SNLA266A January   2016  – December 2023 DP83822H , DP83822HF , DP83822I , DP83822IF , DP83825I , DP83826E , DP83826I

 

  1.   1
  2.   DP8382x IEEE 802.3u Compliance and Debug
  3.   Trademarks
  4. 1Terminology
  5. 2Standards and System Requirements
    1. 2.1 Standards
    2. 2.2 Test Equipment Suppliers
    3. 2.3 Test Equipment Requirements
  6. 3Ethernet Physical Layer Compliance Testing
    1. 3.1 Standard Test Setup and Procedures
    2. 3.2 100BASE-TX Compliance Testing
      1. 3.2.1 Template (Active Output Interface)
      2. 3.2.2 Differential Output Voltage
      3. 3.2.3 Rise and Fall Time
      4. 3.2.4 Waveform Overshoot
      5. 3.2.5 Jitter
      6. 3.2.6 Duty Cycle Distortion
      7. 3.2.7 Return Loss
    3. 3.3 10BASE-Te Compliance Testing
      1. 3.3.1 Link Pulse
      2. 3.3.2 10BASE-Te Standard
        1. 3.3.2.1 TP_IDL
        2. 3.3.2.2 MAU, Internal
        3. 3.3.2.3 Jitter With TPM
        4. 3.3.2.4 Jitter Without TPM
        5. 3.3.2.5 Differential Voltage
        6. 3.3.2.6 Common-Mode Voltage
        7. 3.3.2.7 Return Loss
        8. 3.3.2.8 Harmonic Content
  7. 4How to Tune DP83825 VoD Swing
    1. 4.1 Example of Tuning DP83825 VoD Swing
  8. 5IEEE802.3u Compliance Testing Scripts for the DP8382x
  9. 6References
  10. 7Revision History

3.2.7 Return Loss

Purpose: To verify that the return loss is above the specified attenuation.

Pass Condition: The reflection of any incident signal to the PHY must be attenuated under the following conditions:

  • ≥16 dB over the frequency range of 2 MHz to 30 MHz.
  • ≥10 – 20×log10(f/30) dB over the frequency range of 30 MHz to 60 MHz (f in MHz, where f is the frequency.)
  • ≥10 dB over the frequency range of 60 MHz to 80 MHz.

Specific Test Setup: Verify that the test fixture connections are correct.

Note: A spectrum analyzer can be required depending on the Ethernet Compliance Software used in the test.