JFET高精度可变电阻器的设计及其应用  

Design of voltage-controlled resistor based on JFET and its application in automatic weather station signal simulator

作　　者：行鸿彦[1,2] 赵晨[1,2] 余炳莹[1,2] 徐伟[1,2] 

机构地区：[1]南京信息工程大学气象灾害预报预警与评估协同创新中心,南京210044 [2]南京信息工程大学江苏省气象探测与信息处理重点实验室,南京210044

出　　处：《仪器仪表学报》2015年第8期1884-1891,共8页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金(61072133);江苏省产学研联合创新资金计划(BY2013007-02;BY2011112);江苏省高校科研成果产业化推进项目(JHB2011-15);江苏省"信息与通信工程"优势学科;江苏省"六大人才高峰"计划课题资助

摘　　要：根据JFET线性区漏源之间沟道电阻受栅源电压控制的机理,推导JFET电流公式,对可变电阻的性能进行了分析。通过PSpice软件仿真了JFTT压控可变电阻,提出了改善JFET可变电阻非线性及扩展电阻动态范围的方法。结合单片机和D/A转换器,利用该方法设计了程控JFET可变电阻,其阻值范围为75.703~141.004Ω,分辨率低于0.025Ω,满足了自动气象站信号模拟器温度通道所需电阻阻值范围80.305~130.894Ω及分辨率低于0.03Ω的要求,为数据采集器温度通道的检定提供标准的可变电阻信号。According to the mechanism that the drain-source channel resistance of JFET transistor in the linear region is controlled by the gate-source vohage, the current formula of JFET is deduced, the performance of the variable resistor is analyzed. The PSpice software is used to simulate the JFET voltage controlled variable resistor, and the method for improving the nonlinearity of the JFET variable resistor and expanding its dynamic range is proposed. Based on above, combining single chip computer and D/A converter with JFET, a pro- grammable JFET variable resistor was designed. The resistance range of the designed variable resistor is 75. 703- 141. 004Ω, and the resolution is below 0.025Ω, which meets the requirements of the resistance range of 80. 305-130. 894Ω and resolution below 0.03Ω for the temperature channel of automatic weather station signal simulator. This variable resistor provides a standard variable resistor signal for the verification of the temperature channel of data collectors.

关 键 词：结型场效应管 压控可变电阻 模拟温度传感器 PSPICE 

分 类 号：TH811[机械工程—仪器科学与技术]