EMI susceptibility of high speed differential wireline communication front-ends

This paper presents an in-depth electromagnetic susceptibility (EMS) analysis for three commonly used differential high speed wireline interfaces, namely: low voltage differential signaling (LVDS), current mode logic (CML) and voltage mode logic (VML). The behavior of each differential transmitter structure is explained in detail on how its operation is being affected when subjected to a worst case EMI injection. A comparative analysis shows how the CML transmitter structure is more robust to EMI than its voltage mode counterparts. Simulation results are presented to demonstrate how EMI corrupts the transmitters' signal integrities despite the differential signalling scheme. These results illustrate that EMI can corrupt each structure by completely closing the differential logic magnitude starting from a 175mV differential amplitude when EMI is not present. Furthermore, both LVDS and VML are affected by EMI at a frequency range spanning from 30MHz to 300MHz while CML is affected from 300MHz to 1.5GHz. These transmitters were designed and simulated using UMC 180nm process. © 2016 IEEE.