| 摘要 |
PURPOSE:To simplify the adjustment and to facilitate the production of a temperature compensation voltage by constituting a surround temperature detector, an A/D converter, a memory circuit, a D/A converter by one integrated circuit and mounting the integrated circuit and a circuit voltage controlled oscillator respectively onto 1st and 2nd circuit boards and sealing them into an airtight package. CONSTITUTION:One integrated circuit 9 integrating the temperature detector 4, the A/D converter 5, the memory circuit 6 and the D/A converter 7 is mounted on a ceramic board 10 as the 1st circuit board. Moreover, the circuit having the voltage controlled oscillator 8 and the crystal oscillator 8a are mounted on the ceramic board 14 as the 2nd circuit board to constitute the voltage controlled oscillator 8. The digital quantity required for temperature compensation is stored in advance in the memory circuit 6 by sealing the oscillator 8 in the airtight package 15. Thus, even if there is a difference in the temperature characteristic of individual component, since it is not required to apply approximation calculation by a computer or the like, the adjustment is facilitated and the sure frequency is oscillated stably.
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