CN213279679U - Spread spectrum clock crystal oscillator - Google Patents

Abstract

The utility model relates to an electromagnetic compatibility technical field just discloses a spread spectrum clock crystal oscillator, including spreading the spectrum crystal oscillator, it is connected with central processing unit to spread the spectrum crystal oscillator, central processing unit electric connection has synchronous clock, synchronous clock is electric connection 32 bit wide clock chip treater, bluetooth sleep clock, audio digital analog converter respectively. The utility model discloses mainly through expanding spectrum crystal oscillator and central processing unit with the clock signal of synchronous clock according to certain law shake, make signal spectral line widen, and the receiver receiving bandwidth who uses with synchronous clock is certain, consequently when spectral line widen, some energy is outside the bandwidth of receiver, thereby make the measured value diminish, and harmonic frequency is higher, the suppression effect is better, and make the product pass through the electromagnetic compatibility experiment easily through expanding spectrum synchronous clock, its energy in whole frequency range does not change.

Description

Spread spectrum clock crystal oscillator

Technical Field

The utility model relates to an electromagnetic compatibility technical field specifically is a spread spectrum clock crystal oscillator.

Background

In order to solve the above problems, a person skilled in the art generally adopts an RLC filtering technology to suppress clock harmonics, but the filtering function is local, and only partial harmonic components of one path of clock can be reduced, the harmonic components can be recovered again after the frequency division, frequency multiplication or redriving of the path of clock, and the problem of radiation superscript in electromagnetic compatibility still exists.

SUMMERY OF THE UTILITY MODEL

The utility model provides a not enough to prior art, the utility model provides a spread spectrum clock crystal oscillator has solved the problem that above-mentioned background art provided.

The utility model provides a following technical scheme: a spread spectrum clock crystal oscillator comprises a spread spectrum crystal oscillator, wherein the spread spectrum crystal oscillator is connected with a central processing unit, the central processing unit is electrically connected with a synchronous clock, and the synchronous clock is respectively and electrically connected with a 32-bit wide clock chip processor, a Bluetooth sleep clock and an audio digital-to-analog converter.

Preferably, the reference frequency generated by the spectrum-spreading crystal oscillator is subjected to frequency division, frequency multiplication or driving by the central processing unit, and the synchronous clock of the spectrum-spreading crystal oscillator is subjected to spectrum spreading.

Preferably, the receiving device of the synchronous clock connection is a receiver.

Compared with the prior art, the utility model discloses possess following beneficial effect:

1. the utility model discloses mainly through expanding spectrum crystal oscillator and central processing unit with the clock signal of synchronous clock according to certain law shake, make signal spectral line widen, and the receiver receiving bandwidth supporting with synchronous clock is certain, consequently when spectral line widen, some energy is outside the bandwidth of receiver, thereby make the measured value diminish, and harmonic frequency is higher, the suppression effect is better, and make the product pass through the electromagnetic compatibility experiment easily through expanding spectrum synchronous clock, its energy in whole frequency range does not change.

Drawings

FIG. 1 is a schematic view of the structure and operation principle of the present invention;

FIG. 2 is a schematic diagram of the harmonic curve of the clock of the standard clock of the structure of the present invention;

FIG. 3 is a schematic diagram of the harmonic curve of the structure spread spectrum crystal oscillator clock of the present invention;

FIG. 4 is a graph illustrating the data curve of the RC filtering experiment of the present invention;

fig. 5 is a graph showing experimental data curves of the structure expanding crystal oscillator of the present invention.

In the figure: 1. a spread spectrum crystal oscillator; 2. a central processing unit; 3. synchronizing the clocks; 4. a 32-bit wide clock chip processor; 5. a Bluetooth sleep clock; 6. an audio digital-to-analog converter.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Referring to fig. 1-5, a spread spectrum clock crystal oscillator includes a spread spectrum crystal oscillator 1, the spread spectrum crystal oscillator 1 is connected to a central processing unit 2, the central processing unit 2 is electrically connected to a synchronous clock 3, a reference frequency generated by the spread spectrum crystal oscillator 1, and the synchronous clock 3 whose reference frequency is divided, multiplied or driven by the central processing unit 2 has spread spectrum, a receiving device connected to the synchronous clock 3 is a receiver, the clock signal of the synchronous clock 3 is dithered according to a certain rule by the spread spectrum crystal oscillator 1 and the central processing unit 2 to widen the signal spectrum, and the receiving bandwidth of the receiver matched with the synchronous clock 3 is certain, so when the spectrum is widened, a part of energy is out of the bandwidth of the receiver, thereby making the measured value smaller, and the higher the harmonic frequency, the better the suppression effect, and the product is easy to pass the electromagnetic compatibility experiment by the spread spectrum synchronous clock 3, the energy of the synchronous clock 3 in the whole frequency range is not changed, and the synchronous clock is electrically connected with a 32-bit wide clock chip processor 4, a Bluetooth sleep clock 5 and an audio digital-to-analog converter 6 respectively.

The working principle is as follows: when in use, the RC filtering and the spectrum-spreading clock crystal oscillator radiation data comparison are adopted, firstly, the harmonic components of an SD clock and a screen clock of an electronic product cause radiation problems, the RC filtering experiment is adopted on two clock lines, after the completion, data are stored and an RC filtering experiment data curve graph is drawn, then, a spectrum-passing crystal oscillator in the SD clock is replaced by a spectrum-spreading crystal oscillator 1, the Spread percent is set to be 1.0%, the Frequency Stability is set to be 20PPM, the data storage and the spectrum-spreading crystal oscillator experiment data curve graph are drawn, the data comparison between the two is realized, a spectrum-spreading clock crystal oscillator scheme is adopted, the spectrum spreading is carried out on the SD clock and the screen clock, the harmonic component inhibition is obvious, the test data are superior to the RC filtering, in addition, different radiation test results can be obtained by adjusting the spectrum-spreading clock crystal oscillator parameters within an allowable range,

it is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Simultaneously in the utility model discloses an in the drawing, fill the pattern and just do not do any other injecions for distinguishing the picture layer.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (3)

1. A spread spectrum clock crystal oscillator comprises a spread spectrum crystal oscillator (1) and is characterized in that: the spread spectrum crystal oscillator (1) is connected with a central processing unit (2), the central processing unit (2) is electrically connected with a synchronous clock (3), and the synchronous clock (3) is respectively and electrically connected with a 32-bit wide clock chip processor (4), a Bluetooth sleep clock (5) and an audio digital-to-analog converter (6).

2. The spread spectrum clock crystal of claim 1, wherein: the reference frequency generated by the spectrum-spreading crystal oscillator (1) is subjected to frequency division, frequency multiplication or driving by the central processing unit (2), and the synchronous clock (3) of the spectrum-spreading crystal oscillator (1) is subjected to spectrum spreading.

3. The spread spectrum clock crystal of claim 1, wherein: and the receiving equipment connected with the synchronous clock (3) is a receiver.

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