The next several slides will deal with Reverse Current Blocking. The PMOS on the left shows a parasitic diode from drain to source that allows current to flow in the case that V_OUT has a VF higher than V_IN. A simple solution on the right uses back to back PMOS devices to prevent reverse current flow when the two PMOS devices are in the off state. This state will be defined as reverse current blocking. This solution uses two MOSFETs which leads to higher cost and poorer R_DS(ON). A new issue arises if the two MOSFETs are in the ON State. The system is now bi-directional and there is no way to limit current when V_OUT is greater than V_IN. True Reverse Current Blocking is an integrated circuit solution that solves this issue of the ON state switch.