Testing the new normal, how to conquer today’s complex design challenges
Today’s world is driven by the latest technologies and trends creating a strong demand for a new generation of electronic devices. Electronic engineers currently face ever more complex design challenges, and test & measurement suppliers need to provide the essential know-how, education and resources to support engineers.
With today’s increasingly sophisticated test and measurement solutions, as well as classical lab equipment and handheld tools, it can be a challenge for electronic design engineers to know how to achieve the best results from their equipment, especially when working with advanced integrated board architectures. Manufacturer training and educational resources, from test & measurement (T&M) suppliers such as Rohde & Schwarz, covers a wide range of these complex challenges across design, development and test topics that today’s electronic designers currently face.
Collaboration is key in DfT
Design-for-Test (DfT) strategies are well established for digital circuits, whilst for analogue and mixed signal circuits, few techniques have been proposed and implementation of custom approaches is rare. Fortunately, T&M manufacturers offer ample support and resources.
The increasing density of components on PCBs coupled with the difficulty of accessing internal nodes via bed-of-nails fixture have put functional and final tests at PCB level to the fore. This is being addressed with new analogue measurement technologies for in-production testing of modules. As with most revolutionary changes, the best approach is for the board manufacturer to work in partnership with trusted test and measurement specialists. The integration of solutions into a production line, the use of fixtures and programs absorb much more capital than the test system itself. So, for a supplier of test solutions, the first essential requirement is its support for a variety of general production tests, including in-circuit, functional and optical tests. The second prerequisite is having the special know-how and technology for the application in hand, for example mobile radio communications. Last, but not least, the T&M partner should be able to conceive complete systems/projects right through to in-line production, and to provide the required support throughout the world.
Design for demanding data rates
Of course, these challenges are not confined to production testing. Modern high-speed digital designs face increasing demands from data rates and compact form factor. This creates new technical challenges on components as well as board-level and system-level designs. One example is the need for verification, debugging and compliance testing of high-speed digital designs. Here, signal and power integrity are of fundamental importance. Growing integration complexity and varying signal and crosstalk scenarios require thorough measurements to ensure proper system functionality, even under worst case conditions.
Such high-speed designs also necessitate debugging with high-performance oscilloscopes and network analysers. With today’s interfaces operating at data rates over 5Gbps such as USB 3.0, DDR4, etc., key test challenges are being addressed with advanced methods and tools for debugging digital designs including measurement methods and solutions for signal integrity of PCB transmission lines, cables and connectors. Available test solutions provide powerful tools for system validation and debug of digital designs, such as signal and power integrity as well as protocol-level debugging.
Powerful tools for high-speed digital interfaces
High-speed digital interfaces are at the core of all electronic designs. Increasing data rates and growing integration density create new challenges for designs at the IC, board and system level. Signal integrity is a key requirement, which needs to be ensured in the presence of nearby wireless signals, other high-speed interfaces and disturbances on the power rails. To efficiently capture worst case scenarios, high acquisition rates and powerful triggering are required.
A key requirement is the system verification and debugging of USB interfaces, commonly used to connect computers and peripheral devices. The demand for higher data rates and faster charging speed as well as the integration of Thunderbolt and DisplayPort technologies are driving standardization efforts in the USB Implementers Forum (USB-IF). Test and measurement manufacturers are working closely with USB-IF to provide powerful test solutions for interface testing, PCB, cable and connector testing, and also power delivery testing. Test solutions help to efficiently verify and debug system level designs and get products to market faster.
Internal interfaces are important, too. The PCIe architecture is the core of most computer designs, connecting processor and memory subsystems to the endpoint devices via the root complex. Here, the growing demand for speed is driving standardisation efforts in PCI-SIG and their adoption in data centres, PCs and embedded applications. As well as solutions for PCIe compliance testing, today’s test solutions help to efficiently verify and debug designs at the board and system level, including in the presence of other interfaces and wireless signals.
Evolving T&M for 5G Evolution
To pick one example, 5G New Radio is driving demand in multiple directions that are as diverse as the applications for 5G. For the first time, mass products will go beyond 24GHz, enabling high data rates through wide RF bandwidths of hundreds of megahertz. Beamforming will be an essential part of 5G systems. Antenna designs and RF frontends (including RF upconverters, filters and amplifiers) will look different than common solutions from former standards. Engineers face complex challenges when designing, developing and testing these components. When building modules and complex systems, engineers need to select the best solution for their specific environment and make sure it performs.
