摘要
一些小型地磁传感器输出噪声电压水平在10 nV/Hz左右,现有nV级噪声水平的前置放大器体积太大难以满足其信号调理需求.针对这个问题,本文阐述了低噪声放大电路输入级设计原理,利用Multisim对输入级电路等效输入噪声电压等指标进行仿真,研制出一种基于差分输入的小型低噪声前置放大电路.给出了电路关键性能指标的仿真和测试结果,测试结果表明该电路具有良好的噪声特性和共模抑制比,噪声电压水平仅为3.7 nV/(Hz)～(1/2)@3.5 kHz,共模抑制比110 dB,增益为100～1 000连续可调.
The output noise voltage level of some small-size geomagnetic sensors is about10nV/√Hz.How -ever, existing comparative level pre-amplifier products are so large that could not satisfy conditioning requirement. To solve the problem, a small-size low noise amplifier circuit based on differential input is designed. The design principles of input-stage are expounded in this paper. Key indicators of equivalent input noise voltage and gain are simulated by Multisim. Finally, simulation and testing results are given, and testing results show that the circuit has achieved low noise voltage of 3.7 nV/√Hz@3.5kHz,high CMRR of 110 dB andvariable gain from 100 to 1 000.
出处
《测试技术学报》
2012年第6期518-523,共6页
Journal of Test and Measurement Technology
基金
国家自然科学基金"三轴一体化磁力线聚集调制GMR磁传感器关键技术研究"(51175507)资助项目
关键词
低噪声
前置放大器
噪声仿真
噪声电压测试
low noise
pre-amplifier
noise simulation
noise voltage measurement
