Introducing the eye diagram method in this app note from ON Semiconductors in determining signal integrity of USB lines. Link here (PDF)
The Universal Serial Bus (USB) has become a popular feature of PCs, cell phones and other electronic devices. USB makes data transfer between electronic devices faster and easier. USB 2.0 transfers data at up to 480 Mbps. At these data rates, any small amount of capacitance added will cause disturbances to the data signals. Designers are left with the challenge of finding ESD protection solutions that can protect these sensitive lines without adding signal degrading capacitance. This document will discuss USB 2.0 and evaluate the importance of low capacitance ESD protection devices with the use of eye diagrams.
from Dangerous Prototypes https://ift.tt/2m0seMo