A 40 Gb/s transversal filter in 0.18 /spl mu/m CMOS using distributed amplifiers

This paper describes a fully-differential 3-tap transversal filter in 0.18 mum CMOS capable of equalizing NRZ data up to 40 Gb/s. Each tap gain comprises a cascade of two distributed amplifiers with adjustable gain. Passive-LC delay lines in the distributed amplifiers also provide the 25 ps tap delays. The design is 1 mm times 1 mm (900 mum times 600 mum active area) and consumes up to 70 mW from a 1.8 V supply depending on the tap gains. It is the first reported CMOS transversal filter operating at 40 Gb/s