High availability systems often employ dual feed power distribution to achieve redundancy and enhance system reliability. ORing diodes join the feeds together at the point of load, most often using Schottky diodes for low loss. MOSFET-based ideal diodes can be used to replace Schottky diodes for a signifi cant reduction in power dissipation, simplifying the thermal layout and improving system effi ciency. Figure 1 shows the LTC4355 and LTC4354 combining the inputs and returns in a –48V, 5A dual feed application. This solution reduces the power dissipation from 6W using Schottky diodes to just 1.1W with MOSFETs.Ideal Diodes Protect Against Power Supply Wiring Errors
Design Note 444
Meilissa Lum
Introduction such errors. Wiring errors could include reverse polarity
High availability systems often employ dual feed power or cross-feed connections. Knowing this, circuit design-
distribution to achieve redundancy and enhance system ers are accustomed to using discrete diode solutions to
reliability. ORing diodes join the feeds together at the protect against such mishaps. It is important that active
point of load, most often using Schottky diodes for low ……