1. Prof R T KennedyEMC & COMPLIANCE ENGINEERING 1 EET 422 EMC & COMPLIANCE ENGINEERING

2. Prof R T KennedyEMC & COMPLIANCE ENGINEERING 2

3. Prof R T KennedyEMC & COMPLIANCE ENGINEERING 3 SMPS DISTURBANCES

4. Prof R T KennedyEMC & COMPLIANCE ENGINEERING 4 I CM I DS I DS = I DM I DS V DS Cp I CM 0 0 0

5. Prof R T KennedyEMC & COMPLIANCE ENGINEERING 5 INSULATION C M NOISE PATHWAY ~ = I CM

6. Prof R T KennedyEMC & COMPLIANCE ENGINEERING 6

7. Prof R T KennedyEMC & COMPLIANCE ENGINEERING 7 DIFFERENTIAL MODE INTERFERENCE

8. Prof R T KennedyEMC & COMPLIANCE ENGINEERING 8

9. Prof R T KennedyEMC & COMPLIANCE ENGINEERING 9 COMMON MODE INTERFERENCE

10. Prof R T KennedyEMC & COMPLIANCE ENGINEERING 10 FLYBACK SMPS CCM DCM

11. Prof R T KennedyEMC & COMPLIANCE ENGINEERING 11 10 mV : Excellent 100 mV : Average 1 V : Excessive

12. Prof R T KennedyEMC & COMPLIANCE ENGINEERING 12 SMPS CONDUCTED EMISSIONS

13. Prof R T KennedyEMC & COMPLIANCE ENGINEERING 13

14. Prof R T KennedyEMC & COMPLIANCE ENGINEERING 14

15. Prof R T KennedyEMC & COMPLIANCE ENGINEERING 15 ‘INTRINSIC’ DIFFERENTIAL MODE NOISE I DS I DS(AC) o o DM noise normally due to SMPS pulsating current ac component LISN presents 100  impedance (2 series 50  if capacitor esl significant then HF DM  source RECTIFIER ‘ON’  HIGHER DM X C  2 k  @ 1 MHz X C  2 M  @ 10 kHz

16. Prof R T KennedyEMC & COMPLIANCE ENGINEERING 16 ‘INTRINSIC’ DIFFERENTIAL MODE NOISE I DS I DS(AC) o o DM noise normally due to SMPS pulsating current ac component LISN presents 100  impedance (2 series 50  if X C << 100  most DM diverted from LISN X C  2 k  @ 1 MHz X C  2 M  @ 10 kHz

17. Prof R T KennedyEMC & COMPLIANCE ENGINEERING 17

18. Prof R T KennedyEMC & COMPLIANCE ENGINEERING 18 COMMON MODE NOISE: MOSFET TURNING ON X C  2 k  @ 1 MHz X C  2 M  @ 10 kHz I DS I DS(AC) V DS o o o CM noise normally due to SMPS parasitic capacitance and LISN presents 25  impedance (2 parallel 50 

19. Prof R T KennedyEMC & COMPLIANCE ENGINEERING 19

20. Prof R T KennedyEMC & COMPLIANCE ENGINEERING 20 COMMON MODE NOISE: MOSFET TURNING OFF X C  2 k  @ 1 MHz X C  2 M  @ 10 kHz I DS I DS(AC) V DS o o o CM noise normally due to SMPS parasitic capacitance and LISN presents 25  impedance (2 parallel 50  L N G LISN C esr esL PP

21. Prof R T KennedyEMC & COMPLIANCE ENGINEERING 21

22. Prof R T KennedyEMC & COMPLIANCE ENGINEERING 22 COMMON MODE NOISE: PARASITIC CAPACITANCE CM noise normally due to SMPS parasitic capacitance and LISN presents 25  impedance (2 parallel 50  X C  2 k  @ 1 MHz X C  2 M  @ 10 kHz I DS I DS(AC) V DS o o o

23. Prof R T KennedyEMC & COMPLIANCE ENGINEERING 23 SMPS: INPUT FILTER

24. Prof R T KennedyEMC & COMPLIANCE ENGINEERING 24 SMPS: NO INPUT FILTER

25. Prof R T KennedyEMC & COMPLIANCE ENGINEERING 25