Product development by power-supply manufacturers and producers of AC-DC and DC-DC converter modules has resulted, over the past 20 years, in steady, incremental improvement. Year by year, the power density, energy efficiency and regulation performance of power supplies and power modules have become better, but the process has been one of evolution rather than revolution.
This might soon change, for two reasons. On the one hand, the pressure on OEMs to comply with strict regulations governing power efficiency has never been greater. And on the other, technology which could provide dramatic gains in power-supply performance is reaching a level of maturity at which it can seriously be considered for widespread adoption.
Two of the most important technological underpinnings of the next generation of high efficiency power systems may be found in this issue of FTM. The first is Silicon Carbide (SiC), a material with extraordinary electrical and thermal properties which far outperforms silicon in high-power and high-frequency switching power supplies. The superiority of SiC in power components has been known for some time, but the high cost of SiC diodes and MOSFETs, and the limited choice of available parts, have dampened OEMs’ enthusiasm for using the devices in production designs.
As more manufacturers introduce more parts, however, unit costs tend to fall, and of course the choice of parts becomes wider. This trend is evident in FTM: Fairchild’s FFSH40120ADN, on page 17, and ROHM Semiconductor’s SCS3xxAP series, on page 16, are new SiC diodes; whilst STMicroelectronics offers a range of SiC power MOSFETs, on page 24. All of these devices enable power-system designers to achieve dramatic improvements in system efficiency and power density while providing valuable extra headroom for the thermal design: the ST MOSFETs, for instance, are rated for operation at a maximum temperature of 200°C. And a SiC diode, which offers a high reverse-current capability, can enable users to eliminate snubber circuitry, reducing the size and component count of the power-system design.
The other big technological change in power-system design is the growing sophistication of digital control techniques. An excellent example of this is provided by the Technical View on pages 26-27, which describes a fully digital 2kW AC-DC power supply which achieves a power factor of >0.99, and efficiency peaking at almost 92%, while providing for easy tuning of the control system in software. CUI’s NDM3Z-90, on page 21, is another illustration of the benefits of digital power topologies, providing compensation-free regulation of point-of-load power supplies.
For help in taking advantage of the new power components and power supplies featured in this issue of FTM, or to request advice from the power-design experts at Future Power Solutions, contact Future Electronics via email@example.com.
Business Development Manager
Future Power Solutions