We will look at how usb works and how it might be implemented. Ian grout, in digital systems design with fpgas and cplds, 2008. Universal serial bus signal integrity analysis for highspeed. New techniques to address layout challenges of high speed. Written by the foremost experts on the subject, it leverages concepts and techniques from non. Review of signal integrity concepts at frequencies in the gigahertz range, a host of variables can affect signal integrity. A full appreciation of how usb works and how it may be implemented in an embedded system. Specific io pins are used to cover special functions.
This book brings together uptotheminute techniques for finding, fixing, and avoiding signal integrity problems in your design. Introduction high speed pcb design referes to the techniques that must be followed in order for a circuit to function properly when. Robustness the key advantage of the usb protocol is its robustness. Modify the behavior of the interconnect to meet the constraints. Usb universal serial bus usb otg usb onthego usb 2.
Hp extended range wireless lan isolates the wireless antenna to improve signal integrity and range, minimizing interruptions so you can work all day without a hitch. Various electromagnetic interference emi aspects also need to be considered when. No need to risk riding someone elses network when you have your own. New techniques to address layout challenges of high speed signal routing. Decades of oscilloscope design experience can be seen in improved pulse response and bandwidth flatness. Therefore, formation of an appropriate decoupling circuit is important for both noise suppression and circuit operations. And8319 how to maintain usb signal integrity when adding. Understanding data eye diagram methodology for analyzing high speed digital signals introduction the data eye diagram is a methodology to represent and analyze a high speed digital signal. Design for signal integrity raw cable managing loss and skew loss per inch skew impedance connector minimizing discontinuities footprints contact geometries middle gnd plates. Quickspecs hp zbook 14u g6 mobile workstation overview c06277908 da 16467worldwide version 3 november 21, 2019 page 2 right 1.
If two wires are placed adjacent to each other, it is possible that the two magnetic fields interact causing a crosscoupling of energy between signals known as crosstalk. All other signals, like aux channel and hpd, have the same signal assignment in both the source and sink. Signal integrity all four cables passed high speed signal integrity, meaning they will perform well at usb 2. Improve usb typec signal quality using signal conditioner usb sig con tusb501 tusb211 sn65lvpe512 ss txrx 1 ss txrx 2 cc1 cc2 ss txrx ss txrx typec switch hd3ss2522 gigabit signals are subject to signal integrity degradation due to long trace, cross connectors, long cable and capacitance lines. The origin of this simple rule of thumb relating the rise time of a signal and the highest sine wave frequency we need to consider in the signal is based on a very simple type of signal. To put it simply, high speed pcb design is any design where the integrity of your signals starts to be affected by the physical characteristics of your circuit board, like your layout, packaging, layer stackup, interconnections, etc if you start designing boards and run into problems like delays, attenuation, crosstalk, reflections, or. This paper analyzed the signal integrity of high speed usb io and ic package. However, digital signals are fundamentally analog in nature, and all signals are subject to effects such as noise, distortion, and loss. Reza zamani signal integrity engineer, intel usb developer days 2019. It would seem from the methodology that to calculate the pdf of a pulse. Any time an electrical signal is transmitted, signal integrity is a concern.
Signal integrity issues and printed circuit design doug brooks prentice hall isbn 0141884x pcb design for realworld emi control bruce r. They maintain excellent signal integrity for highspeed communications with 3 db differential mode cutoff frequencies up to 6. The universal serial bus is a network of attachments connected to the host computer. Signal integrity issues and printed circuit design doug brooks. Reproduction of significant portions of ti information in ti data books or data. Connect a pda to a computer as a device to load data such as an address book or. Application manual for power supply noise suppression and. Each signal that transmits in an rs232 system appears on the interface connector as a voltage with reference to a signal ground. Receiver can reject any signal that is common to both lines radiation reduced cancellation of fields impedance measurements have slightly different meaning compared to singleended measurements. Differential circuit topology is commonlyused as an implementation method, with the goal of enhancing the data carrying capable of the physical layer. Signal integrity journal, a sister publication to microwave journal, covers signal integrity, power integrity and emcemi related topics with industry news, technical articles, white papers, products, buyers guide, webinars, videos and more. Identify signal integrity constraints driver to load delays including effects of crosstalk and ringback overshoot voltages other signal quality measures eye opening 2. Overcoming the high frequency design challenges of usb 3. Signal integrity affects the electrical signals as they pass through the tracks in the pcb.
Select or type in the location to save your document. Acceptable signal qualities are often defined with the use of a mask. Over short distances and at low bit rates, a simple conductor can transmit. How to insert a digital signature into a pdf document last updated. Adobe acrobat requires that a document be resaved before inserting a digital signature. Signal integrity may vary according to quality and length of cable and the quality of. These attachments come in two types known as functions and hubs. It is recommended that manufacturers distinguish usb 3. Usb cabling has been shipping in high volume since 1998, and hence it is important to estimate signal integrity in existing usb cables. The max3421e usb peripheralhost controller contains the digital logic and analog circuitry necessary to implement a fullspeed usb peripheral or a fulllowspeed host compliant to usb specification rev 2. Likewise, a digital signal with good integrity has clean, fast transitions. Builtin 4g lte leverages the sim card from your wireless provider for enhanced security.
