Circuit for supplying a filtered reference voltage (V'ref), comprising: - a voltage reference receiving a supply voltage (Va) and providing a reference voltage (Vref); - a low-pass filter which has a cutoff frequency of less than 1 Hz, is electrically connected to the voltage reference and comprises a stage formed by a stage resistance (Re) electrically connected at a midpoint to a stage capacitor (Ce), the stage resistance (Re) and the stage capacitor (Ce) at least partially defining a time constant of the filter and the midpoint carrying the filtered reference voltage (V'ref); - a switching circuit comprising a control electrode, and two conduction electrodes, one of which is electrically connected to the midpoint, the switching circuit having an on-state resistance between the two conduction electrodes, the value of which resistance is less than the value of the stage resistance (Re); - a control circuit (Cde) connected to the control electrode of the switching circuit and configured to turn the switching circuit on when the circuit is turned on for a predetermined startup period, the on-state resistance of the switching circuit combining with the stage capacitor (Ce) to raise the filtered reference voltage (V'ref) with a settling time constant less than the filter time constant, the control circuit (Cde) producing a control signal having a control time constant greater than or equal to the settling time constant, the control circuit (Cde) comprising an RC series circuit defining a control midpoint (Mc) connected to the control electrode of the switching circuit, the RC series circuit being arranged between a control voltage (Va; Vref; V'ref; Va) and the ground of the circuit. - a voltage reference receiving a supply voltage (Va) and providing a reference voltage (Vref); - a low-pass filter which has a cutoff frequency of less than 1 Hz, is electrically connected to the voltage reference and comprises a stage formed by a stage resistance (Re) electrically connected at a midpoint to a stage capacitor (Ce), the stage resistance (Re) and the stage capacitor (Ce) at least partially defining a time constant of the filter and the midpoint carrying the filtered reference voltage (V'ref); - a switching circuit comprising a control electrode, and two conduction electrodes, one of which is electrically connected to the midpoint, the switching circuit having an on-state resistance between the two conduction electrodes, the value of which resistance is less than the value of the stage resistance (Re); - a control circuit (Cde) connected to the control electrode of the switching circuit and configured to turn the switching circuit on when the circuit is turned on for a predetermined startup period, the on-state resistance of the switching circuit combining with the stage capacitor (Ce) to raise the filtered reference voltage (V'ref) with a settling time constant less than the filter time constant, the control circuit (Cde) producing a control signal having a control time constant greater than or equal to the settling time constant, the control circuit (Cde) comprising an RC series circuit defining a control midpoint (Mc) connected to the control electrode of the switching circuit, the RC series circuit being arranged between a control voltage (Va; Vref; V'ref; Va) and the ground of the circuit.