| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method of determining a design value of a crystal oscillation circuit by making clear a relationship of a load capacitance CL value, a negative resistance RL value and a drive current Ios value of the oscillation circuit employing a crystal oscillator. <P>SOLUTION: In a crystal oscillation circuit, two of three design values of a negative resistance value RL, a load capacitance value CL and a drive current Ios are determined to determine the remaining one value using a relational expression or a relational graph. When the negative resistance value RL is defined as a fixed value, a relational expression of the drive current Ios and the load capacitance value CL is represented by a secondary expression of Ios=α*(CL)<SP POS="POST">2</SP>+β*(CL)+γ (α, β and γ are constant numbers). Furthermore, when the drive current Ios is defined as a parameter (fixed value), a relational expression of the load capacitance value CL and the negative resistance value RL is represented by a power expression of CL=a*(RL)<SP POS="POST">b</SP>(a and b are constant numbers). As a result, the drive current can be reduced by decreasing the CL of the crystal oscillation circuit, and power consumption of the crystal oscillation circuit can be reduced. <P>COPYRIGHT: (C)2012,JPO&INPIT |
