Pre-Emphasis Driver For High Speed Data Transmission

At high frequency, currents tend to flow on the surface of a metal wire. The higher the data rate, the larger the effective resistance becomes since the path for the current becomes narrower. This is called “skin effect”. Due to this effect, when high frequency signal travels on a long channel, it will be distorted, and data in one clock interval may spread into next cycle, causing inter symbol interference (ISI). To compensate the distortions, a pre-emphasis driver can be applied to generate a modified waveform and to reduce the ISI. In frequency domain, the pre-emphasis driver can compensate the low-pass behavior of the channel by boosting high frequency components up; and in time domain, the tail of the original pulse can be canceled out [1]. The traditional pre-emphasis driver is built with 2-tap finite impulse response (FIR) filter, which can generate a reversed and delayed version of the original data. In this project, a modified driver with a logic block, which is used to detect the transition from “1” to “0”, is proposed and examined. A common used channel, FR4, is modeled with W-element and the performances of the proposed circuit and the traditional one are simulated with HSPICE. The eye diagrams of data at receiver end are observed and analyzed. The results prove the improvements of the proposed driver.unpublishednot peer reviewedU of I OnlyUndergraduate senior thesis not recommended for open acces