應用於人工電子耳之低功率金氧半帶通濾波器

Abstract

本論文提出一個應用於CMOS轉導電容式濾波器的低轉導運算放大器，濾波器具有低功耗與可調能力，可廣泛的應用於生物醫學領域。運算轉導放大器偏壓操作於弱反轉區，放大器轉導值大小可經由偏壓電流調整而改變。使用運算轉導放大器完成四階帶通電感電容梯型濾波器設計，並使用 TSMC 0.18-μm Mixed Signal 1P6M CMOS 製程完成晶片製作，將轉導電容式濾波器操作在0.65伏特的供應電壓時，可得到最低的功率消耗，在1伏特的操作電壓下，當輸入信號為300 Hz 峰對峰值電壓為0.1伏特，第一顆IC濾波器整體的功率消耗為225nW，總諧波失真為-48.58 dB，第二顆IC濾波器整體的功率消耗為61nW，總諧波失真為-50.23 dB，晶片面積皆為0.04mm2。

In this thesis, a CMOS Gm-C filter based on operational transconductance amplifiers (OTAs) with low power and tuning ability for biomedical applications is proposed. The OTA works in the weak-inversion region. The transconductance 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 Mixed Signal 1P6M CMOS process. The supply voltage of the OTA-C filter can be as low as 0.65V for minimum power. The power consumption of the first IC is 225nW for a sinusoidal input signal of 300 Hz 100 mVPP with 1V supply voltage. Its Total Harmonic Distortion (THD) is -48.58 dB. The power consumption of the second IC is 61nW for a sinusoidal input signal of 300 Hz 100 mVPP with 1V supply voltage. The THD is -50.23 dB. They both have the same active area of 0.04mm2.