Ideal Diode Controller from Linear Technology Integrates 5A MOSFET

The LTC4358 regulates the forward voltage drop across the internal MOSFET to ensure smooth switchover from one path to another without oscillation. A fast pull-down circuit minimizes reverse current transients in the event a power supply fails or is shorted. The LTC4358 can be viewed as a three terminal diode for general purpose applications such as reverse battery protection in automotive applications, or ORing power supplies together in applications that demand high system reliability.

The LTC4358 single ideal diode controller is useful in applications where multiple, redundant power supplies are paralleled to provide load sharing. In N+1 redundant systems, the LTC4358 provides a convenient method to OR together an additional supply to safeguard the system in the event one of the N supplies fail. This ORing technique provides necessary isolation for live insertion and removal of converters onto the power bus and to provide isolation from the bus during a hard short. If the power source fails or is shorted, the LTC4358 ensures a fast 500ns turn-off to minimize reverse current transients.

The LTC4358 joins a growing family of ideal diode-OR controllers, including the LTC4355 positive voltage ideal diode-OR, LTC4354 negative voltage ideal diode-OR, and the LTC4357 and LT4352 single ideal diode controllers.