Hubs basically act like a double adapter does on a powerpoint, converting one socket, called a port, into multiple ports. Csma means that each node on a bus must wait for a prescribed period of inactivity before attempting to send a. However, a real track will alter the shape of the signal and so corrupt its integrity. For optimal performance, it is recommended that you use the modules with a usb 2. The eye diagram allows key parameters of the electrical quality of the signal to be quickly visualized and determined. This is mostly a matter of convenience and ease of use.
And9075 understanding data eye diagram methodology for. Degraded signal integrity that is, more jitter and reduced signal amplitude. To record to a usb stick, perform the following steps. For example, the transmitted data from a dte device appears on td with respect to gnd.
Highspeed interface layout guidelines 1 introduction 1. Unfortunately, some industry standard interfaces usb. If the measured traces cross the mask boundaries the signal quality is considered unacceptable. During usb certification, the usb signal quality is measured by performing the eye diagram test.
Switching in usb consumer applications analog devices. All usb cables and tracks should have a singleended impedance of 45 ohms to preserve signal integrity. The universal serial bus usb was designed to be a lowcost way to connect a wide variety of peripherals to a computer in literally the simplest possible wayideally, almost as simply as plugging a lamp into a socket. The usb has signal integrity which enables it to use differential drivers, receivers. Time domain modeling and measurement were studied and compared. Even at the lower usb high speed data rate of 480 mbps, usb signals are subject to signal degradation over cables, trace loss, and passive components in the. All devices connected to the usb must draw power from some source. And9114 maintaining signal integrity when selecting esd. Usb is ubiquitous in modern computer systems and, hence, designed into many embedded systems. Scillc reserves the right to make changes without further notice to any products herein. The dt9800 series modules are usb powered no external power supply needed. Introduction timing relationship between signal transmission line parasitic effects of resistor, capacitor and inductor power supply pdn design power plane stack up design simulation using hspice crosstalk designing for emi tips for singal.
Careful frontend design and shielding reduce noise, crosstalk and harmonic distortion. The larger the eye the better the data signal integrity. The mask consists of a hexagon in the middle of the eye and rectangles above and below the eye. This book is designed to provide contemporary readers with an understanding of the emerging highspeed signal integrity issues that are creating roadblocks in digital design.
Eric bogatin is signal integrity evangelist at bogatin enterprises, which specializes in training. This means the cables are thicker, heavier, less flexible and more expensive than 2. In digital electronics, a stream of binary values is represented by a voltage or current waveform. Signal integrity tutorial this tutorial is intended for printed circuit board designers who wish to get an insight into the design of high speed digital pcbs. Usbb connector ft232 usb uart interface chip, tssop28 2x5 programming input header 0.
Interface ics provide complete electronic interface circuit functions in a single chip which increases reliability while providing significant savings in design effort, design size and cost. The main link signals that comprise four differential pairs get reversed within the cable. Usbif certification amazon advertises these cables are usbif certified compliant for usb 2. Archambeault kluwer academic publishers group isbn 1402072 digital design for interference specifications a practical handbook for emi suppression david. This presentation provides an overview of the test requirements for usb 2. Signal integrity characterization techniques keysight. Functions are the peripherals such as mice, printers, etc. How to insert a digital signature into a pdf document. Usb 3 an introduction for embedded software developers. Interface devices control and manage signal communications between diverse electronic systems.
Our wide selection of interface ics enable robust, reliable. Fundamentals of signal integrity mouser electronics. High data speed, up to 20 gbits, requires a carefully designed pcb layout to maintain signal integrity. Picoscope 2000 series high signal integrity here at pico technology, were proud of the dynamic performance of our products. Signal integrity basics by anritsu field application engineers table of contents 1.
Lines may have to be routed nonparallel near connectors and controllers. Max3421e usb peripheralhost controller with spi interface. Differential pair an overview sciencedirect topics. Sparameter measurements basics for high speed digital engineers frequency dependent effects are becoming more prominent with the increasing data rates of digital systems.
Ideally, the signal should not be altered by the electrical properties of the track. Login or register for mysemtech to gain access to restricted product documentation and to add documents to your watch list for update alerts. And8319 how to maintain usb signal integrity when adding esd. Introduction to the controller area network can rev. We assume the signal is a 50% duty cycle clock signal that has a finite 1090 rise time.
From preroute design exploration and whatif analysis through detailed verification and signoff to. Signal and power integrity simplified download free pdf. The controller performs as a standard hispeed dualrole device drd, operating as either a usb 2. The dp connector pin assignments in the source and sink side are shown in figure 4. Identify signal integrity problems with integrated measurement tools.
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