EMI Reduction by Spread-Spectrum Clocking in Digitally-Controlled DC-DC Converters

Ibuki MORI; Yoshihisa YAMADA; Santhos A. WIBOWO; Masashi KONO; Haruo KOBAYASHI; Yukihiro FUJIMURA; Nobukazu TAKAI; Toshio SUGIYAMA; Isao FUKAI; Norihisa ONISHI; Ichiro TAKEDA; Jun-ichi MATSUDA

doi:10.1587/transfun.E92.A.1004

Special Section on Advanced Technologies Emerging Mainly from the 21st Workshop on Circuits and Systems in Karuizawa

EMI Reduction by Spread-Spectrum Clocking in Digitally-Controlled DC-DC Converters

Ibuki MORI, Yoshihisa YAMADA, Santhos A. WIBOWO, Masashi KONO, Haruo KOBAYASHI, Yukihiro FUJIMURA, Nobukazu TAKAI, Toshio SUGIYAMA, Isao FUKAI, Norihisa ONISHI, Ichiro TAKEDA, Jun-ichi MATSUDA

Author information

Ibuki MORI
Department of Electronic Engineering, Graduate School of Engineering, Gunma University
Yoshihisa YAMADA
Department of Electronic Engineering, Graduate School of Engineering, Gunma University
Santhos A. WIBOWO
Department of Electronic Engineering, Graduate School of Engineering, Gunma University
Masashi KONO
Department of Electronic Engineering, Graduate School of Engineering, Gunma University
Haruo KOBAYASHI
Department of Electronic Engineering, Graduate School of Engineering, Gunma University
Yukihiro FUJIMURA
Department of Electronic Engineering, Graduate School of Engineering, Gunma University
Nobukazu TAKAI
Department of Electronic Engineering, Graduate School of Engineering, Gunma University
Toshio SUGIYAMA
Toko, Inc.
Isao FUKAI
Toko, Inc.
Norihisa ONISHI
Toko, Inc.
Ichiro TAKEDA
Toko, Inc.
Jun-ichi MATSUDA
Toko, Inc.

Keywords: PWM control, spread-spectrum clock modulation, EMI, digitally-controlled DC-DC converter

JOURNAL RESTRICTED ACCESS

2009 Volume E92.A Issue 4 Pages 1004-1011

DOI https://doi.org/10.1587/transfun.E92.A.1004

Details

Abstract

This paper proposes spread-spectrum clock modulation algorithms for EMI reduction in digitally-controlled DC-DC converters. In switching regulators using PWM, switching noise and harmonic noise concentrated in a narrow spectrum around the switching frequency can cause severe EMI. Spread-spectrum clock modulation can be used to minimize EMI. In conventional switching regulators using analog control it is very difficult to realize complex spread-spectrum clocking, however this paper shows that it is relatively easy to implement spread-spectrum EMI-reduction using digital control. The proposed algorithm was verified using a power converter simulator (SCAT).

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