| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a voltage controlled crystal oscillation circuit having a simple circuit configuration suitable for integration so as to allow the variable width of an oscillation frequency to be wider. <P>SOLUTION: The voltage control crystal oscillation circuit includes a CMOS inverter; a crystal vibrator and a feedback register which are connected in parallel between the input and output of the CMOS inverter; fixed capacities and variable capacity diodes for forming the load capacity of the crystal vibrator; and a resistance for inputting a control voltage and varying the capacity of the variable capacity diodes. The voltage control crystal oscillation circuit includes a voltage converting circuit for inputting the control voltage and changing an output voltage in response to the change of the control voltage. The output voltage of the voltage converting circuit is supplied to the power source voltage of the CMOS inverter. Then the frequency variable width is made to be wider than the frequency variable width which is determined by the capacity value of the variable capacity diode and the capacity value of the fixed capacity. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
