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					    EE 164 Group 2 – Presentation 7


             Gigabit Ethernet




Ungtae Lee         April 8th 2004
 Gigabit Ethernet             Project Status 3/22-4/7

  Completed/ In Progress             Upcoming Tasks
   Built the Tx/Rx                   Build and test aggressive
   Troubleshoot the Tx/Rx             design Rx
   Built the aggressive design       Evaluate crosstalk
    Tx                                 between Tx/Rx
   Optically test aggressive Tx      Possible second design?
                                      Alignment tolerance
                                       testing for unconn.
                                       VCSEL


Group 2 – Presentation 7           April 8th 2004
  Gigabit Ethernet         Normal Design Rx/Tx
                           Heated up due to short




                                      Heated up due to short




Group 2 – Presentation 7     April 8th 2004
  Gigabit Ethernet         Normal Design Rx/Tx

                           To fix problem, used Etcher to
                           separate the ground plane
                           with the power supply.

                           -Unfortunately, it did not solve the
                           problem of shortage. Receiver still
                           heated up.




Group 2 – Presentation 7   April 8th 2004
  Gigabit Ethernet                          Normal Design Rx
                      -Electrical and optical testing showed the Transmitter to be
                      nonfunctional.
                      -Compared test board with our Rx.
                      -Found pins 15 and 7 were not grounded in the test board
                      -Etched out and removed pins from the Maxim 3264 chip
                                                -Made no difference in test
                                                results
                                                -Decided to move on to
                                                aggressive design




Group 2 – Presentation 7               April 8th 2004
   Gigabit Ethernet                                    Aggressive Design Tx




                                                               Output from probe shows eye (using
  Electrically Probed one of the differential output             PRBS7 input, connected dots)

     -Initial Electrical test proved to be successful.
     -Used the probe to detect an eye in the differential output of the Tx


Group 2 – Presentation 7                               April 8th 2004
  Gigabit Ethernet         Aggressive Design Tx
                                        -Did not have the correct
                                        adapter
                                        -Manually held up the
                                        output of the VSCEL to
                                        the input of the Optical
                                        Spectrum Analyzer




Group 2 – Presentation 7   April 8th 2004
  Gigabit Ethernet                    Aggressive Design Tx

                                                  -Surprisingly, the Optical
                                                  Spectrum Analyzer detected
                                                  an optical signal at
                                                  approximately 849nm
                                                  -Verification that the VSCEL
                                                  was working




     849 nm optical signal was detected

Group 2 – Presentation 7                  April 8th 2004
  Gigabit Ethernet         Aggressive Design Tx

                                   -Initial optical testing of the
                                   transmitter shows a rough eye
                                   -only one PRBS 7 input




Group 2 – Presentation 7   April 8th 2004
  Gigabit Ethernet         Aggressive Design Tx

                                      -Overview of the Tx optical
                                      testing
                                      -Noted that using both
                                      differential inputs produced
                                      better results
                                      -example of how optical
                                      attenuators were added
                                      together using connectors




Group 2 – Presentation 7   April 8th 2004
  Gigabit Ethernet               Aggressive Design Tx




       0 dB attenuation    2 dB attenuation
                                                    PRBS7 input with
                                                    2 sec persistence




       3 dB attenuation    4 dB attenuation


Group 2 – Presentation 7           April 8th 2004
  Gigabit Ethernet                         Aggressive Design Tx




            5 dB attenuation                  6 dB attenuation




                                                                 PRBS7 input with
                                                                 2 sec persistence



                               7 dB attenuation

Group 2 – Presentation 7                      April 8th 2004
Any questions?

				
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