Control device for a PFC converter and corresponding control method

A switched-mode power supply, comprising:

• a power converter including switching circuitry including an inductive element, a switching element, and a phase node formed at an interconnection of the inductive and switching elements, the switching circuitry coupled to receive an input voltage and configured to generate an output voltage based upon a driving signal;
• a control device coupled to the switching circuitry and configured to generate the driving signal to control the switching element to generate the output voltage, the driving signal being based on a value of the output voltage and the control device configured to estimate a value of the output voltage based on a value of the input voltage and a duty cycle of the switching element, the duty cycle being based on a zero-current condition of the inductive element and on a corrective factor that is based on a resonance condition of a voltage on the phase node;
• and
• an output power converter coupled to the power converter to receive the output voltage.

A method of controlling a power converter, the method comprising:

• determining a value of an input voltage supplied to switching circuitry of the power converter, the switching circuitry including a switching element, an inductive element, and a phase node defined at an interconnection of the switching and inductive elements;
• determining a duty cycle of the switching element based on a zero-current condition of the inductive element and on a corrective factor that is based on a resonance condition of a voltage on the phase node;
• estimating a value of the output voltage based on a value of the input voltage and the duty cycle;
• and
• generating a driving signal to control the duty cycle of the switching element, the driving signal being based on the estimated value of the output voltage.