How to Set up an Eye Diagram on an Oscilloscope?

时间： 2023-08-09 来源：Keysight zhihu

Eye diagrams are extremely helpful in testing the physical layer fidelity of clock or serial data, but many engineers don't know:

What they are
Why they should use one
How to easily set one up

They actually aren't that complex when broken down.

Eye diagrams can quickly give you insight into your signal, along with any jitter or anomalies that may be present that you might know exist.

What they are:
What is an eye diagram? Eye diagrams are a layered view of every bit of transition combination. There are eight of these in total. You can see in Figure 1 how each of these is layered to make up the eye. This provides a composite picture of the overall quality of a system’s physical layer characteristics like amplitude variation, timing uncertainties, or infrequent glitches.

Why you should care

An eye diagram is used to detect jitter,
but what is jitter and why is jitter bad?

Jitter can cause errors in the data that you are trying to transmit. If there is too much of it riding on your signal, the data that is sent will be interpreted incorrectly by the receiving end because the edge crossings aren’t occurring when they should be.

How to create an eye diagram

One of the first things many people think when they see an eye diagram on an Oscilloscope is “How do you get it to look like that?”

This layered view of bit transitions is not something that a normal trigger would be capable of displaying. The answer is, the oscilloscope utilizes a built-in clock recovery system. Clock recovery is actually pretty straightforward. Some signals have an explicit clock signal, and some have an embedded clock. An explicit clock can be driven right into one of the oscilloscope channels, but embedded clocks have to somehow be de-embedded, or recovered, hence “clock recovery.”

There are three different ways to utilize the clock recovery system, which all depend on how well you know the bitrate of your signal (the width of each bit):

Fully automatic

1. The oscilloscope will calculate the ideal bitrate (or nominal data rate) of your signal.

2. This should be used when you have no idea what the bitrate is and you need the oscilloscope to figure it out.

3. However, this method is only about 80% accurate.

Semi-automatic

1. In most situations, you should have a rough idea of what the bitrate should be. You can very easily make a bitrate measurement on the oscilloscope to find this estimation. This method allows you to enter your rough measurement and then use that information as a seed as it calculates the exact ideal bitrate.

2. This method is significantly more accurate.

Manual

1. This method should be used if you know the exact ideal bitrate of your signal.

2. This is the most accurate method of clock recovery.

There are a few other settings within the clock recovery menu.
To learn more about these, make sure you check out: the video's at the end of this article.

Once you have your clock recovery system set up, all you have to do to set up the eye is press “auto setup”. You will see in just a few seconds that the eye diagram has begun to form. Over time, you will be able to see if there is any jitter or anomalies in your signal. Generally, you will want to let the test run for a longer period of time.

The longer you let it run, the more data is collected, and the more jitter, anomalies, or any infrequent events you can see.

From here, you can analyze the eye diagram further by using the color grading key. This allows you to visually analyze the frequency of each edge crossing. You can also very easily turn on a histogram of the eye to determine whether the jitter is deterministic or random. This will help you decide if this is something you can fix with a phase-locked loop filter or if you have to redesign the component.

发送到邮箱 |
+1 赞 0
收藏
评论 0
| 转发至：

本文由FY转载自Keysight zhihu，原文标题为:How to set up an Eye Diagram on an Oscilloscope如何在示波器上设置眼图，本站所有转载文章系出于传递更多信息之目的，且明确注明来源，不希望被转载的媒体或个人可与我们联系，我们将立即进行删除处理。

平台合作

提交评论

全部评论（0）

暂无评论

Electrostatic Discharge (ESD) Tips Every Engineer Should Know

This blog tells the 7 tips that Keysight UXR Oscilloscope will help you avoid ESD damage.

2022-07-23 - 设计经验

Keysight（是德科技）示波器探头和附件选型指南

Oscilloscope Probes Accessories Passive probes Single-ended active probes Differential active probes current probes Optical-to-electrical converter Oscilloscope Accessories

