Hello,
We have made multiple PCBs with the DRV8353SRTAT BLDC motor driver, and with about a third of the PCBs, we have the issue that an "Over Temperature Warning" (OTW) and/or "Over Temperature Shutdown" (OTSD) error occurs eventhough the chip is not warm at all. Even when using a thermal plate, a heatsink (600cm2) and letting the chips cool down over the weekend, we instandly get a OTSD error as soon as we power up the chips.
We found out that the SPI communication works (does not give a nFault) as long as we keep the voltage (Vvm and Vvdrain are connected together) under 8,5V. As soon as we increase the voltage above 8,5V the chip goes into over temperature mode. I assume that since Vvm requires at least 9V, that this is part of the problem, but I expect that if an error occurs, that the chip will give a supply error (VW_UV, VDR_UV, VCP_UV, VGLS_UV), an overcurrent error (VDS_OCP, SEN_OCP), or a gate fault (GDF) and not an over temperature fault/warning (OTW, OTSD).
We can also reset the error by removing the supply and directly supply it with a voltage below 8,5V. So it does not seem to be releated to the temperature that much.
Do you have any idea what the issue could be and how we can fix / prevent this from happening?
Best Regards
Tom