Multichannel EMI filter performance assessment

Electromagnetic interference filters are being characterized in terms of their insertion loss. CISPR 17 provides measurement procedures for assessing normal, common, and differential mode insertion loss. Respectively, this requires three different setups to fully characterize the filter. This paper shows an alternative to the CISPR 17 setup resulting in a time-efficient measurement approach that allows the evaluation of all modes of insertion loss of the filter in a single measurement setup. Furthermore, it is extended to an approximate worst-case measurement, as in CISPR 17. Complimentary, the suggested setup is used to perform insertion loss measurements of a filter including line impedance stabilization networks, to assess the more realistic performance of the filter in the conducted emission test.