| 摘要 |
PROBLEM TO BE SOLVED: To provide a warm-up control method, a clock generating circuit using this method and a communication base station device for mobile communication for preventing a warm-up time from being set longer than necessary or from being running short by detecting the output clock frequency stability of a crystal oscillator having a thermostat concerning the reference clock of a radio transmission/reception card in the communication base station, and starting the supply of a clock when the stability converges on the range of frequency stability required for the communication base station device system for mobile communication. SOLUTION: This warm-up control method of a crystal oscillator having a thermostat is provided to warm up the environmental temperature of at least a crystal oscillator among components including the crystal oscillator arranged in an oscillator, and to generate a clock whose frequency is stabilized by maintaining a predetermined temperature. As far as the frequency of the clock does not reach predetermined stability, it is judged that the warm-up of the thermostat is not completed, and the clock of the crystal oscillator having the thermostat is not outputted. When the frequency of the clock reaches predetermined stability, it is judged that the warm-up of the thermostat is completed, and the clock of the crystal oscillator with the thermostat is outputted. COPYRIGHT: (C)2004,JPO
|
