Download Weekly Progress Report 9

Gigabit Ethernet PMD
Opto-Link, Inc. – Status Report 9
Vinh Nguyen
April 14, 2005
Gigabit Ethernet:
Progress Summary
Next Week’s Tasks
Completed Tasks



Finished
troubleshooting
Updated Bill of
Materials
Updated budget to
reflect latest purchases




Complete second board
layout
Design review for next
fabrication
Place order for board
fabrication
Assemble second board
Gantt Chart
Current Budget
Part Description:
Vendor:
Vendor Part Number:
CAP 10000PF 50V CERAMIC X7R 0603 (back ordered) BC Components
Digi-Key
BC1252CT-ND
$
0.0290
RES 30.0 OHM 1/10W 1% 0603 SMD
RES 100 OHM 1/10W 1% 0603 SMD
RES 115 OHM 1/10W 1% 0603 SMD
RES 3.00K OHM 1/10W 1% 0603 SMD
POT 1.0K OHM 3/8" SQ CERM SL MT
POT 10K OHM 3/8" SQ CERM SL MT
Digi-Key
Digi-Key
Digi-Key
Digi-Key
Digi-Key
Digi-Key
RHM30.0HCT-ND
RHM100HCT-ND
RHM115HCT-ND
RHM3.00KHCT-ND
3296W-102-ND
3296W-103-ND
$
$
$
$
$
$
0.0760
0.0760
0.0760
0.0760
2.5000
2.5000
10
10
10
10
5
5
$
$
$
$
$
$
0.76
0.76
0.76
0.76
12.50
12.50
Digi-Key
490-1034-1-ND
$
0.1200
50 $
6.00
PCB Fabrication Run
Rohm
Rohm
Rohm
Rohm
Bourns Inc
Bourns Inc
Murata Electronics North
America
Express PCB
Express PCB
$
59.0000
1 $
59.00
AOC 2.5 Gbps VCSEL
Advanced Optical Components
Advanced Optical Components HFE419x-541
$
14.5000
4 $
58.00
AOC 1.25/2.5 Gbps ROSA
Advanced Optical Components
Advanced Optical Components HFD3180-103
$
10.0000
4 $
40.00
CONN PWR JACK 2.1MM SMD
Right-Angle SMA Jack
CUI Inc.
Amphenol
Digi-Key
Jameco
CP-002APJ-ND
188525
$
$
0.7300
4.2000
6 $
10 $
4.38
42.00
CAP 10000PF 50V CERAMIC X7R 0603
RES 100 OHM 1/10W 1% 0603 SMD
RES 200 OHM 1/10W 1% 0603 SMD
RES 2.00K OHM 1/10W 1% 0603 SMD
RES 24.9 OHM 1/10W 1% 0603 SMD
RES 34.8 OHM 1/10W 1% 0603 SMD
Shipping and Handling
BC Components
Rohm
Rohm
Rohm
Rohm
Rohm
Digi-Key
Digi-Key
Digi-Key
Digi-Key
Digi-Key
Digi-Key
BC1252CT-ND
RHM100HCT-ND
RHM200HCT-ND
RHM2.00KHCT-ND
RHM24.9HCT-ND
RHM34.8HCT-ND
$
$
$
$
$
$
0.0169
0.0760
0.0760
0.0760
0.0760
0.0760
FERRITE CHIP 1000 OHM 100MA 0603
Manufacturer:
Unit Cost:
Quantity:
Total Part Cost:
100 $
100
20
10
10
10
10
Total:
2.90
$
$
$
$
$
$
$
1.69
1.52
0.76
0.76
0.76
0.76
22.28
$
268.85
Projected Budget
Part Description:
Manufacturer:
CAP 10000PF 50V CERAMIC X7R
0603 (back ordered)
BC Components
Digi-Key
BC1252CT-ND
$
0.029
100
$
2.90
RES 30.0 OHM 1/10W 1% 0603 SMD
Rohm
Digi-Key
RHM30.0HCT-ND
$
0.076
10
$
0.76
RES 100 OHM 1/10W 1% 0603 SMD
Rohm
Digi-Key
RHM100HCT-ND
$
0.076
10
$
0.76
RES 115 OHM 1/10W 1% 0603 SMD
Rohm
Digi-Key
RHM115HCT-ND
$
0.076
10
$
0.76
RES 3.00K OHM 1/10W 1% 0603 SMD
Rohm
Digi-Key
RHM3.00KHCT-ND
$
0.076
10
$
0.76
POT 1.0K OHM 3/8" SQ CERM SL MT
Bourns Inc
Digi-Key
3296W-102-ND
$
2.500
5
$
12.50
POT 10K OHM 3/8" SQ CERM SL MT
Bourns Inc
Digi-Key
3296W-103-ND
$
2.500
5
$
12.50
Digi-Key
490-1034-1-ND
$
0.120
50
$
6.00
$
59.000
2
$
118.00
Murata
FERRITE CHIP 1000 OHM 100MA 0603 Electronics North
America
PCB Fabrication Run
Express PCB
Vendor:
Vendor Part Number: Unit Cost:
Express PCB
Quantity:
Total Part Cost:
AOC 2.5 Gbps VCSEL
Advanced Optical Advanced Optical
Components
Components
HFE419x-541
$
14.500
4
$
58.00
AOC 1.25/2.5 Gbps ROSA
Advanced Optical Advanced Optical
Components
Components
HFD3180-103
$
10.000
4
$
40.00
CONN PWR JACK 2.1MM SMD
CUI Inc.
Digi-Key
CP-002APJ-ND
$
0.730
6
$
4.38
Amphenol
Jameco
188525
$
4.200
10
$
42.00
BC Components
Digi-Key
BC1252CT-ND
$
0.017
100
$
1.69
RES 100 OHM 1/10W 1% 0603 SMD
Rohm
Digi-Key
RHM100HCT-ND
$
0.076
20
$
1.52
RES 200 OHM 1/10W 1% 0603 SMD
Rohm
Digi-Key
RHM200HCT-ND
$
0.076
10
$
0.76
RES 2.00K OHM 1/10W 1% 0603 SMD
Rohm
Digi-Key
RHM2.00KHCT-ND
$
0.076
10
$
0.76
RES 24.9 OHM 1/10W 1% 0603 SMD
Rohm
Digi-Key
RHM24.9HCT-ND
$
0.076
10
$
0.76
RES 34.8 OHM 1/10W 1% 0603 SMD
Rohm
Digi-Key
RHM34.8HCT-ND
$
0.076
10
$
0.76
$
22.28
$
327.85
Right-Angle SMA Jack
CAP 10000PF 50V CERAMIC X7R
0603
Shipping and Handling
Total:
Estimated Bill of Materials
Vendor Part
Number:
Quantity/B
oard:
Manufacturer:
Mfg. Part Number:
Vendor:
CAP 10000PF 50V
CERAMIC X7R 0603
BC
Components
VJ0603Y103KXACW1BC
Digi-Key
BC1252TR-ND
0.00346
18
0.06228
RES 30.0 OHM 1/10W
1% 0603 SMD
Rohm
MCR03EZPFX30R0
Digi-Key
RHM30.0HTRND
0.00203
1
0.00203
RES 100 OHM 1/10W
1% 0603 SMD
Rohm
MCR03EZPFX1000
Digi-Key
RHM100HTR-ND
0.00203
3
0.00609
RES 115 OHM 1/10W
1% 0603 SMD
Rohm
MCR03EZPFX1150
Digi-Key
RHM115HTR-ND
0.00203
1
0.00203
RES 3.00K OHM
1/10W 1% 0603 SMD
Rohm
MCR03EZPFX3001
Digi-Key
RHM3.00KHTRND
0.00203
1
0.00203
POT 1.0K OHM 3/8"
SQ CERM SL MT
Bourns Inc
3296W-1-102
Digi-Key
3296W-102-ND
1.092
1
1.092
POT 10K OHM 3/8"
SQ CERM SL MT
Bourns Inc
3296W-1-103
Digi-Key
3296W-103-ND
1.092
1
1.092
MAX3286 Laser Driver
Maxim IC
MAX3286+CTI
Maxim IC
MAX3286+CTI
4.07
1
4.07
MAX3264 Limiting
Amplifier
axim IC
MAX3264CUE+
Maxim IC
MAX3264CUE+
4.00
1
4.00
PCB Fabrication Run
Express PCB
Production Service
Express PCB
1.35438
1
1.35438
AOC 2.5 Gbps VCSEL
AOC
HFE419x-541
AOC
HFE419x-541
7.25
1
7.25
AOC 1.25/2.5 Gbps
ROSA
AOC
HFD3180-103
AOC
HFD3180-103
5
1
5
Total Per Board:
Unit Cost:
Total Part
Cost:
Part Description:
$23.93
Transmitter Testing




