Impact of gate voltage bias on reverse recovery losses of power MOSFETs

A behavioral power MOSFET model is shown that includes the dependence of body diode reverse recovery on the gate voltage. That dependence is strongly associated with the so called ´body effect´, i.e. the enhanced sub-threshold channel conduction in the third quadrant. The model requires two parameters that can be derived from FE device simulations. These parameters agree with those found in a measurement. Step-down converter simulation examples demonstrate the impact of the gate bias of the synchronous rectifier on both reverse recovery and gate bouncing and hence on total switching losses.