基于斩波技术的静电悬浮加速度计驱动电路噪声抑制方法研究

Research on Noise Suppression Method of Electrostatic Suspension Accelerometer Driving Circuit Based on Chopper Stabilization

静电悬浮加速度计驱动电路作为整机噪声的主要来源之一,其低频噪声性能直接决定静电悬浮加速度计整机分辨率。为满足静电悬浮加速度计驱动电路超低测量频带内(1mHz^1Hz)噪声均低于5×10^-5V/Hz1/2要求,依据斩波稳定技术对于低频噪声的抑制作用,设计了基于斩波稳定技术的静电悬浮加速度计驱动电路。对实际电路进行测量,利用静电悬浮加速度计噪声曲线拟合测量结果。结果表明,经斩波后驱动电路低频噪声转折频率与低频噪声均下降一个数量级,在测量频带内电路噪声均低于2×10^-5V/Hz1/2,满足了设计指标要求。

The driving circuit of electrostatic suspension accelerometer is one of the main sources of the whole machine noise.In order to meet the requirement that the noise in the ultra-low measurement frequency band(1 mHz^1 Hz)of the electrostatic suspension accelerometer drive circuit is less than 5×10^-5V/Hz1/2,according to the suppression effect of chopper stabilization technology on low frequency noise,the drive circuit of electrostatic suspension accelerometer based on chopper stabilization technology is designed.The actual circuit is measured and the noise curve of electrostatic suspension accelerometer is used to fit the measurement results.The results show that,the turning frequency and low frequency noise of the driving circuit decrease by an order of magnitude with chopper driving circuit,and the circuit noise in the measured frequency band is less than 2×10^-5V/Hz1/2,which meets the requirements of the design index.