A versatile ECL multiplexer IC for the Gbit/s range

A new approach to digital multiplexing for communication systems operating in the Gbit/s range is presented. With a single function, monolithically integrated in the established silicon bipolar process, many operations required by the communication system's multiplex equipment are achieved at data rates of up to 3 Gbits/s. The IC is a four-channel multiplexer designed to interface readily with ECL families. Demonstrations of the ICs performance include pseudorandom pattern generation by multiplexing ECL inputs up to 2 Gbits/s, demultiplexing into ECL registers at 1 Gbits/s, clock extraction in a 560 Mbit/s coaxial cable transmission system, and a modulo-n divider technique for timing generation using ECL feedback shift registers for frequencies up to 1.6 GHz. The demonstrations highlight the multiplexer's ability to effectively extend the system speed limit of commercially available ECL from a few hundred Mbits/s to the Gbit/s range. An eight-input multiplexer using three chips in a hybrid assembly is demonstrated multiplexing a static input pattern up to 2.8 Gbits/s.