Journal of South China University of Technology (Natural Science Edition) ›› 2011, Vol. 39 ›› Issue (2): 7-11.doi: 10.3969/j.issn.1000-565X.2011.02.002

• Electronics, Communication & Automation Technology • Previous Articles     Next Articles

Design of Digitally-Controlled Crystal Oscillator for GSM/EDGE Radio-Frequency Integrated Chip

 Chen Xu1 Chen Xiao-qiang2 Xu Feng1 Wang Xin-an1   

  1. 1. Beijing university shenzhen graduate school integration Microsystems key laboratory, shenzhen, guangdong 518055; 2. Zte stock Co., LTD xian r&d center, xian in shaanxi 710065
  • Received:2010-04-21 Revised:2010-08-09 Online:2011-02-25 Published:2011-01-02
  • Contact: 陈勖(1977一)，男，讲师，博士，主要从事RFIC研究 E-mail:chenxu@szpku.edu.cn
  • About author:陈勖(1977一)，男，讲师，博士，主要从事RFIC研究
  • Supported by:

    国家“863”计划项目(2006AA04A112)；深圳市产学研资助项目(SZKJ-2008005)

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Abstract:

By analyzing the quartz crystal oscillator with the equivalent small-signal model,a digitally-controlled crystal oscillator（DCXO） for GSM/EDGE RF transceiver chips is designed and implemented.DCXO,in Colpitts structure,uses the automatic-gain negative feedback to control the circuit amplitude and adopts a digitally-controlled capacitor array to adjust the stability of transient frequency.The whole circuit is implemented via the TSMC 0.18μm CMOS technology,with a center frequency of 26MHz.Simulated results in the case of 1.8V power supply show that（1） DCXO is of a digitally-controlled range of 123×10-6@26MHz,a regulation accuracy of 0.0075×10-6 per step,a startup time of about 1.5ms and an oscillation peak of about 1.2V;（2） the phase noises respectively reach-145.800dBc/Hz at 1kHz and-153.032dBc/Hz at 10kHz offset;and（3） the total power consumption of DCXO is only 3 mW.

Key words: digitally-controlled crystal oscillator, phase noise, automatic frequency control