應用於心電圖之大信號低功耗金氧半帶通濾波器

Abstract

在人口高齡化及少子化的趨勢下，現代人對於醫療服務的需求與日俱增，尤其是健康管理及居家照護等方面已成為全球共同的趨勢。其中心臟訊號及時監控系統是結合了醫學與科技的產物。 本論文提出一應用於轉導電容式濾波器的大信號暨低功耗轉導運算放大器，濾波器具有低功耗與中心頻率可微調能力，可廣泛的應用於生醫訊號檢測系統。轉導運算放大器使用源極退化架構增加線性度，電晶體則操作於弱反轉區以達到降低功耗，透過調整轉導運算放大器偏壓電流而改變轉導值大小同時實現調整濾波器中心頻率。最後使用轉導運算放大器完成四階電感電容梯型帶通濾波器設計，並透過台灣積體電路公司所提供之0.18微米1P6M的標準互補式金氧半製程來完成晶片製作。 轉導電容式濾波器在1.8伏特操作電壓時，整體功率消耗為410nW，總諧波失真為-59.60dB，晶片面積為0.064mm2。

Nowadays, in the aging society with fewer children, people need more medical services, especially health management, and all aspects of home care has become a common trend in the world, in which the heart signal monitoring system is a combination of medicine and technology. In this thesis, a CMOS Gm-C filter based on operational transconductance amplifiers (OTAs) with low power and center frequency tuning ability for Bio-analytical applications is proposed. The OTA uses source degeneration to increase the linearity. In order to achieve low power consumption, MOSFETs are designed to work in the weak inversion region. The transconductance and center frequency of the filter can be tuned by changing its bias current. A Fourth-Order Butterworth LC ladder Gm-C bandpass filter implemented with the OTAs was fabricated by TSMC 0.18-μm 1P6M CMOS process. The total power consumption is 410nW and Total Harmonic Distortion is -59.60dB when the Gm-C filter operates at 1.8V power supply. The active area is 0.064mm2.