A DC-DC converter includes a transformer having primary and secondary windings, a power oscillator applying an oscillating signal to the primary winding to transmit a power signal to the secondary winding, a rectifier obtaining an output DC voltage by rectifying the power signal at the secondary winding, and comparison circuitry generating an error signal representing a difference between the output DC voltage and a reference voltage value. A transmitter connected to the secondary winding performs an amplitude modulation of the power signal at the secondary winding to transmit an amplitude modulated power signal to the primary winding, the amplitude modulation based upon the error signal and modulating a stream of data to the primary winding. A receiver coupled to the primary winding demodulates the amplitude modulated power signal to recover the error signal and the stream of data. An amplitude of the oscillating signal is controlled by the error signal.