The LTC®4227 offers ideal diode-OR and Hot Swap™ functions for two power rails by controlling external Nchannel MOSFETs. MOSFETs acting as ideal diodes replace two high power Schottky diodes and the associated heat sinks, saving power and board area. A Hot Swap control MOSFET allows a board to be safely inserted and removed from a live backplane by limiting inrush current. The supply output is also protected against short-circuit faults with a fast acting current limit and internal timed circuit breaker. The LTC4227 regulates the forward voltage drop across the MOSFETs to ensure smooth current transfer from one supply to the other without oscillation. The ideal diodes turn on quickly to reduce the load voltage droop during supply switchover. If the input supply fails or is shorted, a fast turn-off minimizes reverse-current transients. The LTC4227 allows turn-on/off control, and reports fault and power good status for the supply.
