Balanced switching converter to reduce common-mode conducted noise

Because conventional switching converters have usually used unbalanced circuit topologies, parasitic capacitance between the drain/collector of an active switch and the frame ground through its heat sink may generate the common-mode conducted noise. This paper proposes a balanced switching converter circuit, which is an effective way to reduce the common-mode conducted noise. As an example, a boost converter version of the balanced switching converter is presented, and the mechanism of the common-mode noise reduction is explained using an equivalent circuit. This good feature is confirmed by experimental results. The concept of the balanced switching converter is applied to some other types of switching converters.