Signal Integrity Solutions
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Signal Integrity Solutions Find Problems Now, Prevent Problems Next Time A New Perspective on the Design Process In all evolving technologies, you Agilent is constantly researching hundreds of channels simulta- eventually reach a point where you new ways to assist design engi- neously with a logic analyzer must change your way of thinking to neers and has developed a and eye diagram feature, eye go past a certain level. The methods comprehensive set of tools that scan. An oscilloscope or bit and rules of thumb you have used will keep signal integrity problems error ratio tester (BERT) help under control as you move into characterize jitter. in the past are no longer adequate. higher-speed designs. Instead of To move forward, you must step relying on guessing and the old rules Signal integrity is no longer back and look at the design process of thumb, you can measure critical something to be looked at just from a new perspective. components and create accurate once at the beginning of a project To move to the next level in high-speed models to simulate and verify your when laying out the device or new designs before committing board. Everyone must be aware digital design, with sub-nanosecond them to hardware. Once the hard- of signal integrity and evaluate edge rates and slim design margins, ware is built, you can accurately it throughout the project, and you must add additional problem measure the physical layer to must have the proper tools to solving tools to your trusty toolbox. validate the signal paths prior to accomplish this sometimes The ubiquitous oscilloscope, though installing components. daunting task. The challenging important, requires complementary high-speed digital designs of software and/or instrumentation to When the components are first today’s data rates require careful adequately address today’s difficult installed, you can use pulse use of a wide variety of engineer- signal integrity and jitter issues. generators to test your system ing tools. It is important for with live signals. High-speed designers to learn these new tools scopes and active probes enable effectively to avoid multiple you to see what is going on. Once re-design efforts. the system is running, you can monitor the signal integrity of 2 www.agilent.com/find/si The breadth of tools available from characterize the physical layer also be used to ensure that errors Agilent Technologies enables signal of your design. After you are are within the required range. integrity evaluation throughout the satisfied with the results, you can Finally, when all of the signals entire design process. You can use install components and bring the have been checked, the entire sys- a vector network analyzer (VNA) system up. Capable pulse pattern tem can be tested with Agilent’s or time domain reflectometer generators can provide live signals protocol analyzers and exercisers. (TDR) for device and inter- to stimulate portions of the system You can stress your design with connect characterization. The as you bring it up. For jitter very specific and controllable measurement data is used to characterization, use the histogram worst-case scenarios to give you enhance your model database mode of the oscilloscope or the the confidence that your system so that design simulation will bathtub curve from a BERT. is ready to ship. produce accurate results. For those who do not want to invest When the system is running, you Agilent has the knowledge, tools, in the equipment and expertise can use eye diagrams to validate and methods to help you move to for characterization, Agilent can signal quality. The eye diagram the next level in system perform- provide device characterization can be acquired with a scope ance by addressing all of the signal and modeling services. when you want to see a few integrity issues. You may have to signals, or with a unique, signal look at the signal integrity problem Once the device or board is integrity-aware logic analyzer if from a different perspective, but created, a wide variety of tools you want to check hundreds of with Agilent’s help, you will not from Agilent enable you to signals in a short time. BERTs can be looking at it alone. DESIGNDESIGN SIMULATIONSIMULATIONDEVICE DEVICE && BOARDBOARDSYSTEM SYSTEM Link to Model Devices & Prototype Bring-Up System Integration Database Interconnect Characterization Test & Functional Characterization & Validation Validation PHYSICAL LAYER LINK LAYER Passive Interconnect Measurements Active Live Signal Measurements IMPEDANCE, CROSSTALK... VOLTAGE, JITTER, BER, TIMING, PACKETS... Device Characterization and Modelling Services Serial/Parallel BERT Protocol Analyzer & 81133/4 Pulse Pattern Generator Exerciser Physical Layer Test System 16700 Series Logic System w/Eye Scan & Soft Touch Probes (PLTS) ADS 86100 Infiniium DCA SPICE/IBIS 54855 6 GHz Infiniium Oscilloscope 86100 PNA with Series TDR VNA InfiniiMax Probing System Figure 