PCBDesignforReal-WorldEMIControlPreparedByJiaWu2003-11-202023/1/41PCBDesignPreparedByJiaWuPCBDesignforReal-WorldEMIControlThecontents1.IntroducetheEMC2.AbouttheBasicEMCDesignIntention3.IntroducetheElectromagneticInduction4.TheMythoftheGround5.IntroducetheReturnCurrentRoute6.TheConclusions2023/1/42PCBDesignforReal-WorldEMI1.IntroducetheEMC1.1EMIandEMCconcepts1.2ThesourceofEMI1.3IntroducetheInductance1.4IntroducetheGround1.5IntroducetheShielding2023/1/431.IntroducetheEMC1.1EMIan1.1.1EMIconceptsEMI:ElectromagneticInterferenceAnyelectromagneticdisturbancethatinterrupts,obstructs,orotherwisedegradesorlimitstheeffectiveperformanceofelectronics/electricalequipment.Itcanbeinducedintentionallyandunintentionally,asaresultofspuriousemissionsandresponses,intermodulationproducts,andthelike.2023/1/441.1.1EMIconceptsEMI:ElectrEMC:ElectromagneticCompatibilityTheconditionwhichprevailswhenequipmentisperformingitsindividuallydesignedfunctioninacommonelectromagneticenvironmentwithoutcausingorsufferingunacceptabledegradationduetounintentionalelectromagneticinterferencetoorfromotherequipmentinthesameenvironment.Theabilityofsystems,equipment,anddevicesthatutilizetheelectromagneticspectrumtooperateintheirintendedoperationalenvironmentswithoutsufferingunacceptabledegradationorcausingunintentionaldegradationbecauseofelectromagneticradiationorresponse.1.1.2EMCconcepts2023/1/45EMC:ElectromagneticCompatibiElectromagneticCompatibilityEMCInterference(EMI)Susceptibility(EMS)ConductedEmissionRadiatedEmissionConductedImmunityRadiatedImmunityEMCStructureChart1.1.2EMCconcepts(Continue)2023/1/46ElectromagneticCompatibilityI1.2TheSourceofEMIHighspeedclockgenerator;Highspeedbussignal;Powernode;DigitalandAnalogGND;I/OCableandConnector2023/1/471.2TheSourceofEMIHighspee1.3IntroducetheInductanceTheinductancehereisnotonlyfortheinductor.Inductanceiscriticalforhighspeedsignals.AvoltagedecreasewillcausethechangeofElectromagneticfield.ThischangeofintensityandshapeisasourceofEmission.2023/1/481.3IntroducetheInductance1.4IntroducetheGroundGround:Thereferencepoint.DifferentkindsofGroundshouldbeseparatedfromeachothers.SuchasEarthreference,Powerreference,Chassisreference.Thiscanmitigatetheinterferencebetweendifferentsignalsandkeepthempure.2023/1/491.4IntroducetheGroundGround1.5IntroducetheShieldingShieldingisausefulwaytolimitEMI.Themagnitudeofreflectionlossdependsontheratioofbarrierimpedancetowaveimpedance,whichinturndependsonitsdistancefromthesourceandwhetherthefieldiselectricormagneticorwhetheritisaplanewave.Foraslotwithadimensionequaltoorlessthanahalf-wavelength,theshieldingeffectivenessis:Wherelismaximumdimensionofslot.2023/1/4101.5IntroducetheShieldingShi1.5IntroducetheShielding(Continue)2023/1/4111.5IntroducetheShielding(C2.BasicEMCDesignIntention2.1TheimportanceforEMCdesign2.2CouplingMechanisms2.3IntroducetheSignalSpectra2.4IntroducetheResonanceEffect2.5PotentialInterferenceSource2023/1/4122.BasicEMCDesignIntention2.1TheImportanceofEMCdesign1.EMCDesignisimportantforcost-down.2.Needcertificatestoenterintodifferentcountriesandregions,commonmarks: CCC-> China CE-> EuropeanUnion VCCI-> Japan BSMI-> Taiwan FCC-> UnitedStates2023/1/4132.1TheImportanceofEMCdesi2.2CouplingMechanismsElectricalFieldCoupling2023/1/4142.2CouplingMechanismsElectriMagneticFieldCoupling2.2CouplingMechanisms(Continue)2023/1/415MagneticFieldCoupling2.2Cou2.3SignalSpectra2023/1/4162.3SignalSpectra2022/12/27162.4ResonanceEffectsMostEMIisnarrowband,notbroadband.Theresonancefrequencyincavityis:Thea,bandcisthedimensionofthecavity.

