A voltage booster circuit including an input for receiving a supply voltage, a plurality of stages for producing an output voltage from the supply voltage by the transfer of charges between at least two of the plurality of stages, and circuit for coupling and decoupling stages to vary the number of stages operatively connected together. A method for producing an output voltage from a supply voltage by using a voltage booster circuit, the circuit includes an input for receiving the supply voltage, a plurality of stages, and a selection switch for the selective isolation of the stages or for the selective connection of the stage. The method includes the following steps: starting the circuit; comparing the value of the output voltage with a decrementation threshold; and decreasing the number of stages which are connected if the decrementation threshold is reached by the value of the output voltage.