Circuit device and oscillator

An oscillator configured to switching between a first mode in which phase noise of an output clock signal is lower than that in a second mode and the second mode in which power consumption is smaller than that in the first mode, the circuit device comprising:

• a resonator;
• and
• a circuit device, wherein
• the circuit device includes
• an oscillation circuit configured to oscillate the resonator to generate an oscillation signal;
• an output circuit configured to output the output clock signal based on the oscillation signal;
• a temperature sensor configured to output a temperature detection signal;
• a temperature compensation circuit configured to perform temperature compensation on an oscillation frequency of the oscillation circuit based on the temperature detection signal;
• and
• a control circuit configured to perform control such that a power supply voltage supplied to the oscillation circuit in the first mode is higher than a power supply voltage supplied to the oscillation circuit in the second mode, and perform control such that at least one of a reference voltage supplied to the temperature compensation circuit based on the power supply voltage and a reference current supplied to the temperature sensor based on the power supply voltage does not change between the first mode and the second mode.