| 摘要 |
PROBLEM TO BE SOLVED: To provide an oscillator which performs a highly precise temperature compensation on the basis of the respective temperature characteristics of an oscillation circuit and a crystal resonator. SOLUTION: The oscillator includes: an oscillation part having a varactor which oscillates the crystal resonator; a temperature compensation part which compensates fluctuation of an oscillation frequency of the oscillation part by each temperature characteristic of the crystal resonator and the varactor; and a control part which controls the temperature compensation part. The temperature compensation part has: a first control signal output part which outputs three control signals with different voltage levels; a second control signal output part which outputs a reference signal at a voltage level having a primary temperature characteristic; a first comparison part which compares a first control signal with the reference signal to output a first signal in a low temperature region; a second comparison part which compares a second control signal with the reference signal to output a second signal in a high temperature region; a third comparison part which compares a third control signal with the reference signal to output a third signal in a normal temperature region; a first current control part which controls a current value of the first signal; a second current control part which controls a current value of the second signal; and a signal synthesis part which synthesizes the first to third signals. COPYRIGHT: (C)2009,JPO&INPIT
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