Tool/software:
I tried capturing the voltage across the MOSFET using trigger. I could only get the waveforms during the start of the converter. The waveforms did not show any voltage spike across the MOSFET which could damage the MOSFET. However, the MOSFET, sense resistor, gate resistor, and controller IC got damaged. While going through the PCB layout, I could find sensed voltage across the current sense resistor track crossing the gate signal track. Different grounds are not connected in a single star-point way. Resistor in low pass filter for current sense signal was approximately 2-3 cm far from the capacitor. Could it be possible that the flyback converter is getting damaged because of overcurrent due to the malfunction of internal comparator of the controller IC. The sensed signal from the current sense resistor is getting distorted because of the noisy gate signal?
