Patent ID: 7859869
Filing Date: 2010-12-28
Classification: H02M

Abstract:
1. A control circuit for use in a power converter, comprising: a first controlled current source having a first current that is substantially directly proportional to an input voltage to be applied to a winding of a transformer; a second controlled current source having a second current that is substantially directly proportional to a reset voltage to be applied to the winding of the transformer; a first switch that is adapted to charge an integrating capacitor with the first current while the input voltage is applied to the winding of the transformer; a second switch that is adapted to discharge the integrating capacitor with the second current when the reset voltage is applied to the winding of the transformer, and a third switch that is adapted to remove the input voltage from the winding of the transformer when the voltage on the integrating capacitor is not less than a first threshold voltage, and to prevent application of the input voltage to the winding of the transformer when the integrating capacitor discharges to a second threshold voltage.