An experimental 25 A peak current gate drive ASIC (IGD) for large IGBTs (insulated gate bipolar transistors) has been developed. The gate charge current is delivered by a powerful all-npn totem pole output stage designed for maximum power efficiency. The IGD features various programmable control functions like dV/dt and dI/dt limitation during the switching transients or collector-emitter voltage monitoring for over-current protection. The control parameters are transmitted to the ASIC by a flexible digital interface. The circuit has been fabricated in a 2um highvoltage BiCMOS process.
The maximum deliverable peak output current of the output stage at room temperature has been measured to be 27 Amperes. This extensive peak current allows to apply a charge of 5 uCoulombs in less than 200 ns to the gate capacitance, which is needed for fast and efficient switching of the IGBTs.