A voltage reference generator comprises a voltage reference, a variable gain amplifier connected to an output terminal of the voltage reference, a sampling capacitor connected to an output terminal of the voltage reference generator and to an output terminal of the variable gain amplifier via a sampling switch. The switch is adapted to close during a first portion of a switching period, and open during a second portion of the switching period. The voltage reference generator also comprises a ripple monitor adapted to estimate a magnitude of variation of an output voltage of the voltage reference generator resulting from charging and discharging of the sampling capacitor, and based on the estimate, perform one of control of the sampling switch to reduce a switching frequency of the sampling switch to increase a magnitude of the variation of the output voltage, and control of the sampling switch to increase the switching frequency.