Details

Autor(en) / Beteiligte

• Paramesh, J.
• von Jouanne, A.

Titel

Use of sigma-delta modulation to control EMI from switch-mode power supplies

Ist Teil von

• APEC '99. Fourteenth Annual Applied Power Electronics Conference and Exposition. 1999 Conference Proceedings (Cat. No.99CH36285), 1999, Vol.1, p.153-159 vol.1

Ort / Verlag

IEEE

Erscheinungsjahr

1999

Quelle

IEL

Beschreibungen/Notizen

• Conducted electromagnetic interference (EMI) is a major cause of concern in switch-mode power supplies (SMPS) which commonly use standard pulsewidth modulation (PWM). In this paper, sigma-delta (/spl Sigma//spl Delta/) modulation is proposed as an alternative switching technique to reduce conducted EMI from SMPS. The result of using /spl Sigma//spl Delta/ modulation is a spread in the spectrum of the conducted emissions so that large concentrations of power at discrete frequencies are avoided. Experimental time-domain waveforms and spectra of the switching function of first-order and second-order /spl Sigma//spl Delta/ modulators are presented to prove the viability of the scheme for EMI mitigation. These modulators are then applied to a DC-DC power converter in an off-the-shelf computer power supply and experimental results show a reduction of roughly 5-10 dB/spl mu/V in EMI emissions over standard PWM modulators.