US Patent 10516392 IGBT gate current slope measure to estimate miller plateau

A method and apparatus are provided for controlling a drive terminal of a power transistor by applying a turn-off voltage to the drive terminal at a turn-off time, measuring a gate current at the drive terminal to detect a predetermined gate current slope, determining a first time increment after the turn-off time when the predetermined gate current slope is detected, determining a second time increment which is proportional to the first time increment and which expires within a Miller plateau for the power transistor, and lowering the gate current at the drive terminal to a predetermined current level upon expiration of the second time increment in order to reduce overvoltages at the power transistor.