Physics-based insulated-gate bipolar transistor model with input capacitance correction

Abstract

Insulated-gate bipolar transistor (IGBT) terminal capacitances play an important role in IGBT switching transients. The terminal capacitance modelling is a difficult task because of their operating-point-dependent characteristics. In particular, the input capacitance needs careful treatment if accurate modelling is to be performed. Previously, for the planar gate IGBT, the Miller capacitance's voltage dependency is modelled by considering the depletion region growth pattern. For modern trench gate designs, however, there is no similar dynamic model available. Also, its current dependency needs to be accounted for. This study presents an improved IGBT physics-based model with input capacitance correction. By comparison of experimental and simulation results, the proposed model works well for different types of IGBTs (including the state-of-art trench-gate field-stop type) over a wide range of operating conditions and is convenient to implement.