Verification of Optimal EMI Filter Design

Transcription

1 With EMI Analyzer Verification of Optimal EMI Filter Design Cheol-Soo, Kim EMCIS Co., Ltd

2 1. EMI Measurement Table 2. Optimal EMI filter design 3. Verification of EMI Filter Design 4. Case Study 2

3 1. EMI Measurement 1) Total Mode Noise Measurement LISN Goal = Pass the limit lines as Total mode measurement Measured results of Each Line should be passed the requirements/specification. Measure Voltage at 1kΩ point. ( Line and GND ) Impedance of LISN = 50Ω (Link the not-measured output to 50Ω) 3

4 1. EMI Measurement 1) Total Mode Noise Measurement LISN I CM /2+I DM I CM /2-I DM : Differential-mode (DM) noise current (I DM ) path : Common-mode (CM) noise current (I CM ) path I OP : main operating current I CM /2 I OP +I DM I CM /2 EMI Source (EUT) The measured results is the mixture of CM &DM Noises The measured results shown on the instruments is only the higher level between CM & DM noises 4

5 1. EMI Measurement 1) Total Mode Noise Measurement - Takes a long time - Cost up - Larger filter sizes Interpretation difficulties for circuit Multi-stage filter circuit 5 5

6 2. Optimal filter design 1) Must-Be consideration in Optimal Filter Design Cost + No. of Components Size Frame, Material of Case Stage of Filter Directly Linked Additional Cost Location of Filter Ground 6

7 2. Optimal filter design 2) Current Method in Filter Design Measure only Total Mode Noise Try with existing filter Experienced and used approach Target Selection Measured noise- (Limit +Margin) Layout Measure again Total Mode Noise Ground Debugging Changing CM & DM components Layout, Ground Try & Error Measure again Total Mode Noise Finish 7

8 2. Optimal filter design Why Debugging is repeated?? Debugging CM Mode Try & Error Noise Measure ment DM Mode Total Mode CM, DM Noise Solution = 8

9 2. Optimal filter design 3. Filter Design with EMI Analyzer EMI Analyzer EA-300 Impedance Module System 9

10 2. Optimal filter design 3) Filter Design with EMI Analyzer EMI Analyzer (EA-300) 1. Measure Total Mode Noise 2. CM, DM Noise Analysis 3. Source Impedance Analysis 4. Analysis of each components 5. EMI Filter Design (Basic) EMI Measurement and Analysis 10

11 2. Optimal filter design 4) EMCIS Filter Design Process Measure Noise Total Mode Noise Layout, Frame Ground Analysis of Noises Target Decision Source Impedance analysis of CM, DM CM, DM Filter Design CM, DM Mode Noise Measured Noise- (Limit +Margin) Impedance Analysis of each mode under EUT operation CM Mode Filter Design Measure Noise Total Mode Noise Finish 11

12 2. Optimal filter design 4) EMCIS Filter Design Process Total Mode Noise measurement Measure Noise Analysis of Noise, CM and DM Target Decision Layout, Frame Source Impedance Analysis, CM, DM Ground CM, DM Filter Design Measure the results Finish L1 or L2 Noise (Total Noise) 12

13 2. Optimal filter design 4) EMCIS Filter Design Process CM, DM Mode Analysis Measure Noise Analysis of Noise, CM and DM Target Decision Layout, Frame Source Impedance Analysis, CM, DM Ground CM, DM Filter Design Measure the results Finish CM Mode Noise DM Mode Noise 13

14 2. Optimal filter design 4) EMCIS Filter Design Process CM, DM Mode Noise Measurement LISN EMI Analyzer Spectrum Analyzer I CM /2+I DM I CM /2-I DM I OP +I DM Through 2ports of LISN, Pick up Noise (Total Noise) EMI Analyzer separates and analyzes them Common Mode (CM) and Difference Mode (DM) respectively 14

15 2. Optimal filter design 4) EMCIS Filter Design Process Measure Noise 200kHz Total CM Mode DM Mode Layout, Frame Ground Analysis of Noise, CM and DM Target Decision Source Impedance Analysis, CM, DM CM, DM Filter Design Noise Level 90dBuV 81dBuV 86dBuV LIMIT 53dBuV 53dBuV 53dBuV Margin 3dBuV 3dBuV 3dBuV Insertion loss 40dBuV 31dBuV 36dBuV Measure the results Finish Target - Solution 15

