2023 journal article
Methodologies of Cascading to Realize High-Voltage Cascaded Super Cascode Power Switch
Methodologies of Cascading to Realize High Voltage Cascaded Super Cascode Power Switch. IEEE Journal of Emerging and Selected Topics in Power Electronics, 11(6), 5853–5862.
Development of high-voltage (HV) high-current (HC) power semiconductor devices is limited due to relatively low yield, expensive material and fabrication costs, and retracted dynamic performance from paralleling many HV, low-current (LC) devices. An alternative is a serial connection of low-voltage (LV) HC devices to create a supercascode power switch (SCPS). This article describes a methodology of cascading SCPSs to realize an even higher voltage cascaded supercascode power switch (CSCPS), which optimizes switching through multilayered cascades of normally-on devices, e.g., JFETs or depletion-mode GaN HEMTs. The method provides a topology optimization of cascaded cells dependent on switching losses, net charge reduction in network capacitors, and avalanche energy management. Simulation and test results are provided for a single-layer "2S-3C" 6-kV CSCPS. The 6-kV JFET CSCPS showed 408- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{m}\Omega $ </tex-math></inline-formula> ON-resistance, leakage current of 0.7 mA at 4.8 kV, and 40-ns rise with 30-ns fall in current at 4 kV/20 A.