面向免滤波数字D类功放的随机扩频PWM方法研究综述

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中图分类号：TN761.93-34 文献标识码：A 文章编号：1004-373X（2025）15-0169-10

Reviewofrandom spreadspectrum PWMmethodsfor filterless digital ClassDpoweramplifiers

YU Zeqi1，QIANBo²，XU Zenghui²，ZHAO Zongxun²，LIU Haokai² （1.SchoolofElectronicsand Information，Zhengzhou UniversityofLight Industry，Zhengzhou 45ooo1，China; 2.SchoolofComputerScienceandTechnology，ZhengzhouUniversityofLightIndustry，Zhengzhou450ool，China）

Abstract：Compared tothetraditional ClassDpoweramplifiers，filterless digital ClassD poweramplifiers have the advantagesofsmallsize，lowcost，andeasytointerfacewithdigitalaudiosources，whichhaveawiderangeofapplication scenarios.However，duetotheabandomentoftheanaloglow-passfilterinthelaterstage，theflterlessdigitalClassDpower amplifierswillcauseseriouselectromagneticinterference（EM）tothesurroundingcircuitswhiledrivingthespeakertoproduce sound.Random spread spectrum pulse width modulation （PWM）technologycan extendthe peak energyof thePWM signal outputbythefilterlessdigitalClassDpoweramplifiersaroundthepulserepetitionfrequencyanditseachsubharmonicintothe surroundingfrequencydomain，soitiswidelyusedtosolvetheEMIisueofthefilterlessdigitalClass Dpoweramplifiers.The existingrandomspread spectrum PWMmethodsareintroducedon thebasisof abrief explanationof theprincipleof random spread spectrum PWM.Then，the performancesof diferentrandomspread spectrum PWMmethodsare testedandanalyzed by anexperimentaltestingsystem.Thetestresultsindicatethat，comparedtotheothertested methods，thethre-frequencypseudorandomvarying（TFPRV）methodcansignificantlyreducetheout-of-bandpeak spectralamplitudewithalowertotalharmonic distortion （THD） for power amplifiers.

Keywords：filterles;digital Class Dpower amplifier; EMI; random spread spectrum; PWM; pulse repetition frequenc

0 引言

便于与数字音源接口、易集成的优点，成为目前功放领域研究的热点。（剩余15780字）