Hi,
We are using DRV8412 (DDW) to drive a brushed DC motor at 28V. The driver is configured in 1PFB CBC mode. The maximum steady current drawn by the motor is 3A (measured using current probe) where there are momentary spikes reaching 10A. We face a problem of DRV8412 getting damaged after certain duration of motor operation (not continuous operation). Attached the corresponding schematic and damaged driver's picture.
Questions:
1. What could be the probable causes for destruction?
2. Shoot through could be a reason?
3. Is there any possibility that internally both MOSFETs of one half-bridge turns on momentarily and that current not being sensed?
4. If the bottom Power Pad is left floating (not soldered to the PCB), will it cause the junction to thermally break at a maximum total steady current of 3A? Calculation using 110 mOhm RDSon per MOSFET shows that it won't cause a thermal damage from Thermal Information and Package Heat Dissipation Ratings sections in the datasheet.
Regards | Sinoj
