An implantable device (10) is used to emit electrical stimulation signals to surrounding tissue by means of at least one stimulation electrode (17). The device (10) has an input stage which is connected to a supply unit (12) by a cable, by means of which the input stage is supplied with at least one substantially square electrical AC voltage which is, averaged over time, at least virtually free of a DC voltage with respect to an external ground (29), which can be connected to the tissue (64) (FIG. 1).
