A 20Gb/s digitally adaptive equalizer/DFE with blind sampling

As data rates increase, the backplane communication systems suffer from serious inter-symbol interference (ISI). Due to different channel lengths, loss, and environment variations, an adaptive equalizer is an attractive and robust circuit to equalize the received data in high-speed data communications. Several techniques are presented for adaptive equalizers. A spectrum balancing method is presented for an analog equalizer. However, this method is valid only for the random data with fixed data rate. An eye-opening-monitor (EOM) method adopts a two-dimensional map to detect the signal quality. This EOM method needs a synchronous sampling clock and high-speed comparators. It results in high power consumption and furthermore it requires accurate analog circuits.