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US 8,552,804 B1Granted
Frequency synthesizers with dynamic calibration intervals
AssigneeIntegrated Device Technology, Inc.
InventorsChenxiao Ren, Tao Jing
Life of this patent
Estimating the term…
Abstract
An apparatus includes an adjustable oscillator circuit configured to generate an output signal having a frequency that varies responsive to a frequency control signal and a frequency reference generator circuit configured to produce a frequency reference signal. The apparatus further includes a calibration circuit configured to determine a relationship of the output signal to the frequency reference signal and to enable and disable the frequency reference generator circuit based on the determined relationship.
Claims18
An apparatus comprising:
- an adjustable oscillator circuit configured to generate an output signal having a frequency that varies responsive to a frequency control signal;
- a frequency reference generator circuit configured to produce a frequency reference signal;
- and
- a calibration circuit configured to determine a difference between a reference and a measure of transitions of the frequency reference signal occurring during a measurement period defined by the output signal and to disable the frequency reference generator circuit for a period commensurate with the determined difference.
1 more element
An apparatus comprising:
- an adjustable clock generator circuit configured to generate an output clock signal having a frequency that varies responsive to a frequency control signal;
- a crystal oscillator circuit configured to produce a reference clock signal;
- and
- a calibration circuit configured to determine a difference between a reference and a measure of transitions of the reference clock signal occurring during a measurement period defined by the output clock signal and to disable the crystal oscillator circuit for a period commensurate with the determined difference.
1 more element
An apparatus comprising:
- an adjustable oscillator circuit configured to generate an output signal having a frequency that varies responsive to a frequency control signal;
- a frequency reference generator circuit configured to produce a frequency reference signal;
- and
- a calibration circuit configured to generate the frequency control signal based on comparisons of the frequency reference signal to the output signal in respective calibration periods that are variably separated in time based on the comparisons.
1 more element
Dependencies are inferred from the claim text.