摘要
针对传统斩波放大器功耗较大,以及电极的直流极化电压容易使得高增益放大器进入饱和状态的问题,提出一种适合应用于心电信号的放大器.该低功耗斩波放大器电路由一个两级放大器组成,第1级折叠共源共栅放大器的高输出阻抗与第1级和第2级之间的密勒等效电容组成一个低通滤波器,以滤除调制噪声.采用TSMC 0.18μm 1P4M工艺,对所提出的放大器结构进行电路设计.仿真结果表明:整个放大器带宽为0.2～170Hz,功耗为52μW,其等效输入噪声电压为150nV@0.1Hz,等效输入积分噪声为0.68μV(0.1～150Hz),具有较好的低功耗、低噪声特性.
In order to overcome the disadvantages that the conventional chopper amplifier consumes large power and is easily saturated with the DC offset of the skin-electrode interface, a low power amplifier is presented for electroencephalogram （EEG） monitoring applications. The chopper amplifier is composed of a two-stage amplifier. The high output impedance of the first stage folded cascade amplifier and the equivalent Miller capacitance constitute together a low pass filter to filter out the modulation noise. The circuit of the amplifier is designed in TSMC 0. 18μm 1P4M CMOS process. The bandwidth of the whole amplifier is from 0. 2 Hz to 170 Hz, and the power consumption is 52 btW. The equivalent input noise voltage of 150 nV@0. 1 Hz and the input integrated referred noise voltage of 0. 68 μV from 0. 1 Hz to 150 Hz are achieved. Simulation results show that the presented amplifier has characteristics of low power and low noise.
出处
《华侨大学学报（自然科学版）》
CAS
北大核心
2011年第6期633-637,共5页
Journal of Huaqiao University(Natural Science)
基金
福建省自然科学基金资助项目(2010J05135)
华侨大学高层次人才科研启动项目(09BS616)
关键词
斩波技术
放大器
失调电压
噪声
心电信号
chopping technique
amplifier
offset voltage, noise
electroencephalogram
