The TPS25961 implements Overvoltage Protection on V_IN in case the applied voltage becomes too high for the system or device to properly operate. The Overvoltage Protection has a default lockout threshold of V_OVP, which is achieved by connecting the OVLO pin to GND.

It’s possible to override the default OVLO threshold and adjust it to an user defined value as per the system requirements. This can be achieved by dividing the input supply and feeding it to the OVLO pin. Whenever the voltage at the OVLO pin rises above a threshold V_OVLO(R), the device turns OFF the FET. When the voltage at the OVLO pin falls below the threshold V_OVLO(F), the FET is turned ON again. The rising and falling thresholds on this pin are slightly different, thereby providing some hysteresis and ensuring stable operation around the threshold voltage.

The user should choose the resistor divider values appropriately to map the desired input overvoltage level to the OVLO threshold of the part.

The equation below shows the calculations for the resistor divider values to be used to set the OVLO set-point for a given voltage supply.