2023.02ELECTRONICSQUALITY基于容抗法的CDM测试技术设计刘晓1,李帅达2,陈光耀1,魏然1,戴莹1,吕栋1,虞勇坚1(1.中国电子科技集团公司第五十八研究所,江苏无锡214035;2.陆装驻哈尔滨地区第一军事代表室,黑龙江哈尔滨150000)摘要:网络运放输入差模电容可通过电容不同特性计算推导,而实际测试设备的精度往往无法达到理论推导结果的准确性,这主要是由于运放差分输入OFFSET问题导致差分输入信号无法达到完全一致。首先,为了深入地了解寄生电容的主要产生机制,对传统Bipolar器件和CMOS器件的结构以及等效模型进行了分析介绍;然后,分别根据运放频域特性和寄生电容的充放电特性原理,对运放的输入差分寄生电容进行推导;最后,利用仿真方法对测试结果进行了验证。结果表明,采用容抗法测得的结果更接近于真实值,从而验证了所提出的方法的有效性,对于提高差模电容测试精度具有重要的意义。关键词:运放输入差模电容;运算放大器测试;输入电容测试;运放频域特性;寄生电容中国分类号:TN407文献标识码:A文章编号:1003-0107(2023)02-0069-04doi:10.3969/j.issn.1003-0107.2023.02.015DesignofCDMTestTechniqueBasedonCapacitanceMethodLIUXiao1,LIShuaida2,CHENGuangyao1,WEIRan1,DAIYing1,LVDong1,YUYongjian1(1.No.58ResearchInstituteofElectronicsTechnologyGroupCorporation,Wuxi214035,China;2.TheFirstMilitaryRepresentativeOfficeofCRSC,Harbin15000,China)Abstract:Theinputdifferentialmodecapacitorsofnetworkoperationalamplifiercanbecalculatedanddeducedthroughdifferentcharacteristicsofcapacitors.However,theaccuracyofactualtestequipmentisoftenunabletoreachtheaccuracyofthetheoreticaldeductionresults,whichismainlybecausethedifferentialinputsignalscannotreachcompleteconsistencyduetotheOFFSETproblemofoperationalamplifierdifferentialinput.Firstly,inordertodeeplyunderstandthemaingenerationmechanismofparasticcapacitance,thestructureoftraditionalBipolardevicesandCMOSdevicesandequivalentmodelareanalyzed.Then,accordingtothefrequencydomaincharacteristicsoftheoperationalampliferandthecharge-dischargecharacteristicsoftheparasiticcapacitor,theinputdifferentialparasiticcapacitanceoftheoperationalamplifierisderived.Finally,thesimulationmethodisu...