應用於生醫系統之類比數位轉換器設計

The Design of Analog-to-Digital Converter for Bio-Medical Application

許升睿(Sheng-Ruei Hsu)

指導教授 ： 呂學士

國立臺灣大學/電機資訊學院/電子工程學研究所/碩士(2011年)

https://doi.org/10.6342/NTU.2011.10539

摘要

隨著人口老化、社會結構改變，生醫領域相關應用在近幾年蓬勃發展，並逐漸成為顯學。電機電子領域人才開始將研究重點從消費性電子產品轉向生醫領域，並希望對於未來將發生的老年化社會做充足的準備。本論文即順應此潮流，目標在於設計適合應用於生醫系統的類比數位轉換器。
本論文總共設計二個類比數位轉換器。首先是一個三角積分調變器，此架構在過去文獻中顯示適合用於高解析度的應用。我們使用台積電CMOS 0.35um製程，並且使用傳統切換式電容二階的架構，其具有天生良好的的穩定性。預計設計的頻寬為22.05KHz，取樣頻率為2.56MHz，代表超取樣率為56。在3伏的供應電壓操作下，我們量測到最大訊雜比為49dB，大約為7.8有效位元，並且達到54dB動態範圍，面積為0.98x0.68mm2，所消耗的功率為3mW。
第二個電路為連續漸進式類比數位轉換器，其電路特色在於有相當低的功率消耗。我們使用台積電CMOS 0.18um製程，並且操作在1伏的電源供應以達到省電。解析度設定為10位元。我們使用整數型電容橋技術，除了節省面積外，也可以有良好的電容匹配度。我們的取樣頻率為400KHz，在Nyquist rate操作情況下，我們量測結果有最大訊雜比49.3dB，大約為7.9有效位元。靜態參數INL為2/-1.9LSB、DNL為1/-0.9 LSB，功率消耗為9.5uW，達到FOM為99fJ/conv.，其快現在近年來的文獻中，有相當好的競爭力。

關鍵字

生醫 ； 類比數位轉換器 ； 三角積分 ； 連續漸進式

並列摘要

Since the life of human beings has been extended and social structure changed, biomedical application area has been fast developed and becomes a vital issue. Electrical engineers have turned their attention from consumer products to biomedical area. In order to follow this trend, we design ADCs that are suitable for biomedical application.
In this thesis, we have designed two ADCs. First, a sigma delta modulator is presented. Its structure is suitable for high-resolution application from the result of past references. We use TSMC CMOS 0.35um process. The structure is switch-capacitor second-order architecture. Target bandwidth is 22.05KHz and have sampling rate 2,56MHz, that means we have OSR of 56. Under 3-V power supply condition, the maximum SNDR is 49dB, which is about 7.8 ENOB, and achieving 54dB dynamic range. Total area is 0.98x0.68mm2 and power consumption is 3mW.
The second ADC is successive approximation ADC, the property of this circuit is low power consumption. This circuit is fabricated in TSMC 0.18um process and operates under 1-V power supply in order to save power. The target resolution is 10-bit. We use integer capacitor bridge to save chip area and maintain good capacitor mismatch. Our sampling frequency is 400KHz. Under Nyquist rate operation, maximum SNDR is 49.3dB, which is about 7.9 ENOB. Static testing performances INL is 2/-1.9 LSB and DNL is 1/-0.9 LSB. Power consumption is 9.5uW, FOM is 99fJ/conv., which is competitive among references.

並列關鍵字

Biomedical ； ADC ； Sigma-Delta ； SAR

參考文獻

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