A 90 nm CMOS DSP MLSD Transceiver With Integrated AFE for Electronic Dispersion Compensation of Multimode Optical Fibers at 10 Gb/s

Abstract

This paper presents the architecture and circuit design of a single chip 32 mm /5090 nm CMOS DSP transceiver for electronic dispersion compensation (EDC) of multimode fibers at 10 Gb/s, based on maximum likelihood sequence detection (MLSD). This is the first MLSD-based transceiver for multimode fibers and the first fully integrated DSP based transceiver for optical channels reported in the technical literature. The digital receiver incorporates equalization, Viterbi detection, channel es- timation, timing recovery, and gain control functions. The analog front-end incorporates an 8-way interleaved ADC with self-cal- ibration, a programmable gain amplifier, a phase interpolator, and the transmitter. Also integrated are a XAUI interface, the physical coding sublayer (PCS), and miscellaneous test and control functions. Experimental results using the stressors specified by the IEEE 10 GBASE-LRM standard [1], as well as industry-defined worst-case fibers are reported. A sensitivity of 13.68 dBm is demonstrated for the symmetric stressor of [1] in a line card application with a 6 inch FR4 interconnect.