Linear Technology introduced the LTC4354 , a -48V diode-OR controller for high availability systems. By controlling external N-channel MOSFETs for the redundant supply paths instead of traditional ORing diodes, it dramatically improves efficiency and eliminates bulky heat sinks.
Available in a tiny 3mm by 2mm DFN package, the LTC4354 minimizes power dissipation due to the lower forward voltage drop, and also saves vital board space. Operating with supply voltages up to -80V, the LTC4354 turns off the appropriate MOSFET in less than 1µs when either power supply fails. This fast response time prevents reverse currents from reaching damaging levels.
An open drain fault output, capable of driving an LED or opto-coupler, indicates if either FET has excessive voltage drop. This occurs if the FET or series fuse has gone open or if there is a supply overload. By minimizing significant power loss and thereby increasing the system's power efficiency and reliability, the LTC4354 meets the stringent requirements of telecom standards such as Advanced Telecom Computing Architecture (AdvancedTCA) making it suitable for a wide range of high availability applications.
Available from stock and specified over the commercial and industrial temperature ranges, the LTC4354 is available in 8-pin DFN and SO packages. Pricing begins at $1.95 for 1,000 piece quantities.
Linear Technology Ltd , Malow, Buckinghamshire SL7 1FD, UK.