| 摘要 |
PURPOSE:To make it possible to fabricate a highly accuracy electronic timepiece in good yield, by adjusting the temp. characteristics of crystal oscillation output by changing an oscillation condition while performing the adjustment of the absolute value of oscillation frequency by fast and slow logical means. CONSTITUTION:A crystal oscillator circuit 1 is constituted of an amplifier circuit consisting of a CMOS inverter 6 and a feedback resistor 7 and a feedback circuit formed of a drain resistor 8, drain capacitance 9, a crystal vibrator 10 and a trimmer capacitor 11. When the capacity value of the capacitor 11 is changed, the temp., coefficient of the vibrator 10 is changed and the temp. characteristics of the circuit 1 are adjusted. The adjustement to the change in the absolute value of frequency is performed by a logical circuit 5 for controlling a frequency dividing circuit 2. By this mechanism, it is unnecessary to use a crystal oscillator satisfying strict temp. characteristics and a high accuracy electronic timepiece can be fabricated in good yield. |
