| 摘要 |
PROBLEM TO BE SOLVED: To provide a third overtone crystal oscillator using an oscillator IC in which an oscillator circuit for fundamental waves is integrated. SOLUTION: The crystal oscillator includes an oscillator IC 1 and a crystal vibrator 2. The oscillator IC 1 comprises: an emitter-grounded transistor Tr for oscillation wherein a bias resistor R is provided between a collector and a base and a constant current from a constant current source I is supplied to the collector; a first capacitor C1 for oscillation connected to the base via a DC blocking capacitor Cs and to a ground potential; and a second capacitor C2 for oscillation connected between the collector and the ground potential. The crystal vibrator 2 is connected between the first capacitor and the second capacitor. In the crystal oscillator, an inductor L, which forms a parallel resonant circuit with the first capacitor, is independently connected separately from the oscillator IC, and a parallel resonance frequency by the first capacitor and the inductor is set higher than an oscillation frequency of the fundamental wave of the crystal vibrator and lower than an oscillation frequency of the third overtone of the crystal vibrator to attain third overtone oscillation. COPYRIGHT: (C)2008,JPO&INPIT
|
