Transfer of digital data through an isolation

A method of communicating a digital signal from a first circuit to a second circuit, the first circuit being electrically coupled to the second circuit via a transformer, the transformer comprising a primary winding and a secondary winding, the primary winding being electrically connected to the first circuit and the secondary winding being electrically connected to the second circuit, the method comprising:

• transferring the digital signal from the first circuit to the second circuit through the transformer, wherein transferring the digital signal comprises applying to the primary winding of the transformer a frequency-modulated signal, the frequency-modulated signal including one or more first sinusoidal trains of a first duration corresponding to a rising edge of the digital signal and one or more second sinusoidal trains of a second duration corresponding to a falling edge of the digital signal.