How to quickly solve EMI Issues
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The document discusses electromagnetic interference (EMI) problems and solutions. It introduces EMI seminars from KEMET on filtering techniques. It then covers EMI fundamentals like sources, targets, and conducted vs radiated noise. Filter design principles are explained using capacitors, inductors, and EMI cores. Quick solutions like EMI flex suppressor sheets and bus bar EMI cores are presented. The conclusion recommends KEMET's EMI filtering products and solutions for applications up to 1200A.
![Before filtering
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After filtering
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Effect of Using EMI Suppression
Use passive electric components to suppress high frequency noise](https://image.slidesharecdn.com/schnellemiproblemelsen-171110204552/85/How-to-quickly-solve-EMI-Issues-5-320.jpg)
![How? The key is the material
• µ’ = transmission µ’’ = absorption
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How to quickly solve EMI Issues
- 1. Schnell EMI Probleme lösen - Wie?
- 2. KIT Events • KIT – Granna, Sweden November 15, 2017 • KIT – Paderborn, Germany November 21, 2017 • KIT – Nuremberg, Germany November 23, 2017 ec.kemet.com/tech-seminars ANNOUNCEMENT KEMET KIT EVENTS – November 2017
- 3. EMEA Webinars 2017 • Ceramic ESD Capacitors November 17, 2017 • New ALS70/80 Series & Press-Fit December 1, 2017 • Ceramic Safety Capacitors, Avoiding the Confusion December 4, 2017 • Class 1 MLCC Technology December 18, 2017 go.kemet.com/emeawebex ANNOUNCEMENT KEMET EMEA Webinars – November 2017
- 5. Before filtering 30 100050 100 500 0 70 10 20 30 40 50 60 [MHz] [dB(μV/m)] Frequency RadiationNoisedB(µV/m) 30 100050 100 500 0 70 10 20 30 40 50 60 [MHz] [dB(μV/m)] Frequency RadiationNoisedB(µV/m) CISPR14 Class A Limit CISPR14 Class B Limit After filtering EMI Filtering Effect of Using EMI Suppression Use passive electric components to suppress high frequency noise
- 6. Harmonics for Switched Systems 100ns 3,2MHz 10ns 32MHz 1ns 320MHz 0,1ns 3,2GHz Source: AVT: HighTech-/HighSpeed-Baugruppen ∗ FB Elektro- und Informationstechnik der FH Gießen-Friedberg ∗ Prof.Dr.Rainer Thüringer Cutoff frequency
- 7. Filter Basics • Low impedance to ground shorten the noise • High Impedance for high frequencies in the path
- 9. Design and Assembled Filter
- 11. EMI cores
- 12. EMI Core Frequency Range Frequency range depends on the material
- 13. EMI Core Defining Parameters • No inductance, no rated voltage needed • Round or flat cable • Mounting versions • Shape and dimension • Diagrams shows impedance over frequency • Number of turns can increase the impedance
- 14. Quick solution
- 15. Bus Bar EMI Core • Size capability 110 x 50 x 35mm/half peace • -40℃～+155℃ • Ferrite permeability 𝜇 = 5000 • 250Amp 100KW • Common mode current 10Amp • CMC 10uH • DMC 0.2uH • Customized solutions
- 16. PMIC / CPU / Memory / etc. RF ant. Metal Signal NoiseNoise INTEGRATION increase NOISE trouble S/N ratio decreased Signal Noise Flex Suppressor Attenuation Signal NoiseNoise Flex Suppressor ATTENUATES the NOISE S/N ratio improved Signal Noise Noise Suppression on board
- 17. Composite magnetic sheet designed to absorb magnetic energy effectively Flex Suppressor 0 40 80 20 60 µ” µ’ 25~500µm Soft magnetic alloy (ex. Fe-Al-Si) Polymer
- 18. How? The key is the material • µ’ = transmission µ’’ = absorption Permeability 0 40 80 120 160 Frequency[MHz] 1 10 100 1000 10000 µ” µ’
- 19. Definition Inductance • L0 = nominal inductance • µ’ = transmission = inductive part • µ’’ = absorption = resistive part (loss) • µi = initial impedance • µ’ = µi • µ’’ = µi * tan 𝛅
- 20. Absorbing Energy • No significant self heating
- 21. Flex Suppressor sheets • sheet absorbs the electromagnetic noises • create a small mount of heat • shield in 10MHz to 10GHz range • customized cut outs possible • Used also in cables 21
- 23. S21 - Parameter Test Setup
- 24. FLEX SUPPRESSOR Lineup Type Form Current NEW General EFX EFX6 FX2 FX5 UL 94-V0 EFF EFF4 FF1 GHz EFG EFG2 FG1 NFC RM4A Under development FR4
- 25. Conclusion • EMI Filtering becomes more and more important • Noise spectrum depends on rise time of the switching device • KEMET offering: • Complete Filter for Power 1200A • Capacitor and inductors • Flex Suppressor sheets • EMI cores in powerline no leakage current • Snap solutions quick and easy install • Flex Suppressor “sticker“
- 26. Thank You! Axel Schmidt Field application Engineer Cell +49 172 89 25 284 email: AxelSchmidt@kemet.com Hermann-Köhl-Str. 2 86899 Landsberg am Lech Germany www.kemet.com