CN102820772A - Pulse-width modulation (PWM) method and system based on direct spread spectrum technology - Google Patents
Pulse-width modulation (PWM) method and system based on direct spread spectrum technology Download PDFInfo
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- CN102820772A CN102820772A CN2012102822497A CN201210282249A CN102820772A CN 102820772 A CN102820772 A CN 102820772A CN 2012102822497 A CN2012102822497 A CN 2012102822497A CN 201210282249 A CN201210282249 A CN 201210282249A CN 102820772 A CN102820772 A CN 102820772A
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Abstract
The invention discloses a pulse-width modulation (PWM) method and a PWM system based on a direct spread spectrum technology, wherein the method comprises the following steps that step S1, a series of PWM signals and a series of spread spectrum sequences are taken as input signals to be input into a direct spread spectrum arithmetic unit; step S2, the direct spread spectrum arithmetic unit takes one reference signal as standard for carrying out direct spread spectrum operation on the PWM signals and the spread spectrum sequences within a specialized range; step S3, the output state is determined according to the calculation result of the step S2; and S4, the steps S1, S2 and S3 are carried out in a circulating manner to obtain the random direct spread spectrum PWM signal, and the PWM signal is processed for driving a switching tube or directly being used for driving the switching tube. The method is used for solving the problem that the existing switching power supply cannot satisfy the design requirement when being used for inhibiting electro-magnetic interference (EMI), and the power efficiency is improved to a certain extent; and the method has the characteristics of simplicity, high efficiency, controllable modulation and good randomness within the specialized range.
Description
Technical field
The invention belongs to the switch power supply EMI technical field, relate to a kind of PWM (pulse width modulation) modulator approach, relate in particular to a kind of PWM modulator approach based on the Direct-Spread technology; Simultaneously, the invention still further relates to a kind of PWM modulating system based on the Direct-Spread technology.
Background technology
Development along with electronic industry; Various electronic products are also increasingly high to the requirement of power supply; Switching Power Supply is little with volume, loss is little, the efficient advantages of higher; Obtained fast development in field of power supplies, its range of application also more and more widely, switch power technology has become the mainstream technology in the field of power supplies.
But when being applied in the equipment such as communication, instrument and meter, the electromagnetic interference (EMI) that the switching pulse of Switching Power Supply and harmonic wave thereof and parasitic oscillation bring makes that some performance or the index in these systems has decline in various degree.How to reduce Switching Power Supply to other equipment in the system and extraneous electromagnetic interference, be inevitable problem in the power supply design always.Usually, according to the difference of propagation path, the electromagnetic interference that Switching Power Supply produces can be divided into conducted interference and radiated interference two big classes, and conducted interference is propagated along input, the output line of power supply; And radiated interference belongs to radio frequency interference, is main with space radiation.
To the different characteristics of conducted interference and radiated interference, the traditional method that suppresses EMI is respectively to adopt filtering and shield technology.As long as reasonable in design, effect is all apparent in view.But, but be difficult to meet design requirement in some occasion.Spread spectrum is a kind of new technology that is applied in the wireless communication field originally; It is extended to one to RF energy than in the wider frequency through frequency modulation(FM); Spread spectrum is mainly used in square-wave signal, and square-wave signal is made up of fundamental frequency signal and its odd harmonic.And main electromagnetic radiation energy comes from fundamental frequency signal, 3 times and 5 order harmonic components.With the Energy distribution of fundamental frequency signal in certain frequency range, simultaneously also with the Energy distribution of its each harmonic to a wider frequency range.Because through the frequency range of ovennodulation nth harmonic be fundamental frequency scope after ovennodulation n doubly.
Summary of the invention
Technical problem to be solved by this invention is: a kind of PWM modulator approach based on the Direct-Spread technology is provided; Can solve present Switching Power Supply and suppress the problem that EMI is difficult to meet design requirement; And improved power-efficient to a certain extent, have simple, efficient, modulation degree is controlled, in the good characteristics of claimed range randomness.
