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High-efficiency power converters have benefits of minimizing energy consumption, reducing costs, and realizing high power densities. The silicon super-junction MOSFET is an attractive device for high-efficiency applications. However, its highly non-linear output capacitance and the reverse recovery properties of its intrinsic diode must be addressed when used in voltage source converters. A dual-mode switching technique operating in conjunction with intrinsic diode deactivation circuitry is proposed in this paper. The technique is demonstrated in an 800-W inverter-leg configuration operating from a 400-V DC voltage rail and switching at 20 kHz. Intended applications include machine drives. The full-load efficiency reaches approximately 98.7% and no forced cooling is needed.

In this paper a high efficiency DC-DC converter power stage employing silicon Super-Junction (SJ) MOSFETs is presented. These devices have low on-state resistances and fast switching capabilities. However, their intrinsic body diode has a very poor reverse recovery behavior and they have an output capacitance that has a highly non-linear inverse relationship with voltage. These characteristics lead to problematic charging currents when they are used in bidirectional voltage source converters. These problems are addressed through implementation of an auxiliary resonant source charge extraction circuit in conjunction with anti-series MOSFETs. The result is a 5-kW power converter with a power semiconductor stage full-load efficiency exceeding 99% and requiring no forced cooling.