Adaptive gate charge circuit for power FETS.

摘要

An adaptive gate charge circuit for switching a power FET on in response to a control signal. The adaptive gate charge circuit includes driving circuitry that responds to assertion of a control signal by providing a charging current from a charge pump reservoir capacitor to the gate of the power FET for an initial time period sufficient to switch the power FET on. After the initial time period, holding circuitry provides holding current from the charge pump to the power FET gate to compensate for charge leakage. Current limiting circuitry connected to the holding circuitry limits current drain from the charge pump after the initial time period to the holding current required to compensate for charge leakage plus a minimum additional current.