This measurement is necessary because most CMC datasheets lack inductance data versus differential mode current.
In real-world CMCs, the magnetic core can approach saturation due to differential mode inductance and current, reducing core permeability and, consequently, common mode inductance. This reduction affects the CMC's ability to filter common mode noise, especially in applications with high crest factor differential mode currents.
Saturation Characteristics of Common Mode Chokes
TBAIn this document, Vinod Chellat Markose explains an indirect method for measuring the drop in inductance of a CMC at any current using a Bode 100 vector network analyzer.