三階諧波石英晶體振盪器之研究

Abstract

本論文研究用於高頻時脈參考源諧波石英晶體震盪器，文中提到三種架構，針對第一種純由回授電阻選擇負電阻區的震盪器，求得交越零頻率以及諧波處負阻抗公式，進而發展出一套適用於CMOS製程的設計流程，在此設計流程內，考慮了穩定震盪的因素。此外，並討論第二種外加電感電容的架構。在最後並提出一種新的架構，能增加基本波處主動電路提供的正電阻，搭配上正向耦合邏輯輸出級，輸出波型符合ECL 100K之規範，以期待能與數位電路系統作一緊密的結合。

In this thesis, reference high frequency clock sources are studied. especially , the 3rd overtone crystal oscillator is focused. Three types are examined . In the first type, the frequency range of negative resistance is only controlled by the feedback resistance. The origin of the tuning is clearly illustrated. The second type involves external LC network to make circuit resistance positive at fundamental frequency. At last, a new design is presented to enhance the positive resistance at fundamental frequency, and with PECL output stage, desiring to make 3rd overtone crystal oscillator combine with digital circuit system more compactly.