System-level electro-thermal analysis of RDS(ON) for power MOSFET

Abstract

A coupled-electro-thermal RDS(ON) (drain to source ON resistance) co-analysis methodology for Power MOSFET is proposed. The methodology contains two functional modules: 1) physical field solvers and 2) equivalent circuit/network solver. The field solver resolves the electrical and thermal field variables by the conventional 3D finite-element method, while the network solver can achieve accurate and efficient results by connecting the equivalent electrical, thermal and flow circuits that are extracted from the system through advanced numerical computational schemes. The integrated equivalent network can then be solved by a generic circuit solver for steady state and transient responses. The methodology is demonstrated, via simulation and measurement, on a 2.5MHz DCDC buck-boost converter. Good correlation between co-analysis methodology and laboratory measurements is achieved.