A Low Cost, High Performance Optical Interconnect

摘要

The driving force behind Motorola's Optobus program has been to produce an optical interconnect that can beat copper solutions in both cost and performance. The resulting 'link' consists of a pair of ten channel connectorized fiber ribbons and two multi-chip modules packaged as PGAs. The modules run from a single 5V supply and can be directly interfaced to differential PECL levels. The MT connectorized fiber ribbons mate to a pair of ten channel optical ports on the module, one containing ten receiver channels and the other ten transmitter channels. The link is purely transparent, that is, neither clock nor coding are required and the user's timing is retained. As a result, the important performance specification is not the maximum data rate, currently given as 150 Mbit/s per channel, but the 'timing accuracy' which gives the maximum uncertainty in the propagation delay through the link.