Integrated circuit of CMOS type comprising first and second circuit parts arranged close to one another in a single semiconducting substrate, the substrate comprising in each one of the first and second circuit parts: a substrate surface, an active upper layer, a deep doping well and a bulk portion, in the order from the substrate surface towards a back side of the substrate, the bulk portion extending continuously from the first circuit part to the second circuit part, the deep doping well being of a first doping type opposed to a second doping type of the bulk portion, the active upper layer comprising at least one upper doping well (11, 21) of the first doping type and a remaining upper region (12, 22) of the second doping type in each one of the first and second circuit parts, with each upper doping well extending down to the deep doping well from the substrate surface in the corresponding circuit part, highly doped terminals (110, 210) of the second doping type being arranged in the upper doping wells (11, 21) of the first and second circuit parts, and also other highly doped terminals (120, 220) of the first doping type being arranged in the remaining upper regions (12, 22) of the first and second circuit parts, and within the first and second circuit parts: the highly doped terminals (120, 220) in the remaining upper regions (12, 22) being arranged to be connected to a ground supply (gndm), and said remaining upper regions out of the highly doped terminals being arranged to be connected to a substrate supply (gndsm), within the first circuit part: the highly doped terminals in the upper doping well and said upper doping well out of the highly doped terminals being arranged to be connected to a common power supply (vddma) dedicated to said first circuit part, within the second circuit part: the highly doped terminals in the upper doping well being arranged to be connected to a power supply (vddmp) dedicated to said second circuit part, and said upper doping well out of the highly doped terminals being arranged to be connected to a substrate power supply (vddsmp) dedicated to said second circuit part, characterized in that the deep doping well extends continuously from the first circuit part to the second circuit part, and the integrated circuit further comprises an electrically conducting path arranged for connecting to one another the upper doping wells (11, 21) of both first and second circuit parts out of the highly doped terminals (110, 210), so that the common power supply (vddma) dedicated to the first circuit part and the substrate power supply (vddsmp) dedicated to the second circuit part are merged, and the integrated circuit further comprises a switching unit arranged for electrically connecting to one another or isolating from one another the highly doped terminals of the upper doping well of the second circuit part on one hand, and said upper doping well of the second circuit part out of the highly doped terminals on the other hand, so that the substrate power supply (vddsmp) dedicated to the second circuit part further operates as the power supply (vddmp) dedicated to said second circuit part when the switching unit is in connecting state.