KEYSIGHT - INFINIIMAX CONNECTIVITY KIT,差分探头附件,BNC ADAPTER,POWER RAIL PROBE ACCESSORIES,高阻抗探头适配器,示波器附件,电流探头,3D PROBE POSITIONER,INFINIIMAX IN-LINE ATTENUATOR KIT,PROBE ACCESSORY KITS,高灵敏度电流探头配件,PC板微型探针插座,2 GHZ POWER RAIL,DIFFERENTIAL PROBE ACCESSORIES,INFINIIMAX SINGLE-ENDED PROBES,INFINIIMAX SOFT TOUCH PRO PROBE INTERFACE ADAPTER,TWO-ARM PROBE POSITIONER,COIL AC CURRENT PROBE,PROBING ACCESSORIES,INFINIIMAX SINGLE-ENDED SOLDER-IN PROBE HEAD,差分有源探头,1/2GHZ ACTIVE PROB,6 GHZ POWER RAIL,ONE-ARM PROBE POSITIONER,PASSIVE PROBES,HIGH-SENSITIVITY CURRENT PROBE,OPTICAL-TO-ELECTRICAL CONVERTER,探针偏斜校正夹具,INFINIIMAX II MICRO PROBE HEAD,INFINIIMAX DIFFERENTIAL PROBES,探测附件,INFINIIMAX DIFFERENTIAL SOLDER-IN PROBE HEAD,探头接口适配器,混合信号示波器逻辑探头,探头附件,INFINIIMAX FINE-WIRE PROBE TIPS FOR WAFER PROBING,探头定位器,OSCILLOSCOPE ACCESSORIES,精密BNC 50Ω适配器,PROBE INTERFACE ADAPTERS,INFINIIMAX DIFFERENTIAL BROWSER,INFINIIMAX III PROBE AMPLIFIER,HIGH IMPEDANCE PROBE ADAPTER,CURRENT PROBE,INFINIIMAX II DIFFERENTIAL PROBE KIT,CURRENT PROBES,OSCILLOSCOPE PROBES,WEDGE PROBE ADAPTER,探头附件套件,PROBE POSITIONERS,光电转换器,HIGH Z PASSIVE PROBE,SAMPLING OSCILLOSCOPE ADAPTER,INFINIIMAX III ZIF PROBE HEAD,探头抗扭斜和性能验证夹具,INFINIIMAX SMA PROBE HEAD,PROBE ACCESSORIES,示波器探头,DIFFERENTIAL ACTIVE PROBES,INFINIIMAX EXTREME TEMPERATURE EXTENSION CABLE,IC CLIP KIT,PROBES,INFINIIMAX II DIFFERENTIAL SMA ADAPTER,PRECISION BNC 50-Ω ADAPTER,取样示波器适配器,HIGH-SENSITIVITY CURRENT PROBE ACCESSORIES,LOGIC PROBE KIT,单端有源探针,IC夹套件,INFINIIMAX DC BLOCKING CAPS,SINGLE-ENDED ACTIVE PROBES,MIXED SIGNAL OSCILLOSCOPE LOGIC PROBE,16-CHANNEL SOFT TOUCH CONNECTORLESS LOGIC,INFINIIMAX MICRO PROBE HEAD,LOGIC PROBE,TWO-LEG PROBE POSITIONER,INFINIIMAX II DIFFERENTIAL SOLDER-IN PROBE HEAD,楔形探头适配器,PROBE,PC BOARD MINI-PROBE SOCKETS,PROBE DESKEW FIXTURES,12-GHZ DIFFERENTIAL ZIF SOLDER,INFINIIMAX SINGLE-ENDED BROWSER,无源探头,INFINIIMAX LONG-WIRE ZIF PROBE TIPS,电源轨探头配件,RESISTIVE DIVIDER PASSIVE PROBE,PROBE DESKEW AND PERFORMANCE VERIFICATION FIXTURE,QUICKTIP PROBE HEAD,PASSIVE PROBE,POWER MEASUREMENT DESKEW FIXTURE,功率测量抗扭斜夹具,N2870A,E2678B,N2797A,N2830A,N2785A,N2894A,N2882A,N7040A,N7000A,E2614A,10073D,N7024A,N5439A,N1022B,N2878A,N4827A,N2842A,N2826A,N2802A,N2881A,E2643A,E2655C,N2841A,N7007A,N2796A,N2784A,N2893A,1134B,54620-68701,N5444A,1146B,E2615A,N7023A,E2679B,DP0001A,1147B,N2889A,N2801A,N2768A,N2756A,N2877A,N2744A,N2825A,N2783B,E2644A,N7026A,N2880A,N5380B,N2795A,N2783L,N7042A,E2616A,1131B,N5445A,N7002A,E2668B,MX0105A,U1880A,N2888A,N2876A,N2848A,N2824A,N2891A,N2782B,N5381B,E2697A,N2863B,N5450B,1168B,1132B,N7041A,10072A,N7001A,E2669B,MX0023A,N2819A,MX0104A,1169B,N2778A,N2887A,N2766A,N2875A,N2835A,N4822A,N2793A,E5396A,N7004A,N2890A,N2781B,54826-68701,N4863A,N2874A,N5451A,N2862B,10077A,1165A,N7020A,N7032A,54006A,N2818A,N6459-60001,N2822A,N2777A,N7003A,N4864A,N2792A,10070D,N2780B,E2675B,N6450-60001,N2885A,N2873A,N2752A,N2142A,MX0106A,1130B,N2829A,N2833A,N2821A,N2776A,N2805A,10085-68701,N2791A,E2676B,N2884A,N2872A,N2751A,MX0109A,N5477A,10075A,N7022A,N5425B,N5449A,N2828A,N2832A,N2820A,N2787A,N2804A,E2677B,N7005A,N2790A,N2786A,N2871A,N2750A,54904-61615,N2140A,10076C,N5442A,N7021A,N5426A,N7033A,E2613A,MX0100A,N2839A,N2843A,N2831A,N2827A,N2803A,N2879A,EXTREME TEMPERATURE PROBING,AUTOMOTIVE DEVICE,OPTICAL TRANSMITTER,DIGITAL,SURGE MEASUREMENT,MOTORS,DATA COMMUNICATION SIGNALS,AC LINE,LINE CURRENT,HIGH VOLTAGE POWER MEASUREMENT,SWITCHING POWER SUPPLIES,CURRENT MEASUREMENT,HIGH SPEED SYSTEMS,WBG POWER DEVICES,BATTERY POWERED DEVICES,DOUBLE PULSE TESTER,REFERENCE RECEIVER,GENERAL-PURPOSE HIGH-SPEED PROBING,DUT,INTEGRATED CIRCUITS,INFINIIMODE PROBING,MOTOR DRIVE,MOTOR CONTROL,DC POWER RAILS,OPTICAL TELECOMMUNICATION,DIFFERENTIAL SIGNAL MEASUREMENTS,ANALOG DESIGN AND POWER MEASUREMENT,MAGNETIC-DEVICE,ELECTRONIC BALLAST,POWER CONVERTERS,AMPLIFIERS,FULL-BANDWIDTH PROBING SYSTEM,AUTOMOTIVE,POWER SUPPLY DESIGN

