Title :
A Fully Integrated Spread Spectrum Clock Generator Using Two-Point Delta-Sigma Modulation
Author :
Hsieh, Yi-Bin ; Kao, Yao-Huang
Author_Institution :
Inst. of Commun. Eng., Nat. Chiao-Tung Univ., Hsin-Chu
Abstract :
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. 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 SSG has been fabricated in a 0.35mum CMOS process. The clock of 400MHz with center spread ratios of 1.25% and 2.5% are verified. The size of chip area is 0.90times0.89mm2.
Keywords :
CMOS integrated circuits; delta-sigma modulation; electromagnetic interference; interference suppression; phase locked loops; signal generators; voltage-controlled oscillators; 0.35 micron; 400 MHz; CMOS process; EMI suppression; modulation bandwidth; spread spectrum clock generator; two-point delta-sigma modulation; voltage controlled oscillator; Bandwidth; Clocks; Delta-sigma modulation; Digital modulation; Electromagnetic interference; Filters; Frequency; Phase locked loops; Spread spectrum communication; Voltage-controlled oscillators;
Conference_Titel :
Circuits and Systems, 2007. ISCAS 2007. IEEE International Symposium on
Conference_Location :
New Orleans, LA
Print_ISBN :
1-4244-0920-9
Electronic_ISBN :
1-4244-0921-7
DOI :
10.1109/ISCAS.2007.378600
