MARCH 26, 2009 -- Vitesse Semiconductor Corp. (search Lightwave for Vitesse), a provider of advanced IC products for carrier and enterprise networks, is helping system designers develop high-density, 10-Gbps port count SFP+ line cards with the introduction of the newly enhanced VSC8242. The VSC8242 is a clock and data recovery (CDR) IC specifically designed to extend 10-Gbps data transmission in optical, copper cable, and backplane applications. Vitesse says its VScope waveform viewing technology and FlexEQ electronic dispersion compensation (EDC) and adaptive equalization technology in the multiport CDR enables deployment of next-generation networking equipment for storage, blade servers, carrier telecom, and datacom applications.
By utilizing VScope waveform viewing technology, the VSC8242 delivers an on-chip micro-oscilloscope capable of calculating rise time, fall time, and s-parameter extraction. The benefits can include signal integrity visibility for system engineers, automatic link optimization, remote monitoring, and potentially improved manufacturing yield and reduced operational expenses for the end customer. The IC enables a self-adjusting mechanism to deal with discontinuities and signal quality variations.
The FlexEQ EDC and adaptive equalization technology can recover error-free data from what appears as a completely unintelligible signal waveform when viewed by conventional oscilloscopes. By combining the self-adjusting properties of FlexEQ with VScope, the company claims, engineers are now able to attain both improved system performance and superior signal integrity analysis using a single integrated circuit.
According to Vitesse, for longer distances, the device extends optical transmission at 10G data rates on singlemode fiber by more than 50% and compensates for both chromatic and polarization mode dispersion for distances greater than 10 km on exiting 2.5G networking infrastructure. For shorter optical distances, where high density and lower system cost is paramount, the device enables a 10X speed upgrade on low-grade FDDI fiber from 1GbE to 10GbE for distances greater than 220 m. The flexible equalization technology also enables deployment of low-cost Twinax passive copper cables to distances greater than 15 m for data center interconnect applications, a 100% improvement over the current standard.
"For high-density systems, new economics and simplicity in system debug and remote monitoring of system performance are required. The VSC8242 provides the features and performance necessary to meet these demands for 10G high-density SFP+ applications," says Raymond Fontayne, senior product marketing manager for Vitesse. "Several of the advanced diagnostics and remote monitoring features of the device are an excellent fit for our customers."
The FFE-DFE architecture compensates for loss of optical system performance or margin due to inter-symbol interference and chromatic and polarization mode dispersion. The device is compliant to 10-Gbps SFP+ 10GBase-SR, 10GBase-LR, 10GBase-LRM, SFF-8431, and 8.5G Fibre Channel FC-PI-4 specifications and is capable of independently running any channel at high speed, supporting data rates between 8.5 and 11.3 Gbps. The chip is able to autonomously speed negotiate to legacy data rates including 1GbE and 1G, 2G, and 4G Fibre Channel.
On-chip user programmable equalization, output pre-emphasis, and adjustable drive levels provide solutions to difficult signal integrity issues for board designers and allow 10G signals to be easily routed between SFP+ modules, processing circuits, and backplanes on PCBs. Signals up to 11.3 Gbps can be transmitted over 40 in. of legacy backplane traces with multiple connectors in the path designed to support only 3-Gbps data rates.