Hello,
I am having an issue with the DRV8353RH-EVM. I am driving a sensored BLDC with a voltage of 48V. In order to use 1x PWM mode, I have removed R30 and R23, as well as adding jumpers to R48, R50, and R52.
A separate microcontroller (3.3V logic) is wired into J1 and J2 in order to provide control signals for ENABLE, DIR (set to 0), PWM (varied duty for speed), and nBRAKE (low when not driving PWM, high when driving PWM).
This previously seemed to be working well, and I was able to drive our motors at various speeds as expected. I have successfully driven three different motors with this setup, free-spin, as well as loaded. The unit was then left on the bench for a few days with power off.
The next time I came to perform some tests, the motor just twitched, and the nFAULT LED lit up. Some probing around, and I found that the high side gate driver for A was not driving at all. So I presumed the fault was a gate driver fault.
I procured a replacement EVM and performed the same minor rework to configure it for 1x PWM mode. Now with this EVM, as soon as I drive the ENABLE pin, the nFAULT LED illuminates immediately. I checked the gate drivers, and they sit a different voltages ranging from 0V-6V during the fault. Removing the EN signal clears the fault, and the gate drivers all go low. It draws ~100mA when the EN pin is driven, compared to a few mA when it is not enabled. This fault occurs whether I have a motor connected or not. Any ideas as to what might have caused these failures? I am not sure if they were caused by the same thing.
Regards,
Vincent
