摘要 |
PROBLEM TO BE SOLVED: To provide a crystal oscillation circuit capable of suppressing useless oscillation other than an original oscillation frequency by surely making oscillation in a series arm of a crystal oscillator when an extension coil is inserted. SOLUTION: In the crystal oscillation circuit in which the extension coil L1 is inserted between one end of the crystal oscillator XL and a base of a transistor Q, an additional capacitor Cx is connected to the crystal oscillator XL in parallel, a capacitor C1 connected to the other end of the crystal oscillator XL and a capacitor C2 connected to the base are used as variable capacitors, a variable capacitor C3 is provided between the extension coil L1 and the base, and the variable capacitors are controlled by a temperature compensation voltage generation circuit 3. COPYRIGHT: (C)2010,JPO&INPIT |