Hi Ti,
I am using UCC27511 as a PFC MOSFET gate driver and we found an issue during AC cycling,
during AC cycling (264Vac/63hz on-stage 3s, off-state 10ms), PFC MOSFET VGS will have few-cycle and did not reach fully on-state voltage level.
Please refer to the file as attach, also UCC27511 OUTH and OUTL have a different voltage level in the meantime.UCC27511 waveform.docx