Patent ID: 7982551

Claim:
A voltage controlled oscillator circuit comprising: a temperature detector circuit for detecting a temperature, generating a first control voltage for coarse adjustment corresponding to the detected temperature, and outputting the first control voltage; a switch for selecting one of an inputted second control voltage for fine adjustment and the first control voltage for coarse adjustment; a resonance circuit having a predetermined resonance frequency, and including a varactor element having a capacitance value adjusted based on a control voltage selected by the switch, at least one capacitor, and an inductor; and an oscillator for generating an oscillation signal having an oscillation frequency corresponding to the resonance frequency using the resonance circuit, and outputting the oscillation signal; wherein the temperature detector circuit changes a range of the oscillation frequency of the oscillator by generating the first control voltage for coarse adjustment having a first output voltage value when the detected temperature is lower than a predetermined threshold temperature, and generating the first control voltage for coarse adjustment having a second output voltage value higher than the first output voltage value when the detected temperature is equal to or higher than a predetermined threshold temperature.