High-Speed Continuous Time Linear Equalizer for Multi-Purpose SerDes Applications

The integration of versatile Continuous Time Linear Equalizers has emerged as a very critical technology to help in enhancing the quality of the signal and system performance in modern high-speed communication links. With the demand for high data rates CTLEs will play a key role in mitigating inter-symbol interference and become crucial for channel loss compensation in densely packed multi-gigabit systems. This paper reviews some of the basic operation principles of CTLE, including the inductor-bypass and peak-control techniques proposed, underlying versatility from various points of view. A part of the work deals with the investigation of the challenges imposed by transmission media and explains in detail how advanced CTLE designs can be used for their compensation by means of dynamic response adjustments and precision control of frequency characteristics. Further, the paper suggests incorporating inductor-bypass and peak-control techniques into the traditional CTLE architecture. The implementation of the inductor-bypass technique within the CTLE design leads to a significantly enhanced performance that allows operation at low loss for small channel sizes. By enabling it, the peak gain of the CTLE drops by 5db. To support lower data rates, the peak-control technique was later introduced in the paper. This option appropriately equalizes the lower Nyquist frequencies and extends the range of frequency support into a variable spectrum between 10 and 28GHz with no significant negative impacts in operational efficiency and power dissipation.