Conducted EMI analysis and filter design for MHz active clamp flyback front-end converter
- Resource Type
- Conference
- Authors
- Huang, Xiucheng; Feng, Junjie; Lee, Fred C.; Li, Qiang; Yang, Yuchen
- Source
- 2016 IEEE Applied Power Electronics Conference and Exposition (APEC) Applied Power Electronics Conference and Exposition (APEC), 2016 IEEE. :1534-1540 Mar, 2016
- Subject
- Power, Energy and Industry Applications
Electromagnetic interference
Junctions
Flyback transformers
Windings
Impedance
Switching frequency
Capacitance
Gallium nitride device
active clamp flyback
soft-switching
common-mode noise
differential-mode noise
transformation
EMI filter
- Language
High frequency is the major catalyst for size reduction in the advancement of power conversion technology. It is essential to understand the EMI characteristic of high frequency converter since the EMI filter typically occupies one third of total system volume. This paper presents an insight view of CM/DM noise transformation in Flyback converter for low power adapter applications. The so-called mixed-mode noise is DM noise transformed from CM noise due to unbalanced impedance when the diode-bridge is off. The transformer shielding technique can effectively reduce the CM noise, and therefore it can significantly reduce the magnitude of CM transformed noise. A 65W (19V/3.3A) prototype of active clamp flyback front-end converter operating around 1MHz with GaN devices is developed to verify the analysis. A single stage EMI filter is designed accordingly with much smaller size compared with industry practice.