Indium phosphide chips hit 80Gbps

Inphi Corporation has announced that it has demonstrated demultiplexers running at a data rate of greater than 80 gigabits per second (Gbps).

These integrated circuits convert a single high-speed serial data stream into four differential outputs within telecommunication transceivers. They are designed in indium phosphide, an extremely fast semiconductor material that is paving the way for robust, error-free OC-768 networks.

Inphi's 80 Gbps achievement in indium phosphide exceeds recently published results in silicon germanium, which reached half-rate speeds of only 56 Gbps. Moreover, although Inphi's half-rate demultiplexer operates at a much higher speed than the silicon germanium circuits, it dissipates the same amount of power. At a reduced data rate of 40 Gbps, for example, Inphi's half-rate demultiplexer dissipates only 400 milliwatts of power, which is approximately one third the power as silicon germanium half-rate circuits operating at the same speed.

The Inphi 80 Gbps circuits are based on a half-rate architecture, which is equivalent in terms of clock rate to a full-rate circuit running at 40 Gbps. These half-rate circuits dissipate 1.3 watts of power at 80 Gbps operation and 400 milliwatts of power at 40 Gbps operation - levels comparable to existing OC-192 components.

"This latest achievement clearly solidifies Inphi's position as a technology leader in the optical components space," said Gopal Raghavan, co-founder and CTO of Inphi Corporation. "We have now demonstrated the fastest half-rate and full-rate indium phosphide parts for applications at speeds of 40G and higher."

In a half-rate design, the clock driver samples the incoming signal on both the rising edge and the falling edge of the clock. By contrast, in a full-rate design, the signal is sampled on only one clock edge, either rising or falling but not both. Most commercial integrated circuits are based on full-rate architectures; half-rate architectures are more sensitive to actual transport system variations such as duty cycle distortion and thus are generally used only in short-reach and lower-performance systems.