A Low Power Gm-C Filter for EEG Conditioning

• Main Authors: Chia-MingKuo, 郭嘉銘
• Other Authors: Ming-Shaung Ju
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/58420025163780222890

碩士 === 國立成功大學 === 奈米科技暨微系統工程研究所 === 98 === In this thesis, two kinds of fifth-order differential Gm-C low pass filters are presented. Three operational transconductance amplifiers (OTAs) are employed to realized the filters, namely, the multiple-input-differential-output (MIDO) OTA, the current-mirror-output-differential-input (CMDI) OTA, and the multiple-output-differential-input (MODI) OTA. The fifth-order OTA-C low pass filter was micro-fabricated by using the CMDI and MODI OTA design which required smaller area of die and lower power consumption. The simulated results showed a dynamic range of 51.2dB, while harmonic distortion components were below -50dB for differential input signals up to 100mV peak to peak (Vp-p). The power consumption of this filter was below 320nW, the supply voltage was 1V, and the active area of die was 0.176 mm2. This chip was fabricated with 0.18-μm CMOS process in TSMC. The measured results indicated that this low-voltage and low-power filter possessed the dynamic range of 30.5dB, while total harmonic distortion was less than -40dB for 60mVp-p input. According to the testing results, this filter can be adopted to eliminate the out-of-band interference of the electroencephalography (EEG) whose signal bandwidth is below 100Hz.