一种高精度模拟量输出电路在工业仪表中的应用  

Application of A High Precision Analog Output Circuit in Industrial Instruments

作　　者：李之尧 孙冬梅 LI Zhiyao;SUN Dongmei(College of Electrical Engineering and Control Science,Nanjing Tech University,Nanjing Jiangsu 210009,China)

机构地区：[1]南京工业大学电气工程与控制科学学院,江苏南京210009

出　　处：《电子器件》2025年第1期211-217,共7页Chinese Journal of Electron Devices

基　　金：《FAC微小流量自动控制器》研究与开发产学研项目(2021年第2批)。

摘　　要：PWM(脉冲宽度调制)信号具有便于产生、稳定的优点。但在工业现场,因为电流信号具有优良抗干扰性,一般都是用电流模拟量进行信号传输来控制生产。提出一种新的PWM信号转换为4 mA~20 mA电流模拟量输出电路设计方案,该设计包含光耦隔离模块、积分电路模块、放大电路模块等模块。将产生的PWM波通过电路运算得到对应的模拟量,从而实现DAC功能。该设计通过理论计算设计与Multisim仿真,验证了其能达到预期功能。该设计采用全新设计的电路,只通过模拟电路,实现数模转换的功能,提高了DAC精度,且具有成本低、结构简单等优势,在工业仪表中具有一定的应用价值。PWM(Pulse Width Modulation)signal has the advantages of easy generation and stability.However,in the industrial field,because the current signal has good anti-interference feature,it is generally used to control production by signal transmission using cur-rent analogue.A new design of current analogue output circuit for converting PWM signal to 4 mA-20 mA is presented,which includes photocouple isolation module,integral circuit module,amplifier circuit module and so on.The resulting PWM wave is calculated by the circuit to get the corresponding analogue value,thus achieving the DAC function.The design is verified to achieve the expected function by theoretical calculation design and Multisim simulation.This design uses a newly designed circuit,which only uses analog circuit to realize the function of digital-to-analog conversion,improves the accuracy of DAC,and has the advantages of low cost and simple struc-ture.It has certain application value in industrial instrumentation.

关 键 词：高精度 PWM信号 4 mA~20 mA电流输出 数模转换 电路设计 

分 类 号：TN702[电子电信—电路与系统]