Synchronous rectifier as a test circuit for high-frequency power MOSFET model verification

The power vertical double diffused MOSFET (DMOSFET) structure incorporates many parasitic structures which are difficult to model in physically based circuit simulators. Low voltage ultralow on-resistance vertical power DMOSFETs were used as synchronous rectifiers in a high-density microelectronics power supply. The circuit was first simulated using an advanced mixed device and circuit simulator in which the power DMOSFETs were represented as two-dimensional (2-D) finite element grid structures and semiconductor transport and charge balance equations were solved subject to terminal boundary conditions imposed by the circuit operation. Mixed simulation results are compared with pure circuit simulation results using an advanced behavioral circuit simulator in which a high-frequency lumped equivalent circuit model is used to represent the DMOSFETs. The proposed approach is a powerful tool to validate circuit simulation models of complex power devices.