JP2008211757A5 - - Google Patents

Claims (8)

A temperature compensated piezoelectric oscillator comprising a piezoelectric vibrator, and a frequency temperature compensation circuit having a first MOS capacitor element, a second MOS capacitor element, and a third MOS capacitor element,
A configuration in which a reference voltage is supplied to one terminal of the first MOS capacitor element and one terminal of the second MOS capacitor element;
A configuration in which a first control voltage having a characteristic that a voltage changes with a temperature change is supplied to the other terminal of the first MOS capacitor;
A configuration in which a second control voltage having a characteristic that a voltage changes with a temperature change is supplied to the other terminal of the second MOS capacitor;
A configuration in which the first control voltage is supplied to one terminal of the third MOS capacitor element and the second control voltage is supplied to the other terminal of the third MOS capacitor element. A temperature-compensated piezoelectric oscillator characterized by The frequency temperature compensation circuit includes a configuration in which the third MOS capacitance element is connected in series to the first MOS capacitance element, and a configuration in which the second MOS capacitance element is connected in parallel to the series connection configuration. The temperature-compensated piezoelectric oscillator according to claim 1, further comprising: The frequency temperature compensation circuit includes a configuration in which a first capacitor is connected in series to the first MOS capacitor, a configuration in which the second MOS capacitor is connected in parallel to the series connection, and the parallel connection. The temperature compensated piezoelectric oscillator according to claim 1, further comprising: a configuration in which the third MOS capacitor element is connected in series to the configuration described above. The frequency temperature compensation circuit includes a first configuration in which a first capacitive element is connected in series to the first MOS capacitive element, and a second configuration in which a second capacitive element is connected in series to the third MOS capacitive element. The temperature compensated piezoelectric oscillator according to claim 1, comprising: a configuration; and a configuration in which the first configuration, the second configuration, and the second MOS capacitor element are connected in parallel. 5. The temperature-compensated piezoelectric oscillator according to claim 4, wherein the second configuration is a configuration in which the third MOS capacitive element, the second capacitive element, and a third capacitive element are connected in series. A configuration in which the first control voltage is supplied to one terminal of the third MOS capacitive element via a first amplifier, and a second amplifier to the other terminal of the third MOS capacitive element The temperature-compensated piezoelectric oscillator according to any one of claims 1, 2, 3, 4, and 5, further comprising: a configuration in which the second control voltage is supplied. . A configuration in which one of the first reference voltage and the first control voltage is selected and supplied to one terminal of the third MOS capacitor;
2. The configuration according to claim 1, further comprising: selecting and supplying either the second reference voltage or the second control voltage to the other terminal of the third MOS capacitor element. The temperature compensated piezoelectric oscillator as described. The piezoelectric resonator is a crystal resonator, and the frequency temperature characteristic of the crystal resonator is flat at normal temperature, a characteristic having a maximum value and a minimum value across an inflection point, or a right shoulder against an increase in temperature. The temperature compensated piezoelectric oscillator according to claim 7, which corresponds to any of the rising characteristics.