High-Performance Backplanes: Where They Headed? DesignCon 2000 Sa

The Datasheet Archive - 100 Million Datasheets from 7500 Manufacturers.

High-Performance Backplanes: Where They Headed? DesignCon 2000 Sa

Datasheet Thumbnail

Top Searches for this datasheet

Multi-Level Signaling
High-Performance Backplanes: Where They Headed?
DesignCon 2000 Santa Clara, February 2000
Howard Johnson HIGH-SPEED DIGITAL DESIGN
copyright 2000
www.signalintegrity.com Seminars, Books, Tools, Advice. Slide
Performance Improves with Time
Paper-tape transmission
Distance (mi)
modems Adaptive
0.01
0.001
Terminations What' next??
0.0001
1000
1004
1005
1006
1007
1008
1009
1010
Speed, (Hz)
Simple implementations each technology initially fall basic speed-distance curve. Over time, development additional end-unit circuitry always improves performance. Howard Johnson HIGH-SPEED DIGITAL DESIGN
copyright 2000
www.signalintegrity.com Seminars, Books, Tools, Advice. Slide
Channel Characteristics Trace)
Skin effect only
Transmission gain (dB)
Skin effect dielectric loss
Signal-tonoise ratio (SNR)
Loss slope near -20dB/decade
Channel noise slope +20dB/decade
Operating frequency (Hz) stripline FR-4 loss tan=0.02
Channel losses dominated skin effect dielectric loss Channel noise dominated crosstalk connectors, packages, near deteriorates dB/decade Howard Johnson HIGH-SPEED DIGITAL DESIGN
copyright 2000
www.signalintegrity.com Seminars, Books, Tools, Advice. Slide
Multi-Amplitude Signaling (MAS) Concept
your circuits could fast wanted, complexity were free, your slope least dB/decade worse, THEN multi-level signaling
number informational bits carried baud signaling rate (where rate) number levels 1/(N-1) 1/(2B-1) reduction spacing between levels simplistic model things might this
What GAIN reduction baud rate: log(B)*(SNR slope) Exceeds what LOSE reduced level-spacing: log(2B-1) With large enough slope always GAIN more than LOSE Howard Johnson HIGH-SPEED DIGITAL DESIGN
copyright 2000
www.signalintegrity.com Seminars, Books, Tools, Advice. Slide
Example Gb/s
(dB)
4-level penalty (lose less, depending coding) Improved with
Reduce frequency (gain 13.6 Start Gb/s (2.5 GHz)
Operating frequency (Hz)
stripline FR-4 loss tan=0.02
When slope exceeds dB/decade operating frequency, 4-level signaling almost always superior. Howard Johnson HIGH-SPEED DIGITAL DESIGN
copyright 2000
www.signalintegrity.com Seminars, Books, Tools, Advice. Slide
Architecture
What' required actually
transmitter receiver thresholds
make work practical world will also need.
thresholds
While you' doing that, might well add.
equalization problems with channel pulse response line coding problems with
Howard Johnson HIGH-SPEED DIGITAL DESIGN
copyright 2000
www.signalintegrity.com Seminars, Books, Tools, Advice. Slide
Possible?
Already Common
analog modems Kb/s modems Mb/s Ethernet 1000 Mb/s
technology high-speed multiple-amplitude signaling exists today first applications will large backplanes with substantial dielectric loss
Howard Johnson HIGH-SPEED DIGITAL DESIGN
copyright 2000
www.signalintegrity.com Seminars, Books, Tools, Advice. Slide
Howard Johnson HIGH-SPEED DIGITAL DESIGN
copyright 2000
www.signalintegrity.com Seminars, Books, Tools, Advice. Slide

High-Performance Backplanes: Where They Headed? DesignCon 2000 Sa

Top Searches for this datasheet

Other recent searches