Colorado Springs, Colo. - Analogix Semiconductor Inc., a startup with operations split between Silicon Valley and Beijing, is promoting DSP-based receiver techniques in a next-generation backplane serializer/deserializer for 5- and 10-Gbit/second systems. The company's D-PHY family of products is being sampled just as such former competitors as Velio Corp. and Accelerant Networks Inc. have been acquired by larger companies. But Analogix still is convinced of its ability to carve out a unique mixed-signal niche and remain independent.
Analogix is combining the analog programmable pre-emphasis techniques typically used in transmit chains with a combination of analog and DSP techniques on receive chains. As an alternative to the multitap distributed-feedback equalizer generally used in a receiver, Analogix is using a continuous-time linear equalizer in the analog domain. It augments the receive block with a suite of adaptive signal-conditioning methods called WideEye, which perform adaptive equalization, adaptive reflection, crosstalk cancellation and error-correction coding.
In DSP techniques, Analogix is closest to SolarFlare-which it does not count as a direct competitor, since SolarFlare concentrates only on 10-Gbit Ethernet-and to Vativ Inc. Ted Rado, vice president of marketing at Analogix, said that Vativ appears the most innovative in design approaches, but "the current products use multilevel signaling, while we are binary-encoded to ensure compatibility with a wide range of systems."
Of Analogix's 45 employees, 40 are engineers. Some 30 employees are stationed in China, with the remaining 15 in Santa Clara, Calif. All basic design of the serdes devices takes place in the United States, with ancillary design, simulation, layout and verification performed in China. The high-profile presence in China was one factor that won Analogix its first customer, Huawei-3Com Co. Ltd. The Hangzhou-based joint venture of 3Com Corp. and Huawei Industries will use the serdes devices in a range of routers and switches.
Analogix has a four target markets: carrier switches, enterprise switches, server farms and distributed storage. It specifically looked at backplanes and very short-reach interconnect. Many switch and storage-area-network developers in this field are examining 5-Gbit/s backplanes, Rado said, so the company avoided leaping directly to 10-Gbit backplanes.
The most important factor in intrasystem designs is the ability to use FR-4 materials and low-cost connectors for high-speed systems, so Analogix has made sure its serdes chips can support such materials from the standpoint of both power dissipation and noise. The company promises 6.25-Gbit/s performance over 60 inches of FR-4 material.
Before bringing out its native 10-Gbit serdes, Analogix will offer a 5-Gbit/s serdes in both dual-channel and quad-channel versions. The chips will support ranges of 3.12 to 6.25 Gbits/s in high-speed mode or 1.25 to 3.15 Gbits/s in legacy mode, to interface with traditional physical-layer devices. Fabricated in 0.13-micron CMOS from TSMC, the devices all comply with the Optical Internetworking Forum's Common Electrical I/O 6G+ specification, the company said.
To keep power dissipation to a minimum, Analogix offers a PowerSelect feature, in which the WideEye DSP functions can be selectively enabled or disabled on individual transceivers to reduce power to 2.9 watts per device. The parts also feature a range of built-in self-test functions.
"We aimed to price our quad device in volume at less than $50," Rado said. "Customers were telling us they wouldn't even consider a physical-layer device in the $100 range, no matter what its specs." The volume price is $49 for the quad-channel 5-Gbit/s chip and $28 for the 2 x 5G. Both come in 260-lead heat-slug BGA packages.