In the first APEC highlight roundup, we pointed out that the high turnout for the show underscored the renewed awareness of the importance of power electronics as a value-adding enabler. Not only is power required to drive any given electronic system, an energy-efficient system is more useful and more reliable (from the reduced thermal stress alone) than those less efficient.
Another aspect of the show was the variety of advanced power electronics, advanced in both materials and topology, sometimes both manifested in the same solution. Wide-bandgap semiconductors got a lot of attention, with lots of products based on both GaN and SiC at the show. There were also some excellent Silicon-based products at APEC, and we covered some of them in a separate piece called “The Silicon Strikes Back.” Here are some of the wide-bandgap solutions we saw at the show.
One of the areas where wide-bandgap is expected to make a significant impact is in the automotive space. However, you need automotive-qualified devices to do so. One company putting parts into the system is ON Semiconductor, who introduced some automotive-qualified SiC MOSFETs to create efficient, small form factor, rugged, and cost-effective high-frequency designs. The new devices not only address automotive, but also renewable energy and data center power systems.
The AEC-Q101 automotive grade NVHL080N120SC1 aligns with the needs of the latest high-frequency designs, combining a high-power density with efficient operation, significantly reducing operating costs and overall system size, as well as improved thermal management. Key features and associated design benefits of the new devices include class-leading low leakage current, a fast-intrinsic diode with low reverse recovery charge, and a low forward voltage, with a low device capacitance.
The NVHL080N120SC1 has been designed to withstand high surge currents and offers high avalanche capability and robustness against short circuits. A maximum operating temperature of 175°C enhances suitability for use in automotive designs, as well as other target applications where high density and space constraints are pushing up typical ambient temperatures.
Solantro and GaN Systems
Some of the solutions at the show combined both advanced power supply topologies with next-generation Gallium Nitride (GaN) transistors to create sophisticated energy systems. One of the more interesting demonstrations at APEC involved a digitally-controlled 1.5 kW bridgeless totem-pole PFC, coupled with 650V GaN enhancement-mode HEMTs (E-HEMT), for a solution with a high-power density, reliable start-up, reduced heat sinking, improved cooling, and low EMI. The topology is bi-directional and can be easily scaled and incorporated as a front-end of AC/DC converters for EV on-board chargers and industrial power supply applications.
The setup consisted of a Solantro SA4041 32-bit, 50 MHz digital power processor, leveraging the performance benefits of GaN Systems’ 650V E-HEMT family. The SA4041 integrates high-speed analog peripherals, digital accelerators, event driven timers, and digital processing. GaN Systems’ GS66508B 650 V E-HEMTs use the company’s Island Technology cell layout for reduction of device size and cost, with substantially higher current. The bottom-side cooled transistor has exceptionally low total gate charge and output capacitance, resulting in low switching losses and therefore high efficiency.
Alex Lidow has been a strong and vocal advocate for Gallium Nitride since his days as International Rectifier’s CEO. Now running Efficient Power Conversion, he had an array of solutions at APEC, leveraging the performance of his novel packageless approach to wide-bandgap semiconductors. The company unveiled the EPC2052, a 100V, 13.5 mΩ, eGaN power transistor capable of 74A pulsed operation. Provided in a 1.50mm x 1.50mm chipscale package, the device achieves greater than 97 percent efficiency at 500kHz, and greater than 96 percent at 1MHz.
For example, operating in a 48V to 12V buck converter, the EPC2052 achieves greater than 97 percent efficiency at a 10A output at 500 kHz, and greater than 96 percent at 1MHz. The company also showed the EPC9092 development board, a 100V maximum device voltage half-bridge using the EPC2052 along with the LMG1205 gate driver from Texas Instruments. The 50.8 mm x 50.8 mm board is designed for optimal switching performance and contains all critical components for easy evaluation of the 100 V EPC2052 eGaN FET.
Wide-bandgap semiconductors are still in their infancy, with a great deal of development and new device creation ahead. However, there are a great many solutions already available, both SiC and GaN based, that can significantly improve the performance of your next design. These, along with the other solutions presented at or after the show, are a potent vanguard of a new wave of power electronics design.