Abstract: A semiconductor device includes a substrate layer having a floating base region of a first conductivity type. A first well of a second conductivity type and the floating base region form a first pn junction. A first conductive structure is electrically connected to the first well. A barrier region of the second conductivity type and the floating base region form an auxiliary pn junction. A second conductive structure is electrically connected to the floating base region through a rectifying structure. A pull-down structure is configured to produce a voltage drop between the barrier region and the second conductive structure, when charge carriers cross the auxiliary pn junction.