Digitally compensated crystal oscillator based on the self crystal as temperature sensor

Digital compensation in temperature techniques for crystal oscillators is presented. Error due to temperature and compensation data resolution is evaluated. Different thermal coefficients between sensor and crystal are studied through experiments on dynamic and static sweeps in temperature. A sensor based on the crystal oscillator has been used to reduce the uncertainty gap in compensation. A specific integrated circuit has been designed to produce thermal data from a dual mode oscillator and correct the output frequency. The calibration function has been programmed in a HCMOS microcontroller, where the thermal transient is evaluated to optimize power consumption.<
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