Analysis of the Performance of MOSFET, IGBT and GaN FET Power Switches Used as Switching Elements on Buck Type DC-DC Converter

In switched DC-DC converters, the main component that affects the performance of the circuit is the semiconductor power transistors used as switching elements. Widely used Silicon (Si) - based semiconductor power transistors have certain limits in terms of being able to withstand high voltage and provide higher efficiency in high-speed switching applications. In this study, the effects of MOSFET, IGBT and GaN (Gallium Nitride) based semiconductor power transistors on Buck type DC-DC converters were examined and the prominent features of the GaN-FET switching element were evaluated. Firstly, simulations were carried out via MATLAB/Simulink using the data sheet information of the three transistor types used. Then, simulations were carried out with the LTspice circuit analysis program using SPICE models of the transistors. In this study, a 36V-12V Buck type DC-DC converter was designed using a GaN-FET-based switch, and the power loss of the system under 50 kHz switching frequency was obtained to be 23.2 mW and its efficiency was found to be 96.771%. Additionally, simulations were made at different switching frequency values. As a result of these simulations, it was determined that the switching loss was proportionally much less in the circuits simulated with the GaN-FET semiconductor power switch.