基于∑-△調(diào)制的閉環(huán)D類功率放大器的設(shè)計.pdf

1、浙江大學(xué)碩士學(xué)位論文基于∑△調(diào)制的閉環(huán)D類功率放大器的設(shè)計姓名：周小爽申請學(xué)位級別：碩士專業(yè)：電路與系統(tǒng)指導(dǎo)教師：何樂年20060220Abstract：Becauseofitshighefficiency，classDpoweramplifierisappliedtoaudiosystemmorefrequentlyThetraditionalclassDamplifieriscomposedofthreeparts：modulati

2、oncircuit，drivingcircuitandpoweramplificationcircuitHowever，inviewofstructure，classDamplifierisaswitchamplifiersothenonlineardistortioninevitablyappearsattheoutputsignalFurthermore，classDisaopenloopsystem，itcan’tsuppress

3、thenonlinearityandnoiseintroducedbyintermediatestageForabovedisadvantagesofclassD，itsapplicationinhighfidelityaudiosystemisrestrictedGenerally90dBSNDRisrequiredbvllighfidelityandiosystemandthisthesiswillfollowthisrequire

4、mentAsweknow，∑一Amodulationtechniquehastheadvantageofsuppressingthelowfrequencyquantizationnoise，soitisfrequentlyapplledinthemodulationcircuit0fdassDButinopenloopsystem，∑一AmodulationCallonlyassurethehi疊hSNDRofinputsignaln

5、ottheoutputsignalbecauseofthenoiseandnonlinearityintroducedbypowetintermedlatestagesHowevercloseloopsystemcansuppressthenoiseandnonlinearityintroducedbyintermediatestagesatthepremiseofhighloopgain，and∑一Amodulationjusthas

6、thischaracteristicatlowfrequencyInthisthesis∑一AmodulationandcloselooptechniquesareintegratedandanewstructureofclassDisbroughtupWiththisnewstructurenotonlyishighefficiencyobtained，butalsothe1lighSNDRAt5Vsupplyvoltage，itsm

7、aximSNDRisincreasedto91dB，e彤ciency80％。andmaximoutputpower057WThisthesisisdividedintofourpartsInchapter1thesignificanceofresearchonclassDamplifierisbrieflyintroduced。theresearchlevelofclassDisanalyzcddifferenttechniquesar

8、ecomparedOnbaseoftheconcludedexperiencefromchapter1，acloseloopclassDstructurebasedon∑一Amodulationisbroughtup’whichismodeledandsimulatedatsystemlevelwithMatlabandstructureandparametersofmodulationcircuitaredecidedTransist

9、orlevelcircuitdesignisdoneandsimulationisrunwithdesignedcircuitThesimulationresultsindicatethatnotonlyisSNDRimprovedwithnewstructure，butalsothehighefficiencyisobtained，thetargetisreachedInchapter4，asummaryofwholethesisis