I'm back with another question about the LM5070. I recently posted my schematic here (
) as I was having some issues with it. I now noticed that there is some noise on the output 3.3V line to the extent where my devices downstream were resetting periodically. Looking closer I noticed the SS line was restarting about twice a second for some reason, so the entire LM5070 was restarting rapidly. I finally traced this down to a voltage on VCC raising to about 20V (absolute max is 16V and target is around 12V). When I removed the resistor/diode combo from the secondary winding of the transformer (as supplying voltage to VCC is optional), everything seemed to work fine. What might cause this voltage to increase to 20V? I'd like to reattach the secondary at some stage, as efficiency is very important for my design.
Thanks!
