近年來由於可攜帶式電子產品蓬勃發展，在能量消耗考量為主的應用中，如可攜式行動裝置、生醫電子系統、以及無線感測器等，這類型產品的一大電源議題就是本身都會是難以更換電池，甚至是無法更換，也因此透過能量擷取電路的特性來緩解產品的電源議題。
然而，在以大自然能量為來源的前提下，輸入變化卻往往會超過一般設計中能穩定操作的範圍，也因此在電路的設計上就以擴大輸入電壓範圍為目標進行。
本論文所提出的架構使用了開關電容陣列的切換來達成提升輸入電壓範圍至250mV~1.2V，並給予輸出電壓可離散性的變換7個不同準位高低，以及維持全系統輸入輸出端對端轉換效率在40%以上(300mV~1.2V輸入)的結果，並將全設計以台積電90奈米製程實作，大部份運作關鍵的電容皆已經整合入晶片中，因此外部印刷電路板僅有使用者的測試訊號開關以及電源端的去耦合電容存在，更加的符合體積的需求，並且全晶片不需接外部參考電壓輸入下運作，但仍具有保留從外部擴充關鍵被動元件的設計。

This thesis proposes a method to take advantage of the configurable capacitor array to cope with the input voltage instability caused by changes in ambient energy input variation in energy harvesting applications. The work attempts to integrate all the circuit components including most parts of passive components on a chip. The proposed design can operate with only on-chip capacitors, so it will reduce the total PCB layout area comparing to other designs with off-chip capacitors or inductors.

The proposed energy harvesting circuit can extend its input voltage to a much wider range in theory and is not limited by the boundary of set-up conversion or step-down conversion when implemented only one, but not both. It is because the proposed work can provide both step-up and step-down conversion simultaneously. At the output side, the circuit adds a custom digital regulator to make the output voltage adjustable to seven different voltage levels by only control signals without additional reference voltages.

The design achieves 77% in overall end-to-end peak efficiency. With adaptive conversion ratio control, the work can maintain its conversion efficiency above 40% for the input range from 300mV to 1.2V.

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