1. Agilent Technologies helps you address signal integrity and jitter issues throughout the entire design process. www.agilent.com/find/jitter 3 Oscilloscopes and Probes Prototype Characterization Bring-Up Test When you suspect a signal As an experienced scope user, you When you are developing even integrity-related problem, the know that your measurements are faster systems that have edge rates first instrument you grab is an only as good as your probing less than 40 ps, you will need a oscilloscope. The scope is the system. And as bandwidth scope with significant bandwidth. best instrument for finding out increases, it’s increasingly The 86100C Infiniium DCA-J what a signal looks like. It will important to ask the question: accepts modules that provide up continue to be an important tool am I measuring my circuit or my to 80-GHz of electrical bandwidth. for understanding signal integrity scope probe? Nothing is more A remote sampling head for the problems, but it is only one of frustrating than chasing down an 86100C allows the user to minimize many tools that are now required. apparent design problem, only to bandwidth loss due to long cables. find that it was caused by an You will need a scope that can inferior scope probe. Testing today’s high-speed serial accurately measure sub 50 ps buses is simplified with application edge rates. The Infiniium 80000 Together, the newest Infiniium software for the Infiniium 80000 Series provides up to 13 GHz scopes and the innovative Series oscilloscopes. Perform mask bandwidth and an intuitive InfiniiMax high-performance testing and characterize serial data Windows® interface that makes probing systems offer an streams that employ embedded it easy to analyze signals and end-to-end measurement system clocks and 8b/10b encoding. get the information you need. It with unmatched performance, Verify compliance to standards can characterize critical signal accuracy and connectivity. such as PCI Express, Serial ATA, parameters, such as setup and InfiniiMax II probes, with up to DVI, and Gigabit Ethernet. hold time violations, edge rates, 13 GHz bandwidth, can measure overshoot, and jitter. differential and single-ended Characterizing jitter is easy using signals. Their flexibility supports the Infiniium 80000 Series real- even the most demanding time oscilloscope or 86100C mechanical access Infiniium DCA-J with the optional requirements without jitter analysis software that sacrificing performance. include histogram, spectrum, and The result is measurements random/deterministic jitter you can trust and better (RJ/DJ) separation capabilities. insight into circuit behavior. Figure 3. The Agilent 86100 DCA-J is a digital communications analyzer, a wide-bandwidth oscilloscope, a jitter analyzer, and a Figure 2. The Agilent 80000 Series Oscilloscopes and InfiniiMax II time-domain reflectometer. Series probes deliver a high-performance 13 GHz end-to-end measurement system. 4 www.agilent.com/find/si Logic Analysis System Prototype Characterization Bring-Up Test System Integration & Functional Validation Hundreds of signal traces moving data along wide data paths at high speeds can present quite a challenge to the high-speed digital designer. The interaction of these hundreds of signal lines keeps signal integrity in the forefront. You must validate the signal integrity of each signal path in order to be fully confident of your design. The typical method for validating all of the signals is to use a 2- or 4-channel scope and measure eye diagrams. This can take a considerable amount of time and is often deleted from the project as many back-end tests fall victim to sliding schedules. The ideal alternative to making hundreds of Figure 4. View the eye diagrams of many eye-diagram measurements with a channels simultaneously with a logic scope is a novel technology called analyzer and spot sub-nanosecond “eye scan.” problems faster than conventional methods. With eye scan, you can have the same eye-diagram capability in a logic analyzer that you have in your scope, and cover up to 340 loading to preserve your system’s layout issues. With less than channels at a time. Eye scan gives signal integrity. It has an equivalent 0.7 pF capacitive loading, you you a rapid, comprehensive bandwidth of 2.33 GHz when can maintain tight timing margins overview across hundreds of using eye scan. with the soft touch probe signals simultaneously. Eye scan is attached to your board. available in the Agilent 1680/1690 On your next project, use Agilent’s Series standalone logic analyzers innovative, time-saving eye scan and the 16950A, 16760A, 16750 technology for a comprehensive Series, and 16740 Series logic overview of the system’s signal analyzer modules for the 16900 integrity. Immediately spot Series logic analysis systems. If problems and identify the eye scan finds a bad signal and offending signals. Use the time you need more detail, you can you gain to check out signal take a closer look by making a integrity under all conditions.