A study of common mode noise in switching power supply from a current balancing viewpoint

Common mode noise current is a major source of EMI in switching mode power supplies. The generation mechanism is studied from a current balancing point of view in this paper. A proper understanding of common mode noise provides a systematic approach to solve common mode interference in SMPS. Impedance balance and noise source balance analysis of a boost converter are presented. Simulation and experiment results are shown to verify this concept.