A Novel 4.5 kV Nonlatching IGCT for Turn-On di/dt Controllability without a Clamp Circuit

A new 4.5 kV nonlatching IGCT is proposed based on the integrated gate-commutated thyristor (IGCT) platform. This innovative design enables turn-on di/dt control without requiring an external clamping circuit. As the term ‘nonlatching’ implies, this IGCT achieves proportional anode current (IA) behaviour relative to the input gate current (IG), resulting in improved controllability and a soft turn-on process. While the new IGCT focuses exclusively on optimizing the turn-on process, it can be integrated with conventional IGCTs as a single device or used as an RC-IGCT parallel to the conventional IGCTs. This approach retains the established benefits of IGCTs while adding enhanced turn-on control capabilities. The proposed nonlatching IGCT has been evaluated through TCAD simulations and physical measurements on fabricated prototype wafers. Additionally, key dependency factors influencing turn-on performance are discussed.