Compact and Reliable Isolated DC/DC and SiC Gate Driver for Automotive Application

Abstract:
SiC enables light weight, compact and efficient on-board chargers (OBC) and traction inverters for plug-in hybrid electric vehicles (PHEV) or battery powered electric vehicles (EV), however, it brings also challenges for gate driver and its power supply. Faster SiC switching leads to high common mode transients, and large common mode currents may lead to system EMI challenges. System architectures for EV OBC, auxiliary power DC/DC converter and power train inverters using integrated isolated DC/DC converters and SiC gate drivers will be introduced. On-chip transformer based isolation provides common mode transient immunity over 200kV/µS and small isolation barrier capacitance with only a few pF induces small common mode current and system noises. Without discrete transformers for gate driver and its power supply that may suffer from mechanical vibration resonance, these integrated DC/DC converters and gate drivers are extremely reliable against continuous or shock vibration present in PHEV/EV. These SiC gate drivers have also excellent timing and fast short circuit protection.