Then the next time when I am powering on VCC voltage maintains 5V and switching not happening(its latched). also I connected OPP pin to ground.

is there any fault?

 

[Harald Kapp]

similar like this

Like what?
Please show us a schematic diagram of your circuit.

 

[Balaji1998]

Oh sorry i forgot to upload schematic