We are using UCC27710 to drive a synchronous buck converter with a bus voltage of 65V and Max load output current 5A at the lowest output voltage of 12V. We have failures on the IC alone when the buck converter transitions from no load to higher load (during transient response from open circuit to load). We believe that the high di/dt and dv/dt is causing the failure but we are properly driving the IC using the right gate resistors and an RC snubber to eliminate this effect. Any suggestions on how to solve this issue, I am thinking of a soft start PWM to gradually increase the load current. in steady state the operation is not affected.
upon looking on the scope on the HO on a damaged IC the HO is locked in HI. A PIN to PIN impedance measurement comparison between a damaged and good IC does not show any damaged pin