SNLA466A August   2024  – October 2024 DP83822I , DP83826E , DP83826I , DP83867E , DP83867IR , DP83869HM

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Abbreviation
  5. 2Introduction
  6. 3EMC Emission
    1. 3.1 Radiated Emission
      1. 3.1.1 Test Setup for Radiated Emission Test
      2. 3.1.2 Main Radiated Emission Sources
    2. 3.2 Conducted Emission
      1. 3.2.1 Test Setup for Conducted Emission Test
      2. 3.2.2 Main Conducted Emission Sources
    3. 3.3 Debug Procedure on EMC Emission
      1. 3.3.1 General Debug Procedure
      2. 3.3.2 RE Specific Debug
      3. 3.3.3 CE Specific Debug
  7. 4EMC Immunity Test
    1. 4.1 EMI Passing Criteria
    2. 4.2 Common EMI Knowledge
    3. 4.3 IEC61000 4-2 ESD
      1. 4.3.1 ESD Test Setup
      2. 4.3.2 Possible Root Cause of Failure
      3. 4.3.3 Debug Procedure
        1. 4.3.3.1 Follow the Test Setup
        2. 4.3.3.2 Remove External Factors on Cable or Link Partner
        3. 4.3.3.3 Areas to Explore to Improve ESD Performance
          1. 4.3.3.3.1 Air or Capacitive Coupling Discharge ESD Recommendations
          2. 4.3.3.3.2 Direct Contact Discharge ESD Recommendation
        4. 4.3.3.4 Schematic and Layout Recommendations
    4. 4.4 IEC 61000 4-3 RI
      1. 4.4.1 RI Test Setup
      2. 4.4.2 Possible Root Cause of Failure
      3. 4.4.3 Debug Procedure
        1. 4.4.3.1 Follow RI Test Setup
        2. 4.4.3.2 Remove External Factor on Cable or Link Partner
        3. 4.4.3.3 Found out Main Emission Area
        4. 4.4.3.4 Schematic and Layout Recommendation
    5. 4.5 IEC 61000 4-4 EFT
      1. 4.5.1 EFT Test Setup
      2. 4.5.2 Possible Root Cause of Failure
      3. 4.5.3 Debug Procedure
        1. 4.5.3.1 Follow EFT Test Setup
        2. 4.5.3.2 Remove External Factor on Cable or Link Parnter
        3. 4.5.3.3 Areas to Explore to Improve EFT Performance
        4. 4.5.3.4 Schematic and Layout Recommendation
    6. 4.6 IEC 61000 4-5 Surge
      1. 4.6.1 Surge Test Setup
      2. 4.6.2 Possible Root Cause of Failure
      3. 4.6.3 Debug Procedure
        1. 4.6.3.1 Follow Surge Test Setup
        2. 4.6.3.2 Remove External Factor on Cable or Link Partner
        3. 4.6.3.3 Area to Explore to Improve Surge Performance
        4. 4.6.3.4 Schematic and Layout Recommendation
    7. 4.7 IEC 61000 4-6 CI
      1. 4.7.1 CI Test Setup
      2. 4.7.2 Possible Root Cause of Failure
      3. 4.7.3 Debug Procedure
        1. 4.7.3.1 Follow CI Test Setup
        2. 4.7.3.2 Remove External Factors on Cable or Link Partner
        3. 4.7.3.3 Areas to Explore to Improve CI Performance
        4. 4.7.3.4 Schematic and Layout Recommendation
  8. 5Schematic and Layout Recommendation for All EMC, EMI Tests
    1. 5.1 Schematic Recommendation
    2. 5.2 Layout Recommendation
  9. 6Summary
  10. 7References
  11. 8Revision History

3.3.1 General Debug Procedure

  1. Follow the test setup for both RE test and CE test.
    • At least 10cm distance between DUT and link partner to prevent noise coupling
    • No sources of noise between DUT and Link Partner
    • Check on background noise and verify background noise is low (RE testing)
    • Tested radiated equipment does not need to be present on the test bench (RE testing)
    • Power supply needs to always be shielded during the test (RE testing)
    • Verify Coupling De-coupling Network (CDN) is properly grounded (CE testing)
      • CDN and cable mismatch (especially shielded/unshielded combination) can increase emissions due to discontinuous ground in the signal lines
  2. Cable in CE and RE test recommendation:
    • Shielded cable is preferred to reduce emissions by the Ethernet cable
    • Prefer no cable loops are present during test. Cable loops can enhance the crosstalk effect and increase emissions.
    • Verify the Ethernet cable is not close to any external noise sources
      • Power supply, test equipment, and another electrical device are the possible external noise sources
    • If possible, orient the cable farther away from the antenna
    • Verify the cables type on both side of Coupling De-coupling Network (CDN) match (CE testing)
    • Verify the cable type matches with CDN specification (CE testing)