| 摘要 |
PROBLEM TO BE SOLVED: To improve a phase noise (C/N) characteristic in a temperature compensated piezoelectric oscillator employing a MOS capacitor at low and high temperatures. SOLUTION: In a temperature compensated piezoelectric oscillator comprising a piezoelectric vibrator, an oscillation circuit, a MOS capacitor and a temperature compensation voltage generating circuit for feeding a temperature compensation voltage to the MOS capacitor, the temperature compensation voltage generating circuit comprises: a temperature compensation current generating circuit for outputting a temperature compensation current which linearly decreases in response to a temperature change and is interrupted at a predetermined temperature or higher; a current-voltage converting circuit for converting the temperature compensation current to a temperature compensation voltage; and a temperature setting circuit for setting the predetermined temperature, and the temperature compensation voltage is fed to the MOS capacitor. COPYRIGHT: (C)2006,JPO&NCIPI
|
