基于二分程控法消失调电压的微电流测量方法  

Microcurrent Measurement Method Based on Dichotomy Programmable Eliminating Offset Voltage

作　　者：王选择[1,2] 马丹 陈泽远 张天 杨练根[1,2] WANG Xuan-ze;MA Dan;CHEN Ze-yuan;ZHANG Tian;YANG Lian-gen(Mechanical Engineering College,Hubei University of Technology,Wuhan 430068,China;Key Laboratory of Modern Manufacture Quality Engineering,Wuhan 430068,China)

机构地区：[1]湖北工业大学机械工程学院,湖北武汉430068 [2]湖北省现代制造质量工程重点实验室,湖北武汉430068

出　　处：《仪表技术与传感器》2019年第9期107-111,共5页Instrument Technique and Sensor

摘　　要：针对微电流测量存在需要进行细小分辨的问题,提出了一种快速消除失调电压的检测方法,从硬件设计和软件算法方面详细描述了测量系统。选择偏置电流较小的运算放大器,设计了一种消失调电压的微电流检测电路;结合STM32单片机技术,采用二分法利用程序控制数模转换(DAC)模块自动快速调压,在0输入状态,使测量电路尽快达到0输出的稳定状态,消除运放失调电压的影响,提高微电流的测量精度与测量速度。实验结果表明:该方法能够快速有效地消除失调电压的影响,完成0.1μA级精度的电流测量,达到微电流测量要求。Aiming at the problem of fine resolution in microcurrent measurement,a fast detection method for eliminating offset voltage was proposed,and the measurement system was described in detail from the aspects of hardware design and software algorithm.An operational amplifier with smaller bias current was selected to design a microcurrent detection circuit for eliminating offset voltage.Combining with STM32 single chip technology,a dichotomy method was adopted to automatically and rapidly regulate the voltage by using program-controlled digital-to-analog conversion(DAC)module.In the zero input state,the measuring circuit can reach the stable state of zero output as soon as possible,eliminating the influence of the operational amplifier offset voltage and improving the measurement precision and measuring speed of microcurrent.The experimental results show that the method can quickly and effectively eliminate the influence of offset voltage,complete the current measurement with 0.1μA accuracy,and meet the requirements of microcurrent measurement.

关 键 词：微电流测量 二分程控法 失调电压 自动调压 快速调压 

分 类 号：TM933.1[电气工程—电力电子与电力传动]