Temperature-Dependent Reverse Recovery Characterization of SiC MOSFETs Body Diode for Switching Loss Estimation in a Half-Bridge

Abstract

In a hard switched <small>mosfet</small> based converter, turn-<small>on</small> energy losses is predominant in the total switching loss. At higher junction temperature the turn-<small>on</small> energy loss further increases due to the reverse recovery effect of the complementary <small>mosfet</small>s body diode in a half-bridge configuration. Estimation of the switching loss under different operating conditions at an early design stage is essential for optimizing the thermal design. Analytical switching loss models available in literature are generally used for estimating the switching losses due to its accuracy and simplicity. In this article, the inaccuracy in the reported loss models due to non-inclusion of temperature-dependent reverse recovery characteristics of body diode, is investigated. A structured method to determine the temperature-dependent switching loss of a SiC <small>mosfet</small> in a half-bridge is presented. A simple methodology has been proposed to analyze the carrier lifetime&#x0027;s temperature dependencies of a SiC <small>mosfet</small>s body diode. Device parameters from a <inline-formula><tex-math notation="LaTeX">$\text{1.2}\,\text{kV}/36\,\text{A}$</tex-math></inline-formula> SiC <small>mosfet</small>s datasheet are used for developing the loss model and experimental validation of the model.