| 摘要 |
<p>PURPOSE:To adjust a frequency of an oscillator by providing a capacitor connecting to an input section of at least one inverter among plural inverters and a terminal to one end of the capacitor through which an external voltage is applied and varying a charge/discharge time of the inverter depending on the voltage applied to the terminal. CONSTITUTION:One terminal of a capacitor 6 is connected between an external terminal 7 and an input terminal of an inverter 2-2. A voltage applied to the external terminal 7 is fed to the one terminal of the capacitor 6 and the capacitor 6 is charged in response to the applied voltage. The capacitor 6 is connected in parallel with a load capacitor of the inverter 2-2. and the charge of the capacitor 6 is changed to vary the frequency of an oscillator 3. The voltage applied to the external terminal 7 is varied by changing a voltage division ratio of resistors R1, R2 and the charge in the capacitor 6 is changed accordingly. Thus, the oscillating frequency of the oscillator 3 is adjusted by changing the voltage applied to the external terminal 7.</p> |
