JPH01124014A - Digital apparatus - Google Patents

Abstract

PURPOSE:To reduce noise, to suppress unnecessary radiation and to improve the stability of a circuit by generating a sine wave, applying the side wave to a digital circuit as a reference clock and converting the sine wave into a square clock on the digital circuit side. CONSTITUTION:A reference clock generating circuit 1 is provided with a sine wave oscillating circuit 3 for outputting a sine wave to the digital circuit 2 as a reference clock. In the digital circuit 2, a waveform shaping circuit for slicing the sine wave at a prescribed level and forming clocks consisting of square waves is connected to the input part of the reference clock. Consequently, the sine wave reduced at its higher harmonic component is applied to the digital circuit 2 as the reference clock noise is reduced, unnecessary radiation in a clock signal line can be reduced, and the stability of the circuit can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to various digital devices such as personal computers and game machines, and particularly to their basic clocks.

<Prior Art> Digital devices generally use a square wave as a basic clock, and this square wave is applied to a digital circuit via a clock signal line. However, as shown in the frequency spectrum of Fig. 4, the square wave has
Because it contains many harmonic components compared to the fundamental wave,
There are disadvantages such as becoming a source of unnecessary radiation, affecting other signal lines and other equipment, causing circuits to malfunction, and generating noise on TV screens, radios, etc.

<Objective of the Invention> The present invention has been made in view of the above-mentioned points, and an object thereof is to reduce noise, suppress unnecessary radiation, and improve circuit stability.

<Configuration of the Invention> In order to achieve the above-mentioned object, the present invention provides a digital device including a basic clock generation circuit that generates a basic clock and a digital circuit to which the basic clock from the basic clock generation circuit is provided. The basic clock generation circuit includes a sine wave oscillation circuit that generates a sine wave and outputs it as the basic clock to a digital circuit, and the digital circuit has a basic clock input section that receives the sine wave at a predetermined level. A waveform shaping circuit is provided that slices the signal into a square wave clock.

According to the above configuration, a sine wave with few harmonic components is applied to the digital circuit as a basic clock.

<Example> Hereinafter, an example of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram of an embodiment of the present invention.

The digital device of this embodiment includes a basic clock generation circuit 1 that generates a basic clock, and a digital circuit 2 to which this basic clock is applied.

The basic clock generation circuit 1 consists of a sine wave oscillation circuit 3 that generates a sine wave as a basic clock, and a capacitor C that cuts the DC component of this sine wave, and uses the sine wave with the DC component cut as the basic clock. signal line 4
to the digital circuit 2 via.

The digital circuit 2 includes an inverter 5 as a waveform shaping circuit that slices a sine wave at a predetermined level to produce a square wave clock at the input part of the basic clock, and a digital TC 6 to which the clock from the inverter 5 is applied. It is equipped with R is a bias resistor, which applies a predetermined bias voltage to the sine wave obtained by cutting off the DC component from the basic clock generation circuit l. Note that in FIG. 1, signal waveforms are also shown.

In the digital device of the present invention, the basic clock generating circuit 1 generates a sine wave with few harmonic components as shown in the frequency spectrum of FIG. A square wave clock is used on the circuit 2 side.

Therefore, compared to the conventional example in which a square wave with many harmonic components is applied as a basic clock to a digital circuit, noise is reduced, unnecessary radiation in the clock signal line 4 is reduced, and the stability of the circuit is improved.

FIG. 2 is a block diagram of another embodiment of the present invention, and parts corresponding to the embodiment of FIG. 1 are given the same reference numerals.

In the embodiment described above, a bias voltage was applied to the sine wave on the digital circuit 2 side, but in this embodiment, a predetermined bias voltage is applied on the basic clock generation circuit la side as a basic clock, and the basic clock is applied to the digital circuit 2a. I have to. Note that R1 and R2 are bias resistances. The other configurations are the same as those in the above embodiment.

<Effects of the Invention> As described above, according to the present invention, a sine wave is generated, this sine wave is given to the digital circuit as a basic clock, and the digital circuit side uses it as a square wave clock. Compared to the conventional example in which a square wave containing many wave components is used as a basic clock to a digital circuit, noise is reduced, unnecessary radiation is suppressed, and the stability of the circuit is improved.

[Brief explanation of the drawing]

FIG. 1 is a schematic block diagram of one embodiment of the present invention, FIG. 2 is a schematic block diagram of another embodiment, FIG. 3 is a frequency spectrum of a sine wave, and FIG. 4 is a frequency spectrum of a square wave. 1... Basic clock generation circuit, 2... Digital circuit, 3... Sine wave oscillation circuit, 5... Inverter.

Claims (1)

[Claims] (1) In a digital device comprising a basic clock generation circuit that generates a basic clock and a digital circuit to which the basic clock from the basic clock generation circuit is given, the basic clock generation circuit generates a sine wave to generate the basic clock. A sine wave oscillator circuit that outputs a clock to a digital circuit is provided, and the digital circuit is provided with a waveform shaping circuit that slices the sine wave at a predetermined level and generates a square wave clock at a basic clock input section. A digital device characterized by: