Microwave-acoustic-based isolated gate driver for power electronics
This work provides a new approach to isolated gate driving for power electronics, addressing the challenge of simultaneous power and signal transmission with high isolation and wide temperature range.
The paper demonstrates a mechanically-isolated gate driver using microwave-frequency surface acoustic wave devices that achieves 2.75 kV galvanic isolation with ultralow capacitance (0.032 pF), delivering 13.4 V open-circuit voltage and 44.4 mA short-circuit current, and validates its operation in a GaN transistor with 108.8 ns turn-on time and a buck converter.
Electrical isolation is critical to ensure safety and minimize electromagnetic interference (EMI), yet existing methods struggle to simultaneously transmit power and signals through a unified channel. Here we demonstrate a mechanically-isolated gate driver based on microwave-frequency surface acoustic wave (SAW) device on lithium niobate that achieves galvanic isolation of 2.75 kV with ultralow isolation capacitance (0.032 pF) over 1.25 mm mechanical propagation length, delivering 13.4 V open-circuit voltage and 44.4 mA short-circuit current. We demonstrate isolated gate driving for a gallium nitride (GaN) high-electron-mobility transistor, achieving a turn-on time of 108.8 ns comparable to commercial drivers and validate its operation in a buck converter. In addition, our SAW device operates over an ultrawide temperature range from 0.5 K (-272.6 °C) to 544 K (271 °C). The microwave-frequency SAW devices offer inherent EMI immunity and potential for heterogeneous integration on multiple semiconductor platforms, enabling compact, high-performance isolated power and signal transmission in advanced power electronics.