A Random Modulation Spread-Spectrum Digital PWM for a Low System Clock Digital Buck Converter

IEEE Access

卷:9

Seong-Won Lee¹  Ching-Jan Chen²  Chan-Ho Moon³ 

[1] Department of Computer Engineering, Kwangwoon University, Seoul, South Korea;

[2] Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan;

[3] Hanwha VisionNext, Seongnam, South Korea;

关键词: Digitally controlled buck converter;    spread spectrum;    dithering;    pulse-width modulation;   

DOI  :  10.1109/ACCESS.2021.3126556

来源: DOAJ

【 摘 要 】

The need for a high-efficiency power system has emerged since many IoT devices are mainly operated by batteries. A power system with analog control can have a high control bandwidth, but it is relatively vulnerable to noise disturbances and may suffer from control problems. On the other hand, a digitally controlled power system has high reliability and great controllability at the expense of switching noise and EMI issues. To implement a digitally controlled PWM with high resolution and low EMI, this study proposes a random carrier frequency modulation with dithered duty cycle method, where wide spectrum dithering and random modulation of spread spectrum PWM are tightly integrated. The proposed system was not only able to suppress voltage ripples, but also possible to minimize the occurrence of dependent frequencies due to the fixed dithering pattern. The spectrum of the output voltage showed that the switching frequency component was reduced by about 6.1dB and the output voltage ripples was also reduced compared to the existing PWM techniques.

【 授权许可】

Unknown