带隙基准源(外文论文、文献)

526IEEEJOURNALOFSOLID-STATECIRCUITS,VOL.37,NO.4,APRIL2002ASub-1-V15-ppm/CCMOSBandgapVoltageReferenceWithoutRequiringLowThresholdVoltageDeviceKaNangLeung,StudentMember,IEEE,andPhilipK.T.Mok,SeniorMember,IEEEAbstract—Asub-1-VCMOSbandgapvoltagereferencere-quiringnolowthresholdvoltagedeviceisintroducedinthispaper.InaCMOStechnologywiththnthp09Vat0C,theminimumsupplyvoltageoftheproposedvoltagereferenceis0.98V,andthemaximumsupplycurrentis18A.Atemperaturecoefficientof15ppm/Cfrom0Cto100Cisrecordedaftertrimming.Theactiveareaofthecircuitisabout0.24mm2.IndexTerms—CMOSbandgapvoltagereference,lowvoltage,temperature.I.INTRODUCTIONLOWVOLTAGEandlowpoweraretwoimportantdesigncriteriainboththeanaloganddigitalsystems.Itisex-pectedthatthewholesystemwillbeabletooperatedowntoasingle1-Vsupplyinthenearfuture.Avoltagereference,asoneofthecorefunctionalblocksinbothanaloganddigitalsys-tems,shouldbeabletooperatefromasingle1-Vsupplyforbothsystems.InCMOStechnology,aparasiticverticalbipolarjunctiontransistor(BJT)formedinap-orn-welliscommonlyusedtoimplementabandgapreference[1]–[3].Theminimumsupplyvoltageneedstobegreaterthan1Vduetotwofactors:1)thereferencevoltageisaround1.25Vwhichexceeds1-Vsupply[4],[5]and2)low-voltagedesignoftheproportional-to-abso-lute-temperature(PTAT)currentgenerationloopislimitedbythecommon-collectorstructureoftheparasiticverticalBJT[2]andtheinputcommon-modevoltageoftheamplifier[4],[6].Thefirstproblemcanbesolvedbyresistivesubdivisionmethods[7],[8]toscaledownthe1.25-Vreferencevoltage.ThesecondproblemcanbesolvedbyusingBiCMOSprocess[6]orbyusinglowthresholdvoltagedevices[7],[8].AsshowninFig.1(a),theminimuminputcommon-modevoltageofanamplifierwithannMOSinputstagemustbelessthanone(i.e.,),whichimpliesthatVisrequired(assumingVandmV).ThisisacceptableasnMOStransistorswithVcanbeeasilyfoundinmanytechnolo-gies.However,thetemperatureeffectonthebase–emittervoltageandthresholdvoltageshouldbeconsidered.Thetemperaturecoefficient(TC)ofthebase–emittervoltageisapproximately2mV/K[9]whilethatofthethresholdvoltageofthenMOStransistormaybegreaterthan2mV/K,forManuscriptreceivedApril13,2001;revisedNovember16,2001.ThisworkwassupportedbytheResearchGrantCouncilofHongKongSAR,ChinaunderProjectno.HKUST6022/01E.TheauthorsarewiththeDepartmentofElectricalandElectronicEngineering,TheHongKongUniversityofScienceandTechnology,ClearWaterBay,HongKongSAR(e-mail:[e-mail]).PublisherItemIdentifierS0018-9200(02)02563-5.example,1.4mV/KinAMS10.6-mn-wellCMOStech-nology[10].Athightemperatures,maybelessthan,andthereferencecircuitwillnotfunctionproperly.Thus,eithernativenMOStransistors[7]ornMOStransistorswithV[8]arerequiredtoallowthereferencecircuitinFig.1(a)tooperatedowntoasingle1-Vsupply.WhenthereferenceusesanamplifierwithapMOSinputstage,asshowninFig.1(b),theminimumsupplyvoltageis,andsolessthan0.2Visrequiredtoimplementa1-Vreference.Toaddresstheabove-mentioneddesignproblems,asub-1-VbandgapreferencecircuitinastandardCMOSprocessispre-sentedinthispaper.Thekeyfeatureoftheproposedreferencecircuitisthatnolowthresholdvoltagedeviceisneeded.Thedesigntechniquesforachievingagoodperformancearealsopresentedindetail.II.PROPOSEDSUB-1-VBANDGAPVOLTAGEREFERENCEINCMOSTECHNOLOGYThestructureandthecompleteschematicoftheproposedsub-1-VbandgapvoltagereferenceareshowninFigs.2and3,respectively.ThereferencecorecircuitryismodifiedfromtheoneproposedbyBanbaetal.[7].ThemaindifferencesarethatanamplifierwithapMOSinputstageisusedandtheinputsoftheamplifierareconnectedtonodesandinsteadofnodesand.Aself-biasapproachisusedinthiscircuittobiastheamplifier.Thecompensationcapacitor[11]isusedtostabilizethereference.Alargerprovidesbetterstability,butthestartuptimewillbelonger.AsillustratedinFig.2,theamplifierenforcesnodesandtohaveequalpotential.Asaresult,nodesandalsohavethesamepotentialwhenand.Therefore,theloopformedbyandgeneratesacurrentgivenby(1)whereistheemitterarearatio,isthethermalvoltage,and.ThecurrentisinjectedtobythecurrentmirrorformedbyM1,M2,andM3,andthisgivesthereferencevoltageasfollows:(2)Ascaled-downbandgapreferencevoltagecanbeobtainedbyanappropriateresistorratioofto.Moreover,trimming1AustriaMikoSystemeGroup,Austria0018-9200/02$17.00©2002IEEEAuthorizedlicenseduselimitedto:IEEEXplore.DownloadedonOctober30,2008at06:01fromIEEEXplore.Restrictionsapply.IEEEJOURNALOFSOLID-STATECIRCUITS,VOL.37,NO.4,APRIL2002527Fig.1.BandgapvoltagereferencesinCMOStechnologyusinganamplifierwith(a)nMOSinputstage,and(b)pMOSinputstage.Fig.2.Proposedsub-1-Vbandgapvoltagereference.ontheresistorratio(ratioofto)toachieveagoodTCcanbedoneonandsimultaneously.Whenthesumofthevoltagesacrossand(orand)isequalto,thevoltagewithrespecttogroundatandis.There-fore,theminimumsupplyvoltage,whichshouldbeevaluatedatthelowestoperatingtemperature,isgivenby(3)Theminimumsupplyvoltageissubstantiallyreducedwhenissettoasmallvalue.ThisstructureissuitableforanyCMOStechnologytoimplementlow-voltagebandgapreference.Moreover,thereisnoincreaseonthetotalresistancecomparedtotheoneproposedbyBanbaetal.A.OperationinHigh-GainRegionbyForwardBiasingtheSource–BulkJunctions