I am using the DRV8353HRTAT to implement a 45 Hz trapezoidal drive waveform with a 4-MOSFET H-bridge to drive a specific load, so I'm only using 4 of the 6 outputs. The trapezoid waveform is created by using 57kHz PWM to generate 2ms ramp up and ramp down intervals of the waveform, and the H-bridge is solid high/low or low/high during the non-ramp portions of the waveform. The circuit works very well up to 50V, but above 50V I am damaging the DRV8353. The MOSFETs seem unharmed. Once damaged, I am seeing a near short to ground on SHA (roughly 40 ohms to ground). Thinking it was the low-side MOSFET, I lifted the source pin on the FET and still saw the same near short. That confirmed it was the IC and not the FET that was damaged. Once the IC is damaged, it must be replaced to get the board working again.
I am using VM = 24V, and Vdrain I can set to 24V or vary between 43V and 85V. When Vdrain gets above 50V is when I see damage occurring to the IC.
On one of the boards that I damaged, I actually heard and saw a tiny explosion on the DRV. Visual examination showed a tiny crater on the IC near pin 5, which is VCP. On this particular board, VCP is shorted to ground after this damage and I'm also seeing the typical near short to ground at the SHA pin. I don't see damage at the SHB pin. VCP has a 1uf 25V cap to Vdrain. I checked this cap on another board and it measured 0.9uf, which is within tolerance. I have another board working at Vdrain = 43V and VCP is sitting at about 53V, so that looks correct.
I'm running with 100 mA of gate drive selected, which seems to be enough to drive the FDD770N15A MOSFETs.
I am aware that the DRV8353 has many features to prevent damage in case of faults, but it is not protecting itself in my circuit, and I don't understand what is happening at higher voltages to cause the damage. I am not getting close to the 100V spec on the IC.
I am afraid to damage more boards and was hoping that someone on this forum might have had a similar experience or can supply some insight.