Patent ID: 7049899

Claim:
A temperature compensated piezoelectric oscillator comprising: an active oscillation element; a piezoelectric vibrator connected to the active oscillation element; a variable capacitance diode connected to the piezoelectric vibrator; a temperature compensation circuit connected to one end of the variable capacitance diode; and an external frequency control terminal for varying an oscillation frequency of the active oscillation element by applying a voltage to said variable capacitance diode; wherein said external frequency control terminal is connected to ground via a first resistor and a second resistor in series, and a connection point of said first resistor and said second resistor is connected to the other end of said variable capacitance diode; a first capacitor is provided between the connection point of said first resistor and said second resistor and ground; and an impedance of the first capacitor at a frequency lower than the oscillation frequency of the active oscillation element is sufficiently low so as to be capable of bypassing electrical-current noise generated from said first resistor and said second resistor to ground.