Current Source Gate Driver Integrated with Short Circuit Protection and Soft Turn-off Scheme

The state-of-the-art power electronic switches such as silicon carbide (SiC) MOSFET are capable of switching faster than its predecessor silicon (Si) IGBT. In order to turn on and off these devices an external circuits termed as gate drivers are required. The conventional voltage source gate driver (VSD) charges the gate source capacitance using the RC charging principle. However, with the increase in switching frequency the conventional VSD limits the operation due to the increases losses occurred in it due to the presence of gate resistor. On the other hand, the current source gate driver (CSD) provides a constant current during the switching transition which accelerates the switching process results in high frequency switching capability of the device. The inductor based CSD are the most suitable among all due to ability to provide a constant current of a defined magnitude by charging the inductor for the appropriate duration. However, such inductor-based CSDs are still under investigation and are not commercially available yet. One of the avenues of research in this domain is the integration of a short circuit protection system for the driven device as can be found in the commercial voltage source gate drivers. This paper presents the integration of short circuit protection and soft turn-off scheme with a current source gate driver to provide holistic protection to SiC MOSFETs. Analysis and simulation results are provided for validation of the system. A prototype is also constructed for experimental validation.