第九章实际EMI控制

EMI9.1EMI,EMICADEMI`EMIElectromagneticinterferenceEMC(Electromagneticcompatibility)(susceptibility)EMV(Electromagneticvulnerability)EMIEMI9.2EMI1EMIHzf8103×=λ(m)¼1cm600MHz10701cm9.1EMI1cm9.11m60MHzEMI180%9.3+Uin9.39.29.3+Uin9.29.4+U-U9.4EMI9.4+U-U;+U-U9.29.3EMI71EMI9.59.6+Uin9.6Uin9.5100kHz300A3mA101100kHz9.7729.8PCBPWMMOSFET9.9PCBPCB9.9dlmΩ=5.0Rld35mPCBPCBPCBIR+L(dI/dt)9.109.10100mA739.11PCBPCB9.11PCBPCB9.119.12MOSFETMOSFETMOSFET6A9.13MOSFETPCBPCBPCBPCB9.12VVcc0.1uF4.7uF9.13TTLMOSFETMOSFETMOSFET9.14MOSFET6AMOSFETMOSFET9.151749.14MOSFET9.15PCB4510kPCBPCBPCBPCB.PCBPCB100nFPCBMOSFETMOSFET9.59.5.175LISNLineImpedanceStabilizationNetworkLISN,5050ESR9.16LC40dB/dec100kHz20dB100kHz/1030kHz30kHz40dB/Dec30kHzLCLC9.5.2YX9.17LISN50509.16LISNLC1mH4.7nF4.7nF1mH9.173kV6kVLC2489.189.189.4nF4mH26kHzEMIESRRC100FESR100m16kHzEMIEMI1F1MHz1MHz100nF10MHz1F100nF10nF1mH100pF500kHz76Y471482-472AL1100dB,660~80dBPCB100dB9.610MHzMHz100MHzMOSFETMOSFETMHz10A10MHz1MHz501m1H10MHz609.7Buck775V2.5VBuck0.50.5A1A100kHz4/A300kHz4/3500kHz4/54/1004/30010MHz30MHz,LCEMIMIL-STD-461EMI10FEMIUoC()1MIL-STD-46110F2ISC()(MLC)3LCCLmC1LL1MIL-STD-46110FC21m1HZ1,Io()10FmoCoLcZbaUIωωω++++=)()((1)78(L+L1)b=Z2(L+L1)(C+C1)c=2(L+L1)(C+C1)Lm.LC1.L11mC2MIL-STD-46110FMIL-STD-461EMIIo()Io()U()Z()Z1LmCLmCIo()MIL-STD-461MPP20%23200HAinVolL≈1F50VCKR06233FUinVolc≈UCLm1CLm1QEMIMiddlebrook20dB79