System level approach for assessing and mitigating differential skew for 10+ Gbps SerDes applications

A 5 Gb/s Automatic Within-Pair Skew Compensator for Differential Data in 0.13 $\mu{\hbox{m}}$ CMOS

“…Here, and are the channel resistance of and , respectively, and both transistors operate in the deep triode region. The term can be calculated as (8) To simplify the analysis, we assume the following condition and define a new term, :…”

“…In reality, there are differences between these two paths, for example, unequal conductor length, unmatched twists or kinks in the cable, unmatched via stubs and via transitions, as well as local variation of the dielectric constant. These differences can cause positive and negative paths to deliver their signals at different moments at the end of a differential channel [1]- [8]. Within-pair skew (WPS), also called intra-pair skew, is defined as the time difference in propagation between two complementary signals transmitting through a differential signaling channel.…”

Mitigating differential skew by rotating meshed ground for high-density layout in flexible printed circuits

“…There is known a problem with the differential skew, such as the differential skew occurring in the differential transmission lines on a printed circuit board because of dielectric problems with the board's glass cloth [20,21,22,23]. It has been reported that the differential skew becomes a relatively small value when the angle between the trace of the differential transmission lines and the thread of the glass cloth is around 40 • [24].…”