My customer have the below questions.
1. What conditions it will turn off the AVDD and internal MOSFET of the FB pin?
2. The IFB typical value of UCC256403 is 164uA, if the IFB current is over the value, may I know to have any side effects?
3. The CTR of the Opto-coupler(BPC-1009SC) is 200~400%, based on the below circuit, the current(If) flowing into the Opto-coupler, what are the values of minimum and maximum?