一种超低非线性失真的采样系统设计

DESIGN OF AN ULTRA-LOW NONLINEAR DISTORTION SAMPLING SYSTEM

提出一种应用在数字采样电桥中的超低非线性失真的采样系统的设计方法,该采样系统的非线性失真在1 V范围内不超过40μV,在5 V范围内不超过32μV/V。在采样过程中,为降低信号切换开关对处于平衡状态的数字电桥的影响,在采样系统的模拟前端使用了分布参数匹配的方法。给出设计的采样系统在数字电桥中的应用,该数字采样电桥在1 kHz激励频率下对四端对标准电阻、电感及电容进行测量,实验结果表明,该桥的测量精度可达0.01%。

This paper proposes a method of ultra-low nonlinear distortion sampling system applied in digital sampling bridge.The nonlinear distortion of the sampling system did not exceed 40μV in the range of 1 V,and did not exceed 32μV/V in the range of 5 V.In the sampling process,in order to reduce the influence of the signal switching switch on the balanced digital bridge,a distributed parameter matching method was used in the analog front end of the sampling system.The paper gave the application of the designed sampling system in the digital bridge.The digital sampling bridge measured the four-terminal standard resistance,inductance and capacitance at the excitation frequency of 1 kHz.The experimental results show that the accuracy of the bridge is up to 0.01%.