Patent ID: RE43516

Claim:
A device for correcting a power factor in a forced switching power supply , comprising: an output terminal; a converter that provides configured to provide a regulated voltage on the output terminal, the converter including a power transistor having a control terminal; a control device coupled with the converter to obtain the regulated voltage , the control device including an error amplifier having a first input and a second input that receives configured to receive a first reference signal; a first resistance coupled between the output terminal and the first input of the error amplifier; a second resistance coupled between a reference voltage terminal and the first input of the error amplifier; an error detector having a first input coupled to the first input of the error amplifier and an output coupled to the control terminal of the power transistor, the error detector being structured to turn off the power transistor in response to detecting that a voltage at the first input of the error amplifier is below a first threshold voltage; and a conduction element coupled between the first resistance and the first input of the error amplifier, wherein the error detector includes a second input coupled to an intermediate node between the first resistance and the conduction element, the error detector being structured to turn off the power transistor in response to detecting that a voltage at the intermediate node is less than the voltage at the first input of the error amplifier.