September 21, 2020 - 选型指南

Infinium EXR系列示波器产品说明书

Infiniium EXR系列示波器结合了Keysight S系列示波器的高性能和InfiniiVision系列示波器的集成速度，成为500 MHz至2.5 GHz频段内最佳选择。EXR系列具有更快的波形更新率、更高的准确性和更丰富的测试功能，包括8个模拟通道、多种分析工具和升级选项。

KEYSIGHT - 示波器,OSCILLOSCOPE,S-SERIES,EXR-SERIES,INFINIIUM S-SERIES,INFINIIVISION 6000 X-SERIES,INFINIIUM EXR-SERIES

October 6, 2020 - 商品及供应商介绍

Keysight InfiniiMax 4 Series High-Bandwidth Oscilloscope Probes Deliver Bandwidths up to 52GHz Brickwall

Keysight introduces the InfiniiMax 4 Series high-bandwidth oscilloscope probes, expanding its portfolio of high-frequency probes to cover bandwidths up to 52 GHz. The InfiniiMax 4 series provides digital designers with a turn-key probing solution for high-speed digital, semiconductor, and wafer applications.

2024-01-31 - 产品

DSO/DSA81204B和DSO/DSA81304B示波器推广

本促销活动于2007年9月1日开始，至2007年12月31日结束。活动期间，购买Infiniium 12或13 GHz 20/40 GSa/s 4通道示波器（DSO/DSA81204B或DSO/DSA81304B）的客户可享受25%的折扣。此外，购买DSO81204B或DSO81304B的客户还需购买1-2M内存升级（DSO80000-001）。所有促销产品需在同一订单中购买，且不支持与其他促销活动同时进行。

KEYSIGHT - 示波器,OSCILLOSCOPE,DSO81204B,DSO81304B,DSO80000-001,DSA81204B-DSA,DSA81304B-DSA,DSA81204B,DSA81304B

September 1, 2007 - 商品及供应商介绍

Keysight Technologies（是德科技） View Scope Logic Analyzer and Oscilloscope Correlation

