SLUAAH3 October 2021 UCC28056
An OVP2 comparator with a fixed threshold (VOvp2Th) monitors the ZCD/CS pin voltage during the TDCH period. A fixed blanking period (TOvp2Blk) is applied after the falling edge of the DRV waveform to ensure that the OVP2 comparator is not tripped by inductive spikes on the leading edge of the drain waveform.
The waveform in Figure 4-3 shows the controller entering into OVP2.