An eye‐opening measurement circuit for a feed‐forward equalizer

Abstract

An eye‐opening measurement circuit provides information about the signal quality of the high‐speed data through the band‐limited channel. Thus this information can be used to evaluate the channel performance, especially when the communication environments are changing constantly. By implementing this as a system‐on‐a chip, it is possible to realize the reconfigurable system such as an adaptable feed‐forward equalizer, which will adapt itself through the changes of the communication channel. Moreover, the highly integrated single‐chip eye‐opening monitoring block can achieve more efficient and cost‐effective communication chip test. In this article, we propose a new eye‐opening measurement circuit, which can work up to 10 GHz. Using the fall time and rise time of the signal, which are affected by intersymbol interference, the corresponding characteristic is converted to DC values to assess the channel performance. The proposed eye‐opening measurement circuit and tunable delay line are fabricated in 0.18‐µm CMOS technology. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2136–2141, 2014