| 摘要 |
PURPOSE:To realize a stable high accuracy electronic clock without changing the oscilating condition remarkably, by jointly using the variable frequency division and the variable oscillating condition for compensaing a frequency temperature characteristic. CONSTITUTION:A temperature detecting circuit 5 outputs a temperature information value which A/D-converts a temperature sensible characteristic of a current-voltage characteristic, etc. of p-n junction of a thermistor or a semiconductor, to a frequency dividing ratio controlling circuit 6 and a constant-current transistor controlling circuit 7. The frequency dividing ratio controlling circuit 6 controls a frequency dividing ratio of a variable frequency dividing circuit 2 so that it becomes an optimum frequency dividing ratio by the temperature information value from the temperature detecting circuit 5. The constant-current TR controlling circuit 7 for controlling the gate voltage of a constant-current transistor 8 also compensates oscillation frequency by varying a current applied to the oscillating circuit by temperature information. That is to say, the temperature compensation of frequency is executed by varying a current for supplying the frequency of an oscillating circuit 1 to the frequency dividing ratio of the variable frequency dividing circuit 2 and the oscillating circuit, by a temperature. |
