霍尔式传感器Hallsensor车辆检测技术Vehicle

郑州铁路职业技术学院霍尔式传感器Hallsensor车辆检测技术Vehicledetectiontechnology主讲人：时蕾FUNDAMENTALSOFSENSORTECHNOLOGYLecturer:ShiLei任务三霍尔式传感器Hallsensor01掌握霍尔式传感器的工作原理，基本结构MastertheworkingprincipleandbasicstructureofHallsensor02熟悉霍尔式传感器的基本测量电路及补偿方法FamiliarwiththebasicmeasurementcircuitandcompensationmethodofHalltypesensor03分析霍尔式传感器的应用TheapplicationofHallsensorisanalyzed学习目标/LEARNINGGOALS霍尔传感器是基于霍尔效应的一种传感器HallsensorisakindofsensorbasedonHalleffect发展：随着半导体技术的发展,开始用半导体材料制成霍尔元件,由于它的霍尔效应显著而得到应用和发展。Development:Withthedevelopmentofsemiconductortechnology,Hallcomponentsbegantobemadeofsemiconductormaterials,andwereappliedanddevelopedbecauseofitssignificantHalleffect.起源：1879年美国物理学家霍尔首先在金属材料中发现了霍尔效应,但由于金属材料的霍尔效应太弱而没有得到应用。Origin:In1879,theAmericanphysicistHallfirstdiscoveredtheHalleffectinmetalmaterials,butbecausetheHalleffectofmetalmaterialsistooweak,ithasnotbeenapplied.应用：霍尔传感器广泛用于电磁测量、压力、加速度、振动等方面的测量。Application:Hallsensorsarewidelyusedinelectromagneticmeasurement,pressure,acceleration,vibrationandotheraspectsofmeasurement.一、霍尔式传感器1霍尔式传感器的工作原理HowHallsensorswork一、霍尔式传感器霍尔效应：

半导体薄片置于磁感应强度为B的磁场中，磁场方向垂直于薄片，当有电流I流过薄片时，在垂直于电流和磁场的方向上将产生电动势EH，这种现象称为霍尔效应。Halleffect:ThesemiconductorsheetisplacedinamagneticfieldwithamagneticinductionintensityofB,andthedirectionofthemagneticfieldisperpendiculartothesheet.WhenacurrentIflowsthroughthesheet,theelectromotiveforceEHwillbegeneratedinthedirectionperpendiculartothecurrentandthemagneticfield.ThisphenomenoniscalledtheHalleffect.产生的电动势称霍尔电势，半导体薄片称霍尔元件。TheresultingelectromotiveforceiscalledtheHallpotential,andthesemiconductorsheetiscalledtheHallelement.当磁场垂直于薄片时，电子受到洛仑兹力的作用，向内侧偏移，在半导体薄片c、d方向的端面之间建立起霍尔电势。Whenthemagneticfieldisperpendiculartothewafer,theelectronsaredeflectedinwardsbytheLorentzforce,creatingaHallpotentialbetweenthesurfacesofthesemiconductorwaferinthecandddirections.一、霍尔式传感器一、霍尔式传感器霍尔电势：式中RH－－霍尔常数I－－控制电流（A）B－－磁感应强度（B)d－－霍尔元件的厚度Hallpotential:WhereRHisHall'sconstantI--Controlcurrent(A)B--Magneticinductionintensity(B)d-ThicknessofHallelement车身到位检测若磁感应强度B不垂直于霍尔元件，而是与其法线成某一角度

时，实际上作用于霍尔元件上的有效磁感应强度是其法线方向（与薄片垂直的方向）的分量，即Bcos

，这时的霍尔电势为IfthemagneticinductionintensityBisnotperpendiculartotheHallelementbutatanAngletoitsnormalline,theeffectivemagneticinductionintensityactingontheHallelementisactuallyacomponentofitsnormaldirection(perpendiculartothewafer),thatis,Bcos,thentheHallpotentialis

UH=KHIBcos

磁场不垂直于霍尔元件时的霍尔电动势HallelectromotiveforcewhenthemagneticfieldisnotperpendiculartotheHallelement一、霍尔式传感器一、霍尔式传感器结论：当磁场和环境温度一定时：

霍尔电势与控制电流I成正比；Whenthemagneticfieldandambienttemperatureareconstant:TheHallpotentialisproportionaltothecontrolcurrentI;当控制电流和环境温度一定时：

