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.