Anatomy of an Eye Diagram Tektronix（解剖学的眼图美国泰克）.pdfVIP

Anatomy of an Eye Diagram Application Note Abstract This paper describes what an eye diagram is, how it is constructed, and common methods of triggering used to generate one. It then describes different ways that information from an eye diagram can be sliced to gain more insight. It also discusses some basic ways that transmitters, channels, and receivers are tested. It is designed to give an engineer new to this field a basic grasp of the concepts commonly used. Application Note Figure 1. Overlaying of bit sequences to form an eye diagram. Eye Measurements Basics What does it show? Eye diagrams are a very successful way of quickly and Eye diagrams show parametric information about the signal intuitively assessing the quality of a digital signal. A properly – effects deriving from physics such as system bandwidth constructed eye should contain every possible bit sequence health, etc. It will not show protocol or logical problems – if a from simple 101’s and 010’s, through to isolated ones after logic 1 is healthy on the eye, this does not reveal the fact that long runs of consecutive zeros and other problem sequences the system meant to send a zero. However, if the physics of that often show up weaknesses present in system design. the system mean that a logic one becomes so distorted while passing through the system that the receiver at the far end mistakes it for a zero, this should be shown in a good eye diagram. Common ways of characterizing an eye are to