以標準CMOS製程實現1V輸入切換電容式升壓至3V到6V之神經刺激器

A 1V Input, 3-to-6V Output, Switched-Capacitor Type Stimulator Using Standard CMOS Technology

柯聖安(Sheng-An Ko)

指導教授 ： 黃柏鈞

國立清華大學/電機資訊學院/電機工程學系/碩士(2014年)

摘要

從已知的研究顯示，功能性電刺激可以用來治療許多的神經性疾病，如心律不整、感覺神經性耳聾、帕金森氏症等疾病，將輸入訊號刺激組織細胞進而調節神經細胞非正常的活動來治療疾病。在生醫植入式裝置中神經刺激器的設計考量中，為了達到有效的刺激效果，需要在電路中產生高電壓，並且一則考量電路的面積大小達到能夠整合於植入式裝置中，另一則考量電路的轉換效率達到有利於長時間的使用。
在本論文中，研究可以提供功能性電刺激的神經刺激器，其中包含升壓電路和高電壓驅動器電路。在升壓電路方面，提出新的混合式架構與分析其電路的數學模型。為了使電路在大範圍輸出電壓皆在高轉換效率的操作，提出切換級數的電路操作。進一步考量寄生電容對轉換效率的影響，提出輔助寄生提升路徑來達到提升整體電路轉換效率的電路技巧。利用混合式架構可以使用製程中不同種類的電容，將不同製造方式的電容整合在相同面積下達到面積最小化。使用0.18um標準CMOS製程的實驗結果顯示，升壓電路在負載電流為30uA-240uA的情況，可以將1V的輸入電壓達到3V-6V的輸出電壓。整體系統利用切換級數的操作可以在3V-6V的大範圍輸出電壓之中，達到轉換效率皆在48%-58%之間。在高電壓驅動器電路方面，改裝可以提供定電壓輸出的高電壓驅動器使其可以提供定電流的輸出。整合升壓電路和驅動器電路的模擬顯示，最高可以達到提供60us脈衝時間、120uA脈衝電流的功能性電刺激訊號。

關鍵字

功能性電刺激 ； 生醫植入式裝置 ； 神經刺激器 ； 升壓電路 ； 高電壓驅動器電路

並列摘要

Recent studies have shown that functional electrical stimulation can be used to treat neurological disorders, like cardiac dysrhythmia, sensorineural hearing loss, Parkinson's disease, and other diseases. A high voltage neuron stimulator is used in biomedical implantable devices. The chip size is considered to achieve an implantable device. High efficiency of the converter is also important to have long operating life.
In this thesis, a neuron stimulator, which provides a functional electrical stimulation, consists of a voltage multiplier and a high voltage driver circuit. A novel hybrid architecture is proposed and analyzed with a mathematical model. The circuit supplies a wide range output voltage of high efficiency with the proposed switching stages circuit operation. The hybrid architecture allows the use of different types of on chip capacitor to minimize the chip area. The proposed circuit technique of parasitic auxiliary path improves the efficiency of the whole circuit.
The voltage multiplier with 1V input can achieve 3V to 6V output voltage under the loading current from 30uA to 240uA using a standard 0.18um CMOS process technology. The measurement results demonstrate that the efficiency of the overall system reaches 48% to 58% over a wide range of output voltages. A constant voltage output circuit is transformed into a constant current output circuit. The simulation shows that the 60us pulse width and 120uA constant current functional electrical stimulation is provided by an integrated voltage multiplier and high voltage driver.

並列關鍵字

functional electrical stimulation ； biomedical implantable device ； neuron stimulator ； voltage multiplier ； high voltage driver

參考文獻

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