Primary side switched converter for providing a voltage supply to an led load

An isolated primary side switched converter (300) for providing a voltage supply to an LED load (401), comprising:

• a galvanic isolation stage (301),
• an auxiliary winding (L51c) on the primary side of the galvanic isolation stage which is magnetically coupled to at least one secondary side winding (L51a, L51b),
• wherein the auxiliary winding (L51c) is configured to receive a feedback signal corresponding to a secondary side voltage,
• a control unit (303) configured to determine an LED supply voltage based on the feedback signal,
• a processing unit (305) configured to calculate a threshold value based on a constant reference voltage and an adjustment factor,
• wherein the adjustment factor is a dynamic factor whose absolute value increases with increasing LED current, and
• wherein the converter (300) is configured to interrupt the voltage supply to the LED load if the determined LED supply voltage exceeds the threshold value.