Oscillation control apparatus

An oscillation control apparatus equipped with a PLL comprising:

• a voltage controlled oscillator that has a variable resonator that changes f/v sensitivity according to a control signal;
• a frequency divider that has an output signal of said voltage controlled oscillator as input, and performs frequency division;
• a phase comparator that has an output signal of said frequency divider and a reference signal as input, and performs phase comparison;
• and
• a low-pass filter that has an output signal of said phase comparator as input, and outputs a control voltage to said voltage controlled oscillator,
• wherein said oscillation control apparatus has:
• a voltage detection circuit that has an output signal of said low-pass filter as input and detects a predetermined voltage;
• a CPU that has an output signal of said voltage detection circuit as input and outputs predetermined serial data in accordance with a detection result;
• and
• a serial decoder that has an output signal of said CPU as input and outputs a control signal to said resonator.

An f/v sensitivity adjustment method of an oscillation control apparatus that performs adjustment of f/v sensitivity in a voltage controlled oscillator, said f/v sensitivity adjustment method comprising:

• setting a PLL circuit to a reference frequency;
• setting an output signal of a low-pass filter included in said PLL circuit to a reference voltage at said reference frequency;
• setting said PLL circuit to a detection frequency;
• detecting an output voltage of said low-pass filter, and detecting f/v sensitivity based on an operating threshold value;
• maintaining a detection result as a control signal;
• and
• adjusting said f/v sensitivity to an optimal value for said voltage controlled oscillator based on said control signal.