16 2. Optimal filter design 4) EMCIS Filter Design Process Measure Noise Source Impedance Analysis CM Mode 1) Select CM Mode Analysis of Noise, CM and DM Target Decision 1 st frequency over the Limit Layout, Frame Source Impedance Analysis, CM, DM Ground CM, DM Filter Design Measure the results 2) Set up Frequency Finish Input Frequency 16

17 2. Optimal filter design 4) EMI Filter Design Process Source Impedance Analysis 3) Input Noise Level CM Mode 4) Auto changing/tracing the LeveI by IMP Module 17

18 2. Optimal filter design 4) EMCIS Filter Design Process Source Impedance Analysis CM Mode DM Mode Impedance is same as CM case 18

19 2. Optimal filter design 4) EMCIS Filter Design Process Source Impedance Analysis CM Mode Z L Vo Z S Z S Z N Z L V N V 0 LISN Z S Z N V N EUT v IL 20log v N O 20log ( L) 2 ( Z Z S N Z S ) 2 DM Mode vo Z N Z s Z s Z C ( Z s Z N ) Z C v N V 0 LISN Z S Z C Z N V N EUT IL 20log 20log v v N O 20log ( CZ S Z N ) scz 2 Z S S ( Z Z N N Z Z S Z S N ) 2 Z S

20 2. Optimal filter design CM Mode 4) EMCIS Filter Design Process Source Impedance Analysis 200kHz -11dB L1 (7.4mH) Z N 2.6kΩ v O Z S v N 88dBuV -> 77dBuV = -11dB IL = 20log Zn CM Z-200kHz IL = 20log 2.6kΩ 9.5kΩ = -11.3dB 20

21 2. Optimal filter design 4) EMCIS Filter Design Process DM Mode Source Impedance Analysis 200kHz -15dB v O Z S Z N C=0.47uF 10Ω v N 87dBuV ->72dBuV = -15dB IL = 20log XC Z - 200kHz Zn IL = 1.7Ω 20log = db 10Ω 21

22 2. Optimal filter design 5) Filter Design Source Impedance Analysis EMI Filter CM, DM Mode Noise Analysis Characteristic s of Components (L,C) Circuit Design Layout, GND Optimal Design (Cost down) Fast Solution (Competitiveness) Optimized Layout and Structure (Cost, Competitiveness) 22

23 2. Optimal filter design 5) EMI Filter Design (Basic) (CM Mode) (DM Mode) 23

24 3. Verification of EMI Filter Design 1) Verifying by Noise characteristics Check the proper margin (from the limit line) at each mode, CM,DM, and Total Mode with EMI Analyzer Recommended/acceptable about 3dB margin at Low frequency range CM Mode Noise Total Mode Noise DM Mode Noise

25 3. Verification of EMI Filter Design 2) Theatrical Verification of Filter Design CM Mode Filter CM L 38dB CM Mode Noise v O Z S Y-Cap Z N v N 200kHz L1 0.8mH Check the capacity of CML & Y-Capacitor is reasonable?? 21Ω v O Z S L1 Z N 1kΩ v N L1 45mH Ref L = 20log Z N 2π F 0.8mH 45mH = 0.8mH (-3dB) =-35dB =-38dB 25

26 3. Verification of EMI Filter Design 2) Theatrical Verification of Filter Design CM Mode Filter L1 0.8mH L1 45mH 4.5mH+9400PF 20log 20log CS YC 10PF 9400PF 1/10 of YC resonance =-59.5dB 45mH+9400PF 45mH+9400PF =-58dB (200kHz) 20dB Margin 20log 45mH 4.5mH =+20dB 45mH 9400PF 4.5mH 9400PF 26

27 3. Verification of EMI Filter Design 2) Theatrical Verification of Filter Design DM Mode Filter 32dB DM Mode Noise 84Ω Z S XC Z N 10Ω 200kHz Ref XC = 20log 1 2π F Z N 0.08uF 3.3uF = 0.08uF = -32dB =-35dB 40 db Z S 84Ω DM L 10uH XC 3.3uF Z N 10Ω 20log XC L DM L 20log 100nH 10uH 1/10 of DML resonance frequency = -40 db 27

