The LTC4361 and LTC4360 (no RSENSE) can be used with various external MOSFET configurations. The simplest configuration is a single N-channel MOSFET. It has the lowest RDS(ON) and voltage drop and is thus the most power efficient solution. When the GATE voltage is pulled to ground, the N-channel MOSFET can isolate OUT from a positive voltage at supply input up to the drain-to-source breakdown voltage of the MOSFET. However, reverse current can still flow from OUT to IN via the MOSFET’s parasitic body diode. For overcurrent protection a sense resistor is added as shown. For near zero reverse-leakage current protection when the GATE is pulled to ground, back-to-back N-channel MOSFETs can be used. Adding an additional P-channel MOSFET provides negative input voltage protection down to the source-to-drain breakdown voltage of the P-channel MOSFET. The final configuration consists of a P-channel MOSFET and an N-channel MOSFET. This provides protection against overvoltage and negative voltage but not against reverse current flow.