Circuit device and oscillator

A circuit device, comprising:

• an oscillation circuit configured to oscillate a resonator, the oscillation circuit including:
• a first variable capacitance circuit whose capacitance change characteristic with respect to a first capacitance control voltage is a positive characteristic;
• and
• a second variable capacitance circuit whose capacitance change characteristic with respect to a second capacitance control voltage is a negative characteristic;
• a temperature compensation circuit configured to output a temperature compensation voltage for temperature compensating an oscillation frequency of the oscillation circuit;
• and
• a frequency control circuit configured to output a frequency control voltage for frequency controlling the oscillation frequency of the oscillation circuit, wherein
• in a first mode, the frequency control voltage is input as the second capacitance control voltage to the second variable capacitance circuit, and the temperature compensation voltage is input as the first capacitance control voltage to the first variable capacitance circuit, and
• in a second mode, the frequency control voltage is input as the first capacitance control voltage to the first variable capacitance circuit, and the temperature compensation voltage is input as the second capacitance control voltage to the second variable capacitance circuit.

An oscillator, comprising:

• a resonator;
• and
• a circuit device, the circuit device including:
• an oscillation circuit configured to oscillate the resonator, the oscillation circuit including:
• a first variable capacitance circuit whose capacitance change characteristic with respect to a first capacitance control voltage is a positive characteristic;
• and
• a second variable capacitance circuit whose capacitance change characteristic with respect to a second capacitance control voltage is a negative characteristic;
• a temperature compensation circuit configured to output a temperature compensation voltage for temperature compensating an oscillation frequency of the oscillation circuit;
• a frequency control circuit configured to output a frequency control voltage for frequency controlling the oscillation frequency of the oscillation circuit;
• and
• a switch circuit configured to:
• receive the temperature compensation voltage at a first input terminal thereof;
• receive the frequency control voltage at a second input terminal thereof;
• output a first output voltage selected from a plurality of voltages to a first output terminal thereof to which the first variable capacitance circuit is coupled;
• and
• output a second output voltage selected from the plurality of voltages to a second output terminal to which the second variable capacitance circuit is coupled,
• wherein the plurality of voltages include the temperature compensation voltage, the frequency control voltage, a reference voltage, and a ground voltage.

An oscillator, comprising:

• a resonator;
• and
• a circuit device, the circuit device including:
• an oscillation circuit configured to oscillate a resonator, the oscillation circuit including:
• a first variable capacitance circuit whose capacitance change characteristic with respect to a first capacitance control voltage is a positive characteristic;
• and
• a second variable capacitance circuit whose capacitance change characteristic with respect to a second capacitance control voltage is a negative characteristic;
• a temperature compensation circuit configured to output a temperature compensation voltage for temperature compensating an oscillation frequency of the oscillation circuit;
• and
• a frequency control circuit configured to output a frequency control voltage for frequency controlling the oscillation frequency of the oscillation circuit, wherein
• in a first mode, the frequency control voltage is input as the second capacitance control voltage to the second variable capacitance circuit, and the temperature compensation voltage is input as the first capacitance control voltage to the first variable capacitance circuit, and
• in a second mode, the frequency control voltage is input as the first capacitance control voltage to the first variable capacitance circuit, and the temperature compensation voltage is input as the second capacitance control voltage to the second variable capacitance circuit.