| 摘要 |
PROBLEM TO BE SOLVED: To maintain an output frequency to a constant frequency, even without measuring data for each oscillation circuit by providing a storing part which stores correction data that corrects the deviation of temperature characteristics of a crystal resonator. SOLUTION: An oscillation circuit 1 uses a crystal resonator and a variable capacity element. A temperature sensor 2 detects the peripheral temperature including the circuit 1, and an A/D converter 3 converts it into digital value and outputs it to a CPU 5. The CPU 5 refers to information that is four finding the temperature-frequency deviation characteristic information of a crystal resonator single body, which is stored in a 1st storage circuit 8 and the temperature-frequency deviation characteristic of the circuit 1, which is stored in a 2nd storage circuit 9 and outputs control voltage value (digital signal), corresponding to an applicable temperature to a D/A converter 6. The converter 6 converts it into an analog value and outputs it to the circuit 1 via an integration circuit 7.
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