Low voltage isolation switch, in particular for a transmission channel for ultrasound applications

A low voltage isolation switch is coupled between an input terminal suitable for receiving a high voltage signal and an output terminal suitable for transmitting this high voltage signal to a load. The isolation switch includes a first driving transistor coupled between a first reference terminal and an intermediate node, a second driving transistor coupled between the intermediate node and the second reference terminal, a control transistor connected across a diode block coupled between the input and output terminals. The control transistor has a control terminal connected to the intermediate node through a low voltage decoupling block that includes first and second substrate terminals, first and second parasitic capacitive element connected to these first and second substrate terminals, and first and second decoupling transistors coupled in parallel to each other and having control terminals connected to the first and second parasitic capacitive elements, respectively.