Temperature compensated crystal oscillator
AssigneeMicro Analog Systems Oy
InventorsJarkko Routama, Klaus Turhanen
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Abstract
The present invention relates to an integrated circuit for a temperature compensated crystal oscillator having an external crystal. The integrated circuit comprises a temperature compensation having one fixed or at least two selectable 3rd and/or 4th and/or 5th and/or higher order temperature compensation functions for at least one specific type of external crystal. The temperature compensation can be calibrated at one temperature, in other words without use of temperature variation, by means of an external voltage or current source overdriving a respective temperature-dependent voltage or current supplied from an internal temperature sensor to the temperature compensation.
Claims14
An integrated circuit for a temperature compensated crystal oscillator having an external crystal, the circuit comprising
- a temperature compensator having one fixed or at least two selectable 3rd and/or 4th and/or 5th and/or higher order temperature compensation functions for at least one specific type of external crystal, and
- calibrator circuitry for the temperature compensator, said calibrator circuitry being configured to a calibration procedure at one temperature without use of temperature variation.
A temperature compensated crystal oscillator comprising an external crystal having a known temperature compensation function, an integrated circuit including
- a temperature compensator having one fixed or at least two selectable 3rd and/or 4th and/or 5th and/or higher order temperature compensation functions for at least one specific type of external crystal, and
- calibrator circuitry for the temperature compensator, said calibrator circuitry being configured to a calibration procedure at one temperature without use of temperature variation.
An integrated circuit for a temperature compensated crystal oscillator having an external crystal, the circuit comprising
- an internal temperature sensor,
- a temperature compensator having one fixed or at least two selectable 3rd and/or 4th and/or 5th and/or higher order temperature compensation functions for at least one specific type of external crystal, and
- calibrator circuitry for the temperature compensator, said calibrator circuitry being configured to be connected an external voltage or current source for calibration procedure of the temperature compensator, said external voltage or current source overdriving a respective temperature-dependent voltage or current supplied from said internal temperature sensor to the temperature compensator, whereby enabling the calibration procedure to be performed at one temperature without use of temperature variation.
Dependencies are inferred from the claim text.