1. GIGABIT ETHERNET DESIGN ECE164.02 - Spring 2004
Presentation #3

2. Introduction Tested Transmitter Evaluation Board
Eye Testing
BER Testing
Built Practice Board Receiver
Intro to Design
Exposure to Surface Soldering
Tested Practice Board
Attenuation Effects
Modified Gantt Chart

3. Evaluation - Transmitter Testing
Test Setup for
Reading in Scope

4. Evaluation - Transmitter Testing
Ugly Eye Shown
No attenuation
Ran out of “film”
Disk Problems with Oscilloscope

5. More Problems Evaluation - Transmitter Testing
Poor BER
High Error Rate
Again, no more space on digital camera

6. Evaluation – Receiver Testing
Test Setup to Scope for the Evaluation Receiver Circuit

7. Evaluation – Receiver Testing
Very Descent Eye
No attenuation
Small Undesirable Line on Right-hand Side
No detectable errors

8. Adding Attenuation
As expected, the eye degrades with more and more attenuation
(20 dB shown for eye) (34 dB shown for BER)
BER = 4.8E-07

9. Getting Our Feet Wet Soldering
Flux is Useful for surface that are not “sticky”
Need good contact for a good signal

10. Building Receiver
Better feel for how the circuit works and where the signal is going
Surface Soldering is not frustrating
Proper Power Supply Connectors Unavailable – Used wires to begin testing

11. Practice – Receiver Testing
Setup for eye testing in oscilloscope

12. Practice – Receiver Testing
Differential Outputs Verification
Pretty much symmetric waveforms

13. Practice – Receiver Testing
Poor Eye with no attenuation
But…

14. Practice – Receiver Testing
Adding 10 dB attenuation results in a very clean eye
Why?

15. Practice – Receiver Testing
20 dB
40 dB
50 dB
30 dB

16. Practice – Receiver Testing
BER insignificant for dB range (as shown), but was high when no attenuation was applied

17. Circuit Design & Layout
Building the Practice Board introduces Circuit Design & Layout by way of example
These are scheduled in later weeks

18. Gantt Chart

19. Next Week
Optical Link Budget has been delayed, It will be a top concern in the coming week
Transmitter Construction & Assembly
PCB Design & Layout