Frequency based bias voltage scaling for phase locked loops
AssigneeApple Inc.
InventorsAndreas Roithmeier, Thomas Gustedt, Herwig Dietl-Steinmaurer, Christian Wicpalek
Life of this patent
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Abstract
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.
Claims19
A phase locked loop system, comprising:
- bias voltage adjustment circuitry configured to:
- determine a reduction term based at least on a target operating frequency for an oscillator;
- and
- subtract the reduction term from a base bias voltage associated with the oscillator to compute a scaled bias voltage;
- a voltage regulator configured to:
- input the scaled bias voltage and a selected core voltage, wherein the selected core voltage is selected based on the target operating frequency of the oscillator;
- generate a smoothed core voltage;
- and
- provide the smoothed core voltage to the oscillator.
A method, comprising:
- determining a reduction term based at least on a target frequency for an oscillator;
- subtracting the reduction term from a base bias voltage associated with the oscillator to compute a scaled bias voltage;
- and
- applying the scaled bias voltage to a voltage regulator supplying a smoothed core voltage to the oscillator.
A phase locked loop system, comprising:
- an oscillator configured to:
- input a smoothed core voltage;
- select an operating point based on the smoothed core voltage;
- and
- operate at the selected operating point to generate a signal having a frequency within a frequency band associated with the operating point;
- a voltage regulator configured to:
- input a scaled bias voltage and a selected core voltage, wherein the selected core voltage is selected based on a target frequency of the oscillator;
- generate the smoothed core voltage;
- and
- provide the smoothed core voltage to the oscillator;
- and
- bias voltage adjustment circuitry configured to compute the scaled bias voltage by:
- determining a reduction term based at least on the target frequency;
- and
- subtracting the reduction term from a base bias voltage associated with the oscillator.
Dependencies are inferred from the claim text.