霍尔电势与磁场的磁感应强度B成正比；Whenthecontrolcurrentandambienttemperatureareconstant:TheHallpotentialisproportionaltothemagneticinductionintensityBofthemagneticfield.当环境温度一定时：

输出的霍尔电势与I和B的乘积成正比。Whentheambienttemperatureisconstant:TheoutputHallpotentialisproportionaltotheproductofIandB.讨论：一、霍尔式传感器霍尔电势：

霍尔常数：

霍尔灵敏度：任何材料在一定条件下都能产生霍尔电势，但不是都可以制造霍尔元件;绝缘材料电阻率ρ很大，电子迁移率μ很小，不适用；金属材料电子浓度n很高，RH很小，UH很小;半导体材料电阻率ρ较大RH大，非常适于做霍尔元件，半导体中电子迁移率一般大于空穴的迁移率，所以霍尔元件多采用N型半导体（多电子）;霍尔电势与导体厚度d成反比，厚度d越小，霍尔灵敏度KH

越大，霍尔电势值越大所以霍尔元件做的较薄，通常近似1微米(d≈1μm)。AnymaterialcanproduceHallpotentialundercertainconditions,butnotallcanproduceHallelements.Insulationmaterialresistivityρisverylarge,electronmobilityμisverysmall,notapplicable;Metalmaterialshavehighelectronconcentrationn,smallRH,andsmallUH;SemiconductormaterialresistivityρlargeRHlarge,verysuitableforhallcomponents,electronicmobilityinsemiconductorsGenerallygreaterthanthemobilityofholes,soHallcomponentsmostlyuseN-typesemiconductors(multi-electron);TheHallpotentialisinverselyproportionaltotheconductorthicknessd,thesmallerthethicknessd,thelargertheHallsensitivityKH,thelargertheHallpotentialvalue,sotheHallelementisthinner,usuallyapproximately1micron(d≈1μm).Hallpotential:Hallsensitivity:hallconstant:2霍尔元件的结构StructureofHallelement霍尔元件的结构很简单，它是由霍尔片、四根引线和壳体组成的一块半导体单晶薄片(一般为4mm×2mm×0.1mm)。ThestructureoftheHallelementisverysimple,whichisasemiconductorsinglecrystalsheetcomposedofaHallsheet,fourleadsandashell(generally4mm×2mm×0.1mm).2、2′引线为霍尔输出引线，称霍尔电极。电极宽度与基片长度之比要小于0.1，否则影响输出。2,2'leadsareHalloutputleads,calledHallelectrodes.Theratioofelectrodewidthtosubstratelengthshouldbelessthan0.1,otherwisetheoutputwillbeaffected.霍尔片是一块矩形半导体单晶薄片，引出四根引线：1、1′两根引线加激励电压或电流，称激励电极（控制电极）AHallwaferisarectangularsemiconductorsinglecrystalwaferwithfourleads:1,1'twoleadsplusexcitationvoltageorcurrent,calledexcitationelectrode(controlelectrode)在电路中，霍尔元件一般可用两种符号表示，如图（b）所示。Inacircuit,Hallelementscangenerallyberepresentedbytwosymbols,asshowninFigure(b).霍尔元件的壳体是用非导磁金属、陶瓷或环氧树脂封装的。ThehousingoftheHallelementisenclosedinanon-magneticmetal,ceramicorepoxyresin.如图（a）所示。

AsshowninFigure(a).一、霍尔式传感器中国产霍尔元件别号的命名方法如下

ThenamingmethodofHallcomponentsmadeinChinaisasfollows常见的国产霍尔元件型号有HZ—1、HZ—2、HZ—3、HT—1、HT—2、HS—1等。CommondomesticHallcomponentmodelsareHZ-1,HZ-2,HZ-3,HT-1,HT-2,HS-1andsoon.一、霍尔式传感器3霍尔传感器基本测量电路Hallsensorbasicmeasurementcircuit一、霍尔式传感器霍尔晶体的外形为矩形薄片有四根引线，两端加激励，两端为输出，RL为负载电阻TheshapeoftheHallcrystalisarectangularsheetwithfourleads,bothendsareexcited,bothendsareoutput,andRListheloadresistance实测中可把I*B作输入，也可把I或B单独做输入通过霍尔电势输出测量结果。

