Patent ID: 8243478
Filing Date: 2012-08-14
Classification: H02M

Abstract:
1. A power converter, comprising: an energy transfer element having an input winding coupled to an input of the power converter and an output winding coupled to an output of the power converter; a switch coupled to the input winding to control a transfer of energy from the input to the output of the power converter; a controller coupled to switch the switch between an ON state and an OFF state to regulate the output of the power converter, wherein the controller is adapted to terminate the ON state of the switch in response to a switch current flowing through the switch reaching a switch current threshold; and a current offset circuit coupled to the input to be directly powered from an input voltage of the power supply, wherein the current offset circuit generates an offset current to flow through the switch only during the ON state of the switch in response to a magnitude of the input voltage, wherein an input current of the power converter is adjusted in response to the offset current.