Radiated EMI Reduction by Layout Improvement in Power Converters in Automotive Applications

Power converter layout is a critical factor for the radiated EMI. Because the radiation excitation is generated by the power converter and it is significantly influenced by the layout. The power converter layout includes the component location and the PCB trace layout. This paper develops noise modeling techniques to reveal the mechanisms of the layout's influences. And based on the modeling researches, layout improvement guidelines for reducing the radiated EMI are produced, including the component location improvement, and the PCB layout improvement. Experimental verifications including the semi-anechoic chamber testing are conducted on a buck-boost power converter and on a buck power converter in automotive applications.