Balanced buck-boost switching converter circuit to reduce common-mode conducted noise

摘要

Common-mode conducted noise in switching converters frequently causes radiated noise emission from power cord, so it is important to reduce this noise enough to meet EMC. Because conventional switching converters have been usually using unbalanced circuit topologies, parasitic capacitance between drain/collector of the active switch and the frame ground through its heat sink may generate the common-mode conducted noise. The anothers proposed a balanced switching converter, which is a way to reduce the common-mode conducted noise. In this paper, a buck-boost converter version of the balanced switching converter is presented and described its mechanism of the common-mode noise reduction. This good feature is confirmed by experimental results.