TMS320F280049C: Issue with the DRV8353RS-EVM

We are currently developing a BLDC motor driver with DRV8353RS-EVM and F280049C MCU.

We are facing repeated failures of the DRV8353RS chip when trying to run the board with the motor connected.

Most of the time the gate driver failure occurs and the gate pin of one of the Mosfet gets damaged.

The test setup consists of

1. DRV8353RS-EVM board
2. LaunchXL F280049C microcontroller card
3. A custom daughter card to connect these two boards
4. BLDC motor (R 0.245 ohm, L 30uH, 2pole, 80,000 rpm motor)
5. 24V 5A CV/CC power supply.

Configuration settings

1. PWM Carrier: 100kHz center-aligned HRPWM
2. 6 step control (Bipolar commutation)
3. 6 PWM IN Mode
4. Gate Drive current 150mA/300mA, tdrive 1us (taken from FOC example used in GUI)
5. Deadtime (50ns in DRV, 45ns in the controller)
6. OCP Mode (cycle by cycle) / 50us retry time
7. VDS OCP set to 0.100V and deglitch time of 2us
8. SEN OCP set to 0.25V (8.33A with 0.030 ohm shunt)

Board Modifications

1. Changed shunt resistors to set current trip at 8.33A

When we try to accelerate the motor by giving a higher PWM duty cycle, and the current crosses 8.33A. The gate drive in one of the phase fails.

The SPI status register shows Gate Drive Failure (GDF) and one of the MOSFET (VGSxx) failure.

We have tried similar PWM inputs/overcurrents in DRV8301-HC-EVM. It never failed.

We have checked the PWMs and found no cross conduction/shoot through happening.

In a recent case, the Failed driver gives 3V continuously to the MOSFET and the charge pump voltage is also around 3V.

The Failed Mosfet gate to source resistance shows (Mosfet in still in the board) around 91 ohms. (good one shows >100k)

Kindly suggest any modifications/workarounds we can to mitigate the driver failure.