Low-power oscillator
AssigneeNordic Semiconductor ASA
InventorsOla Bruset, Tor Oyvind Vedal
Life of this patent
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Abstract
An integrated oscillator circuit comprises an oscillator configured to be switched between a first frequency and a second frequency. A switching circuit receives an input representing a target frequency and switches the oscillator between the first and second frequencies at intervals determined by the input, so as to cause the average output frequency of the oscillator to approximate the target frequency.
Claims20
An integrated oscillator circuit comprising:
- an oscillator configured to be switched between a first frequency and a second frequency;
- a calibration controller configured to perform a coarse calibration of the oscillator by adjusting the values of the first or second frequencies so that they span a target frequency;
- and
- switching circuitry configured to receive an input representative of the target frequency and to switch the oscillator between the first and second frequencies at intervals determined by the input so as to cause the average output frequency of the oscillator to approximate the target frequency, wherein the calibration controller is further configured to use a reference clock to perform a fine calibration of the oscillator at intervals in order to generate an updated input to be provided to the oscillator.
A method of operating an integrated-circuit oscillator, wherein the oscillator is configured to be switched between a first frequency and a second frequency, the method comprising:
- receiving an input representative of a target frequency;
- coarsely calibrating the oscillator by adjusting the values of the first or second frequencies so that they span the target frequency;
- switching the oscillator between the first and second frequencies at intervals determined by the target frequency so as to cause the average output frequency of the oscillator to approximate the target frequency;
- and
- finely calibrating the oscillator at intervals using a reference clock, to generate an updated input representative of the target frequency.
Dependencies are inferred from the claim text.