本計畫主要目標是開發在低供應電壓操作下，透過自動補償回授機制，補償因製程、電壓及溫度漂移之高穩定度低電壓參考時脈。現今，可攜式與消費性電子產品多需具有長時間使用的需求，以及維持穩定正常運作的能力，因此產品除須具有低功耗特性外，還須有穩定工作的能力及低製作成本優勢。本電路設計將捨棄原有大面積高耗電的類比數位/數位類比轉換器電路；在電流源方面將以金氧半場效電晶體作設計，減少晶片面積與功耗；並使用環形振盪器，取代大面積的電感電容振盪器；且加入自動補償回授機制，尋找元件本身對溫度、電壓及製程變化影響振盪器輸出頻率之相關係數，將其轉換成控制信號，以完成高穩定度之新型低供應電壓參考時脈電路設計，並進行晶片實現、驗證與測試。 The purpose of this project is to implement a high stability low-voltage reference clock generator with high process、voltage and temperature immunity by using auto-calibration feedback control mechanism in low supply voltage. Most of portable and consumer electronics need to meet long using time and stable operation requirements. Hence, those products have not only low-power but also working stable and low-cost characteristic. In order to reduce area and power dissipation, the ADC/DAC and Bandgap reference are not used in this design. Moreover, the LC oscillator is replaced by ring oscillator to reduce chip area. The process, voltage and temperature monitor circuits are designed to measure oscillator frequency variation for auto-calibration utilization. The oscillator performance is ensured by using auto-calibration feedback control mechanism. Therefore, the proposed high stability low-voltage reference clock generator will be implemented and measured.
