A phase locked loop system includes bias voltage adjustment circuitry and a voltage regulator that outputs a smoothed core voltage to an oscillator. The bias voltage adjustment circuitry is configured to compute a scaled bias voltage based at least on a target frequency for the oscillator. The voltage regulator is configured to input i) the scaled bias voltage and ii) a selected core voltage that is selected based on the target operating frequency of the oscillator and generate the smoothed core voltage for output to the oscillator.