An electronic device, comprising plurality of source metal strips in a first metal level; a plurality of drain metal strips in the first metal level; a source metal bus in a second metal level above the first metal level; a drain metal bus, in the second metal level; a source pad, coupled to the source metal bus; and a drain pad, coupled to the drain metal bus. The source metal bus includes subregions shaped in such a way that, in top-plan view, each of them has a width which decreases moving away from the first conductive pad; the drain metal bus includes subregions shaped in such a way that, in top-plan view, each of them has a width which decreases moving away from the second conductive pad. The first and second subregions are interdigitated.