Clock generation apparatus, clock generation method, adjustment apparatus, adjustment method, and non-transitory computer readable medium

A clock generation method for generating an output clock signal, comprising:

• a first voltage-controlled oscillator outputs the output clock signal;
• an AD converter outputs, with a second voltage-controlled oscillator, an internal clock signal phase-locked to the output clock signal in response to a digital temperature signal having become a value corresponding to an analog temperature signal from a temperature sensor, detects a phase difference between the output clock signal and the internal clock signal, and generates the digital temperature signal according to the phase difference which has been detected, to output it to the second voltage-controlled oscillator;
• and
• a digital temperature compensation circuit compensates a frequency of the output clock signal of the first voltage-controlled oscillator by using the digital temperature signal;
• wherein
• the digital temperature compensation circuit compensates the frequency of the output clock signal by using a compensation function associated with each of a plurality of temperature zones into which a predetermined temperature range is divided, and
• the digital temperature compensation circuit controls the frequency of the output clock signal of the first voltage-controlled oscillator by using a temperature compensation value stored in a lookup table, in response to the digital temperature signal indicating temperature of a boundary portion between the temperature zones.

A clock generation apparatus which generates an output clock signal, comprising:

• a first voltage-controlled oscillator which outputs the output clock signal;
• an AD converter which includes:
• a second voltage-controlled oscillator which outputs an internal clock signal phase-locked to the output clock signal in response to a digital temperature signal having become a value corresponding to an analog temperature signal from a temperature sensor;
• a phase comparator which detects a phase difference between the output clock signal and the internal clock signal;
• and a digital temperature signal generator which generates the digital temperature signal according to the phase difference detected by the phase comparator, to output it to the second voltage-controlled oscillator;
• and
• a digital temperature compensation circuit which compensates a frequency of the output clock signal of the first voltage-controlled oscillator by using the digital temperature signal, wherein
• the digital temperature compensation circuit includes a function generation circuit that generates an N-th order compensation function from the digital temperature signal using an adjustment parameter stored in a storage unit, and
• the digital temperature compensation circuit controls the frequency of the output clock signal of the first voltage-controlled oscillator by using the generated compensation function.