Other Parts Discussed in Thread: UCC2818A, UCC2818
Hi again,
I tried to supply the IC with a solution similar to the one at pag.11 of the UCC2818A-Q1 datasheet: startup resistors + auxiliary winding on the boost inductor.
The differences from my circuit and the one at pag.11 are:
1) I used a half-wave rectifier (diode + cap 1uF) instead of a voltage doubler.
2) I placed a 15V zener diode after the 100R resistor because I'm not sure the UCC2818A has one inside.
Result: the IC is supplied and the boost converter works, but I made some measures and seems that half of the supply current flows on the startup resistors even after the startup.
I didn't find any application note about the design of this supply circuit, could someone help me?
Regards,
Marco