An electric circuit includes a supply terminal to receive an outer supply voltage and a voltage regulator coupled to the supply terminal and to provide supply and resting voltages. A lock-out circuit is switchable between active and inactive states and receives the supply voltage at a supply node to generate, in the active state, an output voltage on a output terminal thereof. A protection circuit protects against electrostatic discharge, having at least one first diode coupled between the supply node and the output terminal. A cut-off electronic lock couples, in the inactive state, the supply node to the supply terminal by reverse biasing the at least one first diode to make a voltage of the output terminal float.