I am attempting to drive a sensorless BLDC motor using BEMF control. I'm fairly early in the development cycle and am currently trying to determine the proper settings to use in order to ramp the motor up to a speed at which we can transition over to BEMF control. Quite often, when I try to transition from the alignment phase to the ramp phase, the DRV8301 reports a fault at the nFault pin as well as "FAULT" in status register 1. No other fault bits are set in status register 1, and status register 2 has a value of 0x01 (just the device ID).
What does only the "FAULT" bit set in Status Register 1 indicate? Could this have something to do with detection of overcurrent through the FETs? I am not currently monitoring the OCTW pin in interrupt, just through polling, so if it is getting asserted for a brief time I could be missing it.
