A voltage regulator including an output stage to generate an output voltage based upon a control voltage determined as a function of a difference between a reference voltage and a voltage representative of the output voltage. A sense resistor is coupled in series with the output stage and an auxiliary power stage is coupled in parallel with the output stage and cooperates therewith to supply a load as a function of a voltage drop across the sense resistor. A scaled replica stage of the output stage is controlled by the control voltage to generate a replica voltage of the output voltage. A bias network biases the scaled replica stage and output stage with identical currents to keep constant bias voltages. The output stage, the auxiliary power stage, the scaled replica stage, and the bias network each have high voltage transistors. The bias network is input with a square-wave control signal and an externally generated boosted voltage, to bias the scaled replica stage and the output stage in conduction states with the identical currents at the externally generated boosted voltage, when the square-wave control signal is active.