DRV8870: Driving BLDC Motor with DRV 8870

I am using this chip for a slightly unconventional application of driving a BLDC MOTOR with sinusoidal drive. The motor is rotating but all of a sudden the driver is failing, 24 volts is shorting to ground. The voltage is 24v, pwm frequency 1khz, average current is 1.24 A. I am using 2 driver chips to form 3 half bridges

Thank you

Anish bekal