A method of transmitting power and data across a galvanic isolation barrier, corresponding system and apparatus

In one embodiment, power and data are transmitted via a transformer (T) including primary side (T1) and secondary side (T2) windings so that a primary side signal generates a secondary side signal, by : - producing a primary side (T1) signal by coupling (k12) a first oscillator signal (P1; 10) modulated with a data signal (DATA; DI1) for transmission to the secondary side (T2) of the transformer (T) with a second oscillator signal (P2; 20) selectively switched on and off (21) to control power supply transmission to the secondary side (T2) of the transformer (T), and - applying to the secondary signal (P12 + DATA) thus generated: - i) demodulation (16, 18) to recover (DO1) at the secondary side (T2) of the transformer (T) the data signal (DATA; DI1) modulating the first oscillator signal (P1; 10), and - ii) rectification (200) to recover at the secondary side (T2) of the transformer (T) a power supply (VOUT, IOUT) controlled by switching on and off the second oscillator. In certain embodiments, a further data signal (DI2) may be coupled (200) to the secondary side (T2) of the transformer (T) for transmission to the primary side (T1) of the transformer (T), with demodulation (26, 28) applied at the primary side (T1) of the transformer to recover (DO2) at the primary side (T1) of the transformer (T) the further data signal (DI2).