Simulation of a Monolithic Integrated CMOS Preamplifier for Neural Recordings  

提取神经电信号的单片集成CMOS前置放大器的仿真研究(英文)

作　　者：隋晓红[1] 刘金彬[1] 顾明[1] 裴为华[1] 陈弘达[1] 

机构地区：[1]中国科学院半导体研究所集成光电子学国家重点联合实验室,北京100083

出　　处：《Journal of Semiconductors》2005年第12期2275-2280,共6页半导体学报（英文版）

基　　金：国家高技术研究发展计划(批准号:2003AA302240,2003AA312040);国家自然科学基金(批准号:60536030)资助项目~~

摘　　要：A monolithic integrated CMOS preamplifier is presented for neural recording applications. Two AC-coupied capacitors are used to eliminate the large and random DC offsets existing in the electrode-electrolyte interface. Diode-connected nMOS transistors with a negative voltage between the gate and source are candidates for the large resistors necessary for the preamplifier. A novel analysis is given to determine the noise power spectral density. Simulation results show that the two-stage CMOS preamplifier in a closed-loop capacitive feedback configuration provides an AC in-band gain of 38.8dB,a DC gain of 0,and an input-referred noise of 277nVmax, integrated from 0. 1Hz to 1kHz. The preamplifier can eliminate the DC offset voltage and has low input-referred noise by novel circuit configuration and theoretical analysis.提出一种用于提取神经电信号的新型单片集成CMOS前置放大器.在放大器输入端引入的交流耦合电容可以消除存在于电极电解液之间的电极极化电压,栅源电压为负值的二极管连接的nMOS晶体管能够作为大电阻,并且占用很小芯片面积,可以通过此大电阻为前置放大器提供直流偏置,同时不影响输入阻抗值.通过对输入级进行理论噪声分析,确定了放大器中的各个器件参数.仿真结果表明,由于采用电容负反馈结构,此放大器的交流增益为38.8dB,无直流增益,在0.1Hz～1kHz频率范围内,总输入等效噪声为277nVrms.

关 键 词：PREAMPLIFIER DC offset input-referred noise 

分 类 号：TN722.71[电子电信—电路与系统]