KEYSIGHT - 逻辑分析仪,示波器,OSCILLOSCOPE,LOGIC ANALYZER,7000,MSO8104A,MSO6054A,DSO90804A,MSO6034A,DSO7014A,DSO7034A,DSO7054A,1682A,MSO7054A,1690A,1692AD,MSO7104A,DSO6102A,1680 SERIES,16804A,16901A,DSO5034A,DSO5054A,6000,MSO6102A,DSO5014A,1683A,DSO91304A,1690AD,1691A,1681AD,MSO7012A,1683AD,DSO81004A,DSO6034A,16800,16803A,DSO6054A,16900A,16823A,MSO6052A,MSO6032A,DSO90604A,5000,DSO8064A,DSO7012A,1692A,DSO7032A,DSO91204A,DSO7052A,MSO7032A,MSO7052A,1680A,U4154A,1691AD,DSO6104A,1693AD,DSO81304A,16806A,MSO8064A,16903A,16802A,16822A,DSO5012A,DSO7104A,8000,DSO5032A,DSO90000,MSO6104A,1681A,1693A,1690,DSO5052A,1680AD,DSO81204A,MSO7014A,1682AD,MSO7034A,DSO8104A,DSO80000,DSO6052A,16902A,DSO6032A,DSO90404A,DSO90254A,16902B,16801A,16900,16821A

August 1, 2014 - 数据手册

使用Keysight N5477A采样示波器适配器

Keysight N5477A采样示波器适配器可用于将InfiniiMax III探头系统连接到86100D DCA-X宽带示波器或其他射频仪器。该适配器通过连接探头功率输出或电源模块，将示波器探头的频率范围从13 GHz扩展至30 GHz。此外，适配器还可用于将InfiniiMax III探头系统连接到通用50Ω测试设备。

KEYSIGHT - WIDEBAND OSCILLOSCOPE,取样示波器适配器,宽带示波器,INFINIIMAX III探测系统,SAMPLING OSCILLOSCOPE ADAPTER,INFINIIMAX III PROBING SYSTEM,N2800A SERIES,DCA-X,86100D DCA-X,N5477A,N2800A,86100D

August 2010 - 用户指南

N1000A DCA-X宽带宽示波器主机和模块规格书

N1000A DCA-X是一款高性能宽带示波器主框架和模块，适用于高速数字设计的精确测量，频率范围从50 MBd到超过80 GBd，最多可同时处理16个通道。应用领域包括光收发器设计和生产测试、电气ASIC/FPGA/IC设计和特性分析、串行总线特性分析以及通过TDR/TDT和S参数测量通道、电缆和PCB的测量和故障排除。

KEYSIGHT - 宽带示波器,DIGITAL COMMUNICATION ANALYZER,数字通信分析仪,WIDE BANDWIDTH OSCILLOSCOPE,N1000AU-PLK,N1030A-65U,R1282A,N1060A-E33,N1076B-JSA,N1000A-GPI,N1060A-264,N1046A,N1046A-71F,N1091BACA,N1091BMCA,N1078A-216,N1055A-34M,N1091APCA,N1000A-UK6,N1046A-84F,N1000AU-PTB,N1078A-EVA,N1045B,N1055A-34F,N1077A-SXT,N1055A-FS1,N1091CKCA,N109212CA,N1010100A,N109310CA,D9010UDAA,N1060A-085,N1060A-JSA,N1078A-SXT,N1030B-IRC,N1046A-81F,N1094BS1A,N1000AU-LOJ,N1076B-264,N1060A-A1X,N1000A-LOJ,N1055A-32M,N1046A-14F,N1077A-216,N1046A-82F,N1030A-280,N1078A-264,N1060A-A1F,N1055A,N1055A-32F,N1030A-560,N1040A-033,N1060A-A1M,N1091BSCB,N1010300A,N1000A-STB,N1045B-02M,N1046A-11F,N1030B-65U,N1060A-216,N1060AU-264,N1030A,N1045B-02F,N1078A-253,N1030B,N1076B-EVA,N1055A-54M,N1060A-232,N1000A-AX4,N1046A-12F,N1077A-JSA,N1077A-232,N1078A-S50,N1055A-54F,N109256CB,N1000A-AXE,R1280A,N1076B-216,N1030A-IRC,N1060A-EVA,N1000A-PTB,N1045B-04M,N109228CA,N1060AU-085,N1040A-060,N1060A-CA1,N1060A-DC2,N1095BSCA,N1060A-CA2,N1078A-232,N1000A,N1045B-04F,N1000A-PLK,N1000A-AFP,N1078A-JSA,N1030A-EC1,N1091BJCA,N1055A-52M,N1055A-52F,N1046A-74F,N1060A-050,N1010200A,N1077A-SMS,N1060AU-232,N1030B-560,N1078A-225,N1030B-280,N1076B-232,N1060A-PTB

