Abstract: A conditioning circuit for the transfer of electric charge, which includes a converter module including an energy-storage element applied to which is an input voltage (Vi) and a respective field-effect-transistor switch controlled by a respective driving signal (Vpa, Vpb) for selectively enabling transfer of charge from the energy-storage element to an energy-storage circuit. The field-effect-transistor switch includes a corresponding field-effect transistor and a biasing circuit for biasing a substrate of the transistor, the biasing circuit being connected between the substrate and a reference node at a potential suitable for enabling operation of the transistor in the linear region or in the region of saturation, the biasing circuit being configured for providing a limiting resistance in regard to the current that flows from the reference node in the transistor when it operates in the inhibition region.