用於生醫應用之回授型自動增益控制儀表放大器 及十位元連續逼近式類比數位轉換器

A Feedback Type Automatic Gain Control Instrumentation Amplifier with A 10-bit Successive Approximation ADC

王沛宜(Pei-Ye Wang)

指導教授 ： 呂學士

國立臺灣大學/電機資訊學院/電機工程學研究所/碩士(2009年)

https://doi.org/10.6342/NTU.2009.01685

摘要

近年來，隨著製程的縮小，使得系統單晶片的概念能夠實行，並且大量的應用在生醫方面。隨著科技的發展，藉著生醫晶片，人類的健康控制能夠更詳細，更完整且是及時且有效率的。在生醫應用中，由於生醫訊號通常都非常的微小且緩慢，所以我們需要一個前端的放大電路，先將這些微小的訊號放大到適合的大小來做後續的處理。在生醫應用中通常都需要非常低的功率消耗，故我們使用的是低功率，解析度中等及速度比較慢的漸近式類比數位轉換器在此應用當中。

在本論文的第一部份，一個低功率消耗十位元的漸近式類比數位轉換器將被實現，此類比數位轉換器利用門閘式時脈、功率開關及直接供應電壓為參考電壓之技巧，量測結果顯示此晶片操作於十萬赫茲轉換速度，其最高有效位元超過8.7位元。微分型線性誤差介於+0.6118/-1最小單位位元，積分型非線性誤差介於+1.4431/-1.4425最小單位位元，晶片面積為1.13mmx1.07mm，以TSMC 0.35um CMOS 2P4M製程製作。

另一方面，一個用於生醫應用之回授型自動增益控制儀表放大器及十位元漸近式類比數位轉換器將被實現。在此電路中，當需要自動增益控制時，漸近式類比數位轉換器的數位控制訊號會回授控制可程序控制的儀表放大器來得到不同的增益。此可程序控制儀表放大器有八種不同的增益，其開迴路增益為125dB，向位邊界為76度。此電路以TSMC 0.35um CMOS 2P4M製程製作，其供應電源為3V，功率消耗為504uW，晶片面積為1.25mmx1.36mm。

關鍵字

連續逼近式類比數位轉換器 ； 可程序控制儀表放大器 ； 自動增益控制放大器

並列摘要

In recent years, with the scaling down of process, the concept of system on chip (SoC) can be realized. With the development if technology, people can control their health more detailed and complete, instantaneously and effectively. Due to the features of biomedical signals, which are usually ultra-low slevels, low speed and large noise. Therefore, we need an instrumentation amplifier to amplify the signal to proper scale for the following application. Since the requirement of biomedical application needs low power consumption, a successive approximation analog to digital converter is adopted in our implementation, which has the features of low speed, low power consumption and moderate accuracy.
In the first part of this thesis, a 10-bit, low power, successive approximation is implemented. By using some techniques such as gating-clock, power switch and directly using supply voltage as reference voltage. The measurement results shows that while operating at 100KSPS, the maximum effective number of bits (ENOB) is higher than 8.7 bits. The measurements differential non-linearity (DNL) is between +0.6118/-1 LSB and the integral non-linearity (INL) is between +1.4431/-1.4425 LSB. The die area is 1.13mmx1.07mm fabricated in TSMC 0.35um CMOS 2P4M process.
On the other hand, a feedback type automatic gain control instrumentation amplifier with a 10-bit successive approximation analog to digital converter is realized. In this implementation, while automatic gain control is on, the digital control unit of SAR ADC will produce feedback controlling signals to adjust the gain of programmable instrumentation amplifier (PGIA). This PGIA has eight kinds of gain, its open loop gain is 125db and phase margin is 76 degree. The die area is 1.25mmx1.36mm, which is implemented in TSMC 0.35um CMOS process with 3V supply voltage and the power consumption is 504uW.

並列關鍵字

CMOS ； SAR ADC ； PGIA ； AGC

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