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

Citation
J. Paramesh et A. Von Jouanne, Use of sigma-delta modulation to control EMI from switch-mode power supplies, IEEE IND E, 48(1), 2001, pp. 111-117
Citations number
10
Categorie Soggetti
Eletrical & Eletronics Engineeing
Journal title
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
ISSN journal
02780046 → ACNP
Volume
48
Issue
1
Year of publication
2001
Pages
111 - 117
Database
ISI
SICI code
0278-0046(200102)48:1<111:UOSMTC>2.0.ZU;2-8
Abstract
Conducted electromagnetic interference (EMI) is a major cause of concern in switch-mode power supplies (SMPSs) which commonly use standard pulsewidth modulation (PWM). In this paper, Sigma-Delta (Sigma Delta) modulation is pr oposed as an alternative switching technique to reduce conducted EMI from a n SMPS. The result of using Sigma Delta modulation is a spread in the spect rum of the conducted emissions so that large concentrations of power at dis crete frequencies are avoided. Experimental time-domain waveforms and spect ra of the switching function of first-order and second-order Sigma Delta mo dulators are presented to prove the viability of the scheme for EMI mitigat ion. These modulators are then applied to a dc-ac converter in an off-the-s helf computer power supply and experimental results show a reduction of rou ghly 5-10 dB.muV in EMI emissions over standard PWM modulators.