Title :
Study of phase noise in VCXO with inversion-mode varactors
Author :
Yao Huang Kao ; Teh Chau Liau
Author_Institution :
Dept. of Commun. Eng., Chung Hua Univ., Hsinchu, Taiwan
Abstract :
Voltage controlled crystal oscillators (VCXO) using CMOS varactors are investigated. The varactor is operated in the so-called inversion mode (I-Mode) with source and drain bounded together. Its capacitance is evaluated by the HSPICS-Fourier methodology. The performances of capacitance under small-signal and large-signal operations are classified. Then the frequency tuning and the related phase noise are explored. It is found that the larger the tuning coefficient has, the worse the phase noise has in I-mode varactor. The chip is fabricated by the TSMC 0.35um CMOS process. The total area including pad is 1.358 × 1.350 mm and the current consumption in the core circuit is 300uA.
Keywords :
CMOS integrated circuits; Fourier analysis; circuit tuning; crystal oscillators; integrated circuit design; integrated circuit noise; phase noise; varactors; voltage-controlled oscillators; CMOS varactor; HSPICS-Fourier methodology; I-Mode; TSMC CMOS process; VCXO; current 300 muA; current consumption; frequency tuning; inversion-mode varactor; phase noise; size 0.35 mum; voltage controlled crystal oscillator; Capacitance; Crystals; Phase noise; Resistance; Tuning; Varactors; Crystal Oscillator; Frequency Control; Inversion-mode; VCXO; Varactor;
Conference_Titel :
European Frequency and Time Forum & International Frequency Control Symposium (EFTF/IFC), 2013 Joint
Conference_Location :
Prague
DOI :
10.1109/EFTF-IFC.2013.6702047
