Galvanic isolation coupling device

A system comprising first and second electric or electronic circuits galvanically isolated from each other, and a coupling device coupling the first circuit to the second circuit, the coupling device comprising a variable-capacitance capacitor comprising first and second electrodes mobile with respect to each other, separated by an insulating region, and third and fourth electrodes electrically insulated from the first and second electrodes, capable of receiving a control signal to vary, by an electrostatic, electromagnetic, or piezoelectric actuation mechanism, the relative position of the first and second electrodes, to vary the capacitance between the first and second electrodes,

• wherein the coupling device comprises first and second input terminals connected to the first circuit and capable of receiving an input signal originating from the first circuit, and first and second output terminals connected to the second circuit and galvanically isolated from the first and second input terminals, capable of supplying the second circuit with an output signal which is an image of the input signal,
• wherein the first and second input terminals are respectively connected to the third and fourth electrodes of the capacitor, and
• wherein the first and second output terminals are coupled to the first and second electrodes of the capacitor so that the output signal varies according to the value of the capacitance between the first and second electrodes.