The hybrid switch(HyS), which is a parallel combination of the silicon(Si) insulated gate bipolar transistors(IGBTs) and the silicon carbide(SiC) metal-oxide semiconductor field-effect transistors(MOSFETs), can realize high switching frequency at a reasonable cost. In this paper, a compact HyS half-bridge power module, rated at 1200 V/200 A, was fabricated in house and fully tested for the first time. An electrothermal model of the HyS was set up in LTspice to determine the optimal gate sequence for the HyS. To minimize the HyS power loss, the turn-on gate signals are applied to the Si IGBTs and the SiC MOSFETs simultaneously while a prior turn-off period exists between the turn-off gate signals of the Si IGBTs and the SiC MOSFETs. By considering the power loss of the HyS and the junction temperature of the SiC MOSFETs, a novel index is proposed to select the optimal prior turn-off period. Based on the HyS power modules, a 5 kW air-cooling voltage source inverter and a 30 kW water-cooling voltage source inverter were developed and tested to verify the analysis.