A semiconductor device for protecting electrical circuits from Electrostatic Discharge pulses, said device comprising: - a well region of a given doping type, - a first region of a doping type, opposite the doping type of said well region, said first region being in physical contact with said well region, said first region being connected to a first terminal through an external electrical path between said first region and said first terminal, wherein an ESD pulse can be applied to said first terminal, - a second region of the same doping type as said well region, said second region being in physical contact with said well region, said second region being connected to a second terminal through an external electrical path between said second region and said second terminal, wherein a reference voltage (Vss) can be applied to said second terminal, wherein said device further comprises a third region, which is equally in physical contact with said well region, and which is positioned in between said first and second region (3 and 7), said third region being of the same doping type as said first region, and wherein said third region is floating with respect to said second terminal, and wherein said third region is connected through an external electrical path to said first terminal or to a third terminal that is separate from said first terminal said third region being thereby usable for increasing the resistance (R sub) of a current path, through said well region, between said first and second region (3 and 7), said increase of the resistance being obtainable by the formation of a depletion zone between the third region and the well region. - a well region of a given doping type, - a first region of a doping type, opposite the doping type of said well region, said first region being in physical contact with said well region, said first region being connected to a first terminal through an external electrical path between said first region and said first terminal, wherein an ESD pulse can be applied to said first terminal, - a second region of the same doping type as said well region, said second region being in physical contact with said well region, said second region being connected to a second terminal through an external electrical path between said second region and said second terminal, wherein a reference voltage (Vss) can be applied to said second terminal, wherein said device further comprises a third region, which is equally in physical contact with said well region, and which is positioned in between said first and second region (3 and 7), said third region being of the same doping type as said first region, and wherein said third region is floating with respect to said second terminal, and wherein said third region is connected through an external electrical path to said first terminal or to a third terminal that is separate from said first terminal said third region being thereby usable for increasing the resistance (R sub) of a current path, through said well region, between said first and second region (3 and 7), said increase of the resistance being obtainable by the formation of a depletion zone between the third region and the well region.