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?