Gigabit Ethernet EE 164 Group 2 – Presentation 7 Ungtae Lee April 8th 2004

Gigabit Ethernet Project Status 3/22-4/7 Completed/ In Progress Built the Tx/Rx Troubleshoot the Tx/Rx Built the aggressive design Tx Optically test aggressive Tx Upcoming Tasks Build and test aggressive design Rx Evaluate crosstalk between Tx/Rx Possible second design? Alignment tolerance testing for unconn. VCSEL Group 2 – Presentation 7 April 8th 2004

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

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

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

Gigabit Ethernet Aggressive Design Tx Group 2 – Presentation 7 April 8th Initial Electrical test proved to be successful. -Used the probe to detect an eye in the differential output of the Tx Electrically Probed one of the differential output Output from probe shows eye (using PRBS7 input, connected dots)

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

Gigabit Ethernet Aggressive Design Tx Group 2 – Presentation 7 April 8th nm optical signal was detected -Surprisingly, the Optical Spectrum Analyzer detected an optical signal at approximately 849nm -Verification that the VSCEL was working

Gigabit Ethernet Aggressive Design Tx Group 2 – Presentation 7 April 8th Initial optical testing of the transmitter shows a rough eye -only one PRBS 7 input

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

Gigabit Ethernet Aggressive Design Tx Group 2 – Presentation 7 April 8th 2004 PRBS7 input with 2 sec persistence 0 dB attenuation2 dB attenuation 3 dB attenuation4 dB attenuation

Gigabit Ethernet Aggressive Design Tx Group 2 – Presentation 7 April 8th 2004 PRBS7 input with 2 sec persistence 5 dB attenuation6 dB attenuation 7 dB attenuation

Any questions?