November 11,2021 - 数据手册

用示波器捕捉美洲狮

本文介绍了使用示波器进行山狮捕捉项目的设计与实施。项目旨在通过改进传统捕捉方法，利用超声波传感器和Arduino微控制器，实现更精准的山狮捕捉，同时避免捕捉到小型动物。通过分析传感器信号，调整触发时机，确保捕捉系统可靠运行。

KEYSIGHT - 示波器,OSCILLOSCOPE,EDUX1002A

September 13, 2017 - 技术文档

N1000A DCA-X系列宽带示波器快速入门指南

本资料为N1000A DCA-X系列宽带示波器快速入门指南，内容包括安装步骤、环境要求、安全注意事项等。指南详细介绍了N1000A的安装过程，包括检查设备、工作在防静电工作站、放置设备、安装模块、连接键盘和鼠标、连接电源、开启仪器、配置LAN连接、安装功能许可证、连接打印机、连接外部显示器、校准模块以及学习如何使用和编程N1000A等步骤。此外，还提供了关于可拆卸硬盘、仪器标记和法规信息、联系Keysight等内容。

KEYSIGHT - WIDE-BANDWIDTH OSCILLOSCOPE,宽带示波器,N1000A DCA-X,N1000A DCA-X SERIES

August 2022 - 用户指南

购买低成本示波器时应避免的5个常见错误

本文探讨了在购买低成本示波器时常见的五个错误，包括带宽不足、选择USB示波器、低估易用性、设备支持问题和过度关注规格。文章强调了选择合适带宽的重要性，对比了USB示波器和独立示波器的优缺点，指出易用性对测量效率的影响，并强调了设备支持的重要性。此外，文章还提醒读者不要仅仅关注规格，而应深入了解产品的实际性能和适用性。

KEYSIGHT - 示波器,OSCILLOSCOPE,1000 X-SERIES

June 27, 2019 - 白皮书

Keysight Technologies（是德科技） Oscilloscope Considerations for Multilane MIPI M-PHY Transmitter Validation

本文主要探讨了在多通道MIPI M-PHY发射器验证过程中，选择合适的示波器的重要性。文章详细分析了带宽需求、噪声性能、探头电容负载、探头校正方法、一致性测试自动化以及协议调试等方面，强调了这些因素对测量准确性的影响。文章还介绍了Keysight Technologies的示波器产品，并提供了相关技术支持信息。

KEYSIGHT - 示波器,OSCILLOSCOPE

August 2, 2014 - 应用笔记或设计指南

Keysight Introduces Hardware-Accelerated Oscilloscope with Automated Analysis Tools, Analysis Produce Results at Least 60% Faster Than Most Competitors

Keysight Technologies announces the expansion of its industry-leading portfolio of Infiniium oscilloscopes with the new, hardware-accelerated Infiniium MXR B-Series, offering automated analysis tools that enable engineers to find anomalies quickly and shorten time to market.

2023-09-15 - 产品

Keysight Technologies示波器内存架构–为什么所有采集内存的创建不等于应用注释

本文探讨了示波器采集内存的重要性，分析了不同示波器架构的优缺点，并介绍了如何最佳利用示波器的采集内存。文章指出，采集内存深度与采样率、有效带宽和更新率密切相关，而示波器架构对内存性能有显著影响。文章重点介绍了MegaZoom架构和CPU架构的示波器，并比较了它们在处理深内存和数字通道时的性能差异。此外，文章还介绍了分段内存技术，该技术允许用户更有效地利用深内存。

KEYSIGHT - 示波器,OSCILLOSCOPE,4000 X,6000 X,3000T X

August 2, 2014 - 应用笔记或设计指南

Keysight Technologies（是德科技） U2701A/U2702A USB Modular Oscilloscope

该资料介绍了Keysight Technologies公司生产的U2701A和U2702A型号的USB模块化示波器。这些示波器具有100 MHz和200 MHz的带宽，最高采样率为1 GSa/s，并配备了32 Mpts的波形内存。它们可以通过Hi-Speed USB 2.0连接，支持独立或模块化操作，并配备了Keysight Measurement Manager软件，便于控制和自动化测试。

KEYSIGHT - USB MODULAR OSCILLOSCOPE,USB模块化示波器,U2701A,U2723A,U2722A,U2702A,N2863A,N2862A,U2781A,U2921A-101,U2761A,U2921A-100,U2741A,U2751A,U2701A-200

May 19, 2017 - 数据手册