Analysis of Common-Mode Noise Generated due to Fast-Switching GaN Devices in Totem-Pole PFCs

Abstract:
The adoption of GaN devices has led to an increase in the switching frequency of high-power single-phase power-factor-correction converters, rising from 20-50 kHz to 65-135 kHz. This shift is primarily attributed to the rapid switch-node transitions and the absence of reverse recovery losses in GaN devices. However, the higher switching frequency and switch-node transitions have implications for common-mode (CM) noise filtration. This paper proposes mathematical models to estimate CM noise generated by GaN device switching and analyzes the influence of various factors such as switching frequency, parasitic elements, dv/dt, and voltage ringing on CM noise. Additionally, the study suggests that unlike Si-based converters, CM noise peaks resulting from switch-node voltage ringing appear in the radiated emission range for GaN-based converters.