A circuit of generation of a reference voltage by a first MOS transistor connected to a first terminal of application of a supply voltage, the first transistor being in series with a second MOS transistor controlled by an input stage of a transconductance amplifier and their junction point defining an output terminal providing the reference voltage, a first current source connecting the first supply terminal to a gate of the first transistor, a second current source connecting the second transistor to a second terminal of application of the supply voltage, at least one third MOS transistor connecting the two current sources, and a capacitive element directly connecting the output terminal to a conduction terminal of the third transistor to vary the conduction of this third transistor in case of a variation in output voltage.