An electronic system includes an electronic device of through-hole mounting type comprising an insulating body for embedding at least a chip on which electronic components are integrated, a plurality of conductive leads projecting from the insulating body for said mounting, and a dissipation plate exposed from the insulating body for transferring heat from said electronic component in operation towards the outside of the insulating body. The electronic system includes a heat sink in contact with said dissipation plate for dissipating said heat. The heat sink comprises a first dissipation element, a second dissipation element, and clamping means for clamping the first dissipation element and the second dissipation element together against the insulating body of said electronic device.