This thesis describes offset cancellation technique of CMOS amplifier for biological signal processing LSI. Our labratory try to develop the LSI for s-EMG (surface-Electromyogram). s-EMG has low-frequency and very small signal, so it needs to amplify for signal processing. But offset arises from mismatch caused by process variations, and it is very difficult to discriminate between s-EMG and offset. Thus biological signal processing LSI needs offset cancellation circuit to attenuate offset infection. DC servo circuit is one of the offset cancellation circuit. But DC servo circuit needs large passive component's value for low-frequency signal such as s-EMG. This causes an obstruction to integrate each circuit of biological signal processing LSI into one chip. To solve this problem, I propose hybrid mode servo circuit. This circuit's cut-off frequency (fc) can be lower by reducing transconductance (gm) of OTA used in integrator and increasing attenuation rate of attenuator. So this circuit can cancel offset without large passive component's value for low-frequency signal. The performance of the proposed circuit is evaluated through HSPICE simulation with 0.6μm CMOS device parameters. The simulation results are reported in this thesis.
雑誌名
宮崎大學工學部紀要
巻
45
ページ
153 - 158
発行年
2016-07-29
出版者
宮崎大学工学部
Miyazaki University
Faculty of Engineering, University of Miyazaki
リポジトリのご案内
ハイブリッドモードサーボ方式を用いた増幅回路のオフセット低減に関する研究
本文
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