In addition; The present invention also provides a kind of PWM modulating system based on the Direct-Spread technology; Can solve present Switching Power Supply and suppress the problem that EMI is difficult to meet design requirement; And improved power-efficient to a certain extent, have simple, efficient, modulation degree is controlled, in the good characteristics of claimed range randomness.
For solving the problems of the technologies described above, the present invention adopts following technical scheme:
A kind of PWM modulator approach based on the Direct-Spread technology, said method comprises the steps:
Step S1, a row pwm signal and a row frequency expansion sequence are inputed to a direct spread spectrum arithmetic element as input signal;
Step S2, said Direct-Spread arithmetic element are as the criterion with a reference signal, and pwm signal and frequency expansion sequence are carried out the Direct-Spread computing in prescribed limit;
Step S3, decide the state of output according to the operation result of step S2;
Step S1, step S2, step S3 are carried out in step S4, circulation, obtain the pwm signal of Direct-Spread at random, and this pwm signal is handled the rear drive switching tube, or direct driving switch pipe.
As a kind of preferred version of the present invention, said step S1 also comprises: utilize a pwm signal generation unit to generate modulated pwm signal; The frequency expansion sequence that utilizes a frequency expansion sequence generation unit generation to need.
As a kind of preferred version of the present invention, among the said step S2, said Direct-Spread arithmetic element directly utilizes the spread spectrum code sequence with high code check to adopt various modulation systems to come spread-spectrum; The pseudo noise code of information source and setting is carried out mould two to be added; The handling process of Direct-Spread computing comprises: under triggering signal control, directly pwm signal and pseudo random sequence are carried out XOR.
As a kind of preferred version of the present invention, among the said step S2, modulated pwm signal is selected modulation range arbitrarily.
As a kind of preferred version of the present invention, the reference signal among the said step S2 is produced by inside or is provided by the outside.
As a kind of preferred version of the present invention, among the said step S3, decide its output height state by the normal distribution result who exports; Perhaps operation result is used hash algorithm or inferior power operation, decide its output height state by hash algorithm or inferior power operation result; Perhaps directly the compute mode of determining step S2 is " 1 " or " 0 ", exports its height state.
As a kind of preferred version of the present invention, among the said step S4, pwm signal handled comprise: the PWM to behind the spread spectrum amplifies, takes a sample, gathers one or more in edge, extending length, denoising, the dual sampling of electric current and voltage.
A kind of PWM modulating system based on the Direct-Spread technology, said system comprises:
The pwm signal generation unit is in order to generate modulated pwm signal;
The frequency expansion sequence generation unit is in order to generate frequency expansion sequence;
Signal input unit, the frequency expansion sequence that pwm signal that is used for said pwm signal generation unit is generated and frequency expansion sequence generation unit generate inputs to a direct spread spectrum arithmetic element as input signal;
The Direct-Spread arithmetic element is used for being as the criterion with a reference signal, and pwm signal and frequency expansion sequence are carried out the Direct-Spread computing in prescribed limit;
The state output unit decides the state of output in order to the operation result according to said Direct-Spread arithmetic element.
As a kind of preferred version of the present invention, said system also comprises: signal processing unit is used for after handling through the pwm signal at random of Direct-Spread, being used for the driving switch pipe.
As a kind of preferred version of the present invention, said system also comprises: the modulation range selected cell, and in order to the modulation range of the modulated pwm signal of any selection.
As a kind of preferred version of the present invention, said reference signal is produced by inside or is provided by the outside.
As a kind of preferred version of the present invention, said system utilizes programmable logic device, in programmable logic device, accomplishes, and perhaps utilizes separation module to accomplish.
