Power for change

The market for power devices for use in embedded systems is tough. There are many competitors and a host of different requirements. But ask any specifier or any supplier and you’re likely to find one common theme: cost. Tim McDonald is vice president, emerging technologies, for International Rectifier. He said: “It’s all about cost. There are a lot of high performance power devices, but their cost per feature ratio is broadly comparable with silicon.” That may not strike you as a problem, but McDonald sees it differently. “New devices have to have a better cost/feature ratio, otherwise customers won’t look at them.” McDonald has a close interest in this aspect of the market because IR has recently unveiled what it believes will be a breakthrough power technology. And McDonald said IR’s development of GaN based power devices is the ‘most substantial effort’ in the industry in the last 20 years. “There’s a lot of work been done on GaN as an alternative power semiconductor technology. We’ve focused on commercialisation of the technology, not just hitting figures of merit,” he explained. One of the reasons why IR has chosen to pursue GaN on silicon is because of the available infrastructure. “The power market consumes about 10million 6in wafer equivalents a year. If you’re looking to replace 10% of that with, say, silicon carbide or sapphire based technologies, that’s 1m wafers a year and the infrastructure can’t support that.” By choosing GaN on silicon, IR can meet its cost targets by accessing a well established process. But that’s not to say there aren’t problems. “It’s a cmos compatible process,” McDonald explained, “but the challenges are bigger than they sound. In particular, we have to solve materials problems.” IR’s gallium nitride based power device technology platform provides customers with improvements in key application specific figures of merit (FOM). According to the company, FOMs can be improved by up to a factor of ten compared to silicon based technology. This, it contends, will increase performance and cut energy consumption in a variety of end applications, ranging from computing and communications, automotive and appliances. “This technology platform and IP portfolio extends IR’s leadership in power semiconductor devices and heralds a new era for power conversion,” said IR’s president and chief executive officer Oleg Khaykin. “We fully anticipate the potential impact of this new device technology platform on the power conversion market to be at least as large as the introduction of the power HEXFET by IR some 30 years ago,” he added. The GaN based technology platform is likely to support developments in power conversion solutions. McDonald continued: “If you look at FOMs, lower is better. For example, the power mosfet enabled the switch mode power supply. Before that, with bipolar technology, the power supply would have been as big as a computer.”