A low-power, 20-Gb/s continuous-time adaptive passive equalizer

This paper describes a 20-Gb/s continuous-time adaptive passive equalizer utilizing on-chip lumped RLC components. Passive equalizers offer the advantages of higher bandwidth and lower power consumption compared with conventional designs using active filters. A low-power, continuous-time servo loop is designed to automatically adjust the equalizer frequency response for the optimal gain compensation. The equalizer not only adapts to different channel characteristics, but also accommodates temperature and process variations. Implemented in a 0.25-/spl mu/m, 1P6M BiCMOS process, the equalizer can compensate up to 20 dB of loss at 10 GHz while only consuming 32 mW from a 2.5-V supply.