Beneficial effect of the present invention is: PWM modulator approach and system based on the Direct-Spread technology that the present invention proposes; PWM and frequency expansion sequence are sent into arithmetic unit carry out computing; This arithmetic unit then is for the Direct-Spread of accomplishing PWM and this frequency expansion sequence specially designs, and uses this method just can the specific part that be as the criterion with this frequency expansion sequence to PWM be carried out Direct-Spread.The invention solves present Switching Power Supply and suppress the problem that EMI is difficult to meet design requirement, and improved power-efficient to a certain extent, have simple, efficient, modulation degree is controlled, in the good characteristics of claimed range randomness.
Description of drawings
Fig. 1 is the action principle figure that the present invention is based on the PWM modulating system of Direct-Spread technology.
Fig. 2 is the composition sketch map that the present invention is based on the PWM modulating system of Direct-Spread technology.
Fig. 3 is the Organization Chart of PWM modulating system of the present invention in programmable logic device.
Embodiment
Specify the preferred embodiments of the present invention below in conjunction with accompanying drawing.
Embodiment one
See also Fig. 1, Fig. 2; The present invention has disclosed a kind of PWM modulating system based on the Direct-Spread technology, and said system comprises: pwm signal generation unit 11, frequency expansion sequence generation unit 12, signal input unit 13, modulation range selected cell 14, Direct-Spread arithmetic element 15, state output unit 16, signal processing unit 17.
Pwm signal generation unit 11 is in order to generate modulated pwm signal.
Frequency expansion sequence generation unit 12 is in order to generate frequency expansion sequence.
The frequency expansion sequence that pwm signal that signal input unit 13 is used for pwm signal generation unit 11 is generated and frequency expansion sequence generation unit 12 generate inputs to Direct-Spread arithmetic element 15 as input signal.
Modulation range selected cell 14 is in order to select the modulation range of modulated pwm signal arbitrarily as required.
Direct-Spread arithmetic element 15 is used for being as the criterion with a reference signal, and pwm signal and frequency expansion sequence are carried out the Direct-Spread computing in prescribed limit.Said Direct-Spread arithmetic element directly utilizes the spread spectrum code sequence with high code check to adopt various modulation systems to come spread-spectrum; The pseudo noise code of information source and setting is carried out mould two to be added.In the present embodiment, the handling process of Direct-Spread computing includes but not limited to: under triggering signal control, directly pwm signal and pseudo random sequence are carried out XOR.In addition, be not too large in prescribed limit in order to confirm the band spectrum modulation rate, be no more than 20% such as the modulation rate of regulation frequency expansion sequence and PWM.Said reference signal is produced by inside or is provided by the outside.
State output unit 16 decides the state of output in order to the operation result according to said Direct-Spread arithmetic element.Concrete mode includes but not limited to: the normal distribution result by output decides its output height state; Perhaps operation result is used hash algorithm or inferior power operation, decide its output height state by hash algorithm or inferior power operation result; Perhaps directly the compute mode of determining step S2 is " 1 " or " 0 ", exports its height state.Owing to judge not to be changeless here, only illustrate here: such as, or the state of after computing, judging is 10, is output as high level for a long time when 1 to 0 so, 1 to 0 output low level after a little while, and 1 exports high-impedance state when identical with 0.
Signal processing unit 17 is used for the pwm signal at random through Direct-Spread is handled, and the signal after the processing is used for the driving switch pipe; Certainly, also can be without signal processing unit, and the pwm signal at random that directly will pass through Direct-Spread is used for the driving switch pipe.
System of the present invention can utilize programmable logic device, in programmable logic device, accomplish, and also can utilize separation module to accomplish.As shown in Figure 3, in the present embodiment, system of the present invention utilizes programmable logic device to accomplish.
More than introduced the composition of the PWM modulating system that the present invention is based on the Direct-Spread technology, the present invention has also disclosed a kind of PWM modulator approach based on the Direct-Spread technology when disclosing said system, and said method comprises the steps:
[step S1] inputs to a direct spread spectrum arithmetic element with a row pwm signal and a row frequency expansion sequence as input signal.Particularly, utilize the pwm signal generation unit to generate modulated pwm signal; The frequency expansion sequence that utilizes the generation of frequency expansion sequence generation unit to need.
