Other Parts Discussed in Thread: DRV8301, DRV832X,
We have found a disturbing issue during testing of our motor controller design. It is based on DRV8301 and the few prototypes we have has so far been working fine. But yesterday, in a test where we spun the BLDC motor passively, it went really wrong. Without running active motor control, only mechanically spinning the motor to give a back EMF around 50V, the DRV8301 was damaged and all low-side MOSFETs was shorted. The DRV8301 was not completely damaged as the bucket converter continued to operate. On another controller the same test did no harm but here we had a slightly different SW configuration.
We suspected first that the damage was caused by transients but have not been able to capture anything on the scope. But after rereading the DRV8301 datasheet and also posts on this forum, it seems that there are at least one issue with DRV8301 (see 8.1.1 in DS) that does not exists on the new DRV832x series. The DRV832x series has also more specific datasheet with regards to voltage limits, indicating improved focus on issues that can cause damage.
As we are working on our next board revision we have now a golden opportunity to swap the DRV8301 with something that is equivalent but more robust. The DRV832x series should work fine as our MOSFETs are easy to drive having low gate charge and we run PWM at only 10 KHz. We still need the bucket converter but not the sense amplifiers, and we want a small IC, so DRV8320R seems most compatible. So my question is: By replacing DRV8301 with DRV8320R would that give a more robust solution for applications where the controlled motor is driven by mechanical force, or where the controller operates near its voltage limits?
Kind regards,
Per
