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

摘要

A control circuit for use in a power converter with an unregulated dormant mode of operation includes a drive signal generator coupled to generate a drive signal to control switching of a power switch to be coupled to the control circuit to regulate a flow of energy to a power converter output in response to an energy requirement of one or more loads to be coupled to the power converter output. An unregulated dormant mode control circuit is included and is coupled to render dormant the drive signal generator thereby ceasing the regulation of the flow of energy to the power converter output by the drive signal generator when the energy requirement of the one or more loads falls below a threshold for more than a first period of time. The drive signal generator is coupled to be unresponsive to changes in the energy requirements of the one or more loads when dormant. The unregulated dormant mode control circuit is coupled to power up the drive signal generator after a second period of time has elapsed. The drive signal generator is coupled to again be responsive to changes in the energy requirement of the one or more loads after the period of time has elapsed.