I have designed the charger circuit for Vin - 135 to 200V and Vout = 130V to 200V for two CC 0.1A and 0.5A. The charger working well with with MOSFET PN: STP13NK60Z for both the CC modes. over the input and output voltages. Due to thermal issue at 0.5A CC, I have changed it to PN: IPP65R190CFD7A. In this case the UCC28740 doesn't start and goes into the protection mode (VDD ramps up and down between VDDon and VDDoff thresholds).
May I know which parameter might be affecting the controller to get to protection mode. And what need to be changed.?.