| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a piezoelectric oscillator capable of achieving highly accurate temperature compensation without mutually exerting influence between a temperature compensation function and an AFC function in a circuit configuration provided with the temperature compensation function and the AFC function. Ž<P>SOLUTION: The piezoelectric oscillator 10 includes: an oscillation circuit 20 provided with a piezoelectric vibrator 26, an oscillating amplifier circuit, and voltage control type first and second variable capacitance elements 28, 28b; a temperature compensation voltage generation circuit 30 for outputting a temperature compensation voltage for compensating the frequency temperature characteristics of the oscillation circuit 20 by controlling a value of the first variable capacitance element 28a so as to increase/decrease the value; a compensation voltage detection circuit 40 for outputting an adjustment signal for changing the value of the second variable capacitance element 28b so as to suppress increase/decrease in the AFC sensitivity of the oscillation circuit 20 when the value of the first variable capacitance element 28a is changed due to the temperature compensation voltage; a gain adjustment circuit 60 for receiving the adjustment signal and adjusting an amplification factor of an external control voltage; and an amplifier circuit 50 for outputting a frequency control voltage for controlling the second variable capacitance element 28b. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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