Gate Driver Auxiliary Supply for SiC-based applications

Silicon Carbide (SiC) power semiconductor devices can help to achieve higher efficiency, smaller size and cost savings in modern power systems. One of the key factors enabling this is their much faster swiching speed compared to their silicon-based counterparts like IGBTs. However, a very fast switching speed presents important challenges to their gate driver system, particularly regarding spurious turn-on and off of the devices due to Miller effect as well as common-mode displacement currents across the isolation barrier. Using a negative gate drive voltage for turn-off and reducing the parasitic capacitance across the isolation barrier can help to overcome such issues. In this presentation, this behavior will be briefly explained and optimized reference designs for the isolated gate driver auxiliary supply, with the new WE-AGDT transformers from Würth Elektronik presented, including important considerations for integration in the gate driver system.
Eleazar Falco’s presentation on the Passives & Magnetics-Day at Bodo’s 2022 WBG Event.
He is Application Engineer at Würth Elektronik.