Microwave-acoustic-based isolated gate driver for power electronics

Area of Science:

• Materials Science
• Electrical Engineering
• Physics

Background:

• Electrical isolation is crucial for safety and minimizing electromagnetic interference (EMI).
• Existing methods face challenges in simultaneously transmitting power and signals through a unified channel.
• Advanced power electronics demand compact, high-performance solutions for isolated power and signal transmission.

Purpose of the Study:

• To demonstrate a mechanically-isolated gate driver utilizing microwave-frequency surface acoustic wave (SAW) devices.
• To achieve high galvanic isolation and ultralow isolation capacitance for power and signal transmission.
• To validate the performance and operational range of the SAW-based gate driver in power electronic applications.

Main Methods:

• Fabrication of a mechanically-isolated gate driver based on microwave-frequency SAW devices on lithium niobate.
• Characterization of galvanic isolation (2.75 kV), isolation capacitance (0.032 pF), and output voltage/current.
• Demonstration of isolated gate driving for gallium nitride (GaN) high-electron-mobility transistors and operation in a buck converter.
• Testing the device's operational temperature range from 0.5 K to 544 K.

Main Results:

• Achieved 2.75 kV galvanic isolation with 0.032 pF isolation capacitance.
• Delivered 13.4 V open-circuit voltage and 44.4 mA short-circuit current.
• Demonstrated isolated gate driving for GaN transistors with a 108.8 ns turn-on time and validated operation in a buck converter.
• Confirmed functionality over an ultrawide temperature range (0.5 K to 544 K).

Conclusions:

• The developed SAW-based gate driver offers a viable solution for high-performance isolated power and signal transmission.
• The technology provides inherent EMI immunity and potential for heterogeneous integration.
• This advancement enables compact and efficient isolated power solutions for next-generation power electronics.