宽范围微弱电流对数放大电路设计与仿真  

作　　者：黄梓瑜[1] 高文刚[1] 谭威[1] 范维志 

机构地区：[1]西南石油大学电气信息学院,四川成都610500 [2]中国石油集团测井有限公司吐哈事业部,新疆吐鲁番838202

出　　处：《工业控制计算机》2013年第6期130-131,共2页Industrial Control Computer

摘　　要：介绍了对数放大器测量电流的方法,使用高阻抗的场效应晶体管作为反馈元件,设计了一种宽范围微弱电流的测量电路。选择具有极低输入偏置电流和失调电压的运放提高测量的精度;选择匹配的结型场效应管和热敏电阻实现温度补偿。仿真结果表明,该电路的测量范围为100pA～10mA,测量精度高。A method of measuring current of logarithmic amplifier is introduced.Using the highimpedance Junction Fieldeffect Transistor as a feedback component,a wide range of weak current measuring circuit has been designed.With very low in put bias current and offset voltage operation amplifier to improve the measurement accuracy;JFET which is matched and thermistors for temperature compensation are selected.Simulation results show that the measurement range of the circuit is lOOpAlOmA, with a high accuracy.

关 键 词：输入电流 对数放大器 仿真 

分 类 号：TN722[电子电信—电路与系统]