A low-power and portable spread spectrum clock generator for SoC applications

Abstract—In this paper, a novel portable and all-digital spread spectrum clock generator (ADSSCG) suitable for system-on-chip (SoC) applications with low-power consumption is presented. The proposed ADSSCG can pro-vide flexible spreading ratios by the proposed rescheduling division trian-gular modulation (RDTM). Thus it can provide different EMI attenuation performance for various system applications. Furthermore, the proposed ADSSCG employs a low-power digitally controlled oscillator (DCO) to save overall power consumption significantly. Measurement results show that power consumption of the proposed ADSSCG is 1.2 mW (@54 MHz), and it provides 9.5 dB EMI reductions with 1 % spreading ratio. Besides, the proposed ADSSCG has very small chip area as compared with conven-tional SSCGs which often required large on-chip loop filter capacitors. In addition, the proposed ADSSCG is implemented only with standard cells, making it easily portable to different processes and very suitable for SoC applications. Index Terms—All digital spread spectrum clock generator (ADSSCG), digitally controlled oscillator (DCO), low power, portable, triangular modulation. I