電路板EMC Layout技術實務應

EMCLayout::02-2602305218E-mail:[e-mail]7.8.I/OPort9.PCBEMCLayout10.PCB1.EMCnnnEMCnEMC()=EMI()+EMS()uEMC:ElectromagneticCompatibilityuEMI:ElectromagneticInterferenceuEMS:ElectromagneticSusceptibilityuCE:ConductedEmissionuRE:RadiatedEmissionuCS:ConductedSusceptibilityuRS:RadiatedSusceptibilityEMCnEMC:nEMI:nEMS:nCE:nRE:nCS:nRS:EMIEMCEMC::EMCnEMIu(ConductionTest)150kHz-30MHzu(RadiationTest)30MHz-2000MHznEMSu(ConductionSusceptibility)150kHz-80MHzu(RadiationSusceptibility)80MHz-2000MHzEMCnFCC(Part15SubpartB)nCISPR(CISPR22)nVCCInBSMI(CNS13489)nC-Tick(AS/NZS3548AS/NZS:CISPR22)EMIEMIClassAClassBFrequency(MHz)Limit(dBuV)Limit(dBuV)0.45-1.70560481.705-3069.548Frequency(MHz)Limit(dBuV/m)Limit(dBuV/m)30-88394088-21643.543.5216-9604646Above96049.5541.ClassA2.ClassB3.ClassA10mClassb3m4.FCCCISPR5.FCCCISPREMIClassAClassBFrequency(MHz)Limit(dBuV)Limit(dBuV)Q.P.Ave.Q.P.Ave.0.15-0.5796666-5656-460.5-5.0736056465.0-3073606050Frequency(MHz)Limit(dBuV/m)Limit(dBuV/m)30-2304030230-100047371.ClassA2.ClassB3.10mEMInEMInEMIEMSnEMSu(ESD)EN61000-4-2u(RS)EN61000-4-3u(EFT)EN61000-4-4u(Surge)EN61000-4-5u(CS)EN61000-4-6(ESD)EN61000-4-2kVkV1234x24681234x24815XESD(RS)EN61000-4-380MHz-1000MHzV/m123x1310XRS(EFT)EN61000-4-4I/OkVkHzkVkHz1234x0.51245552.50.250.5125555XEFT(Surge)EN61000-4-5±10%kV1234x0.51.02.04.0XSurge(CS)EN61000-4-6150kHz-80MHz(e.m.f.)Uo[dB(uv)]Uo[V]123x1201130314010XCSEMIEMSnEMInnEMSn(1)n(2)n(3)n(4)EMCnEMCnEMCEMCPCBEMCnnnnn2.EMCnuuunnn1-10V/m1W1m5V/m(ESD)nnnnn(S.P.S)n(EFT)nnnPCBSOURCEANTENNAPATHPCBnSource:nPath:nAntenna:I/OnuRFuRFEMSEMIn(1)n(2)AC/n(3)I/OI/On(4)/I/O(/)I/O(/)(4)(1)(2)(3)nnnnnnIC#1IC#2RSVSPCBnnV2=M12dI1/dtnM12dI1/dtI2I1M12dI/dtnnZSZLnI=Cdv/dtZSZLCZLdV/dtnnnnn150k-30MHz30MHz-1000MHznuuunununESDI/OEMCn:n:n:n:n:PCBRFnnnnn()n()PCBnPCBRFRFn(Z=R+jwL)RnRFnLCRFL(f)C(f)R~~RFn()nnEMInnnPCBuuPCBuRFuuuEMInnnnnnnnI/OnPCBnRF()nnnRFnuRFunRFu()nnnPCBnnnLC()PCBnRXL=2πfLZ=R+jX≅j2πLn100kHz2πfLRFn1/21/4nEMC()1/20n10cm57Ωm80H/cm100kHz5mΩ150MHznnXC