SiC MOSFET Enables High-Voltage Auxiliary Power Supply with Wide Input-Voltage Range

Abstract:
This work introduces a single SiC switch Flyback power supply with a wide input-voltage range. For industry applications with high input voltage, e.g., 1200 VDC or above, two-switch Flyback converter can be used; however, this will lead to more complex control, compromised reliability, and higher cost because of added parts and gate control of high-side power switch. On the contrary, a single switch with high voltage rating for Flyback can provide a simpler and more reliable design. In this paper, practical designs (e.g. the startup circuit and the construction of the Flyback transformer for high voltage input applications) have been addressed, and test results of a 15W Flyback power supply with 12 V DC output by using a 1700V SiC MOSFET is presented.