I am trying to implement a rectifier with PFC boost converter using TI controller UCC28180D. Since this IC works only in closed loop and CCM, I have put some bulb load which has resistance 67 Ohms. For the sake of initial protection, I used another bulb in place of fuse in series of AC supply. The circuit works but not so smooth, some times PWM pulses available, sometimes not. This may be because the 5V feedback is not able to establish due to large drop at the supply side series bulb. When I exclude the series bulb in the input side and turn the supply (230V AC) on the MOSFET blows and also the controller IC together. This maybe due to inrush current or smaller boost inductor value, but I am using an NTC resistor of 5 Ohm in series and inductor size much bigger than the computed value. I am really not able to understand why mosfet is blowing off just at the turning on instant. Can somebody help me out?