METHOD AND APPARATUS FOR IMPLEMENTING AN UNREGULATED DORMANT MODE IN A POWER CONVERTER

摘要

A control circuit for use in a power converter with an unregulated dormant mode of operation is disclosed. In one aspect a power converter includes a drive signal generator that is coupled to generate a drive signal to control switching of a power switch coupled to the control circuit to regulate a flow of energy to an output of the power converter in response to an energy requirement of one or more loads coupled to the output of the power converter. A regulator circuit is coupled to charge a capacitor. The capacitor determines a time period. The regulator circuit is coupled to not charge the capacitor if the energy requirement of the one or more loads coupled to the output of the power converter falls below a threshold. The regulator is coupled to again charge the capacitor after the time period has elapsed. An unregulated dormant mode control circuit is coupled to render dormant the drive signal generator and the regulator circuit during the time period thereby causing regulation of the flow of energy to the output of power converter output to cease. The unregulated dormant mode control circuit is further coupled to power up the drive signal generator and the regulator after the time period has elapsed.