【摘要】 设计了一种应用于生物电信号采集的前端放大器。采用间接电流反馈技术,提高了放大器的线性度和共模抑制比。采用负反馈环路,消除了采集过程中电极产生的极化电压。采用0.18μm混合信号CMOS工艺对电路进行设计,使用Cadence Spectre进行了仿真。结果表明,该电路在3V供电下消耗的静态电流为4.5μA,在0.3Hz~1.3kHz的增益带宽内增益为37dB,能够消除50mV的极化电压,共模抑制比为98dB(50Hz工频处),噪声效率因子为11.5。更多还原

【Abstract】 A front-end amplifier(FEA)intended for biopotential signal acquisition was designed.A novel indirect current feedback instrumentation amplifier(ICFIA)was employed to improve the linearity and common-mode rejection ratio(CMRR)of the FEA.A negative feedback loop was used to eliminate the differential electrode offset(DEO)generated in the electrodes during signal acquisition.The circuit was designed in a 0.18μm mixed-signal CMOS process and simulated with Cadence Spectre.The simulation results showed that the circuit consumed a 4.5μA current from a 3 Vsupply.The gain of the FEA was 37 dB at a gain bandwidth range from 0.3 Hz to1.3 kHz.A DEO of 50 mV was eliminated,and a CMRR of 98 dB was obtained at the mains frequency(50 Hz).The noise efficiency factor(NEF)of the FEA was 11.5.更多还原