Patent ID: 7379310

Claim:
Switched mode power supply comprising: an inductor coupled to an input voltage, a switching transistor coupled with a current input to said inductor and coupled with a current output via a sense resistor to a reference potential, rectifying means coupled to said inductor for providing a rectified output voltage, an integrated controller circuit comprising, a driver circuit being coupled to a control input of said switching transistor a comparator with a feedback input for a regulation of said output voltage, a voltage regulator for providing a reference voltage for said comparator, a first over-voltage protection circuit coupled with an input intemally to said comparator for switching off said driver circuit in case of a low load condition, and a sense input coupled to said sense resistor, a feedback loop coupling said rectified output voltage to said feedback input, and a second over-voltage protection circuit comprising a second comparing circuit, which comprises a first input, to which an output of a first comparing circuit and a short circuit information provided by said inductor is coupled, the output of said second comparing circuit being coupled to said sense input for switching off the controller circuit in case of an interruption of said feedback loop.