Abstract: DC-to-DC converters are protected from damage by, among other things, monitoring and controlling forward and reverse currents in their transformer primary windings. The currents are discontinued if their values fall outside a predetermined range or if they flow during a portion of the switching cycle in a manner that would result in cross-conduction. Power switches in these converters are also protected from damage by adjusting the maximum duty cycles of these converters to vary with their input voltages. In this way, the maximum voltage across the power switches is kept within a relatively narrow range. These protective features can be combined in any number of ways to fit the application at hand.

Abstract: DC-to-DC converters are protected from damage by, among other things, monitoring and controlling forward and reverse currents in their transformer primary windings. The currents are discontinued if their values fall outside a predetermined range or if they flow during a portion of the switching cycle in a manner that would result in cross-conduction. Power switches in these converters are also protected from damage by adjusting the maximum duty cycles of these converters to vary with their input voltages. In this way, the maximum voltage across the power switches is kept within a relatively narrow range. These protective features can be combined in any number of ways to fit the application at hand.

Abstract: Low voltage drop ORing circuits with zero recovery time and reverse current protection. In use, a MOSFET is coupled between a power supply and a load in a multiple power supply, single load system, or between a power supply and a load in a single power supply, multiple load system, or in both locations in multiple power supply, multiple load systems. A controller senses the current through the MOSFET, and turns the MOSFET off when the current falls below a predetermined threshold current. This allows time for circuit delays and the discharge of the gate of the MOSFET to turn the MOSFET off before the current through the MOSFET car reverse. Turn-on of the MOSFET when the current exceeds the threshold may be purposely slowed to avoid current spikes. Addition of another MOSFET controlled by the controller adds a hot swap capability and the control of the VC slew rate.