Intheactualmeasurement,I*Bcanbeinput,orIorBcanbeinputseparatelyMeasuredbyHallpotentialoutput输出U0与I或B成正比关系，或与I*B成正比关系。TheoutputU0isproportionaltoIorB,ortoI*B电源E通过R控制激励电流IB磁场与元件面垂直（向里）PowersupplyEcontrolstheexcitationcurrentIthroughRBThemagneticfieldisperpendiculartothecomponentsurface(inward)一、霍尔式传感器最大允许控制电流：额定控制电流：当霍尔元件有控制电流使其本身在空气中产生10℃温升时，对应的控制电流值。WhentheHallelementhasacontrolcurrentthatcausesitselftoproduceatemperatureriseof10°Cintheair,thecorrespondingcontrolcurrentvalue.以元件允许的最大温升限制所对应的控制电流值。改善散热条件可以增大最大允许控制电流。Thecontrolcurrentvaluecorrespondingtothemaximumtemperatureriselimitallowedbythecomponent.Themaximumallowablecontrolcurrentcanbeincreasedbyimprovingtheheatdissipationcondition.输入电阻Ri：控制电极间的电阻Controltheresistancebetweenelectrodes输出电阻R0:霍尔电极之间的电阻ResistancebetweenHallelectrodes注：测量以上电阻时，应在没有外磁场和室温变化的条件下进行。Note:Whenmeasuringtheaboveresistance,itshouldbecarriedoutintheabsenceofexternalmagneticfieldandroomtemperaturechange.Ri

Ro4霍尔元件的主要技术参数ThemaintechnicalparametersofHallcomponentsRatedcontrolcurrent:Maximumallowablecontrolcurrent:InputresistanceRi:一、霍尔式传感器不等位电阻r0：不等位电势：当霍尔元件的激励电流为I时，若元件所处位置磁感应强度为零，则它的霍尔电势应该为零，但实际不为零。这时测得的空载霍尔电势称为不等位电势。WhentheexcitationcurrentoftheHallelementisI,ifthemagneticinductionintensityatthepositionoftheelementiszero,itsHallpotentialshouldbezero,butitisnotzero.Themeasuredno-loadHallpotentialatthistimeiscalledtheunequalpotentialpotential.不等位电势U0与额定控制电流I之比。RatioofunequalpotentialU0toratedcontrolcurrentI.不等位电阻r0=U0/IUnequalpotential:Unequalresistancer0:Unequalpotentialresistance霍尔电势温度系数

Hallpotentialtemperaturecoefficient在一定磁感应强度和控制电流下，温度每变化1℃时，霍尔电势变化的百分率。它与霍尔元件的材料有关，一般约为0.1%/℃。在要求较高的场合，应选择低温漂的霍尔元件。Underacertainmagneticinductionintensityandcontrolledcurrent,thepercentageofHallpotentialchangewhenthetemperaturechangesby1℃.ItisrelatedtothematerialoftheHallelement,generallyabout0.1%/°C.Inthecaseofhigherrequirements,lowtemperaturebleachedHallcomponentsshouldbeselected.一、霍尔式传感器产生不等位电势的原因主要是：Themainreasonsfortheunequalpotentialare:①霍尔电极安装位置不正确（不对称或不在同一等电位面上）；②半导体材料不均匀造成了电阻率不均匀或是几何尺寸不均匀；③控制电极接触不良造成控制电流不均匀分布等。IncorrectinstallationofHallelectrodes(asymmetricalornotonthesameequipotentialsurface);Thesemiconductormaterialisnotuniform,resultinginunevenresistivityorgeometricsize;Unevendistributionofcontrolcurrentduetopoorcontactofcontrolelectrode.（均是制造工艺造成的)(Allcausedbythemanufacturingprocess)一、霍尔式传感器5霍尔元件误差及补偿Hallelementerrorandcompensation（1）不等位电势误差的补偿Compensationofpotentialerror把霍尔元件视为一个四臂电阻电桥，不等位电势就相当于电桥的初始不平衡输出电压。TheHallelementisregardedasafour-armresistancebridge,andtheunequalpotentialisequivalenttotheinitialunbalancedoutputvoltageofthebridge.一、霍尔式传感器ABCDIR1R2R3R4图中A、B为控制电极，C、D

