Method and apparatus for implementing an unregulated dormant mode in a power converter

摘要

A control circuit includes a drive signal generator controlling switching of a power switch to regulate a flow of energy to one or more loads coupled to a power converter output. A regulator circuit charges a capacitor to a first voltage and stops charging the capacitor if an energy requirement of the one or more loads falls below a threshold. The regulator again charges the capacitor after the capacitor is discharged from the first voltage to a second voltage. An unregulated dormant mode control circuit renders dormant the drive signal generator and the regulator circuit while the capacitor is discharged from the first voltage to the second voltage causing the regulation of the flow of energy to the power converter output to cease. The drive signal generator and the regulator circuit are powered up after the capacitor is discharged from the first voltage to the second voltage.