Title: Smart Gate Driver ICs for GaN Power Transistors
Speaker: Prof. Wai Tung Ng (吳偉東)
University of Toronto, Electrical and Computer Engineering
Toronto ON Canada
GaN power HEMTs are known to offer high switching speed, low on-resistance and much better FOM when compared to their silicon counterparts. However, the ability to operate with high power density in a smaller form factor presents new challenges for reliable and robust operation. Traditional gate driver designs for silicon-based power devices are catered to lower frequencies with large tolerance on the gate voltage swing. They do not adequately address some of the reliability issues that are unique to GaN power transistors. This talk will provide a quick review on the gate driving requirements and limitations for GaN power HEMTs. This is followed by a survey of novel smart gate driving techniques that can further exploit the performance and enhance the reliability of GaN power devices. Topics to be covered include intelligent gate driving schemes such as active gate driving, dead time optimization, and current balancing. Emphasis will be given to designs that can be integrated and those that can monitor the devices for optimum performance and safe operation. Protection features such as short-circuit detection, gate overvoltage prevention, temperature monitoring and compensation will also be discussed. Monolithic integration of power GaN ICs is an exciting area of development with increasingly sophisticated designs reported in recent years. Fully integrated GaN building blocks and state of the art designs will be addressed.
Prof. Wai Tung Ng (吳偉東) is a professor with the Edward S. Rogers Sr. Dept. of Electrical and Computer Engineering from the University of Toronto. He is also the director for the Toronto Nanofabrication Center (TNFC), and open access research facility. Prof. Ng is a recognized researcher in the areas of power semiconductor devices and smart power integrated circuits. His research group has demonstrated many world-first innovative designs, including a digitally reconfigurable DC-DC power converter with resizable output stage [ISPSD 2006], a superjunction power FinFET [IEDM 2010], and a series of smart gate driver integrated circuits for Insulated Gate Bipolar Transistors (IGBTs) and Gallium Nitride (GaN) power transistors. Currently, Prof. Ng’s group is actively engaged in the promotion of digitally reconfigurable gate driver circuits to improve the switching characteristics of GaN and Silicon Carbide (SiC) power transistors. These include many novel features such as one-step dead-time correction, indirect current sensing, dynamic driving strength to suppress Electromagnetic Interference (EMI), liquid-cooled packaging for intelligent power modules (IPMs), etc. Prof. Ng is also the General Chair for the International Symposium on Power Semiconductor Devices and ICs to be held in Vancouver, Canada in May 22-26, 2022.
Prof. Ng earned his bachelor, master and doctoral degrees in Electrical Engineering from the University of Toronto, in 1983, 1985 and 1990, respectively.