CLOCK SIGNAL CIRCUIT AND ELECTRONIC DEVICE-MOUNTED EQUIPMENT MOUNTED WITH THE SAME

PROBLEM TO BE SOLVED: To provide a clock signal circuit capable of sufficiently suppressing harmonics of a clock signal by a spread-spectrum function to reduce the harmonics below a noise level, and provide an electronic device-mounted equipment mounted with the clock signal circuit. SOLUTION: The clock signal circuit has at least a reference oscillator 1 oscillating a reference clock; a phase comparator 2 comparing phases of two signals and sending a signal according to a phase difference; a low pass filter 3 passing a signal in a low-frequency band; a modulator 4 performing a spread spectrum of an input signal; a voltage control oscillator 7 whose oscillation frequency is controlled by an application voltage; and a divider 5 dividing the signal from the voltage control oscillator 7. A harmonic wave filter 6 suppressing the harmonic signal of the reference oscillator 1 is set in at least one position along a signal transmission route of the clock signal circuit, e.g. between the modulator 4 and the voltage control oscillator 7, to prevent application of the harmonic signal of the reference oscillator 1 to a voltage control terminal of the voltage control oscillator 7.