Non isolated feedback for GX family

Posted by: sijulal on 07/26/2012

Hi,

Would like to know whether a simple divider network of 5.8 can be directly given to the control pin as feed back in case of non isolated designs using GX family devices.

Thanks & Regadrs

Comments

This is not recommended as this will give poor regulation since the C-pin pin controls as a function of current. It is better to sense primary aux feeback with a zener and low value resitor in series (12V zener with 100 ohm in series would be good) to keep tight regulation.

Thanks for the information provided. Could you please suggest any other way to provide feedback form the output side with out using an opto in the case of a non isolated requirement. As you said if we are sensing from the aux winding i am not able to get a very good regulation. What I need is to sense the output itself to provide a non isolate feedback. Please help.

Thanks & Regards

Those are really the only options for TOPSwitch. For winding feedback method you can improve it somewhat by closely coupling bias winding (feedback winding) near output winding layer