現在的電子產品中，只要有時序控制的電路，都需要時脈訊號才會運作。時脈訊號的精確度決定了電路的工作穩定度。因此，如何產生一個穩定頻率的時脈訊號，是近年來的重大課題之一。現在大部分的時脈訊號都是由石英振盪器所產生，主要是因為石英為目前頻率穩定度最高的振盪元件。然而，石英晶體有大面積、高功率消耗，及無法與CMOS製程做整合等缺點，因此過去幾十年來無論學界專家或公司研究團隊都試圖尋找能替代石英振盪器的方案。
近年來被提出取代石英振盪的方法有MEMS振盪器、FBAR振盪器，及CMOS振盪器。但是，MEMS與FBAR的製程技術困難，無法與CMOS電路整合；而CMOS振盪器因半導體特性易受環境影響，導致其振盪頻率會因工作溫度與供應電壓的變動而改變。也因此，到目前為止石英振盪器還無法完全被取代。不過，CMOS電路在設計上可加上適當的補償方式將穩定度提高，因此我們致力於CMOS振盪器，以標準製程下實現低功率消耗、具溫度補償的時脈產生器。
本篇論文提出具有優良溫度補償的CMOS時脈產生器，使其振盪頻率對溫度的變異極低。此外，透過只有一組充放電路路徑與除頻器，達到較低的頻率抖動程度(Jitter)與工作週期(Duty Cycle)接近50%的效果。此晶片使用 TSMC 0.18 μm 1P6M標準製程實現。

Clock signal is essential for any electronic circuits that require timing control. How to generate an accurate and stable clock signal becomes one of the most important issues. Nowadays most clock signals are generated by crystal oscillators primarily because of their excellent stability. However, in view of the drawbacks of quartz crystal such as large size, high power consumption, and being unable to be integrated into microelectronic process technology, for several decades, researchers had been exploring other technologies in order to replace quartz oscillators.
Recently, some methods such as MEMS, FBAR and CMOS oscillators were proposed. Unfortunately, MEMS and FBAR oscillators need complex and costly processes to realize and they still cannot be integrated with CMOS circuits. The characteristics of Si devices are easily influenced by the changing variables of the environment, leading the frequency of CMOS oscillators to be sensitive to temperature and supply voltage. These are the reasons why crystal oscillators still cannot be replaced so far. For CMOS oscillators, luckily, we can add some proper compensation to improve their stability. Thus, we tried to develop a CMOS oscillator with low power consumption and high temperature stability.
In this paper, a CMOS relaxation oscillator which is nearly insensitive to temperature variation is proposed. In addition, by using single charging and discharging path and a frequency divider, low jitter and nearly 50% duty cycle were achieved. This chip has been realized in the TSMC 0.18 μm 1P6M process.

摘要 i
Abstract ii
致謝 iii
目錄 iv
圖片目錄 vi
表格目錄 viii
第一章 緒論 1
1.1 研究背景 1
1.2 研究動機 2
1.3 論文章節架構 5
第二章 CMOS振盪電路 6
2.1 CMOS振盪電路簡介 6
2.2 頻率變異來源 7
2.3 前人技術延用 10
第三章 電路設計與改版過程 17
3.1 第一版電路架構 17
3.2 第二版電路架構 25
3.3 第三版電路架構 29
3.4 第四版電路架構 31
第四章 振盪器架構 32
4.1 電路架構 32
4.2 子電路 34
4.3 振盪頻率 42
第五章 模擬結果與晶片布局 43
5.1 模擬結果 43
5.1.1子電路模擬結果 43
5.1.2振盪器模擬結果 49
5.2 晶片布局 54
第六章 量測結果與討論 57
6.1 PCB版設計 57
6.2 量測儀器介紹 58
6.3 量測方法 60
6.4 量測結果 61
6.4.1 振盪器輸出波形 61
6.4.2 頻率受溫度之影響 63
6.4.3 頻率受供應電壓之影響 64
6.5 問題討論 66
第七章 結論與後續研究建議 77
7.1 結論 77
7.2 後續研究建議 78
參考文獻 80
附錄A 振盪器的所有模擬數據 83

[1] 林志遠, “電子產品當中不可或缺的時脈元件”

[2] Crystal oscillator frequencies, wikipedia。網址：https://en.wikipedia.org/wiki/Crystal_oscillator_frequencies

