An analog DFE for disk drives using a mixed-signal integrator

Abstract

An analog adaptive decision-feedback equalizer (DFE) is described. The DFE cancels intersymbol interference using four feedback taps and a fifth tap cancels DC offset. The coefficient for each tap is adapted using a small mixed-signal integrator. The DFE dissipates 220 mW at a data rate of 150 Mb/s. The active area is 1.8 mm 2 in a 1mm CMOS process.