540 MHz 21 mW MDFE equalizer and detector in 0.25 μm CMOS

Abstract

The parts distinguishing a multilevel decision feedback equalization (MDFE) channel to a PRML channel are the forward equalizer and the feedback detector. These two blocks, which are also known as the feedforward filter (FFF) and feedback filter (FBF), are both analog and allow mixed/digital implementations. An all-digital approach based on a simplified digital equalizer function and a random-access-memory based detector in 0.25 μm CMOS is presented. The total power at 540 MHz is 21 mW, equivalent to an energy consumption of 58 pJ for each user bit detected. This is substantially lower than any previously-published decision feedback equalizer and detector circuits.