A system includes a voltage booster circuit to receive an input voltage and provide an output voltage. A first device that is coupled to the voltage booster circuit to receive a digitized input voltage and a digitized output voltage and to determine, based on the digitized input voltage and the digitized output voltage, a first threshold level for the voltage booster circuit to operate in a pulse frequency modulation (PFM) mode. A second device that is coupled to the voltage booster circuit to receive the input voltage and the output voltage and to determine a second threshold level for the voltage booster circuit to operate in the PFM mode. A selector device that is coupled to the first device and the second device to select one of the first threshold level or the second threshold level for the voltage booster circuit.