Adjusting the magnitude of a capacitance of a digitally controlled circuit

A phase-locked loop comprising:

• a phase detector;
• a filter having at least one input coupled to at least one output of the phase detector;
• a controller having at least one input coupled to at least one output of the filter;
• an oscillator having a variable capacitance, the oscillator having at least one input coupled to at least one output of the controller;
• and
• a divider having at least one input coupled to at least one output of the oscillator and at least one output coupled to at least one input of the phase detector;
• wherein the oscillator comprises a plurality of gain elements, the plurality of gain elements comprising one or more positive voltage-to-frequency gain elements and one or more negative voltage-to-frequency gain elements;
• and
• wherein the controller is configured to adjust the magnitude of the capacitance by adjusting the gain provided by respective ones of the gain elements in an alternating sequence of the positive voltage-to-frequency gain elements and the negative voltage-to-frequency gain elements.