=1/2πfCXC:(Ω)f:(MHz)C:(F)n10uF10kHz1.6Ω100MHz160uΩ100MHznXL=2πfLXL:(Ω)f:(MHz)L:(H)n10mH10kHz682Ω100MHz6.2MΩ(FerriteCore)nnnnnnn“”R+jwLjwL|Z|nPCBn(Maxwell’s)nσ:J=σEnμ:B=μHnε:D=εEnJ=A/m2E=V/m2D=/m2B=Web/m2H=A/m2sxH=J+∂D/∂tsxE=-∂B/∂ts·B=0s·D=ρn:n:n:n:PCBEMInPCBEMInnnnu:u:u:u:nu:u:u:u:PCBnPCBPCBuuV:I:R:Z:(R+jX)nRFRFVrf=IrfxZV=IxRnZ=R+jXL+1/jXC=R+jwL+1/jwCnXL=2πfLXC=1/2πfCw=2πfnkHzRnkHzRFnuuRFnPCBRFnRF()RFnn()120πΩ(377Ω)nnnnRFRFn0V()RFRFnn(377Ω)EMIERFnRFnRFnn(clock)(PCB)()nRFRFnnnnRFnRFnnnRFRFnE=263x10-16(f2xAxIS)x(1/r)V/mA:f:(MHz)IS:r:nPCBnE=Af2IS/380rE:(uV/m)r:(m)f:(MHz)IS:(mA)A:(cm2)nPCBA=4cmIS=5mA:f=100MHz10m52.6dBuV/mEN55022ClassB30.6dBuV/mnRFnRFI/Onn()n()nRFEMInI1I2I1I2nRFEMInnnE≅(fICML)/R(V/m)L:ICM:f:R:n(clock)nnλ/2nPCBλ/201.5cm0.15m0.3m10002.5cm0.25m0.5m6005cm0.5m1m3007.5cm0.75m1.5m20010cm1m2m15015cm1.5m3m10030cm3m6m5050cm5m10m30λ/20λ/2λ(MHz)3.ChecknPCBlayoutnnnLayoutnnnnPCBLayoutPCBLayoutnPCBnlayoutbypassClocknPCBLayout3.ChecknClocknnI/OPortnICCPUnnVccGroundClockChecknClockLayoutClocklayoutnnbead()nloopnnclocklayoutclocktreeclockchainchecknIC4layoutnlayoutclocklayoutnICnI/OPortchecknI/OnI/OPortchecknI/OlayoutCPUICchecknCPUICnVccGround0.1FnCPUIClayoutnlayoutVccGroundnVccGroundVcclayoutnGroundnCPUICGroundlayoutnVccGroundcheck0.1FDecouplingnDCInputcheck0.1FDecoupling4.nutracetrace,padpadnuuunn()nnnnnnnnclock5.nPCBI/OuACDCInI/OPortnPCBI/OuPCBI/OnPCBOn/OffPCBOn/OffPCBI/OnPCB1PCB2PCB1PCB2I/OPortPCBI/OI/O6.PlacementnI/OPortnnnThroughHoleI/OPortCPUCLKCPUCLKnPCBADDAAADDnnABABnnnThroughholenlayoutnThroughholenthroughholelayout7.nnnI/OPortnMain-boardnnPCBnADADMnclockCPUICnnnnPCBnI/OCPUGroundI/OGroundnCPUI/OnI/O(QuietArea)I/OPortnI/OPortnI/OI/OGroundGroundnI/OAnlogDigitanI/OPortESD8.I/OPortnAnlogDigitanI/OGroundnI/OGroundI/OGroundI/OPortlayoutI/OPortGroundI/OPortnI/OPortPinBypassBypassI/OGroundnBypass(20p-100p)nBead(500ohm)VccGroundnVccGround0.1FnBeadVccnGroundBead9.PCBEMCLayout1.SwitchingPowerSupplyLayout2.Layout3.Layout10.PCB1.Re-Layout2.Layout