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DRV8874-Q1: What can trigger nFAULT driven LOW?

Part Number: DRV8874-Q1

Hi Experts,

When DRV8874-Q1 is working as direct drive forward-rotating. High side OUT1 short to GND. The nFAULT was driven LOW. What can trigger nFAULT LOW?

According to the fault condition, 

  • The current mirror is on low side, so it can't be trigger by OCP or Itrip.
  • The test Vm is close VBATT, far above UVLO, so it can't be trigger by UV.
  • The nFault can be trigger as soon as short, so it can't be trigger by TSD.

What else reason can trigger this?



  • Frank,

    It is quite simply OCP that is triggering per the table.  Each FET has a seperate current mirror that is different from the low-side sensing.  Low-side sensing is for iPropI reporting, not OCP.