为霍尔电极。在极间分布的电阻用R1、R2、R3、R4

表示，理想情况是R1＝R2＝R3＝R4，即零位电势为零（或零位电阻为零）。但实际上存在着零位电势，则说明此四个电阻不等。Inthefigure,AandBarecontrolelectrodes,andCandDareHallelectrodes.TheresistancedistributedbetweenelectrodesisdenotedbyR1,R2,R3,andR4,ideallyR1=R2=R3=R4,thatis,zeropotential(orzeroresistance).However,thereisactuallyazeropotential,whichmeansthatthefourresistorsarenotequal.补偿原理：将R1、R2、R3、R4视为电桥的四个臂，即电桥不平衡，为使其平衡可在阻值较大的臂上并联电阻，或在两个臂上同时并联电阻。Compensationprinciple:R1,R2,R3,R4isregardedasthefourarmsofthebridge,thatis,thebridgeisunbalanced,andinordertobalanceit,theresistancecanbeparallelonthearmwithalargerresistancevalue,ortheresistancecanbeparallelonthetwoarmsatthesametime.

一、霍尔式传感器一、霍尔式传感器(c)

Severalcommonlyusedcompensationmethods一、霍尔式传感器

温度误差产生原因：Causesoftemperatureerror:霍尔元件的基片是半导体材料，因而对温度的变化很敏感。其载流子浓度和载流子迁移率、电阻率和霍尔系数都是温度的函数。当温度变化时，霍尔元件的一些特性参数，如霍尔电势、输入电阻和输出电阻等都要发生变化，从而使霍尔式传感器产生温度误差。ThesubstrateoftheHallelementisasemiconductormaterialandisthereforesensitivetotemperaturechanges.Itscarrierconcentration,carriermobility,resistivityandHallcoefficientareallfunctionsoftemperature.Whenthetemperaturechanges,somecharacteristicparametersofHallelement,suchasHallpotential,inputresistanceandoutputresistance,willchange,sothatthetemperatureerrorofHallsensorwillbegenerated.（2）温度误差极其补偿

Thetemperatureerrorisextremelycompensated一、霍尔式传感器减小霍尔元件的温度误差方法MethodofreducingtemperatureerrorofHallelement温度变化导致霍尔元件内阻（Ri、Ro)和霍尔灵敏度（KH）等变化，给测量带来一定误差，即温度误差。为了减小温度误差，需采取温度补偿措施：Temperaturechangesleadtochangesintheinternalresistance(Ri,Ro)andHallsensitivity(KH)ofHallelements,whichbringsacertainerrortothemeasurement,thatis,temperatureerror.Inordertoreducethetemperatureerror,temperaturecompensationmeasuresshouldbetaken:选用温度系数小的元件（如砷化铟）;采用恒温措施;采用恒流源供电;Selectcomponentswithsmalltemperaturecoefficients(suchasindiumarsenide);Adoptconstanttemperaturemeasures;Constantcurrentsourcepowersupply;霍尔集成电路可分为线性型和开关型两大类Hallintegratedcircuitscanbedividedintolinearandswitchingtypes线性型三端霍尔集成电路Linearthree-terminalHallintegratedcircuit线性型集成电路是将霍尔元件和恒流源、线性差动放大器等做在一个芯片上，输出电压为伏级，比直接使用霍尔元件方便得多。较典型的线性型霍尔器件如UGN3501等。LinearintegratedcircuitisHallelement,constantcurrentsource,lineardifferentialamplifier,etc.onachip,theoutputvoltageisvolts,whichismuchmoreconvenientthandirectlyusingHallelement.MoretypicallinearHalldevicessuchasUGN3501.二、霍尔集成传感器二、霍尔集成传感器线性型霍尔特性Linearthree-terminalHallintegratedcircuit霍尔线性传感器广泛用于位置、力、重量、厚度、速度、磁场、电流等的测量或控制。Halllinearsensorsarewidelyusedinthemeasurementorcontrolofposition,force,weight,thickness,speed,magneticfield,current,etc.右图示出了具有双端差动输出特性的线性霍尔器件的输出特性曲线。当磁场为零时，它的输出电压等于零；当感受的磁场为正向（磁钢的S极对准霍尔器件的正面）时，输出为正；磁场反向时，输出为负。ThefigureontherightshowstheoutputcharacteristiccurveofalinearHalldevicewithadouble-endeddifferentialoutputcharacteristic.Whenthemagneticfieldiszero,itsoutputvoltageiszero;Whentheperceivedmagneticfieldispositive(theSpoleofthemagneticsteelisalignedwiththefrontoftheHalldevice),theoutputispositive;Whenthemagneticfieldisreversed,theoutputisnegative.二、霍尔集成传感器开关型霍尔集成电路SwitchingHallintegratedcircuit开关型霍尔集成电路是将霍尔元件、稳压电路、放大器、施密特触发器、OC门（集电极开路输出门）等电路做在同一个芯片上。当外加磁场强度超过规定的工作点时，OC门由高阻态变为导通状态，输出变为低电平；当外加磁场强度低于释放点时，OC门重新变为高阻态，输出高电平。较典型的开关型霍尔器件如UGN3020等。SwitchingtypeHallintegratedcircuitisthehallelement,voltageregulatorcircuit,amplifier,Schmidtflip-flop,OCgate(collectoropenoutputgate)andothercircuitsmadeonthesamechip.Whentheappliedmagneticfieldstrengthexceedsthespecifiedoperatingpoint,OCgatechangesfromhighresistancestatetoon-state,andtheoutputbecomeslowlevel.Whentheappliedmagneticfieldstrengthislowerthanthereleasepoint,theOCgatechangesbacktothehighresistancestate,andtheoutputlevelishigh.MoretypicalswitchinghalldevicessuchasUGN3020.霍尔元件