[step S2] said Direct-Spread arithmetic element is as the criterion (said reference signal is produced by inside or provided by the outside) with a reference signal, and pwm signal and frequency expansion sequence are carried out the Direct-Spread computing in prescribed limit.Modulated pwm signal can be selected modulation range arbitrarily, and carries out the Direct-Spread modulation.Said Direct-Spread arithmetic element directly utilizes the spread spectrum code sequence with high code check to adopt various modulation systems to come spread-spectrum; The pseudo noise code of information source and setting is carried out mould two to be added.In the present embodiment, the handling process of Direct-Spread computing includes but not limited to: under triggering signal control, directly pwm signal and pseudo random sequence are carried out XOR.In addition, be not too large in prescribed limit in order to confirm the band spectrum modulation rate, be no more than 20% such as the modulation rate of regulation frequency expansion sequence and PWM.
[step S3] decides the state of output according to the operation result of step S2.Concrete mode includes but not limited to: the normal distribution result by output decides its output height state; Perhaps operation result is used hash algorithm or inferior power operation, decide its output height state by hash algorithm or inferior power operation result; Perhaps directly the compute mode of determining step S2 is " 1 " or " 0 ", exports its height state.Owing to judge not to be changeless here, only illustrate here: such as, or the state of after computing, judging is 10, is output as high level for a long time when 1 to 0 so, 1 to 0 output low level after a little while, and 1 exports high-impedance state when identical with 0.
Step S1, step S2, step S3 are carried out in [step S4] circulation, obtain the pwm signal of Direct-Spread at random, are used for the driving switch pipe after this pwm signal is handled, or directly are used for the driving switch pipe, thereby reach technique effect of the present invention.The mode that pwm signal is handled includes but not limited to: the PWM to behind the spread spectrum amplifies, takes a sample, gathers edge, extending length, denoising, the dual sampling of electric current and voltage or the like.PWM behind the Direct-Spread here be without the PWM of spread spectrum through the random sequence modulation and come, the PWM that is equivalent to behind the spread spectrum has just done some change on original PWM.
In sum; PWM modulator approach and system that the present invention proposes based on the Direct-Spread technology; PWM and frequency expansion sequence are sent into arithmetic unit carry out computing; This arithmetic unit then is for the Direct-Spread of accomplishing PWM and this frequency expansion sequence specially designs, and uses this method just can the specific part that be as the criterion with this frequency expansion sequence to PWM be carried out Direct-Spread.The invention solves present Switching Power Supply and suppress the problem that EMI is difficult to meet design requirement, and improved power-efficient to a certain extent, have simply, efficient, modulation degree is controlled, in the good characteristics of claimed range randomness.
Here description of the invention and application is illustrative, is not to want with scope restriction of the present invention in the above-described embodiments.Here the distortion of the embodiment that is disclosed and change are possible, and the replacement of embodiment is known with the various parts of equivalence for those those of ordinary skill in the art.Those skilled in the art are noted that under the situation that does not break away from spirit of the present invention or substantive characteristics, and the present invention can be with other form, structure, layout, ratio, and realize with other assembly, material and parts.Under the situation that does not break away from the scope of the invention and spirit, can carry out other distortion and change here to the embodiment that is disclosed.
Claims (11)
1. the PWM modulator approach based on the Direct-Spread technology is characterized in that said method comprises the steps:
Step S1, a row pwm signal and a row frequency expansion sequence are inputed to a direct spread spectrum arithmetic element as input signal;
Step S2, said Direct-Spread arithmetic element are as the criterion with a reference signal, and pwm signal and frequency expansion sequence are carried out the Direct-Spread computing in prescribed limit;
Step S3, decide the state of output according to the operation result of step S2;
Step S1, step S2, step S3 are carried out in step S4, circulation, obtain the pwm signal of Direct-Spread at random, are used for the driving switch pipe after this pwm signal is handled, or directly are used for the driving switch pipe.
