LTC4355CS

The LTC4355CS is a positive voltage ideal diode-OR controller manufactured by Linear Technology (LT). It drives two external N-channel MOSFETs, effectively replacing traditional Schottky diodes to reduce power consumption, heat dissipation, and board space. This controller is suitable for ORing power sources together to enhance system reliability.

Key features include a wide operating voltage range from 9V to 80V and a fast 0.3µs turn-off time, which helps limit peak fault current. It also provides input supply and fuse monitoring capabilities. The LTC4355CS can be used to diode-OR two positive supplies or the return paths of two negative supplies, such as in a –48V system. It ensures smooth current transfer without oscillation.

The device is available in a 16-lead SO package and operates within a temperature range of 0°C to 70°C. Its typical quiescent current is 2.6mA, and it has a typical current capability of 20A. The controller utilizes an internal charge pump for FET gate drive.

This ideal diode-OR controller is beneficial in high-availability systems requiring redundant power feeds. By using MOSFETs instead of Schottky diodes, it significantly reduces power dissipation, simplifying thermal management and improving overall system efficiency.