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  • 學位論文

應用於可攜式生醫系統以壓控震盪器為基礎之低功率三角積分調變器

Low Power VCO-Based ΔƩ Modulator for Portable Bio-Medical Applications

指導教授 : 汪重光
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摘要


近年來,由於人口老化與越來越多的慢性疾患者造成了越來越龐大的醫療支出,為了解決這個迫切的問題,以病患為中心的醫療概念因此應運而生。以病患的為中心的概念係指在病患端即可自行監測病況、自行控制病情、自行診斷病因與自行治療病灶,而為了達成以上理念,有越來越多的研究投入如何實現一個可靠的電路系統且方便於病患使用與配戴。在電路系統中,類比數位轉換器是用於溝通自然界的類比訊號與計算機界的數位訊號之橋梁,因其腳色關乎電路系統處理的最終效能,所以尤為重要。本篇論文提出一個以壓控震盪器為基礎的三角積分調變器擔當類比數位轉換器的角色,在擁有足夠的解析度下,僅消耗奈米瓦特並只需零點零六微米平方面積即可實現,亦即達到可攜式生醫系統所需的方便性與可靠性的要求。 此以壓控震盪器為基礎的三角積分調變器,在不需要使用任何的放大器下,利用了電壓縮放技巧與中心頻率自我校正技術,等效提升系統之線性度並最佳化壓控震盪器的供應電壓使調變器達到接近十位元的有效解析度。此晶片以零點一八微米的互補式金屬氧化物半導體製程製作,用於實現以壓控震盪器為基礎的三角積分調變器與中心頻率自我校正技術的面積分別為零點零三與零點零二八微米平方,而其工作所消耗的功率則分別為三百七十九與三百零三奈米瓦。其中,自我校正技術可將壓控震器之中心頻率從一百七十九萬五千赫茲修正至一百七十五萬一千赫茲,其相位雜訊在十萬赫茲偏移頻率位置可達每赫茲負一百零一分貝並只需要一百二十個週期即可校正完成。另外在調變器方面,在輸入頻率為八百八十一點零一赫茲、差分振幅為零點零七伏特且計算頻寬為兩千赫茲下,訊號與雜訊比最大可達到五十九點八分貝,而訊號與雜訊加失真比則可達五十八點五分貝。

並列摘要


Aging population and growing chronic patients are becoming urgent things to be resolved. Patient-centered medical home is a solution to mitigate these impacts by the concepts of self-monitor, self-control, self-diagnosis, and self-treatment. In order to achieve these goals, convenient, flexible and portable circuit systems for bio-medical applications are researched popularly especially in the analog-to-digital converters (ADCs). Because ADCs are bridges of communication between the digital signal and the weak analog signal form nature world. This thesis presents a nano-Watt and 0.06mm2-ranked VCO-based delta-sigma modulator with sufficient resolution for portable bio-medical applications to achieve circuit requirements of convenient and flexible. In the VCO-based delta-sigma modulator, the voltage scaling technique and center frequency self-calibration technique are proposed to achieve near 10 effective-number-of-bits (ENOB) without any additional amplifiers. In addition, the optimum supply voltage of the ring VCO is interpreted. This chip is fabricated in a 0.18μm CMOS process. The VCO-based delta-sigma modulator and center frequency self-calibration technique occupy an active area of 0.032mm2 and 0.028mm2 respectively and separately consume 379nW and 303nW. The self-calibration technique takes 120 sampling periods to correct the center frequency of the ring VCO from about 1.795MHz to 1.751MHz with -101.6dBc/Hz phase noise at 100kHz, which is within the range of 10 ENOB requirement. With an 885.01Hz 0.7Vpp-diff input signal, the modulator achieves peak signal-to-noise ratio (SNR) of 59.8dB and signal-to-noise plus distortion ratio (SNDR) of 58.5dB over bandwidth of 2kHz.

參考文獻


[5] R. F. Yazicioglu, P. Merken, R. Puers, and C. V. Hoof, “A 60μW 60nV/√Hz Readout Front-End for Portable Biopotential Acquisition Systems,” IEEE Journal of Solid-State Circuits, vol. 42, pp. 1100-1110, May 2007.
[6] N. V. Helleputte, S. Kim, H. Kim, J. P. Kim, C. V. Hoof, and R. F. Yazicioglu, “A 160uA Biopotential Acquisition ASIC with Fully Integrated IA and Motion-Artifact Suppression,” IEEE International Solid-State Circuits Conference, pp. 118-120, February 2012.
[7] J. Yoo, L. Yan, D. E. Damak, M. B. Altaf, A. Shoeb, H. J. Yoo, and A. Chandrakasan, “An 8-Channel Scalable EEG Acquisition SoC with Fully Integrated Patient-Specific Seizure Classification and Recording Processor,” IEEE International Solid-State Circuits Conference, pp. 292-294, February 2012.
[9] K. H. Lee, J. Nam, S. Choi, H. Lim, S. Shin, and G. H. Cho, “A CMOS Impedance Cytometer for 3D Flowing Single-Cell Real-Time Analysis with ΣΔ Error Correction,” IEEE International Solid-State Circuits Conference, pp. 304-306, February 2012.
[10] K. Song, H. Lee, S. Hong, H. Cho, and H. J. Yoo, “A Sub-10nA DC-Balanced Adaptive Stimulator IC with Muultimodal Sensor for Compact Electro-Acupuncture System,” IEEE International Solid-State Circuits Conference, pp., February 2012.

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