Mode Conversion in DC-DC Converters with Unbalanced Busbars

In this work, the undesired differential-to-common-mode conversion arising in low voltage DC-DC converter system due to busbar asymmetries with respect to the converter metallic case is investigated. To this end, a typical test setup for conducted emission (CE) verifications is modelled, which exploits two different DC-DC converter topologies. A circuit interpretation of the imbalance introduced by the busbar is provided in terms of differential and common mode equivalent circuits. The proposed simulation results allow putting in evidence the different impact of mode conversion on the DC-bus CM current for the two converter topologies under analysis.