A novel adaptive fully-differential GM-C filter, tuneable with a CMOS fuzzy logic controller for automatic channel equalization after digital transmissions

Abstract

In this paper, an equalizer chip for digital communication channel is presented. The proposed system can equalize the CAT5e UTP cable from 20 to 400 m with a 30 MHz bandwidth. A novel structure has been used to realize GM-C filter. It uses only one GM-cell stage in contrast of conventional structures. This technique leads to improvement excess-phase, area and power consumption. An intelligent fuzzy controller tunes this filter. It changes the filter parameters based on reference eye pattern to achieve the best tuning for the filter. Layout of all circuits has been done in standard 0.35 μ m CMOS process. Total power consumption, area and power supply are 29.3 mW, 87 , 200 μ m 2 and 3.3 V.