Last week’s transmitter
problems persisted
Testing resulted in closed
“eyes” for both the AOC
and the Emcore board
designs
The VCSEL is lasing but
no signal is getting though
to the receiver
Probing the board resulted
in a blown inductor
Transmitter PRBS7 Signal with no attenuation
Troubleshooting

Hypothesis: Limiting resistor values may be
incorrect


Would prevent the VCSEL from receiving enough
current to bias it above threshold
Adjusting the potentiometers would have little
effect on the output signal beyond a certain level
Testing the Hypothesis






Set bias potentiometer to high resistance
Shorted the limiting resistor
Reduced the potentiometer resistance
Resulted in closed eye
Continued reduction of potentiometer
resistance resulted in a blown Emcore VCSEL
Probing the AOC board design resulted in
another blown VCSEL
Repairs



Replaced all damaged components on the
Emcore design
Testing the repaired board resulted in closed
eyes again
Tried to systematically tune potentiometers


Careful tuning did not result in open eyes
Carefully probed inputs and outputs
Test Signals
D21.5 input signal obtained using the probe
Output signal for D21.5 input obtained
using the optical test equipment
Test Signals Cont.

Tried using PRBS7 test signal as input
PRBS7 input obtained using the probe
plotted beside the clock signal
The Magic Probe


Probing between the laser driver and the
VCSEL resulted in the “Magic Probe Effect”
The optical output signal formed excellent eye
diagrams when the probe leads were placed
between the laser driver and the VCSEL
Magic Probe Results
Eye diagram for optical output for PRBS7 input with probe
Possible Explanations


The use of smaller potentiometers may have
resulted in the overdriving of the laser driver
chip
Board layout issues


Unbalanced circuit
Weird layout effects
Testing Hypothesis





Replaced the bias potentiometer with a larger
50 kΩ potentiometer from the practice board
Unable to obtain an open eye diagram by
tuning the potentiometer
Can still obtain good eye diagrams using the
“Magic Probe”
Effectively rules out overdriving hypothesis
Only leaves potential layout issues
Next Week

Complete second board layout






Second board layout will use passive components
to try to replicate the effect of the probe on the
board
Design review for next board fabrication?
Place order for board fabrication
Start Final Report
Assemble second board
Get board blessed in chapel
Board Layout Review