common mode interference (CMI)

Common Mode Interferences(CMI) occur between the conductor within a cable and the reference potential, which usually corresponds to the ground potential.

Common mode interferences are unbalanced interference voltages, they are mostly caused by potential differences in the reference potential, e.g. ground unbalances and the resulting leakage currents. Common mode interferences are characterized by the fact that the interferences occur between the two signal carrying lines or between the terminals and ground. They can be suppressed with common-mode filters, which provide decoupling of the magnetic interference fields.