TEMPERATURE-COMPENSATED CRYSTAL OSCILLATOR AND TEMPERATURE COMPENSATION METHOD FOR OSCILLATOR

摘要

A temperature-compensated crystal oscillator includes an oscillation circuit including an oscillator, a temperature detector, a voltage variable capacitance element coupled to an oscillation loop of the oscillation circuit, and a temperature compensation circuit. The temperature compensation circuit is configured to apply a compensation voltage to the voltage variable capacitance element to compensate a temperature change in response to temperature data detected by the temperature detector. The temperature compensation circuit has a plurality of correction point data. The respective correction point data is set in advance for each divided temperature zone, selects a first correction point data in a lower temperature zone and a second correction point data in a higher temperature zone, as compared with the detected temperature data, performs an interpolation between the first and second correction point data by a weighted averaged first-order interpolation, and generates the compensation voltage.