Gate Voltage Closed-Loop Regulation Technique for High-Voltage Supercascode Power Switches

A normally-off device based high-voltage supercascode switch topology with the gate voltage adaptive closed-loop regulation is proposed for the high-voltage converter application. The gate voltages of each in series device are adaptively regulated to balance through the closed-loop circuits in the proposed supercascode switch. As a result, the turn-<sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> uniformity and the number of devices in series are improved, and the gate voltage overshoots are suppressed. The closed-loop circuit is simple to implement, consisting only of a low-voltage N-channel depletion <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mosfet</small>, two resistors, and a capacitor. A 16-kV/30-A supercascode power switch (SCPS) is built based on the proposed topology, and the turn-<sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> gate voltages of all devices are consistent and stable at +15 V finally during the turn-<sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> process. Compared with the conventional topological gate voltages, the waveform overshoots are suppressed. Furthermore, the SCPS is tested in a double pulse tester at 10 kV and a switching load experiment at 10 kV, 15.6 Hz, demonstrating outstanding switching characteristics.