Getting it right from design to debug
Power components and systems are another case in point. For designers and manufacturers, they represent a key differentiator in the electronic systems and services they offer. It is all the more relevant, considering the rapid growth in renewables, electrification of transportation and industrial automation as well as the increasing storage, transmission and availability of data result in a growing demand for energy and power.
When it comes to the requirements for design and debugging, T&M providers are a key source of help for designers aiming to achieve the necessary excellent performance and compliance. Reliability and power efficiency, reduced size and weight, and compliance issues often lead to contradictory design challenges. For those working on embedded power, power conversion or motor drive electronics, the excellent performance and compliance results of the appropriate electronics test solutions will deliver the right information to get design to market faster.
Today's technologies challenge power converter engineers and technicians to get more and deeper insights into their designs for improvement and verification purposes. And, whilst the faster switching times achieved with advanced materials such as GaN and SiC significantly improve power efficiency, they also increase and generate unwanted EMI problems. Important examples include in-system verification methods for EMC analysis.
Gauging power system performance
To achieve an effective balance between efficiency, performance and compliance with regulation specifications, test solutions require data acquisition and visualization systems, such as oscilloscopes with probes and analysis software, that offer high bandwidths, floating channels and very precise EMI debugging tools. Designers can use the resulting insights to achieve close to best performance in line with EMI limits.
Control loop analysis is another area where test and measurement are crucial, if sometimes problematic or time-consuming. Every power supply has a feed-back loop that monitors the output voltage or current and keeps it within given limits. The behaviour of the control loop determines stability as well as key parameters like load response or start-up behaviour. As well as confirming stability, power system designers need to characterise the power performance of the supply. Whether designing a DC-DC converter for your embedded design or tailoring a reference design to your requirements. Any improvements to meet the performance criteria must be tested. The latest oscilloscopes and probes offer unique features for this task, along with measurement tools to verify and debug power integrity and PDM impedance. T&M manufacturers provide extensive resources – including tips and tricks to verify control loop stability. Technical notes, step-by-step guides, training course and webinars –are all available for engineers to elucidate key requirements such as EMI test for embedded power electronics designs, power integrity testing, power electronics verification and debugging, and analysis of EMI problems during development.
Testing times for the Internet of Things
Power system design is especially critical for IoT and wearable devices, which must minimise power consumption in order to extend battery lifetime. They also need to address the daunting requirements of mobility, connectivity, highest data rates, robustness and power efficiency.
The Internet of Things impacts all industries and ultimately everyone's daily life, so the expectations regarding reliability, performance, quality and long-term availability are extremely high, and wireless connectivity is a critical success factor for IoT devices and network components. Not surprisingly, testing underpins all phases of the product lifecycle, ensuring performance, reliability and fast time to market. T&M providers are helping electronics engineers to understand testing needs and setups and to perform all necessary tests and measurements to bring IoT applications to market as quickly as possible – and with the required quality and performance.
The customer’s quality of experience (QoE) with a mobile device is a major measure for manufacturers. Ensuring coexistence and interference-free operation of all integrated wireless standards is a challenge from the initial design to the production of mobile devices. Mobile device test and measurement solutions cover every aspect of cellular mobile radio, wireless connectivity and navigation standards – from R&D to conformance and production testing.
Helping to meet demanding standards for cable modems and related components
Whilst 5G systems are in development, most Internet connections still rely on copper wire or optic fibre. The DOCSIS®3.1 standard was created to address two primary needs for cable communications providers: higher data throughput to meet consumer demand for high data rate applications, and flexibility to support a variety of applications. Testing to these latest standards need to accommodate previous DOCSIS generations.
Helping to meet these requirements, cable modem testing requires precise measurements on upstream channels with up to 96MHz channel bandwidth. Test and measurement solutions and guidance are available to meet the requirements of physical layer (PHY) testing for cable modems, cable modem termination system components and also for cable network amplifiers, distributed feedback (DFB) lasers and other cable TV components.
Conclusion
These are just a selection of the complex challenges in design, development and test that today’s electronic designers currently face. For circuits and devices right up to complete systems and networks, test and measurement suppliers support their hardware and software with essential know-how, guidance, education and resources engineers need.
Rohde & Schwarz has a wide range of free educational resources on the latest technical challenges that we see engineers coming up against on a daily basis. For the latest resources and advice from R&S please visit our Knowledge Centre to see how we can help or get in contact with our UK based application engineers.
Use this link here to request further information from Rohde & Schwarz on topics such as analogue / digital design and testing, digital bus and interface standards, power electronics and or CATV / DOCSIS.
Sign up to the E&T News e-mail to get great stories like this delivered to your inbox every day.
