The present document relates to a start-up circuit comprising a power switch wherein a circuit charges a supply voltage capacitor. The capacitor provides a supply voltage to a power switch; the power switch forms a switched power converter with a power converter network. The circuit comprises a source and gate interface for coupling the circuit to the power switch; a capacitor interface couples the circuit to the supply voltage capacitor; a start-up path couples the gate interface to the capacitor interface; wherein the startup path provides a voltage at the gate interface which is at or above a threshold voltage of the power switch; and a charging path couples the source interface to the capacitor interface; wherein the charging path provides a charging current to the capacitor interface, when the power switch is in on-state.