28 4. Case Study of EMI Filter Design 1) Battery charger on Hybrid Vehicle Input AC220V Output DC300V 28

29 4. Case Study of EMI Filter Design 2) Customer Design - current Battery charger on Hybrid Vehicle Total Noise Even spending 3months, not POINT TO SOLVE solved Designed/Applied Filter 29

30 4. Case Study of EMI Filter Design 2) Customer design - current Battery charger on Hybrid Vehicle 2 Ferrite cores feed on cable -2 turns (35uH) 3stage Filter design 4 stage Filter design 30

31 4. Case Study of EMI Filter Design 3) Noise Analysis EMCIS Battery charger on Hybrid Vehicle Common Mode Differential Mode Result : the Noise in target is determined as Common Mode Noise

32 4. Case Study of EMI Filter Design Battery charger on Hybrid Vehicle Requirements for Filter Design what the Customer desire Cost down 50% Size 50% 32

33 4. Case Study of EMI Filter Design 4) Measure the noises Total Noise Battery charger on Hybrid Vehicle (Meausre without any filter) 60dB Measure the current noise to decide the target and the Filter design Target 215kHz 112.7dBuv->53dBuV = Min 60dB deduction 33

34 4. Case Study of EMI Filter Design 5) Analyze the Noise characteristics Common Mode Battery charger on Hybrid Vehicle Differential Mode Measure each mode, CM & DM respectively for Filter Design Target CM Mode : 215kHz 123.7dBuV -53dBuV =70dB DM Mode : 240kHz 116.7dBuV -53dBuV =70dB 34

35 4. Case Study of EMI Filter Design 6) Source Impedance Analysis Battery charger on Hybrid Vehicle LISN L CM Mode N G C C L L I CM /2 IMP I OP +I DM I CM /2 CM noise EMI Source (EUT) Frequency By Pass Impedance Module Control Level Difference Source Impedance 216kHz 123dBuV 116dBuV 7dB 7 kω Freq By Pass DM Mode Impedance Module Control Level Difference 240kHz 116.7dBuV 95.2dBuV 21.5dB Source Impedance 16.8Ω 35

36 4. Case Study of EMI Filter Design 7) Filter Design CM Mode Battery charger on Hybrid Vehicle DM Mode 9400pF 3mH 3mH 9400pF 3.3uF 10uH 10uH 3.3uF 21Ω 0.02uF 7kΩ 84Ω 0.005uF 17Ω 2300pF 36

37 4. Case Study of EMI Filter Design 7) Filter Design Battery charger on Hybrid Vehicle CM Mode DM Mode 9400pF 3mH 3mH 9400pF 3.3uF 10uH 10uH 3.3uF 21Ω 0.02uF 7kΩ 84Ω 0.005uF 17Ω 2300pF 37

38 4. Case Study of EMI Filter Design Battery charger on Hybrid Vehicle 8) Measure applying EMCIS design filter The noise is over the limit line beyond 1MHz frequency EMI Filter Design = Very Good!!! This is the Point why EMI solution is impossible for last 3months!! 38

39 4. Case Study of EMI Filter Design 9) Analysis of the Pointed range Common Mode Battery charger on Hybrid Vehicle Measure Noise Analysis of Noise, CM and DM Target Decision Layout, Frame Source Impedance Analysis, CM, DM Differential Mode Ground CM, DM Filter Design Measure the results Finish Results the Cause 1. the problem is by Common Mode Noise 2. Ground 39

40 4. Case Study of EMI Filter Design 10) Circuit modification Battery charger on Hybrid Vehicle Total Noise : L1, L2 * Delete 472Y-CAP * The purpose of Y-Cap in input portion : Coupling noise elimination caused by layout 40

41 4. Case Study of EMI Filter Design 11) Conclusion Battery charger on Hybrid Vehicle Before After 41

42 4. Case Study of EMI Filter Design 11) Conclusion Battery charger on Hybrid Vehicle 70dB 80dB Target 215kHz 112.7dBuv->53dBuV 59.7dB 60dB 이상 70dB Result 215kHz 112.7dBuv->43dBuV 69.7dB 70dB 42

43 Thank you 43