High-Frequency Characterization and Modeling of EMI Filters Under Temperature Variations

Passive components, in particular capacitors and coupled inductors, are the most important parts of electromagnetic interference (EMI) filters. The parasitic elements of these components and the impact of temperature on their frequency behavior are very significant and should not be neglected; these unwanted effects have a major impact on EMI filter performances. In this paper, characterization test-benches and modeling methods of capacitor and coupled-inductor impedances via measurements are presented. The aim of this study is to propose relatively simple models in order to estimate, by simulation, the frequency behavior of EMI filters in a wide range of temperature. The new models are simulated for several values of temperature and the obtained results are compared to the experimental measurements in the frequency domain. The developed models are then translated to VHDL-AMS language for easy implementation in most electrical simulation software.