An Analysis of Current-mode Drivers in 40-nm CMOS Technology

Abstract

This paper compares two prominent high-speed link transmitter driver topologies, cascode current-mode logic (CML) and tailless CML, exploring their design tradeoffs. Analysis and simulation results reveal that the cascode CML exhibits higher output resistance due to the presence of a tail current source, while the tailless CML demonstrates faster operation with reduced output capacitance. Additionally, this study highlights the tradeoff between driver output swing and power consumption.