Improved implementation of high-speed optical interfaces for 10-Gbit Ethernet, Sonet/SDH, and Fibre Channel networks is the catalyst behind the XT38720 CMOS XFI interface. Crafted by Xignal Technologies AG, an intellectual-property company specializing in analog and mixed-signal design, the XT38720 fits into an XPF module for either fiber or copper media. It's especially useful in designing 10-Gbit/s copper coax systems used in the CX4 Ethernet standard.
The interface is a transceiver that serializes and deserializes 32 input data streams to a single output data stream and vice versa (see the figure). The high-speed serial inputs and outputs comply with the XFI interface standard for XFP (10 Gb/s Small Form Factor Pluggable module) specifications, revision 4.
A phase-locked loop in the circuit cleans up the signal with an external configurable resistance-capacitance loop filter. Selectable pre-emphasis ensures optimum signal integrity regardless of the transmission medium. A selectable limiting amplifier also is incorporated.
Power dissipation is only 350 mW with 1.2-V and either 2.5- or 3.3-V I/O supplies. The design is done in 0.13-µm CMOS and occupies an area of 4 mm2. It's available now for broadband equipment vendors, semiconductor companies, ASIC and system-on-a-chip vendors, and EDA companies.
Xignal Technologies AG