The over-current protection operates by reducing the internal gate drive when the drain-source voltage is high enough that a large current would cause excessive dissipation. In normal operation, the full input voltage is delivered to the internal gate as long as the drain-source voltage is small, typically less than 1.5V, and low dissipation is assured. However, if the load current rises sufficiently to generate a substantial drain-source voltage, then the device reacts by reducing the internal gate drive and restricting the drain-source current.

