Isolated voltage converter with feedback on the primary winding, and corresponding method for controlling the output voltage

摘要

An embodiment of a voltage converter, designed to convert an input voltage into a regulated output voltage, having: a voltage transformer having a primary winding receiving the input voltage, a secondary winding supplying the output voltage (Vout), and an auxiliary winding supplying a feedback signal correlated to the output voltage; a control switch, connected to the primary winding; and a control circuit, connected to a control terminal of the control switch for controlling switching thereof as a function of the feedback signal. The control circuit is provided with a sampling stage that samples the feedback signal and supplies a sampled signal. An averager stage is connected to the output of the sampling stage and implements a low-pass filtering of the sampled signal so as to reduce undesirable oscillations due to sampling.