ECL-compatible low-power-consumption 10-Gb/s GaAs 8: 1 multiplexer and 1 : 8 demultiplexer

An emitter coupled logic (ECL) compatible low-power GaAs 8 : 1 multiplexer (MUX) and 1 : 8 demultiplexer (DEMUX) for 10-Gb/s optical communication systems has been developed. In order to decrease the power consumption and to maximize the timing margin, we estimated the power consumption for direct-coupled FET logic (DCFL) and source-coupled FET logic (SCFL) circuits in terms of the D-type flip-flop (DFF) operating speed and the duty-ratio variation. Based on the result, we used SCFL circuits in the clock-generating circuit and the circuits operating at 10Gb/s, and we used DCFL circuits in the circuits operating below 5Gb/s. These ICs, which are mounted on ceramic packages, operate at up to 10Gb/s with power consumption of 1.2 W for the 8 : 1 MUX and LOW for the 1 : 8 DEMUX. This is the lowest power consumption yet reported for 10-Gb/s 8 : 1 MUX and 1 : 8 DEMUX.