INTRODUCING JITTER TO A SWITCHING FREQUENCY BY WAY OF MODULATING CURRENT LIMIT

摘要

A controller for use in a power converter includes a switch controller coupled to a power switch coupled to an energy transfer element. The switch controller is coupled to receive a current sense signal representative of a drain current through the power switch. The switch controller is coupled to generate a drive signal to control switching of the power switch in response to the current sense signal and a modulated current limit signal to control a transfer of energy from an input to an output of the power converter. A current limit generator is coupled to generate a current limit signal. A jitter generator is coupled to generate a jitter signal. An arithmetic operator circuit is coupled to generate the modulated current limit signal in response to the current limit signal and the jitter signal.