Design for common mode reduction in signaling and power distribution systems in electronic device

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K18052
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Electron device/Electronic equipment
• Research Institution: Kyushu Institute of Technology (2017); Kyoto University (2015-2016)
• Principal Investigator: Matsushima Tohlu 九州工業大学, 大学院工学研究院, 准教授 (00571415)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: EMC / コモンモード / 平衡度不整合モデル / パワーエレクトロニクス / 寄生結合 / インピーダンスバランス

Outline of Final Research Achievements

In a printed circuit board and attached cable, a common mode current flowing in a signal transmission system and/or a power supply system causes radiated emission and deterioration of signal integrity.
In this report, a differential transmission line is focused as signaling system. It is formulated that difference of common mode voltages occurs at the point where imbalance degree changes. The imbalance degree is determined by cross section of the transmission line. Reduction of common mode by changing design of the transmission line can be predicted by the calculation of the imbalance. In addition, the power supply system is also focused in this report. In the power supply system, an impedance balance is important for reduction of common mode. Designing parasitic capacitance around power MOSFETs can reduce excitation of common mode in a power electronics circuit.

Free Research Field

環境電磁工学