標題: | A high performance spread spectrum clock generator using two-point modulation scheme |
作者: | Kao, Yao-Huang Hsieh, Yi-Bin 傳播研究所 Institute of Communication Studies |
關鍵字: | phase-locked loops (PLLs);spread spectrum;two-point;fractional-N |
公開日期: | 1-六月-2008 |
摘要: | A new spread spectrum clock generator (SSCG) using two-point delta-sigma modulation is presented in this paper. Not only the divider is varied, but also the voltage controlled oscillator is modulated. This technique can enhance the modulation bandwidth so that the effect of EMI suppression is improved with lower order Sigma Delta modulator and can simultaneously optimize the jitter and the modulation profile. In addition, the method of two-path is applied to the loop filter to reduce the capacitance value such that the total integration can be achieved. The proposed SSCG has been fabricated in a 0.35 mu m CMOS process. The clock of 400 MHz with center spread ratios of 1.25% and 2.5% are verified. The peak EMI reduction is 19.73 dB for the case of 2.5%. The size of chip area is 0.90 X 0.89 mm(2). |
URI: | http://dx.doi.org/10.1093/ietele/e91-c.6.911 http://hdl.handle.net/11536/8733 |
ISSN: | 0916-8524 |
DOI: | 10.1093/ietele/e91-c.6.911 |
期刊: | IEICE TRANSACTIONS ON ELECTRONICS |
Volume: | E91C |
Issue: | 6 |
起始頁: | 911 |
結束頁: | 917 |
顯示於類別: | 期刊論文 |