[3] Maxim Integrated產品介紹。網址：http://para.maximintegrated.com/en/search.mvp?fam=osc_mod&980=XO

[4] Maxim Integrated產品介紹。網址：http://para.maximintegrated.com/en/search.mvp?fam=siliosc&774=No

[5] B. Razavi, Design of analog CMOS integrated circuits. America: McGraw-Hill, 2001, pp. 361-367, pp. 392, pp. 599

[6] K. Sandaresan, P. E. Allen, and F. Ayazi, “Process and temperature compensation in a 7-MHz CMOS clock oscillator,” IEEE J. Solid-State Circuits, vol. 41, no. 2, pp. 433–442, Feb. 2006.

[7] Y. H. Chiang, and S. I. Liu, “A submicrowatt 1.1-MHz CMOS relaxation oscillator with temperature compensation,” IEEE Tran. Circuits Syst. II, Exp. Briefs, vol. 60, no. 12, pp. 837–841, Dec. 2013.

[8] G. Giustolisi, G. Palumbo, M. Criscione, and F. Cutrì, “A low-voltage low-power voltage reference based on subthreshold MOSFETs,” IEEE J. Solid-State Circuits, vol. 38, no. 1, pp. 151–154, Jan. 2003.

[9] H.-M. Chuang, K.-B. Thei, S.-F. Tsai, and W.-C. Liu, “Temperature-dependent characteristics of polysilicon and diffused resistors,” IEEE Trans. Electron Devices, vol. 50, no.5, pp. 1413-1415, May 2003.


[10] B. R. Gregoire and U.-K. Moon, “Process-independent resistor temperature-coefficients using series/parallel and parallel/series composite resistors,” in Proc. ISCAS, May 2007, pp. 2826–2829.

[11] 林妤珊, “一個具有精準責任週期的參考振盪器” , 國立清華大學, 電子工程研究所, 碩士論文, 中華民國一百零二年七月

[12] Y. Tokunaga, S. Sakiyama, A. Matsumoto, and S. Dosho, “An on-chip CMOS relaxation oscillator with voltage averaging feedback,” IEEE J. Solid-State Circuits, vol. 45, no. 6, pp. 1150-1158, Jun. 2010.

[13] Donald A. Neamen, Microelectronics circuit analysis and design, Fourth edition. America: McGraw-Hill, 2010, pp. 1100-1103, pp. 1105-1106

[14] C. F. Lee and P. K. T. Mok, “A monolithic current- mode DC-DC converter with on-chip current-sensing technique,” IEEE J. Solid-State Circuits, vol. 39, no.1, pp. 3-14, Jan. 2004.

[15] F. Sebastiano, L. J. Breems, K. A. A. Makinwa, S. Drago, D. M. W. Leenaerts, and B. Nauta, “A low-voltage mobility-based frequency reference for crystal-less ULP radios,” IEEE J. Solid-State Circuits, vol.44, no. 7, pp. 2002–2009, Jul. 2009.
[16] Y.-H. Lam and S.-J. Kim, “A 16.6μW 32.8MHz monolithic CMOS relaxation oscillator,” in Proc. IEEE Asian Solid-State Circuits Conf., Nov. 2014, pp. 161–164.
[17] Z. Xu, W. Wang, N. Ning, W.-M. Lim, Y. Liu, and Q. Yu, “A supply voltage and temperature variation-tolerant relaxation oscillator for biomedical systems based on dynamic threshold and switched resistors,” IEEE Trans. Very Large Scale Integr. (VLSI) Systems, vol. 23, no.4, pp. 786-790, April 2015.
[18] J. Wang, L.-G. Wang, X. Liu and J. Zhou, “A 12.77-MHz on-chip relaxation oscillator with digital compensation for loop delay variation,” in Proc. IEEE Asian Solid-State Circuits Conf, pp. 1–4, Nov. 2015.

[19] J. Wang and L.-G. Wang, “A 13.5-MHz relaxation oscillator with ±0.5% temperature stability for RFID application,” IEEE International Symposium. Circuit and Systems, pp. 2431–2434, May. 2016.
[20] Y.-K. Tsai and L.-H. Lu, “A 51.3-MHz 21.8-ppm/°C CMOS relaxation oscillator with temperature compensation,” IEEE Trans. Circuit and Systems II, Jun 2016