Power Integrations, Inc.
MULTIPLE STAGE GATE DRIVE FOR CASCODE CURRENT SENSING

Abstract:

A power converter comprising an energy transfer element is coupled between an input of the power converter and an output of the power converter. A cascode circuit generates a first sense signal and a second sense signal. A controller controls the switching of the cascode circuit to transfer energy from the input of the power converter to the output of the power converter. The controller comprising a current sense circuit generates a current limit signal and an overcurrent signal in response to the first sense signal and the second sense signal. A control circuit generates a control signal in response to the current limit signal and the overcurrent signal. A drive circuit comprising a first stage gate drive circuit generates a drive signal in response to the control signal to reduce EMI, and a second stage of gate drive circuit to enable accurate current sensing of the cascode circuit.