隨著科技不斷的發展，行動通訊裝置的功能有著越來越多需求，隨著智慧型手機廣泛的使用，以及越來越多APP的需求，無論是在耗電量亦或是提高速度或是高精準度甚至是面積都是數位類比轉換器設計的趨勢。因此本論文提出一種新的解碼器架構稱為指定編碼法，透過分組與編碼兩種方式減少電流單元開關的次數進而改善效能，並採用分段式電流導向架構使其與溫度計碼做結合，在較低的六個位元採用指定編碼架構而較高的六個位元採用溫度計碼，結合了指定編碼數位類比轉換器低面積低功耗及靜態效能的優點以及溫度計碼數位類比轉換器動態效能的優點，並且相較於傳統四位元二進制加權碼數位類比轉換器加八位元溫度計碼數位類比轉換器，由於電流單元大幅的減少了192個，使得晶片面積大幅的下降，考慮各方面效能、功耗以及所使用的面積設計出一種新的數位類比轉換器。

此設計採用TSMC 90nm製程製作。此數位類比轉換器的取樣速率和解析度分別為1GS/s和12位元。功率消耗為24.3毫瓦。模擬結果顯示，所提出的編碼技術，可以擁有高精度並可以取代溫度計碼以減少晶片面積。

關鍵詞：數位類比轉換器，高速度，高精準度，低面積，指定編碼。

With the continuous development of technology, mobile communication device has more and more demand for function, with the widespread use of smartphones and, increasingly, APP needs, whether in power saving or high speed or high precision even small area is the trend of present digital-to-analog converter circuit design. Therefore, this thesis proposes a new specify code for the decoder architecture. Grouping and Coding are two ways to reduce the switching of the current cell. It adapts a segmented current-steering architecture combining with the thermometer code. The segmented current steering architecture that comprises 6MSB’s thermometer code and 6LSB’s specified code is used, they combine the advantages of the specified code digital-to-analog converter’s small area, low-power and static specification and thermometer code digital-to-analog converter’s dynamic performance. Compare with traditional 8MSB’s thermometer code digital-to-analog converter and 4LSB’s binary-weighted digital-to-analog converter, due to the reduce of the 192 current cell, the chip area is much more small. Considering the performance, the power consumption, and the chip area, a new digital to analog converter is proposed.
The design is designed in TSMC 90nm CMOS process. The sampling rate and resolution of the DAC are 1GS/s and 12-bit, respectively. The power consumption is 24.3mW. The simulation results show that the proposed specified code DAC can achieve high precision and reduce the chip area by adapting the proposed specified code.

Key words: digital-to-analog converter, high speed, high precision, small area, the specified code.

論文審定書 i
中文摘要 ii
Abstract iii
目錄 iv
圖目錄 vi
表目錄 viii
Chapter 1 緒論 1
1.1 研究動機與目標 1
1.2 論文章節組織 2
Chapter 2 數位類比轉換器介紹 3
2.1 數位類比轉換器簡介 3
2.2 電流源式數位類比轉換器 4
2.2.1 二進制加權式數位類比轉換器 4
2.2.2 溫度計碼數位類比轉換器 5
2.2.3 分段式結構數位類比轉換器 8
2.3 數位類比轉換器設計考量 10
Chapter 3 指定編碼解碼器之數位類比轉換器 11
3.1 簡介 11
3.2 六位元指定編碼+六位元溫度計碼數位類比轉換器 11
3.3 六位元指定編碼數位類比轉換器 13
3.3.1 指定編碼法 16
3.3.2 指定編碼的電流單元組與檢視流程 19
3.3.3 編碼的指定方法與流程 21
3.3.4 指定編碼數位類比轉換器改良的優點 24
3.3.5 指定編碼與其他編碼的比較 27
3.4 六位元溫度計碼數位類比轉換器 28
3.5 偏壓電路 29
3.6 晶片佈局(Layout) 30
Chapter 4 模擬結果與電路比較 32
4.1 六位元指定編碼+六位元溫度計碼模擬結果 32
4.2 電路比較 36
Chapter 5 結論與未來展望 37
5.1 結論 37
5.2 未來展望 37
參考文獻 38

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