PALO ALTO, Calif. " Quellan Inc. will announce an analog noise-cancellation chip that supports 5- and 6.25-Gbit/second backplane designs at the International Microelectronics and Packaging Society's IMAPS 2003 symposium opening Nov. 16 in Boston. Quellan's Nx600 noise-canceling receiver extends the "speed reach" of gigabit backplanes, said Tony Stelliga, chief executive officer of the Santa Clara, Calif.-based company.
By lowering the noise and crosstalk of a backplane transmission, the Nx600 effectively raises the clarity with which a high-speed symbol pattern can be deciphered-lowering its bit error rate (BER) and raising its transmission rate, Stelliga said. "We can't increase the length of a 26-inch card cage, but we can raise the data rate from 1 to 6.25 Gbits/s-a 6x improvement," he said. "And we can extend the reach of a 10-Gbit/s cable system from 15 meters to as much as 80 meters."
Quellan's CSP Real Time crosstalk evaluation system, which the company will demonstrate this week, applies sharp equalization, modulation and symbolization to an analog signal transmitted across a backplane. It has a Feed Forward Equalizer and a range of measurement pods for different connector sets. It also allows for high-performance system analysis with single- and dual-channel cancellation.
The Nx600 noise-cancellation device, on which the CSP R/T is based, is a five-tap finite-impulse response filter implemented in 0.18-micron CMOS and housed in a 24-pin package. It is rated for up to 10-dB cancellation of near-field reflections, though the company said that the signal-to-noise improvement can be as great as 26 dB. This can result in a 1,000 times improvement in BER, Stelliga said.
Future iterations of the Nx600 in 0.13-micron and 90-nanometer CMOS are expected to extend data rates to 10 and 20 Gbits/s, respectively, Quellan said. Quellan's chips will allow cards to send data at 5 and 6.25 Gbits/s on legacy backplanes.