The LTC4411 contains a 140m P-channel MOSFET connecting IN to OUT. During normal forward operation, the drop across the MOSFET is regulated to as low as 28mV. Quiescent current is less than 40A for load currents up to 100mA. If the output voltage exceeds the input voltage, the MOSFET is turned off and less than 1A of reverse current flows from OUT to IN. Maximum forward current is limited to a constant 2.6A (typical) and internal thermal limiting circuits protect the part during fault conditions. An open-drain STAT pin indicates conduction status. The STAT pin can be used to drive an auxiliary P-channel MOSFET power switch connecting an alternate power source when the LTC4411 is not conducting forward current.