应用于光电高温计的微电流放大器设计  

Design of the microcurrent amplifier for photoelectric pyrometer

作　　者：刘巨芬 李建民[1] 侯文[1] 卢小丰[2] 王高[1] LIU Jufen;LI Jianmin;HOU Wen;LU Xiaofeng;WANG Gao(School of Information and Communications Engineering,North University of China,Taiyuan 030051,China;National Institute of Metrology,Beijing 102200,China)

机构地区：[1]中北大学信息与通信工程学院,山西太原030051 [2]中国计量科学研究院,北京102200

出　　处：《电子元件与材料》2020年第10期70-76,共7页Electronic Components And Materials

基　　金：国家重点研发计划NQI专项(2017YFF0205902);国家自然科学基金(61573323);山西省回国留学人员科研资助项目(2014054)。

摘　　要：针对光电高温计中光电探测器检测到的电流为10-12~10-5 A,易被噪声淹没,且不利于后续电测仪表的读取,因此设计了一个可变增益的微电流放大器实现不同量程的微电流放大。其电路包含放大电路模块、量程选择模块、数字与模拟模块、电源模块的设计。以ADA4530-1作为放大芯片,采用反馈运算的方法实现pA级的输入电流值的放大和电流-电压的转换,放大倍数为105~109,具有稳定性好、体积小、输入噪声低、偏置电流小等特点。将其应用在温度测量系统中,通过Sakuma-Hattori方程可得电流值所对应的温度,相关实验显示,使用该微电流放大器的光电高温计在600~2200℃的测温范围内不确定度为0.4~1.7℃,已接近国际最高水平。The current of the photoelectric detector in the photoelectric pyrometer is 10-12~10-5 A,which tends to be drowned by the noise and cannot be detected easily by the electric meter.In this work,a variable gain micro-current amplifier was designed to realize the amplification of the micro-current in different ranges.The circuit included amplifier module,range selection module,digital and analog module and power supply module.Use ADA4530-1 as the amplification chip,the feedback calculation method was used to realize the amplification of the pA level input current value and the current-voltage conversion.The amplification factor is 105~109.It has good stability,small size,low input noise and low set current.This amplifier was applied in the temperature measurement system,and the temperature corresponding to the current value can be obtained by using the Sakuma-Hattori equation.The experiment results show that the uncertainty of the photoelectric pyrometer with the micro-current amplifier is 0.4~1.7℃in the temperature measurement range of 600~2200℃,which is close to the highest level in the world.

关 键 词：微电流 放大器 光电高温计 测温 偏置电流 不确定度 

分 类 号：TN722[电子电信—电路与系统]