Them,nandpisinteger,andbebothorallzero.2023/1/4172.4ResonanceEffectsMostEMI2.5PotentialInterferenceSourceShieldedproducts:Viasandholes,connectors,I/Ocables…UnshieldedproductsPCboard,radiators,externalcables,wirelessantennas…2023/1/4182.5PotentialInterferenceSou3.TheInductance3.1IntroducetheInductance3.2ElectromagneticInduction3.3IntroducetheMutualinductance3.4IntroducetheSelf-Induction3.5IntroducethePartialInduction2023/1/4193.TheInductance3.1Introduce3.1IntroducetheInductanceTheinfluenceofinductanceisextremelyimportantinhighfrequencyspectra.Theinductancecanbeanywhereinallcomponentssuchascapacitorsresistors,lines,andplanes.2023/1/4203.1IntroducetheInductanceTh3.2ElectromagneticInductionTheelectromagneticinductanceformulainFaraday’slaw:InasmallareaA,the:2023/1/4213.2ElectromagneticInductionTEffectofPower/GroundInductanceTheinductivereactanceofaconductorisusuallymoresignificantthantheimpedanceresistance.Atime-varyingcurrentpassingthroughaninductorcausesavoltagedrop.Thecurrentwhenacapacitordischarging:Thevoltagewhenachangingcurrentpassingthroughainductance:3.2ElectromagneticInduction(Continue)2023/1/422EffectofPower/GroundInducta3.3IntroducetheMutualInductance2023/1/4233.3IntroducetheMutualInducTheMutualInductancebetweentwoparallellines

3.3IntroducetheMutualInductance(Continue)2023/1/424TheMutualInductancebetween3.4IntroducetheSelf-inductance2023/1/4253.4IntroducetheSelf-induct3.5IntroducethePartialInductanceThePartialInductanceistheinductanceonapartoftheloopcircuit,itcanbesubstitutetotheinductanceofsmallparts.Thisinductancecombinesthemutualandselfinductancesamongtheseresistors.2023/1/4263.5IntroducethePartialIndu4.TheMythoftheGround4.1TheMeaningofGround4.2IntroducetheReferencePoint4.3PCBtoAccessoriesConnection4.4PCBtoGroundConnection2023/1/4274.TheMythoftheGround4.1T4.1TheMeaningofGroundGround-isaplacewherepotatoesandcarrotsthrive.--PCBDesignforRealWorldEMIControl

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B.R.ArchambeaultTheKeytomitigateEMI.Anywhereinthesocalled‘ground’onthePCBdohasvoltagedecrease,foritismetal.ThiscausetheEMI.2023/1/4284.1TheMeaningofGroundGrounAproperdesignforlowfrequencycurrent.4.1TheMeaningofGround(Continue)2023/1/429AproperdesignforlowfrequeSignalsforGNDandreturncurrent.2023/1/430SignalsforGNDandreturncurAsignalreference;Apowerreference;Asthechassisreference;Connectedwithunshieldedcables;Connectedwithshieldedcables;Astheearthsafetyreference.Givethecurrentaproperroutetogoback.Groundcanbe:4.1TheMeaningofGround(Continue)2023/1/431Asignalreference;Groundcan2023/1/4322022/12/2732SignalReferenceandPowerReference4.1TheMeaningofGround(Continue)2023/1/433SignalReferenceandPowerRef4.2TheReferencePoint2023/1/4344.2TheReferencePoint2022/124.3PCBtoAccessories2023/1/4354.3PCBtoAccessories2022/12/4.4PCBtoGround2023/1/4364.4PCBtoGround2022/12/27365.TheRouteforReturnCurrent5.1Introducethereturncurrentroute.5.2TheSplitbetweendifferentPlanes.5.3IntroducetheLayoutindifferentlayers.5.4MotherboardandAccessories.2023/1/4375.TheRouteforReturnCurren5.1Introducethereturncurrentroute.2023/1/4385.1Introducethereturncurre5.2SplitbetweendifferentPlanes2023/1/4395.2SplitbetweendifferentPl5.3Introducethelayoutbetweendifferentlayers2023/1/4405.3IntroducethelayoutbetweElectromagneticInterferenceNearVias5.3Layoutbetweendifferentlayers(Continue)2023/1/441ElectromagneticInterferenceN2023/1/4422022/12/27422023/1/4432022/12/27435.4MotherboardandAccessories2023/1/4445.4MotherboardandAccessorieAbetterchoice5.4MotherboardandAccessories(Continue)2023/1/445Abetterchoice5.4Motherboard6.TheConclusionsAsuccessfulproductwithgoodEMIcharacteristic:Abetterrouteforreturncurrent;Thesenseofground.Toeliminatetheunintentionalradiationbetween/amongcomponentsandlayers.2023/1/4466.TheConclusionsAsuccessfulThankyou!Q&A2023/1/447Thankyou!Q&A2022/12/2747PCBDesignforReal-WorldEMIControlPreparedByJiaWu2003-11-202023/1/448PCBDesignPreparedByJiaWuPCBDesignforReal-WorldEMIControlThecontents1.IntroducetheEMC2.AbouttheBasicEMCDesignIntention3.IntroducetheElectromagneticInduction4.TheMythoftheGround5.IntroducetheReturnCurrentRoute6.TheConclusions2023/1/449PCBDesignforReal-WorldEMI1.IntroducetheEMC1.1EMIandEMCconcepts1.2ThesourceofEMI1.3IntroducetheInductance1.4IntroducetheGround1.5IntroducetheShielding2023/1/4501.IntroducetheEMC1.1EMIan1.1.1EMIconceptsEMI:ElectromagneticInterferenceAnyelectromagneticdisturbancethatinterrupts,obstructs,orotherwisedegradesorlimitstheeffectiveperformanceofelectronics/electricalequipment.Itcanbeinducedintentionallyandunintentionally,asaresultofspuriousemissionsandresponses,intermodulationproducts,andthelike.2023/1/4511.1.1EMIconceptsEMI:ElectrEMC:ElectromagneticCompatibilityTheconditionwhichprevailswhenequipmentisperformingitsindividuallydesignedfunctioninacommonelectromagneticenvironmentwithoutcausingorsufferingunacceptabledegradationduetounintentionalelectromagneticinterferencetoorfromotherequipmentinthesameenvironment.Theabilityofsystems,equipment,anddevicesthatutilizetheelectromagneticspectrumtooperateintheirintendedoperationalenvironmentswithoutsufferingunacceptabledegradationorcausingunintentionaldegradationbecauseofelectromagneticradiationorresponse.1.1.2EMCconcepts2023/1/452EMC:ElectromagneticCompatibiElectromagneticCompatibilityEMCInterference(EMI)Susceptibility(EMS)ConductedEmissionRadiatedEmissionConductedImmunityRadiatedImmunityEMCStructureChart1.1.2EMCconcepts(Continue)2023/1/453ElectromagneticCompatibilityI1.2TheSourceofEMIHighspeedclockgenerator;Highspeedbussignal;Powernode;DigitalandAnalogGND;I/OCableandConnector2023/1/4541.2TheSourceofEMIHighspee1.3IntroducetheInductanceTheinductancehereisnotonlyfortheinductor.Inductanceiscriticalforhighspeedsignals.AvoltagedecreasewillcausethechangeofElectromagneticfield.ThischangeofintensityandshapeisasourceofEmission.2023/1/4551.3IntroducetheInductance1.4IntroducetheGroundGround:Thereferencepoint.DifferentkindsofGroundshouldbeseparatedfromeachothers.SuchasEarthreference,Powerreference,Chassisreference.Thiscanmitigatetheinterferencebetweendifferentsignalsandkeepthempure.2023/1/4561.4IntroducetheGroundGround1.5IntroducetheShieldingShieldingisausefulwaytolimitEMI.Themagnitudeofreflectionlossdependsontheratioofbarrierimpedancetowaveimpedance,whichinturndependsonitsdistancefromthesourceandwhetherthefieldiselectricormagneticorwhetheritisaplanewave.Foraslotwithadimensionequaltoorlessthanahalf-wavelength,theshieldingeffectivenessis:Wherelismaximumdimensionofslot.2023/1/4571.5IntroducetheShieldingShi1.5IntroducetheShielding(Continue)2023/1/4581.5IntroducetheShielding(C2.BasicEMCDesignIntention2.1TheimportanceforEMCdesign2.2CouplingMechanisms2.3IntroducetheSignalSpectra2.4IntroducetheResonanceEffect2.5PotentialInterferenceSource2023/1/4592.BasicEMCDesignIntention2.1TheImportanceofEMCdesign1.EMCDesignisimportantforcost-down.2.Needcertificatestoenterintodifferentcountriesandregions,commonmarks: