A 22 Gb/s decision circuit and a 32 Gb/s regenerating demultiplexer IC fabricated in silicon bipolar technology

A decision circuit and a 1:2 regenerating demultiplexer, which are key components in optical-fiber transmission links, were fabricated in an advanced self-aligning silicon bipolar technology using 0.8-μm lithography. Maximum speed rather than low power consumption was the main goal of these designs. The transistors were individually optimized using a semiphysical transistor model for circuit simulation. At such high operating speeds the influence of the metal lines on the chip has to be taken into account. Worst-case conditions, caused, e.g., by fabrication spread and variation of the junction temperature, were met. The measured data rates of 22 Gb/s for the decision circuit and 32 Gb/s for the demultiplexer, with excellent retiming capability, have not yet been achieved with any semiconductor technology