CPU-CONTROLLED CRYSTAL OSCILLATOR

摘要

PROBLEM TO BE SOLVED: To attain a frequency stability as high as that of a thermostatic chamber type crystal oscillator with an extremely low power consumption compared therewith. SOLUTION: The clam 1 comprises a crystal oscillator circuit and a CPU operative on an oscillation frequency of the oscillator circuit. The CPU is pre- programmed to output a pulse signal as an oscillation output at a timing determined to compensate the oscillation frequency change due to frequency aging characteristics according to a lapse time after power-on. The crystal oscillator circuit has a temperature compensating function. The CPU outputs a pulse signal as an oscillation output at a timing determined to compensate the oscillation frequency change due to frequency aging characteristics according to a detected value given from a temperature sensor. The crystal oscillator circuit provides an oscillation output via a filter for improving the phase noise level. COPYRIGHT: (C)2003,JPO