Tool/software:
Does the UCC28951 clamp or pull down the CS pin once the peak current is detected? I have a generic spice simulation (open loop, without the controller) showing the CS signal does not go to zero after the peak; there is a DC offset in the signal. It appears this is due to the freewheeling current in the transformer primary that is preventing the CS signal from going to zero. When I measure in the lab, I do see the signal go to zero before the current starts ramping up again at the next power phase. The only way I can explain this is if the UCC28951 controller pulls down on the CS pin after the peak current is detected. If this is so, what is the pull down impedance in the UCC28951?
