Power switching transistors differ primarily in how they are controlled, their switching speed, maximum switching voltage, and their power-handling limits. The main types include MOSFETs (up to 100kHz, 600V, 1kW), SiCs (up to 500kHz, 3.3kV, 100kW), GaNs (up to 1MHz, 900V, 10kW), and IGBTs (up to 50kHz, 6.5kV, 1MW).
MOSFETs are most often used in switching power supplies due to their low cost and ease of integration. SiCs and GaNs are utilized for high-frequency switching applications, while IGBTs are preferred for very high power or high-voltage switching.