Intriguing issue: while running a module with UCC28710D, using a convenient 650v GaN device ( from Transphorm, same $), with only 10W operation- but has 2 outputs thnx to very tightly controlled transformer( lkg ~1uH)- so both outputs appear well regulated. The second output is 18V, about 300mA.
DC input never was above 180V during this testing.
the failure came out to be the controller HV pin to GND.
Any idea how to add protection for the controller?WBDesign25_28710_6v2_350mA.pdf
I am following a Web-bench-designed circuit..
Pl see attached