Other Parts Discussed in Thread: DRV8301, LM5060
Hello,
I am using the LM5060 high side protection on a senior design project for school. I have the setup configured to have a UVP and OVP of approximately 20V and 60V respectively. After completely assembling my pcb, when I power on the board and reach the UVP threshold the FETS connected to the GATE pin of the LM5060 come on and the board powers up fine. And when I reach around 55V-60V the board was shutting off. However, after cycling through the process of testing the UVP and OVP multiple times by increasing from below UVP to above OVP limits and down from OVP to UVP limits, the LM5060 eventually fails when reaching the OVP limit and.......well, magic smoke. However, I had tested my high side power protection when the board was partially assembled (basically only the high power side with no loads) and the LM5060 never failed. I assumed there was a fault in the rest of my circuit but could find nothing to confirm my suspicions. I am thinking that the actual cause of the failure could be due to voltage transients when the MOSFETS are shutting off quickly at the OVP limit. I think the reason it didn't fail when no load was present was due to the lower current as compared to the higher current load when I had populated the rest of my board. My fully populated board basically only has a F28035 piccolo MCU, a couple op-amps, CAN transceiver, DRV8301 motor driver, and RS 232 communication hardware. The load current with the populated board was very low, far less than half an amp. Is it possible with such a small current to have dv/dt transients that would cause the LM5060 to fail? Also, the FETS end up shorting source-to-drain upon failure. I attached a picture of my shematic (note: the R13 and C11 have been removed due to too much delay in the FET gate charge time). Thanks for the help.
