An embodiment of a voltage converter, provided with: a voltage transformer having a primary winding receiving an input voltage, a secondary winding supplying an output voltage, and an auxiliary winding supplying a feedback voltage correlated to the output voltage; a main switch, connected to the primary winding; a control circuit, which controls switching of the main switch and has a sampling stage for sampling and holding the feedback voltage and supplying a sampled signal; and a voltage limiting circuit, provided with a clamp capacitor, designed to be connected across the primary winding. A sampling control stage is connected to the sampling stage, and is designed, during a given operating condition of the voltage converter, to enable updating of the sampled signal on the basis of a state of charge of the clamp capacitor.