Optimization of the body-diode of power MOSFETs for high efficiency synchronous rectification

An investigation is performed in this paper upon the impact of the parasitic bipolar junction transistor (BJT) with respect to the body-diode characteristics of the power MOSFET. Simulated and experimental results show that the forward conduction and the reverse recovery characteristics of the body-diode can be improved by enhancing the parasitic BJT, formed by the N/sup +/ source (emitter), P-well (base) and N-epi layer (collector) of power MOSFETs, Furthermore, the trade-off between enhancing the parasitic BJT and retaining the device's unclamped inductive switching (UIS) capability is also addressed.