ABSTRACT
The advent of advanced SiGe technologies in the 0.18 [1] and 0.13mm [2] nodes has enabled the
implementation of silicon-based wired data communications circuits operating at data rates of 40 Gb/
sec and beyond [3-8] targeting standards such as SONET OC-768. Two key classes of circuits for high
data rate communications are serializers, built from a clock multiplying PLL and a multiplexer, and
deserializers, built from a clock and data recovery PLL and a demultiplexer. The raw multiplexing and
demultiplexing functions are critical not only for communications systems, but also for high-speed test
equipment such as pattern generators, which typically generate output patterns in parallel form at low
data rates and multiplex these to generate the high-speed output, and bit error rate testers, which
typically check input patterns in parallel form after a demultiplexing stage.
