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"Design of Gigabit Copper Fiber Channel Equalized Cabling"

See also:
Surface Mount Backplane Connector...
Semiconductor Package Power...
Case Study of Cisco Package Redesign...
Case Study of Package Power...
DDR-II SDRAM Technology...
Infiniband Cable Equalizer...
Motorola WarpLink Reference Design...
OC-48/2.5 Gbps Design Rules...
The limits of FR-4...
SI & Validation of BLVDS...
Gigabit Interconnects...
->Design of Gigabit Copper Fibre Channel...
GTL+ Backplane Termination...
GHz Differential Connector ...
Timing of SDRAM Design...
Transmission Line Skin Effects...
MCM Compute Node Thermal Failure...
QuickRing Backplane System
Bussed Clock Architectures for ATM...
Simplifying FutureBus Backplane...
Infiniband and the limits...
SI Solutions for GTLP...
A Baker's Dozen...

 

Presented at the DesignCon98 and Winner of Outstanding Paper Award

Dr. Edward P. Sayre, P.E.
Dr. Jinhua Chen
Dr. Richard Elco FCI-Berg Electronics

Abstract

North East System Associates, Inc. (NESA) in coordination with Berg Electronics, has created a Gigabit differential equalizer design methodology which, when coupled with appropriate skin effect cable transmission line models, permits the design and evaluation of gigabit copper Fibre Channel cabling. Alternate cable circuit definitions have been used in the cable design; the first is based on the Avanti Star SPICETM (HSPICE) transmission line W model (the Kuznetzov model) and the second is based on the NESA segmented skin effect model previously reported at Design SuperCon '97.

The equalizer design is based on the Bridged-H lossy reactive high pass filter, but contains the appropriate parasitic elements which must be included for valid Gigabit data transmission. The design approach allows the movement of the equalizer matching frequency characteristic so that the designer can choose the amount of low frequency and DC level attenuation while enhancing the high frequencies to make up for the cable skin effect losses. The equalizer parameters can easily be varied to achieve the best eye diagram for a given cable differential impedance, wire gauge and length. The Avanti Kuznetzov transmission line model is useful because the cable specific attenuation parameters are available in the frequency domain and computation is very rapid. NESA's ladder skin effect model can be used with virtually any SPICE simulator and is based on an exact expression for losses. The circuit is realized using a ladder network approximation derived from an exact round copper wire analytic expression. Manufacturers' cable attenuation data can be translated into appropriate skin effect models for either cable representation.

The equalized cable, including MetaGig Fibre Channel connectors, has been end-to-end SPICE simulated in both the frequency domain and with digital logic signals. Signal sources considered are standard 100 W and well as 150 W matched impedance differential test equipment as well as Fibre Channel ECL semiconductor driver and receiver models. Both voltage vs. time as well as eye diagram representations of the K28.5 character were simulated. The eye diagram was created by exporting the SPICE output data to SystemView software for visualization [5]. A number of case studies, both simulated and measured will be presented to demonstrate the suitability of the design methodology to handle different cable types and cable lengths. This work was supported by BERG Electronics, Inc.

->This paper is available from NESA for $15.00 to cover management costs. We accept credit card payment for purchase of the papers. The requested paper will be emailed to you shortly after your order is received. >

 

 

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