Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Optical Gigabit Ethernet Group F.O.R.E. Final Presentation Chris Abbott, Ronen Adato, David Larado 4/21/2005 Overview Purpose was to build physical layer of optical gigabit transceiver Selected active components based on availability, connectorization, quality Designed and laid out two transceiver printed circuit boards Built and tested boards Compiled prototype budget and productionscale bill of materials IEEE 803.z Standard Extinction Ratio Eye-safe power level Criteria for testing Definition of Bit Error Rate Use of eye as guideline, but not for formal test Test Board Built test board to learn soldering and testing techniques Soldered Test Board Test Setup (To oscilloscope) Test Board Results No resistance/Full Setup High resistance/Full Setup <-- High resistance / test board only Ideal resistance / test board only --> Ideal resistance/Full Setup VCSEL Selection Criteria for selecting VCSEL: Good performance (slope efficiency, threshold current) Availability Cost Connectorization (SC over LC) VCSEL Performance Analysis AOC vs Lasermate Performance Similar Lasermate costs more in small quantities (costs comparable in bulk) AOC is LC connectorized, Lasermate is SC Chose Lasermate due to SC connectorization (no patch cords) ROSA vs. PD Past years have used PDs ROSA contains TIA inside package Requires external TIA Possible reduction in noise Easier layout Comparable prices, easier to find Leading PD vendor too expensive Chose ROSA ROSA Selection Lasermate RSC-P85P416 1.25 Gb/s SC ROSA SC connectorized ROSA Costs: 2-3 = $36.00/unit >10,000 = $6.00/unit Optical Link Budget Schematic Design Schematics derived from: Maxim datasheets Maxim application notes Past group’s work Used three element power supply filters Conservatively coupled Vcc and ground with decoupling capacitors Designed for common anode VCSEL configuration Transmitter Schematic Receiver Schematic PCB Layout Considerations Kept traces as short as possible to prevent transmission line behavior Avoided sharp corners on high-speed lines (used 45° angles when needed) Kept high-speed differential lines symmetrical Effectively separated ground plane of transmitter and receiver Conservative Layout Aggressive Layout Conservative Board 1 Soldered all components and tested the Rx circuit for a clear eye SMA/QMA fiasco prevented BER testing for the Rx circuit, and any Tx circuit testing Rx Circuit Test Setup Eye Produced by Rx Circuit, Signal PRBS 7 Conservative Board 2 Rx Reused SMAs from test board, soldered a new board The Rx circuit failed to produce an eye Rx Circuit Waveform Measured Before LA It was determined that the LA (MAX3264) had been damaged Rx Circuit Waveform Measured After LA Conservative Board 2 Tx Soldered board, but had to reuse VCSEL from conservative board 1 Voltage drop across VCSEL was 5V VCSEL could be damaged VCSEL could be connected incorrectly Removed VCSEL and checked behavior by pin-pin resistance Aggressive Board 1 Decided to try Emcore VCSEL on aggressive design to get Tx working Aggressive Tx very similar to conservative Tx Made sure we knew how Emcore fit into board Aggressive Board, TxRx We varied the attenuations with, the transceiver: 4dB 7dB Using different combinations of the optical attenuators, we were able to try these also: 9dB 12dB Aggressive Board, BER BER of less than 10^-9 when each signal was tested PRBS7, at least 5 minutes test runtime Financial Budget Financial Budget Part Description .01μF Ceramic Chip Capacitor 49.9Ω Chip Resistor 100Ω Chip Resistor 115Ω Chip Resistor 150Ω Chip Resistor 50kΩ Potentiometer 1kΩ Potentiometer Ferrite Bead Inductor Right Angle PCB SMA Jack Surface Mount Power Jack 850nm, 1.25Gb/s SC VCSEL 850nm, 1.25Gb/s SC ROSA PCB Board Vendor Digi-Key Digi-Key Digi-Key Digi-Key Digi-Key Digi-Key Digi-Key Digi-Key Newark InOne Digi-Key Lasermate Lasermate Express PCB Stock Number Quantity/Link Unit Price Quantity Cost 399-1091-1-ND 18 $ 0.04200 100 $ 4.20 311-49.9CCT-ND 1 $ 0.08000 10 $ 0.80 311-100CCT-ND 2 $ 0.08000 10 $ 0.80 311-115CCT-ND 1 $ 0.08000 10 $ 0.80 311-150CCT-ND 1 $ 0.08000 10 $ 0.80 3362P-503-ND 1 $ 0.83000 6 $ 4.98 3362P-102-ND 1 $ 0.83000 6 $ 4.98 490-1034-1-ND 6 $ 0.12000 40 $ 4.80 07J2532 4 $ 4.51000 6 $ 27.06 CP-002APJCT-ND1 $ 0.81000 2 $ 1.62 TSC-P85A426-2 1 $ 32.00000 3 $ 96.00 RSC-P85P416 1 $ 36.00000 3 $ 108.00 Custom 1 $ 59.95000 1 $ 59.95 Shipping: $ 29.00 TOTAL $ 343.79 Bill of Materials (BOM) Bill of Materials -Cost per Board at Production Capacity Part Description .01μF Ceramic Chip Capacitor 49.9Ω Chip Resistor 100Ω Chip Resistor 115Ω Chip Resistor 150Ω Chip Resistor 50kΩ Potentiometer 1kΩ Potentiometer Ferrite Bead Inductor Surface Mount Power Jack Laser Driver Limiting Amplifier 850nm, 1.25Gb/s SC VCSEL 850nm, 1.25Gb/s SC ROSA **PCB Board Vendor Digi-Key Digi-Key Digi-Key Digi-Key Digi-Key Digi-Key Digi-Key Digi-Key Digi-Key Maxim Maxim Lasermate Lasermate Express PCB Stock Number Quantity Per Link Production Cost 399-1091-1-ND 18 $ 0.00988 311-49.9CCT-ND 1 $ 0.01682 311-100CCT-ND 2 $ 0.01682 311-115CCT-ND 1 $ 0.01682 311-150CCT-ND 1 $ 0.01682 3362P-503-ND 1 $ 0.36000 3362P-102-ND 1 $ 0.36000 490-1034-1-ND 6 $ 0.06400 CP-002APJCT-ND 1 $ 0.53800 MAX3287 1 $ 4.30000 MAX3264 1 $ 4.30000 TSC-P85A426-2 1 $ 6.95000 RSC-P85P416 1 $ 6.00000 4 Layer Board 1 $ 5.71950 TOTAL **The Express PCB pricing formula is $260+.66*Number of boards*Square inches per board+$1.00*Number of boards w ith a 25% discount for quantities of over 2000 Cost (10k Links) $ 0.17784 $ 0.01682 $ 0.03364 $ 0.01682 $ 0.01682 $ 0.36000 $ 0.36000 $ 0.38400 $ 0.53800 $ 4.30000 $ 4.30000 $ 6.95000 $ 6.00000 $ 5.71950 $ 29.17 Gantt Chart Future work Get Lasermate VCSEL working Write final report Conclusions Project was a success Learned about entire design process