EMC design techniques in power electronic systems

Spread Spectrum (SS) modulation techniques are commonly used in switching power converters to comply with the Electromagnetic Compatibility (EMC) regulations. As a matter of fact, such techniques spread the energy content of interfering signals over a wider bandwidth, significantly reducing the power spectral density of measured emission spectra. While the effects of SS on the spectral characteristics of electromagnetic interference (EMI) signals have been  extensively studied, highlighting a significant (10-20dB) reduction of envelopes of measured EMI spectra, the real value of SS techniques as a means to reduce the potential adverse effects of emissions is a more controversial matter and it has been sometimes questioned. Futhermore, although the effectiveness of SS techniques is nowadays generally accepted, it has been just experimentally observed in very specific applications. In this framework, a theoretical evidence of the effectiveness of SS modulation in reducing the interfering potential of switching signals has not been shown so far and the effectiveness of SS techniques in low-frequency power converters, whose radiated and conducted EMEs could interfere with present day baseband digital systems, has not been specifically considered. In this activity, the impact of EMI generated by a Spread Spectrum based switching mode power converter on a digital data line is experimentally investigated.

ERC Sector:

  • PE7_2 Electrical engineering: power components and/or systems
  • PE7_6 Communication technology, high-frequency technology


  • Electromagnetic compatibility
  • Power conversion
  • Spread Spectrum
  • Compliance measurements

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