New PSPICE model for power MOSFET devices

The common PSPICE model for the power MOSFET device is well known to CAD designers. This paper addresses the problem of how to correctly simulate a nonlinear device by modeling the nonlinear components of its PSPICE model: drain-to-source resistance vs. temperature, drain-to-source and gate-to-source capacitance vs. voltage. By comparing the simulation results of the common PSPICE MOSFET model with the manufacturer's specifications, the drawbacks of the model are revealed. The paper explains the basic theory behind modeling linear and nonlinear capacitors and resistors and describes how to model nonlinear capacitors and resistors using the analog behavioral modeling (ABM) feature of PSPICE. Examples are provided that show the circuit diagrams for various nonlinear capacitors and resistors and PSPICE plots of the transient analysis results. Based on these principles, a new MOSFET model is generated and used in some examples.