The LP5912-EP input is protected against reverse current when the output voltage is higher than the input voltage. In the event that extra output capacitance is used at the output, a power-down transient at the input normally causes a large reverse current through a conventional regulator. The LP5912-EP includes a reverse voltage detector that trips when V_IN drops below V_OUT, shutting off the regulator and opening the p-channel metal-oxide-semiconductor field effect transistor (PMOS) body diode connection, preventing any reverse current from the OUT pin from flowing to the IN pin.

If the LP5912-EP EN pin is low (the LP5912-EP is off) and the OUT pin is held high by a secondary supply, current flows from the secondary supply through the automatic discharge pulldown resistor to ground. This scenario is not reverse current, but is instead automatic discharge pulldown current.

Reverse current (I_RO) is measured at the IN pin.