I want to design 25V and 3.5A LED driver by TOP250YN.
I know how PI get feedback from voltage and hw pi do this by TL431, but how could I limit the current to 3.5A and constant the current on 3.5A?
I read DER136 but I couldnt understand how you get feedback from the output current and give it to led of optocoupler to constant the current to a value.
I also dont know what kind of feedback I should give to control pin (C) to have constant current?
Do you have any suggested circuite for make constant current for TOP250YN ?
PI Expert design is in attachment
Thanks in advansed
Dr. Al Sam