The common-mode noise reduction mechanism in balanced buck-boost switching converter circuits

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. The anothers proposed a balanced switching converter, which is a way to reduce the common-mode conducted noise. In this paper, the path of the noise current in a balanced buck-boost converter circuit is investigated using a micro magnetic field probe, the current waveform which flows parasitic capacitance and FG (Frame Ground) is measured, and the reduction mechanism of common-mode noise current is claritied.