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

fYear

2013

fDate

21-25 July 2013

Firstpage

149

Lastpage

152

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;

fLanguage

English

Publisher

ieee

Conference_Titel

European Frequency and Time Forum & International Frequency Control Symposium (EFTF/IFC), 2013 Joint

Conference_Location

Prague

Type

conf

DOI

10.1109/EFTF-IFC.2013.6702047

Filename

6702047