Equivalent Common Mode Voltage Measurement for Simplified Verification of Suppression Effect in Automotive Common Mode Choke Coils

Abstract

This paper uses a sinusoidal wave with mixed differential mode and common mode components to determine the equivalent common mode voltage generated at the common mode termination on the load side of the components, namely Through, CMC1, and CMC2 (CMC: Common Mode Choke coil), through simulation and measurement.

The relationship to the mixed-mode S-parameters used as a recommended value for CMC was then examined.

Our results show that using the equivalent common mode voltage obtained from the input waveform with mixed modes allows for an evaluation that considers the phase difference between modes caused by the CMC's mixed-mode S-parameters. Therefore, we demonstrated that this can be utilized as one guideline among many parameters used for a performance comparison of CMCs.