Inphi Corp., a Westlake Village, Calif.-based, privately held fabless optical components company, said it has demonstrated demultiplexers running at a data rate of greater than 80 gigabits per second (Gbps).
These integrated circuits (ICs) convert a single high-speed serial data stream into four differential outputs within telecommunication transceivers, officials said. They are designed in indium phosphide (InP), 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 (SiGe), which reached half-rate speeds of only 56 Gbps. Moreover, although Inphi's half-rate demultiplexer operates at a much higher speed than the SiGe 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 SiGe 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.
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 ICs 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.
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