Hi
I am designing a 120W PFC using a Texas instument UCC28051 controller. The converter works as it should when I look at the output voltage, which is about 396 V, but when I look at the current through the inductor it looks like the controller enters some kind of burst mode?!
You can see a plot of the inductor current (green) and gate signal (yellow) below, during a 50 Hz cycle, the converter was delivering 60 watt to a load when the plot was made:
Has anyone seen a PFC behave this way before and know why it behaves as it does?
Regards