Powering the future

It is generally accepted that the number of engineers who design power supplies from first principles is declining. Paradoxically, power is becoming one of the more important design criteria as the industry looks to create products that use power more efficiently. So does the industry see a decline in the numbers of designers? Robert Fischer, director of systems marketing Europe for National Semiconductor, said: "Absolutely." John Perzow, director of marketing for Analog Devices' power management group, agreed: "Unequivocally." "We see companies reducing their power supply staffs and looking to ic vendors to fill the gap," said Robert Kollman, senior applications manager for Texas Instruments. "The number of designs is not decreasing," he added, "but there is probably a reduction in effort spent on them. The manufacturer's engineer, who typically does a design or two a year, is replaced by an expert doing 50 designs a year." Having established the number of designers is declining, we asked the panellists why. "During the last couple of decades, universities have churned out graduates skilled in digital design," claimed Tony Armstrong, Linear Technology's director of product marketing, power products. "But few of these graduates are capable of complex analogue design. These factors combine to produce an 'experience gap' in power electronics." Perzow took a slightly different viewpoint. "Analogue design, in general, was out of fashion in the 1980s and 1990s and fewer university graduates were trained in the art. Analogue design is more of an apprenticed art, so the lack of university focus, combined with fewer apprenticing activities in industry, has led to a general gap in design expertise." Fischer concurred: "Many small to medium sized companies have eliminated – and not just recently – dedicated power designer positions. All this has happened because it was assumed that a dedicated power designer was a costly resource and that power design could be outsourced." What are the challenges facing specialist power designers? "One challenge is the growing complexity of the power supply itself," said Kollman. "Back in the 'old days', you would have a single 5V supply powering all the digital electronics. Now, there are often seven digital supplies with much lower output voltages, much higher currents and stricter regulation requirements." Armstrong added: "Designers of today's portable electronic products are faced with unprecedented challenges. Among these are the demands for high performance power management systems to accommodate growing system complexity and higher power budgets. These systems strive for an optimum balance among competing objectives, including long battery runtime, compatibility with multiple power sources, high power density, small size and effective thermal management." Perzow, meanwhile, contended: "Complexity is increasing and product definitions are changing more quickly." What's the biggest challenge, however? Perzow continued: "The frequency of changes that need to be addressed with custom power architectures and the increased pressure to get quickly to market faster." Kollman said: "I think the increasing emphasis on efficiency while keeping costs in control is the biggest challenge. It is going to require new topologies, improved semiconductors and unique control strategies." Fischer claimed: "Achieving accurate efficiency estimation in portable systems and – more generally – in power systems is crucial, but this still relies mostly on datasheet data and calculated predictions. "On the other hand," he continued, "energy efficiency is stressed all the time. We see more and more customer requests where the efficiency is specified under stringent requirements and the responsibility for meeting this target is left to the vendors competing for the solution." Armstrong's view was: "The most challenging issue is how to best architect a power management system to optimise overall performance and maximise battery run time. "One choice is to architect the system using individual components. This approach yields maximum flexibility but is relatively costly and the components require substantial board space. "At the other extreme," he noted, "designers may choose from a variety of highly integrated power management ics, which typically support a superset of the functionality needed for most applications. But they can be cumbersome to use and most require a substantial investment in firmware just to turn them on [and require] board layout heroics in order to accommodate all the external components." So what can power ic companies do to help the beleaguered power supply designer? Perzow claimed: "First and foremost, offer system expertise. Analog has invested in system experts that understand the technical and commercial challenges of today's market. We work directly with OEM product teams to define architectures that help them differentiate their end products." Armstrong said Linear was taking a product based route. "Linear has recently introduced a family of power management ics that offers designers new choices for the combination of topologies and power levels to best fit their application. These products offer clean and compact solutions to the most difficult power management challenges faced by designers today." According to Kollman, TI has been presenting power supply design seminars around the world for more than 28 years. "We also have power supply design tutorials that are accessed over the web, along with synthesis and design software that make our parts very easy to use." Kollman also noted that TI had 'twice as many field applications engineers' than its rivals, each specialising in power. "Most of these have 20 years design experience," he added. Fischer pointed to National's Webench. "Webench enables novices and experienced power supply designers to 'dial in' their size and efficiency requirements. Real time electrical simulations allow designers to see the behaviour of the circuit under dynamic conditions. When the design is complete, a report is created and a custom prototype power supply kit can be ordered." Will the future see greater demands on manufacturers? "Cost will continue to be the number one driver in the power product market," Kollman believed. "It will be aggravated by increasing emphasis on efficiency and increasing power supply complexity." Armstrong pointed out that battery powered portable handheld devices will need smaller, faster and more efficient dc/dc converters to allow more features and functionality to be squeezed into an ever shrinking form factor. "Clearly, this will require the manufacturers to develop ics that meet all of these criteria. Another factor is to ensure these newer products conform to the Green standards being adopted around the world." Perzow added: "From Analog's perspective, developing new ic technologies and design techniques for higher performance, smaller and cost effective solutions will be crucial." Final thoughts Fischer: "The possibility of achieving further efficiency savings at the product level are limited for the future, so the focus has to shift to system level energy savings." Armstrong: "Energy efficient products will enable customers to convert power more efficiently, consume less power and extend battery life." Kollman: "There are virtually no people with a combination of power supply and digital control expertise. Gaining this experience will probably limit how quickly digital control becomes mainstream." Perzow: "Suppliers need to act as a design partner for selected customers. As resources become scarcer, these customers are becoming more dependent on the supplier for developing competitive solutions that help them differentiate their products."