双端输入、单端输出运放

施密特触发电路OC门霍尔开关集成传感器基本用途有：汽车点火系统、保安系统、转速、里程测定、机械设备的限位开关、按钮开关、电流的检测与控制、位置及角度的检测，等等。

Hallswitchintegratedsensorbasicusesare:Automobileignitionsystem,securitysystem,speed,mileagemeasurement,limitswitchofmechanicalequipment,buttonswitch,currentdetectionandcontrol,positionandAngledetection,etc.1.霍尔特斯拉计（高斯计）Holtslermeter霍尔元件三、霍尔传感器的应用2.霍尔转速表Halltachometer三、霍尔传感器的应用在被测转速的转轴上安装一个齿盘，也可选取机械系统中的一个齿轮，将线性型霍尔器件及磁路系统靠近齿盘。齿盘的转动使磁路的磁阻随气隙的改变而周期性地变化，霍尔器件输出的微小脉冲信号经隔直、放大、整形后可以确定被测物的转速。Ageardiskisinstalledontherotatingshaftofthemeasuredspeed,oragearinthemechanicalsystemcanbeselectedtoplacethelinearHalldeviceandthemagneticcircuitsystemnearthegeardisk.Therotationofthetoothdiskmakesthemagneticresistanceofthemagneticcircuitchangeperiodicallywiththechangeoftheairgap.ThetinypulsesignaloutputbytheHalldevicecanbestraightened,amplifiedandshapedtodeterminethespeedofthemeasuredobject.SN线性霍尔磁铁三、霍尔传感器的应用当齿对准霍尔元件时，磁力线集中穿过霍尔元件，可产生较大的霍尔电动势，放大、整形后输出高电平；反之，当齿轮的空挡对准霍尔元件时，输出为低电平。WhentheteetharealignedwiththeHallelement,themagneticfieldlinepassesthroughtheHallelement,whichcanproducealargeHallelectromotiveforce,andoutputahighlevelafteramplificationandshaping.Conversely,whentheneutralgearofthegearisalignedwiththeHallelement,theoutputislow.三、霍尔传感器的应用带有微型磁铁的霍尔传感器Hallsensorwithmicromagnet若汽车在刹车时车轮被抱死，将产生危险。用霍尔转速传感器来检测车轮的转动状态有助于控制刹车力的大小。Ifthewheelsofthecararelockedwhilebraking,therewillbeadanger.UsingHallspeedsensortodetectwheelrotationstateishelpfultocontrolthebrakingforce.霍尔转速传感器在汽车防抱死装置（ABS）中的应用霍尔转速传感器在汽车防抱死装置（ABS）中的应用ApplicationofHallspeedsensorinautomobileanti-locklockdevice(ABS)3.霍尔式接近开关Hallapproachswitch三、霍尔传感器的应用当磁铁的有效磁极接近、并达到动作距离时，霍尔式接近开关动作。霍尔接近开关一般还配一块钕铁硼磁铁。Whentheeffectivemagneticpoleofthemagnetiscloseandtheoperatingdistanceisreached,theHallproximityswitchisoperated.TheHallproximityswitchisgenerallyequippedwithaNdfebmagnet.用霍尔IC也能完成接近开关的功能，但是它只能用于铁磁材料的检测，并且还需要建