A double loop continuous-time adaptive equalizer

This paper presents a low-voltage CMOS continuous-time adaptive equalizer for short-haul gigabit optical communications. It was designed to compensate the attenuation of a 1.25 Gb/s signal with a simple NRZ modulation, transmitted through a 50-m length 1-mm core step-index plastic optical fiber (SI-POF). The structure includes two adaptation loops to compensate the possible variations in level and spectrum of the input signal. The proposed system was designed in a cost-effective 0.18-µm CMOS process. The system is fed with 1 V and has a total power consumption of 29.3 mW.