Linear Technology Corporation (Milpitas, CA) introduces the LTC4227, a compact, dual ideal diode with Hot Swap™ controller that provides PowerPath™ and inrush current control for redundant supplies operating from 2.9V to 18V. The LTC4227 regulates the forward voltage drop across two external N-channel MOSFETs to ensure smooth current transfer between supplies in diode-OR applications.
The ideal diodes replace two high power Schottky diodes and associated heat sinks, saving space while providing a low loss path to the load. The downstream Hot Swap control MOSFET protects the board and backplane from damage during live insertion and removal, and protects from short-circuit faults with a fast acting current limit and circuit breaker. Prioritization of the two supplies is made possible by a dedicated D2ON# pin, which turns off the ideal diode for a lower priority supply.
In addition to redundant power supply ORing, the LTC4227 makes an excellent diode replacement in supply holdup applications where momentary collapse of supply voltage is isolated from the load.