Design, characteristics and application of pluggable low-inductance switching power cell of paralleled GaN HEMTs

摘要

This paper proposes and designs a switching cell using paralleled gallium nitride (GaN) high-electron-mobility transistor (HEMTs) in the minimized, symmetric power and gate loops. Based on the design, 1Ω gate resistor was successfully applied to speed up the switching transient. The switching cell can be easy to replace on the mother board thanks to the pluggable connector and the cell owns unique heat sinks controlling its airflow, which enables effective heat dissipating. The switching cell design is also generalized for four GaN devices in parallel. The double pulse test was performed to evaluate the switching loss of the two/four paralleled 650V/60A GaN devices, and the commutation between the paralleled devices was analyzed based on the experimental waveforms. The experimental results on the LLC resonant converter using the designed switching cell, switching with up to 500 kHz switching frequency, are presented with 98% peak efficiency and 130W/in³ power density.