LM74502 provides programmable overvoltage protection feature with OV pin. A resistor divider can be connected from input source to OV pin to ground in order to set overvoltage threshold. An internal comparator compares the input voltage against fixed reference (1.25 V) and disables the gate drive as soon as OV pin voltage goes above the OV comparator reference. When the resistor divider is referred from input supply side, device is configured for overvoltage cutoff functionality. When the resistor divider is referred from output side (V_OUT), the device is configured for overvoltage clamp functionality.

When OV pin voltage goes above OV comparator V_OVR threshold (1.25-V typical), the device disables gate drive, however, charge pump remains active. When OV pin voltage falls below V_OVF threshold (1.14-V typical), the gate is quickly turned on as charge pump is kept on and the device does not go through the device start-up process. When OV pin is not used, it can be connected to ground.