MOSFET modeling adapted for switched applications using a state-space approach and internal capacitance characterization

This paper presents a new approach to MOSFET modeling using a state-space technique. The model is based on discrete elements whose values are extracted from measurements, datasheet parameters and SPICE® equations. The switching characteristics of the component are strongly determined by the gate-drain capacitance (C_GD). With help of thorough impedance measurements, characterization of this capacitance as a function of the applied external voltages is possible. Simulations and measurements show good agreement and the model gives possibilities for e.g. controller design thanks to the state-space implementation.