A novel, optically isolated gate driver integrating simultaneous power-and-signal transfer is proposed for series-connected SiC MOSFETs used in medium-voltage (MV) converters. A single laser source continuously delivers optical power while superimposing gate-control signal modulation, thereby addressing electromagnetic-interference (EMI) and common-mode-transient-immunity (CMTI) limitations found in conventional transformer or capacitive isolated gate drivers. On the receiver side, a photovoltaic (PV) cell with a local boost converter provides a regulated bias supply, while dedicated high-bandwidth demodulation circuits reconstruct gate-command information. To mitigate transient voltage imbalance among stacked devices, an active current-source gate driver with per-device drain–source-voltage monitoring and optical feedback is introduced. The feedback loop dynamically injects or withdraws gate charge during switching transitions and adjusts static gate bias in the off-state, achieving uniform voltage distribution and lower switching loss. Simulation results indicates significant reduction of transient imbalance.
.jpg "Junghoon Kim, MA (he/him/his) photo")