Continuous-time adaptive-analog coaxial cable equalizer in 0.5 μm CMOS

The transmission of high-speed data on copper suffers from frequency-dependent losses that can cause significant intersymbol interference. The losses mainly arise from the increase in series resistance at high frequencies due to the skin effect. There are also dielectric losses, which are significant in the GHz range and higher. To correct for frequency dependent losses, an integrated circuit continuous-time analog filter is used. An on-chip adaptive control loop provides correction for any cable length. As part of the present research, many of the building blocks required for a CMOS implementation of the equalizer system have been designed and submitted for fabrication in a 0.5 μm standard-digital-CMOS process. The equalizer is realized in an area of 1.1 mm², with power dissipation of 30 mW, using a 3.3 V power supply