Innovation In Digital Power Supplies

According to analysts, digital power supplies will be one of the fastest growing technology markets, with the Petrov Group predicting annual growth of between 30% and 50% per year to 2014. We discussed the innovation we’re likely to see throughout 2013 and beyond with Mark Adams, senior vice president of CUI Inc., and Patrick Le Fèvre, marketing and communications director of Ericsson Power Modules.

Don Tuite: Digital power is in the early adoption phase with growth coming from the computing, storage, networking, and telecom markets. Are the benefits are limited to these markets?

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Patrick Le Fèvre: Based on our research estimates, 48% of digital-power based supplies in 2012 were used in the telecoms industry. In 2011, digital power crossed the chasm and moved from the early-adopter phase to the early majority. Many applications powered by advanced bus converters and digitally controlled POLs (point-of-load converters) are now being commercialized, and there is a strong trend for other segments to follow this evolution. Server applications, representing 28% of the market, are rapidly implementing digital power, and growing interest in the industrial segment to achieve better energy management is a sign that the technology will be deployed beyond information and communication technology (ICT) applications.

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Mark Adams: No, regardless of the market, design engineers fight the same battles: space, efficiency, price, and time-to-market. Each customer prioritizes these differently, but a mix of these will almost always drive the design decisions. Many of the companies classified as early adopters of digital power had the necessary infrastructure and engineering resources to implement a change from analog power conversion. The next wave of adopters may not have these at their disposal, so the market needs to adapt to reach this new set of customers.

DT: What needs to be done if wide-scale adoption is to take place elsewhere?

MA: For me, the key barrier is complexity, so digital power needs to become easier to both implement and optimise. The industry as a whole has done a great job of releasing some incredible technologies, and if digital power is deployed properly by power supply companies, then it has the ability to become a “plug and play” solution for design engineers across many markets.

PL: Many customers are used to conventional power architectures based on analog control. Digital power is often perceived as being complex and requiring digital-power expertise and deep knowledge of hard coding, but this is not the case in most applications. Like any major technical evolution, it requires efficient training and support from power manufacturers, many of which will need to evolve to a new business model combining hardware, software, and services. From the very large number of applications we have seen migrating from conventional analog to digital architectures, it is now clear that hardware alone will not be enough to gain wide-scale adoption, as application support becomes the most important factor to speed adoption.

DT: How do we achieve this?

MA: The next wave of adopters may not have the necessary infrastructure and engineering resources at their disposal to implement a change to digital. Options to let customers migrate slowly, without needing the bus programming expertise, will therefore be essential. Furthermore, an interface that’s capable of working with multiple digital power IC platforms, with each deploying a proprietary bus, is needed.

PL: As digital power delivers the possibility to control and monitor products and events, it requires board-power designers to address the overall system. This means that power supply manufacturers must offer similar levels of support to that of the system-processor supplier. This requires not only new competences, but also a new way of working and earlier involvement in the applications now being deployed by major companies.

DT: What cutting-edge innovations are we likely to see in 2013, and when will they reach the market?

PL: Three cutting-edge innovations will emerge. First, dynamic energy management and adapting power distribution to load and traffic conditions will become part of the master dc-dc, simplifying board power management. This is already being deployed in high-end telecom/datacom applications. Secondly, the combination of digital control and monitoring with new gallium-nitride power transistor technology will contribute to a significant reduction in energy consumption. Thirdly, new algorithms will make control-loop auto-compensation increasingly stable for a wider range of applications, meaning that designers will not have to worry about the number of capacitors or board parasitic impedances and will have guaranteed dc-dc performance. Some of these innovations will reach the market later in 2013. Others related to new materials or patent applications might not come through until 2015.

MA: We’re starting to hit the limits of existing power topologies, and I think many of the big power launches this year could be based on advanced power topologies. These will deliver significant efficiency gains. Our Solus topology, for example, delivers a substantial reduction in switching losses within a PWM (pulse-width modulation) circuit. Indeed, in tests switching turn-on losses drop by 75% and switching turn-off losses drop by 99% on the control FET when compared to a conventional buck converter.