DC/DC synchronous buck converters cause broadband emissions. A variety of methods are applied to analyze the root cause of the EMI. Time-domain voltage measurement and joint-time-frequency analysis allows to determine the location of the noise source. The near field scan reveals the current paths, and impedance measurement and 3D modeling can be used for further analysis of the noise source. A dual port TEM cell allows to distinguish E from H field coupling, This paper shows the application of those methods to a synchronous buck converter and reveals the sources of EMI leading to advice on the optimal PCB design. Finally, an innovative method of using a TEM cell measurement to predict the maximum possible radiated emissions is introduced.

Meeting Name

2005 International Symposium on Electromagnetic Compatibility, 2008. EMC 2008


Electrical and Computer Engineering

Keywords and Phrases

DC-to-DC converters; Electromagnetic interference

Document Type

Article - Conference proceedings

Document Version

Final Version

File Type





© 2008 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Aug 2008