155MHz基本波壓控石英振盪器之研究

Abstract

本論文針對同步光纖通訊網路STM-1傳輸規格製作一155MHz高頻基本波壓控石英振盪器，以應用在光接收機中的時脈回復電路，作為決策電路的訊號源。石英共振器為Inverted Mesa型，其基本波共振在155MHz，輸出訊號採用正向射極耦合邏輯(PECL)，適合在高速數位系統中使用。除了石英共振器為外掛，電路部份使用TSMC 1P4M 0.35μm CMOS製程實現，以縮小電路體積。其量測結果在3伏特的電源供應下，工作週期為47.9%，當電源變動±5%時，最大頻率飄移為3ppm。在0~2伏特的可調電壓範圍內，可調頻率為±50ppm，輸出訊號抖動方均根值及峰對峰值分別為2.168ps及16.12ps，在載波偏移1KHz處，相位雜訊為-132dBc/Hz，輸出波形符合ECL 100K規範。

In this thesis, a 155MHz high frequency fundamental mode VCXO (Voltage Controlled Crystal Oscillator) for the clock recovery circuit of SONET/SDH STM1 system is presented. The inverted Mesa type crystal operated at fundamental mode is employed. The output level is featured with PECL for high speed applications. Except for the crystal, the circuit is totally integrated by the standard 0.35μm CMOS technology for volume reduction. Under the 3 volt power supply, the supply pulling is 3ppm under ±5% voltage variation. The duty cycle is 47.9% and the tuning range is ±50ppm. The output levels are well within ECL 100K bounds. The measured rms jitter and peak-to-peak jitter are 2.168ps and 16.12ps, respectively. The optimal phase noise is -132dBc/Hz at 1KHz offset.