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Gigabit Ethernet PMD. ECE135 Group 2 – Presentation 3. Bryan Justice February 10, 2005. Updated Gantt chart Reviewed group responsibilities Reviewed IEEE 802.3z Standard regarding the PMD module Selected our VCSELs Researched and selected our ROSAs Preliminary optical link budget.
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Gigabit Ethernet PMD ECE135 Group 2 – Presentation 3 Bryan Justice February 10, 2005
Updated Gantt chart Reviewed group responsibilities Reviewed IEEE 802.3z Standard regarding the PMD module Selected our VCSELs Researched and selected our ROSAs Preliminary optical link budget Placing orders by Feb. 11 Complete optical link budget Build practice board Revise Gantt chart Start working on schematic Thinking about board layout and software Gigabit Ethernet:Progress Summary Completed Tasks Next Week’s Tasks
Group Responsibilities • Andrew Meyerson – Administration, ordering, soldering • Clifton Kerr – Layout, design, testing • Vinh Nguyen – Webpage, report writing • Bryan Justice – Optical link budget, design, testing, report writing
IEEE 802.3z PMD Research • We will be building a Physical Medium Dependent (PMD) sublayer board • PMD should conform to the IEEE 802.3z specifications for type 1000BASE-SX (Short Wavelength Laser)
802.3z Standard • PMD block diagram as found in the 802.3z standard
802.3z Cont. • Transmit characteristics (from 802.3z standard)
802.3z Cont. • Receive characteristics (from 802.3z Standard)
802.3z Cont. • The standard also defines a worst case link power budget and penalties • This will probably be needed for determining the optical link budget
VCSEL Research • Chose VCSEL • Advanced Optical Components • HFE4391-541 VCSEL • 2.5Gbps, 850nm, SC VCSEL • Cost: $14.50 for less than 1000 • $7.25 for 1000 or more • This VCSEL provided what we felt was the best combination of performance, price, and availability • Placing orders by February 11
Other VCSELS We chose to look primarily at 2.5Gbps models because they require less current. Many 1.25Gbps models require more current to operate properly than the Maxim laser driver will be able to provide in the worst case. Other VCSELs examined: Emcore Roithner Lasertechnik Appointech ThorLabs
ROSAs • ROSA has been selected • HFD3381-108 ROSA • 2.5Gbps, 850nm, SC-ROSA • Cost: $10.00 for less than 1000 • $5.00 for 1000 or more • This part, like the AOC VCSEL, provided the best combination of performance, price, and availability
Other ROSAs, drawbacks • Avalon Photonics: LC connectorized only, Swiss, $20.00 • ULM: $25, overseas company • Luxnet: Taiwan company, no response from inquiries • Hamamatsu: unsure about connectors • Copax: No response • Optowell: Korean company, no response to emails • Gigacomm: unsure about connectors, many errors in the data sheet • AOC’s ROSA featured above average performance among this group, was in stock, and had the best price, making the ROSA decision very easy.
Preliminary Budgeting (estimation) • AOC VCSEL: $14.50 (2) • AOC ROSA: $10.00 (2) • Two board fabs: $70.00 • Maxim driver and limiting amp, Digikey passives, and Murata inductors, plus allowances for shipping costs: $80.00 • Total projected budget: • Approximately $210.00
Test Board Problems • First test board kit was misplaced, putting us behind schedule. • Second kit has been obtained • Key to soldering lab did not work, compounding our frustrations • Construction of test board (and testing) should be completed no later than Feb. 13
Next Week • Build and test the test board • Finalize optical link budget • Begin design schematic • Become familiar with board layout and necessary software • Revise Gantt chart as necessary • Order parts
References • IEEE Computer Society (2003). IEEE 802.3 Standard. New York: The Institute of Electrical and Electronics Engineers, Inc. Retrieved Thursday, January 20, 2005, from ECE 164.02 website: http://www.ee.duke.edu/~mbrooke/EE164.02/Spring_2004/group_2/index_files/8023.pdf • ECE164 Group 1 Presentations. (April 26, 2004). ECE164 Group 1 Website. Retrieved January 20, 2005 from http://www.ee.duke.edu/~mbrooke/EE164.02/Spring_2004/group_1/downloads.html • ECE164 Group 2 Presentations. (April 17, 2004). ECE164 Group 2 Website. Retrieved January 20, 2005 from http://www.ee.duke.edu/~mbrooke/EE164.02/Spring_2004/group_2/presentations.html • AOC datasheets for the HFE 4391-541 VCSEL and HFD 3381-108 ROSA