Control and calibration of external oscillators
AssigneeAnalog Devices, Inc.
InventorsHyman Shanan, John Kenney
Life of this patent
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Abstract
Apparatus and methods for control and calibration of external oscillators are provided herein. In certain embodiments, an electronic oscillator system includes a semiconductor die and a controllable oscillator that is external to the semiconductor die. The oscillation frequency of the controllable oscillator is tuned by a first varactor and a second varactor. The semiconductor die includes a phase-locked loop (PLL) that provides fine tuning to the controllable oscillator by controlling the first varactor, and a calibration circuit that provides coarse tuning to the controllable oscillator by controlling the second varactor.
Claims20
An electronic oscillator system comprising:
- a semiconductor die;
- a controllable oscillator external to the semiconductor die and having an output configured to provide an output oscillator signal;
- a first varactor configured to tune an oscillation frequency of the controllable oscillator;
- and
- a second varactor configured to tune the oscillation frequency of the controllable oscillator,
- wherein the semiconductor die comprises a phase-locked loop (PLL) configured to provide a fine tuning to the controllable oscillator by controlling a tuning voltage of the first varactor, and a calibration circuit configured to provide a coarse tuning to the controllable oscillator by controlling the second varactor, the calibration circuit configured to provide the coarse tuning based on the tuning voltage of the first varactor and the output oscillator signal.
A method of electronic oscillator control, the method comprising:
- tuning an oscillation frequency of a controllable oscillator using a first varactor, the controllable oscillator external to a semiconductor die and having an output providing an output oscillator signal;
- tuning the oscillation frequency of the controllable oscillator using a second varactor;
- controlling a tuning voltage of the first varactor to provide a fine tuning to the controllable oscillator using a phase-locked loop (PLL) on the semiconductor die;
- and
- controlling the second varactor to provide a coarse tuning to the controllable oscillator using a calibration circuit of the semiconductor die, the calibration circuit providing the coarse tuning based on the tuning voltage of the first varactor and the output oscillator signal.
A radio frequency communication system comprising:
- a mixer controlled by an output oscillator signal;
- and
- a local oscillator comprising:
- a semiconductor die,
- a controllable oscillator external to the semiconductor die and having an output configured to provide an output oscillator signal,
- a first varactor configured to tune an oscillation frequency of the controllable oscillator, and
- a second varactor configured to tune the oscillation frequency of the controllable oscillator,
- wherein the semiconductor die comprises a phase-locked loop (PLL) configured to provide a fine tuning to the controllable oscillator by controlling a tuning voltage of the first varactor, and a calibration circuit configured to provide a coarse tuning to the controllable oscillator by controlling the second varactor, the calibration circuit configured to provide the coarse tuning based on the tuning voltage of the first varactor and the output oscillator signal.
Dependencies are inferred from the claim text.