Patent ID: 7692505

Claim:
A crystal oscillator comprising: a resonance circuit having a crystal unit and a split capacitor assembly, one end of said split capacitor assembly being connected to said crystal unit, the other end of said capacitor assembly being connected to a ground point, and said split capacitor assembly comprising a first capacitor and a second capacitor serially connected to each other; a transistor for oscillation having a base connected to a connection node between said crystal unit and said split capacitor assembly; a crystal resonator, one end of said crystal resonator being connected to a connection node between the first capacitor and the second capacitor, and the other end of said crystal resonator being connected to an emitter of said transistor; a resistor in parallel connected with said crystal resonator; an emitter resistor, one end of said emitter resistor being connected to said emitter, and the other end of said emitter resistor being connected to said ground point; and a temperature compensation mechanism for compensating the frequency-temperature characteristic of said crystal unit, wherein said temperature compensation mechanism includes a voltage-variable capacitance element connected to said crystal unit and a compensating voltage generation circuit for generating a compensating voltage according to ambient temperature, and said compensating voltage is applied to the voltage-variable capacitance element.