A 10 Gb/s Wide-Band Current-Mode Logic I/O Interface for High-Speed Interconnect in 0.18μm CMOS Technology

Abstract

A low power, area-efficient 10 Gb/s wide-band current-mode logic (CML) I/O interface for high-speed interconnect is presented in this paper. This interface consists of input equalizer, limiting amplifier, CML buffer and output voltage-peaking circuit. Several wide-band techniques for this work are adopted to broaden the bandwidth and realize the circuit in 10Gb/s operation. The techniques include PMOS active load inductive-peaking, active feedback and Cherry-Hooper topology. These techniques can reduce 80% of the circuit area compared to the circuit area with on-chip inductors. The integration of the input equalizer and output voltage-peaking is also verified in this paper to provide robust I/O interface for high-speed interconnect and compensate transmission signal attenuation in the backplane. This work has been implemented in a 0.18μm CMOS technology. The total power consumption of the I/O interface is only 70mW. The area of input and output interface are 0.02mm2and 0.008mm2. The input interface can operate at 10Gb/s with 40dB input dynamic range and 4mV input sensitivity.