Circuit device, oscillator, and manufacturing method

An oscillator comprising:

• a resonator;
• and
• a circuit device configured to generate an oscillation signal by oscillating the resonator, wherein
• the circuit device includes:
• an output circuit including a waveform-shaping circuit configured to waveform-shape the oscillation signal, and configured to output an output clock signal based on a clock signal subjected to the waveform-shaping by the waveform-shaping circuit;
• a bias voltage output circuit configured to output a bias voltage of the oscillation signal input to the waveform-shaping circuit;
• a comparator configured to compare a DC voltage obtained by smoothing the clock signal subjected to the waveform-shaping with a reference voltage;
• a logic circuit configured to set an adjustment value of the bias voltage of the bias voltage output circuit;
• and
• a storage circuit, wherein
• in a test mode of the circuit device, the logic circuit changes the adjustment value to determine a set value of the adjustment value based on output of the comparator when the adjustment value is changed, and stores the determined set value in the storage circuit.

A manufacturing method of an oscillator that includes a resonator and a circuit device configured to generate an oscillation signal by oscillating the resonator,

• the circuit device including:
• an output circuit including a waveform-shaping circuit configured to waveform-shape the oscillation signal, and configured to output an output clock signal based on a clock signal subjected to the waveform-shaping by the waveform-shaping circuit;
• a bias voltage output circuit configured to output a bias voltage of the oscillation signal input to the waveform-shaping circuit;
• a comparator configured to compare a DC voltage obtained by smoothing the clock signal subjected to the waveform-shaping with a reference voltage;
• and
• a storage circuit,
• the manufacturing method comprising:
• setting the circuit device to a test mode;
• changing the adjustment value in the test mode;
• searching for, based on output of the comparator when the adjustment value is changed, the adjustment value for setting a duty ratio of the output clock signal to a predetermined duty ratio;
• determining the found adjustment value as a set value of the adjustment value;
• and
• storing the determined set value in the storage circuit.