An X-ray device according to an embodiment of the invention includes an X-ray detector including a number of detector elements, the detector elements being subdivided into at least two subgroups, each of spatially linked detector elements. The X-ray device or the X-ray detector includes a voltage supply unit for providing a fundamental voltage. The X-ray detector includes two voltage transformers, of which each is associated with respectively one of the two subgroups. And each of the voltage transformers is configured for converting the fundamental voltage into a detector operating voltage for the detector elements, which is lower than the fundamental voltage.