A 100Mb/s, 2.8V CMOS current-mode analogue Viterbi decoder

We describe a K = 3, rate-1/2 analogue Viterbi decoder fabricated in 0.8µm CMOS technology, intended for convolutional decoding applications. The decoder is the first of its kind to employ current-mode analogue circuit techniques. It operates at data rates of at least 100Mb/s and consumes 40mW at that rate from a single 2.8V power supply. The chip contains about 6K transistors of which less than 1K are used in the analogue sections of the system and has a core area of approximately 1mm².