As a new year starts, the electronics industry can look ahead with optimism to the opportunity to rethink and even revolutionise the design of many products’ power systems. Now is the time when a number of technologies start to deliver on their early promise: the reward of dramatically improved performance and functionality is available for those designers who are willing to embrace a change in materials and applications.
One such change is the emergence of a broad portfolio of standard power MOSFETs and diodes made from wide bandgap materials, Silicon Carbide (SiC) and Gallium Nitride (GaN). These devices can operate at frequencies up to ten times higher than standard silicon devices can support, as well as tolerating higher temperatures while producing much lower switching and conduction losses. This enables the development of more compact, lighter and more efficient power circuits.
The savings that designers can make on associated components such as magnetics, capacitors, heat-sinks and housings are helping to alter the calculation of total cost of ownership at a system level when compared to conventional silicon-based designs. This explains why the automotive industry is now adopting wide bandgap technology, and why railway systems manufacturers have started the long process of qualifying SiC and GaN components.
The rapid pace at which new SiC-based standard products are being introduced is reflected in this issue of FTM. STMicroelectronics has been a pioneer of SiC technology, and its 1,200V STPSC10H12 SiC Schottky diode, shown on page 23, is a fine example of the performance that ST is able to extract from this new technology. At the same time, Littelfuse, on page 16 and ROHM Semiconductor, shown on page 22, are actively extending their SiC MOSFET offerings.
SiC MOSFET products are particularly interesting to the designers of new, very high-power Electric Vehicle (EV) chargers. Porsche for instance, with its HPC 2020 programme, is planning to build EV chargers with a power rating as high as 350kW.
Future Electronics expects to see wide bandgap technology adopted extensively in EV chargers: the power stage may use SiC-based, 1,200V/300A half-bridge modules available from suppliers such as Microsemi and ROHM, or even 1,700V or 3,300V SiC FETs for full-bridge topologies where the mains infrastructure will withstand such high-voltage operation. Gate driving is an important functional block in such systems. This issue of FTM features dedicated gate- driver components from manufacturers such as Diodes with its DGD0506, shown on page 19. ST also supplies gate drivers integrated into its PWD13F60 power driver, shown on page 20.
Other new applications for power technology are also entering the mainstream. Perhaps the most prominent is wireless charging, which was first introduced in consumer electronics but is now finding uses in industrial equipment, because of the convenience of wire-free charging. Industrial applications require reliable, secured and certified processes, and the wireless charging market is developing an ecosystem of hardware, software and certification suppliers and tools to ease the technology’s adoption.
Finally, it is well worth studying the applications guidance from Vicor, pages 10-11 and STMicroelectronics, pages 12-13, on new approaches to power-system design. Vicor provides a clear description of the benefits to be gained from distributing power within a system at 48V rather than 12V. And ST shows how designers can achieve nominally zero power consumption in stand-by mode.