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

For high power and high voltage (HV) applications, low power subsystems must have an auxiliary power supply that can take wide-range high voltage input and can generate low DC voltage at the output. In order to improve the efficiency, silicon carbide (SiC) MOSFET with smaller on resistance are considered to replace silicon (Si) MOSFET, and the static and dynamic characteristics of two devices are compared and analyzed. Besides, the Quasi-Resonant (QR) topology is selected to reduce losses and Electromagnetic Interference (EMI) level. In this paper, a SiC-based QR flyback auxiliary power supply for high voltage applications is proposed, and the design scheme for auxiliary power supply is validated.