Sales of electric and hybrid vehicles have grown rapidly over the past few years, reaching 500,000 in 2016 with predictions to top 65 million in 2040. This is an important step in the path towards more sustainable and carbon-free mobility. Yet, as the number of electric vehicles (EVs) surges, several challenges need to be addressed for this technology to be successful. In particular, more energy-efficient power semiconductor solutions with higher power density are required to increase mileage, cut down costs, and reduce battery charging time.
The demand for power semiconductors in electric vehicles is strong and rapidly growing. On the one hand, the main power and subsystems of electric vehicles depend on electrical power, including the motor drive, onboard charger, etc. On the other hand, many traditional mechanical systems are shifting to electric, such as vacuum or start-up control to the electronic control module, wire control drive systems to high-power electro-mechanical actuators, etc.
Traditional silicon-based power semiconductor devices cannot effectively cope with these challenges, resulting in heavier, more expensive, and less efficient electric vehicles. From this point of view, wide-band semiconductor power devices are a perfect fit for electric vehicles, enabling a new generation of integrated and lightweight solutions.
The two essential requirements of power semiconductors for EVs are high power density and high efficiency. GaN power devices and their supporting driving chip are the key technologies to achieve these goals. The low gate capacitance of Gallium Nitride High-Electron Mobility Transistors (HEMTs) leads to faster commutation under hard switching conditions, thus reducing cross-power loss. The low output capacitance of GaN HEMTs enables high-frequency soft-switching operation. In addition, the absence of a body diode in GaN HEMT, contrary to silicon and silicon carbide MOSFETs, results in no reverse recovery losses, making these devices very promising for structures such as totem pole PFCs operating up to thousands of watts, which would be impossible to achieve with traditional silicon-based power devices.
