Description

Paralleling insulated-gate bipolar transistors (IGBTs) becomes necessary for power conversion equipment with higher output power ratings: where a single IGBT cannot provide the required load current. This reference design implements a reinforced isolated IGBT gate control module to drive parallel IGBTs in half-bridge configuration. Paralleling IGBTs introduces challenges at both gate driver (insufficient drive strength) as well as at system level in maintaining equal current distribution in both the IGBT’s while ensuring faster turn on and off. This reference design uses reinforced isolated IGBT gate driver with integrated features like desaturation detection and soft turn off to protect the IGBT during fault conditions. Increased gate drive current (15 A) is obtained through external BJT current booster stage without sacrificing the soft turn off feature. Furthermore: this design demonstrates the mechanism of avoiding gate current loops while operating IGBTs in parallel.