2. the PWM modulator approach based on the Direct-Spread technology according to claim 1, it is characterized in that: said step S1 also comprises:
Utilize a pwm signal generation unit to generate modulated pwm signal;
The frequency expansion sequence that utilizes a frequency expansion sequence generation unit generation to need.
3. the PWM modulator approach based on the Direct-Spread technology according to claim 1 is characterized in that:
Among the said step S2, said Direct-Spread arithmetic element directly utilizes the spread spectrum code sequence with high code check to adopt various modulation systems to come spread-spectrum; The pseudo noise code of information source and setting is carried out mould two to be added; The handling process of Direct-Spread computing comprises: under triggering signal control, directly pwm signal and pseudo random sequence are carried out XOR.
4. the PWM modulator approach based on the Direct-Spread technology according to claim 1 is characterized in that:
Among the said step S2, modulated pwm signal is selected modulation range arbitrarily; Reference signal among the said step S2 is produced by inside or is provided by the outside.
5. the PWM modulator approach based on the Direct-Spread technology according to claim 1 is characterized in that:
Among the said step S3, decide its output height state by the normal distribution result who exports; Perhaps operation result is used hash algorithm or inferior power operation, decide its output height state by hash algorithm or inferior power operation result; Perhaps directly the compute mode of determining step S2 is " 1 " or " 0 ", exports its height state.
6. the PWM modulator approach based on the Direct-Spread technology according to claim 1 is characterized in that:
Among the said step S4, pwm signal handled comprise: the PWM to behind the spread spectrum amplifies, takes a sample, gathers one or more in edge, extending length, denoising, the dual sampling of electric current and voltage.
7. PWM modulating system based on Direct-Spread technology is characterized in that said system comprises:
The pwm signal generation unit is in order to generate modulated pwm signal;
The frequency expansion sequence generation unit is in order to generate frequency expansion sequence;
Signal input unit, the frequency expansion sequence that pwm signal that is used for said pwm signal generation unit is generated and frequency expansion sequence generation unit generate inputs to a direct spread spectrum arithmetic element as input signal;
The Direct-Spread arithmetic element is used for being as the criterion with a reference signal, and pwm signal and frequency expansion sequence are carried out the Direct-Spread computing in prescribed limit;
The state output unit decides the state of output in order to the operation result according to said Direct-Spread arithmetic element.
8. the PWM modulating system based on the Direct-Spread technology according to claim 7 is characterized in that:
Said system also comprises: signal processing unit is used for after handling through the pwm signal at random of Direct-Spread, being used for the driving switch pipe.
9. the PWM modulating system based on the Direct-Spread technology according to claim 7 is characterized in that:
Said system also comprises: the modulation range selected cell, and in order to the modulation range of the modulated pwm signal of any selection.
10. the PWM modulating system based on the Direct-Spread technology according to claim 7 is characterized in that:
Said reference signal is produced by inside or is provided by the outside.
11. the PWM modulating system based on the Direct-Spread technology according to claim 7 is characterized in that:
Said system utilizes programmable logic device, in programmable logic device, accomplishes, and perhaps utilizes separation module to accomplish.
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| CN103368538A (en) * | 2013-06-18 | 2013-10-23 | 国家电网公司 | Switching frequency range-adjustable digital PWM (pulse-width modulation) device and method |
| CN104901605A (en) * | 2014-03-04 | 2015-09-09 | 广州汽车集团股份有限公司 | Automobile air-conditioning system and blower speed regulation controller thereof |
| CN107819423A (en) * | 2016-09-13 | 2018-03-20 | 福特全球技术公司 | Pseudo-random pulse width modulated change based on motor operations point |
| CN115694146A (en) * | 2022-12-30 | 2023-02-03 | 珠海智融科技股份有限公司 | Spread spectrum control circuit, power supply system, spread spectrum control method and controller |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN103368538A (en) * | 2013-06-18 | 2013-10-23 | 国家电网公司 | Switching frequency range-adjustable digital PWM (pulse-width modulation) device and method |
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