Hi TI,
I am designing a custom circuit for the UCC28740 that takes universal AC input and outputs 35.7VDC@0.6A. When testing with a very light load, the supply takes a while to start regulating the output, but eventually starts after ~30 seconds. Attaching a scope probe across the AUX winding seems to help speed up the startup. I have increased VDD to twice the value specified by Webench, but should I increase this even more? What could are some reasons why the supply doesn't start regulating after a while. Is the output capacitance too large?
Thanks for the help,
Bryan Grant