Effect of EMI Filter Improvement Techniques on Conducted Emissions in a 48-12 DC-DC Converter

The current trend towards the increase of switching frequencies in modern power converters is aimed at achieving higher power densities. This poses a great challenge to comply with stringent EMC normative, especially in automotive and aeronautical industries. They are clearly antagonist requirements since filtering and shielding techniques are usually required to fulfill those standards, but generally to the detriment of power density. For this reason, this work checks and compares the effectiveness of some cost-effective EMI filter improvement techniques that may provide modest attenuation enhancement of conducted emissions with a negligible power density cost in a real-case scenario, where the noise source is a laboratory prototype of a DC-DC power converter.