CCC-> China CE-> EuropeanUnion VCCI-> Japan BSMI-> Taiwan FCC-> UnitedStates2023/1/4602.1TheImportanceofEMCdesi2.2CouplingMechanismsElectricalFieldCoupling2023/1/4612.2CouplingMechanismsElectriMagneticFieldCoupling2.2CouplingMechanisms(Continue)2023/1/462MagneticFieldCoupling2.2Cou2.3SignalSpectra2023/1/4632.3SignalSpectra2022/12/27162.4ResonanceEffectsMostEMIisnarrowband,notbroadband.Theresonancefrequencyincavityis:Thea,bandcisthedimensionofthecavity.

Them,nandpisinteger,andbebothorallzero.2023/1/4642.4ResonanceEffectsMostEMI2.5PotentialInterferenceSourceShieldedproducts:Viasandholes,connectors,I/Ocables…UnshieldedproductsPCboard,radiators,externalcables,wirelessantennas…2023/1/4652.5PotentialInterferenceSou3.TheInductance3.1IntroducetheInductance3.2ElectromagneticInduction3.3IntroducetheMutualinductance3.4IntroducetheSelf-Induction3.5IntroducethePartialInduction2023/1/4663.TheInductance3.1Introduce3.1IntroducetheInductanceTheinfluenceofinductanceisextremelyimportantinhighfrequencyspectra.Theinductancecanbeanywhereinallcomponentssuchascapacitorsresistors,lines,andplanes.2023/1/4673.1IntroducetheInductanceTh3.2ElectromagneticInductionTheelectromagneticinductanceformulainFaraday’slaw:InasmallareaA,the:2023/1/4683.2ElectromagneticInductionTEffectofPower/GroundInductanceTheinductivereactanceofaconductorisusuallymoresignificantthantheimpedanceresistance.Atime-varyingcurrentpassingthroughaninductorcausesavoltagedrop.Thecurrentwhenacapacitordischarging:Thevoltagewhenachangingcurrentpassingthroughainductance:3.2ElectromagneticInduction(Continue)2023/1/469EffectofPower/GroundInducta3.3IntroducetheMutualInductance2023/1/4703.3IntroducetheMutualInducTheMutualInductancebetweentwoparallellines

3.3IntroducetheMutualInductance(Continue)2023/1/471TheMutualInductancebetween3.4IntroducetheSelf-inductance2023/1/4723.4IntroducetheSelf-induct3.5IntroducethePartialInductanceThePartialInductanceistheinductanceonapartoftheloopcircuit,itcanbesubstitutetotheinductanceofsmallparts.Thisinductancecombinesthemutualandselfinductancesamongtheseresistors.2023/1/4733.5IntroducethePartialIndu4.TheMythoftheGround4.1TheMeaningofGround4.2IntroducetheReferencePoint4.3PCBtoAccessoriesConnection4.4PCBtoGroundConnection2023/1/4744.TheMythoftheGround4.1T4.1TheMeaningofGroundGround-isaplacewherepotatoesandcarrotsthrive.--PCBDesignforRealWorldEMIControl

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B.R.ArchambeaultTheKeytomitigateEMI.Anywhereinthesocalled‘ground’onthePCBdohasvoltagedecrease,foritismetal.ThiscausetheEMI.2023/1/4754.1TheMeaningofGroundGrounAproperdesignforlowfrequencycurrent.4.1TheMeaningofGround(Continue)2023/1/476AproperdesignforlowfrequeSignalsforGNDandreturncurrent.2023/1/477SignalsforGNDandreturncurAsignalreference;Apowerreference;Asthechassisreference;Con