Silicon Carbide Technology Makes its Power Play
October 16, 2023
Wide-bandgap silicon carbide (SiC) semiconductors are steadily replacing their silicon predecessors in high-power applications like EVs and power electronics where silicon can no longer keep up. Without SiC technology it will be very difficult to electrify transportation, build out the charging infrastructure, or empower a more sustainable future.
SiC advantages range from higher operating temperatures and breakdown voltage than silicon to faster switching speeds, lower RDS(on), and improved thermal performance and ruggedness. These benefits combine to improve the system efficiency and power density of today’s industrial, transportation, medical, aerospace, aviation, defense and communication systems while shrinking their form factors and enabling them to withstand higher operating temperatures with reduced cooling requirements.
Microchip delivers these benefits with its 700V to 3.3 kV mSiC™ products of bare die, discrete MOSFETs and SiC Schottky Barrier Diodes (SBDs), power modules and digital gate drivers. These gate drivers use patented Augmented Switching™ technology to reduce switching losses, reduce ringing and improve system power density, providing a superior alternative to standard analog MOSFET gate drivers. Microchip’s mSiC solutions enable developers to adopt SiC technology with Ease, Speed and Confidence.
mSiC Product Benefits
mSiC MOSFETs and diodes increase system efficiency compared to silicon MOSFET and IGBT-based solutions, while lowering total cost of ownership. They also enable designers to use fewer components in parallel so they can create smaller, lighter, and more efficient higher-power systems. mSiC bare die MOSFETS and diodes are also available and deliver significantly higher power density and efficiency along with customized packaging to optimize system-level performance and efficiency.
mSiC MOSFET ruggedness advantages are proven through extensive testing. Gate oxide stability shows only a negligible shift in threshold voltage (Vth) before and after 1000 hours of High-Temperature Gate Bias (HTGB). Predicted oxide lifetime is more than 100 years and body diode stability does not degrade in pre/post-stress I-V curves and RDS(on) measurements. The use of inherent body diodes rather than freewheeling MOSFETs contributes to the MOSFETs’ high of avalanche ruggedness, parametric stability, ability to survive short circuits, and stability over temperature.
Looking to the Future
As SiC technology moves up the innovation curve, one of its biggest successes has been in the EV industry. Equally exciting developments are underway at higher SiC voltages.
Moving to 3.3 kV device ratings and above is expanding SiC benefits to help solve such critical powering challenges as modernizing the U.S. electric grid. In 2021 this grid infrastructure accommodated 4000 TWh of electric consumption. An estimated 5% (645 Gwh) of all generated electricity evaporates through transmission and distribution (T&D) losses – enough to power 1.5 million U.S. homes for an entire year. By 2050, this aging and inflexible, unidirectional grid must serve an additional 2000 TWh of EV charging demand annually.
SiC technology will play a big role. The International Energy Agency (IEA) does not believe we must immediately overhaul today’s inflexible, unidirectional grid. Instead, we can accelerate the transition to an omnidirectional power flow (power anywhere to anyone at any time) and more efficient integration of renewable energy sources by deploying power electronics at the substation or “grid node” level. This will eliminate the need for harvested energy that has been converted into electrical form to be transmitted over very long distances before being stepped down in voltage and distributed prior to final conditioning and use.
SiC semiconductors have already improved the efficiency of Energy Storage Systems (ESS) and are poised to do the same for the entire grid transmission and distribution (T&D) system. They will ease the integration of Distributed Energy Resources (DERs) and microgrids that would otherwise be vulnerable to the effects of fault conditions caused by reverse or reduced power flows as well as phase imbalances when energy from distributed generation exceeds local consumption. In addition to solving this problem, SiC devices will enable products like compact, air-cooled solid-state transformers that better incorporate distributed energy resources and substations.
As the world electrifies everything from cars and heavy transport to the energy grid, SiC technology has leapfrogged silicon to solve difficult challenges. Offerings like Microchip’s mSiC products can accelerate SiC based designs with broad device options and comprehensive development support. Moving forward, these solutions will be a catalyst for modernizing the grid and making it more reliable, secure, and resilient.