TPS51216-EP sets the overvoltage protection (OVP) when the VDDQSNS voltage reaches a level 20% (typ) higher than the REFIN voltage. When an OV event is detected, the controller latches DRVH low and DRVL high. VTTREF and VTT are turned off and discharged using the non-tracking discharge MOSFETs regardless of the tracking mode.

The undervoltage protection (UVP) latch is set when the VDDQSNS voltage remains lower than 68% (typ) of the REFIN voltage for 1 ms or longer. In this fault condition, the controller latches DRVH low and DRVL low and discharges the VDDQ, VTT, and VTTREF outputs. UVP detection function is enabled after 1.2 ms of SMPS operation to ensure startup.

To release the OVP and UVP latches, toggle S5 or adjust the V5IN voltage down and up beyond the undervoltage lockout threshold.