Category: Power Product of the Year
In May 2020 Nexperia launched a range of SiGe Rectifiers with 120 V, 150 V, and 200 V reverse voltages that combine the high efficiency of their Schottky counterparts with the thermal stability of fast recovery diodes. The devices are AEC Q101-approved and bring significant benefits to high-temperature applications like LED lighting, engine control units and fuel injection systems. Other key applications include communications infrastructure such as 5G base stations and server power.
For the majority of circuit designs the demand is to integrate more functionality in the available area and design for the highest efficiency. For high-temperature applications, this is particularly challenging.
Previously when designing rectifier circuits in the 100-200 V range, engineers had to compromise between efficiency and operating temperature. While Schottky rectifiers offer very high efficiency, they experience thermal runaway at 145degC and beyond, so they offer limited suitability for power circuits in Engine Control Units (ECU) or fuel-injection systems for example, which routinely see temperatures above 150 Â°C. The alternative is to use Fast Recovery rectifiers. These are extremely thermally stable, but they do have a very high forward voltage and therefore low efficiency. Today’s high-performance electronic systems need extremely efficient devices that offer thermal stability and save space. SiGe technology has a smaller band-gap, a faster switching frequency and higher intrinsic charge carrier density than silicon. That brings an advantage in high-frequency switching behaviour which is why it has been employed in radio-frequency transistors within ICs for some time. But until now, SiGe diodes have only been the subject of university papers.
Nexperia’s development of SiGe rectifier technology addresses the demands for high efficiency combined with high temperature operation as its SiGe devices remain stable at up to and beyond 175degC.
In addition, the PMEG SiGe devices (PMEGxGxELR/P) are housed in size- and thermally-efficient CFP3 and CFP5 packages that have become the industry standard for power diodes. By featuring a solid copper clip the packages’ thermal resistance is reduced and transfer of heat into the ambient environment is optimized, allowing small and compact PCB designs. Moreover, simple pin-to-pin replacements of Schottky and fast recovery diodes are possible when switching to SiGe technology.
Nexperia’s SiGe rectifiers provide the solution for today’s high-temperature applications by combining high efficiency with ease of thermal design and fast, smooth switching in rugged small form factor packages.