Buck Converter Current Measurement Using Differential Amplifier

作     者：P.Rajeswari V.Manikandan 

作者机构：Department of Electrical and Electronics EngineeringCoimbatore Institute of TechnologyCoimbatore641014India 

出 版 物：《Intelligent Automation & Soft Computing》 (智能自动化与软计算（英文）)

年 卷 期：2023年第35卷第2期

页      面：1387-1402页

核心收录：

学科分类：080903[工学-微电子学与固体电子学] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 

主　　题：Buck converter common mode rejection ratio common mode gain current sensing differential amplifier differential mode gain shunt resistor 

摘      要：The accuracy of the measured current is a preeminent parameter for Current Control based Power Converter applications to ensure genuine operation of the designed *** current measurement accuracy can be affected by several parameters which includes the type of technology used,components used for the selected technology,aging,usage,operating and environmental *** effect of gain resistors and their manufacturing tolerances on differential amplifier-based buck converter current measurement is investigated in this *** analysis mainly focused on the output voltage variation and its accuracy with respect to the change in gain resistance *** gain resistors with 5%,1%,0.5%and 0.1%manufacturing tolerances taken for the worst-case analysis and the calculated performance results are compared and verified with the simula-tion *** Operational amplifiers(Op-Amp)for high frequency power con-verter applications must operate in a high frequency noise environment and the intended current measuring system must manage common mode noise distur-bances paired with the signal to be *** on the Common Mode Rejec-tion Ratio(CMRR)the common mode voltages and noise signals will effectively getfiltered *** CMRR results in lower common mode signal rejection,resulting in poor precision and noise *** differential amplifiers,the CMRR predominantly depends on gain ***,the variations in Common Mode Rejection Ratio due to gain resistor tolerances also analyzed and compared with the output voltage *** the effects of resistor tolerances,this paper also examines the effect of Op-Amp offset voltage on output accuracy spe-cifically for low magnitude input *** obtained results from this analysis clearly shows that the gain resistors with 0.1%tolerance gives maximum accuracy with improved CMRR and accuracy at low magnitude input currents will get well improved by using Op-Amps with Low Offset voltage specification