Power transistor driver stage with optimally reduced turn-off delay

摘要

A fast-discharge switch is controlled by a comparator sensing the voltage difference between the output node and the input node of a driving integrator stage that controls the slew-rate of a power switching output transistor. The fast-discharge switch turns off automatically when the output power transistor reaches (in the case of a MOS transistor) or exits (in the case of a bipolar transistor) saturation. The circuit of the invention accelerates the discharge thus reducing the turn-off delay and is insensitive of load conditions and does not affect the performance of the integrating (driver) stage that control the slew-rate.