CN110212752A - A kind of noise reduction filtering circuit - Google Patents
A kind of noise reduction filtering circuit Download PDFInfo
- Publication number
- CN110212752A CN110212752A CN201910461246.1A CN201910461246A CN110212752A CN 110212752 A CN110212752 A CN 110212752A CN 201910461246 A CN201910461246 A CN 201910461246A CN 110212752 A CN110212752 A CN 110212752A
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- Prior art keywords
- capacitor
- mode inductance
- differential mode
- coil
- noise reduction
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/44—Circuits or arrangements for compensating for electromagnetic interference in converters or inverters
Abstract
The present invention provides a kind of noise reduction filtering circuits, belong to field of communication technology.The noise reduction filtering circuit, including common mode inductance, the first differential mode inductance, the second differential mode inductance, first capacitor and the second capacitor；The common mode inductance includes toroidal core, first coil and the second coil；The first coil includes first input end and the first output end, and second coil includes the second input terminal and second output terminal.The invention realizes noise reduction by adding a differential mode inductance on the circuit GND.
Description
Technical field
The invention belongs to fields of communication technology, and in particular to a kind of noise reduction filtering circuit.
Background technique
As automotive electronic technology continues to develop, circuit work frequency is gradually increased, and power is gradually increased, so that automobile work
Make to be flooded with electromagnetic wave in environment, electromagnetic interference problem is caused to become increasingly conspicuous, gently then will affect equipment normal work, it is heavy then direct
Electronic component is damaged, equipment failure is caused.
The target of electromagnetic compatibility be related to the distinct device of electromagnet phenomenon under identical environment to run well, and
Insufferable electromagnetic interference is not generated to any equipment in environment.Electromagnetic compatibility problem is that all engineers have to face
The problem of, electromagnetic compatibility technology is concerning automobile particular electronic system and its security reliability of ambient electron system operation.And shadow
An important parameter for ringing Electro Magnetic Compatibility, is the conduction noise signal in signal transduction process.
In the prior art, noise reduction is filtered frequently with EMI FILTER technology.EMI FILTER technology
It is that two parts are filtered by common mode filtering and differential mode to carry out noise reduction process.
Common mode filtering is that filtering is realized by setting common mode inductance.Common mode inductance is that two coils are wound on same iron core
On, the number of turns and phase are all identical (coiling is reversed).In this way, electric current is same when the normal current in circuit flows through common mode inductance
Reversed magnetic field is generated in the inductance coil of phase coiling and is cancelled out each other, and normal signal electric current is mainly by coil resistance at this time
It influences (and on a small quantity because being damped caused by leakage inductance)；When there is common mode current flowing through coil, due to the same tropism of common mode current, meeting exists
The interior induction reactance for generating magnetic field in the same direction and increasing coil of coil, makes coil show as high impedance, generates stronger damping, with
This attenuation common-mode electric current, achievees the purpose that filtering.
Differential mode filtering is connected in parallel with a capacitor between power positive end and negative terminal, and a differential mode electricity is concatenated on positive terminal line road
Sense constitutes differential mode filter circuit.Differential mode filtering can reduce the noise on the power supply of electric current return loop line.In this way, on power supply line
Noise be present on shell and loop line.Differential mode inductance is arranged in power line can block the transmitting of noise, while in power supply
It capacitor is set between loop line, is capable of forming noise impedance path, filtering is achieved the purpose that with this.
But after being filtered noise reduction by existing EMI FILTER technology, after still thering is conduction noise to enter
Grade circuit, influences the stability of late-class circuit system and may interfere with ambient electronics.
Summary of the invention
The purpose of the invention is to overcome above-mentioned the deficiencies in the prior art, a kind of noise reduction filtering circuit is provided.The circuit
By adding a differential mode inductance on the circuit GND, conduction noise is reduced to realize.
In order to achieve the above objectives, the present invention adopts the following technical scheme:
A kind of noise reduction filtering circuit, including common mode inductance, the first differential mode inductance, the second differential mode inductance, first capacitor and
Two capacitors；The common mode inductance includes toroidal core, first coil and the second coil；The first coil and second coil
It is symmetrically wound on the toroidal core, and coiling is contrary；The first coil includes first input end and first
Output end, second coil include the second input terminal and second output terminal, the first input end and the second output terminal
Positioned at the identical side of the toroidal core, it is identical that first output end and second input terminal are located at the toroidal core
The other side；The first input end is connected with one end of first differential mode inductance, the second output terminal and described second
One end of differential mode inductance is connected, and the other end of the other end of first differential mode inductance and second differential mode inductance passes through described
First capacitor series connection；First output end is connected with second input terminal by second capacitor；First differential mode
It is equipped with input port between inductance and the first capacitor, output end is equipped between first output end and second capacitor
Mouthful；The first capacitor and second differential mode inductance indirectly, between second capacitor and second input terminal
Ground connection.
Further, the first coil is identical with second coil dimension, and the number of turns is identical.
Further, the first capacitor and second capacitor are patch capacitor.
Compared with prior art, beneficial effects of the present invention:
A kind of noise reduction filtering circuit provided by the invention is effectively dropped by adding a differential mode inductance on the circuit GND
The low conduction noise at electric power loop end greatly reduces influence of the conduction noise to late-class circuit.Pass through this noise reduction filtering
The technology for the reduction conduction noise that circuit is realized, applied widely and noise reduction effect is significant, such as can be used for realizing automotive grade electricity
The stabilization of sub- Electromagnetic Compatibility；The electromagnetism that environment where system equipment can also be enable to resist it when operating normally generates
Interference, and interference will not be generated to the equipment in environment.
Detailed description of the invention
Fig. 1 is a kind of circuit diagram of noise reduction filtering circuit described in the invention.
Fig. 2 is a kind of principle of noise reduction schematic diagram of noise reduction filtering circuit described in the invention.
Fig. 3 is the EMC Test Drawing of basic filter circuit in the prior art.
Fig. 4 is that the EMC Test Drawing after filter capacitor is added in the front and back of basic filter circuit in the prior art.
Fig. 5 is a kind of EMC Test Drawing of noise reduction filtering circuit described in the invention.
Description of symbols:
Input port VDC
Output port Vout
It is grounded GND
First differential mode inductance L1
Second differential mode inductance L2
First capacitor C1
Second capacitor C2
Common mode inductance CM1
Second output terminal 1
Second input terminal 2
First input end 3
First output end 4
Specific embodiment
To keep the technical problem to be solved in the present invention, technical solution and advantage clearer, below in conjunction with attached drawing and tool
Body embodiment is described in detail.
It please refers to shown in Figure of description 1.
The present invention provides a kind of noise reduction filtering circuits, including common mode inductance CM1, the first differential mode inductance L1, the second differential mode
Inductance L2, first capacitor C1 and the second capacitor C2；The common mode inductance CM1 includes toroidal core, first coil and the second coil；
The first coil and second coil are symmetrically wound on the toroidal core, and coiling is contrary；Described
One coil includes first input end 3 and the first output end 4, and second coil includes the second input terminal 2 and second output terminal 1,
The first input end 3 and the second output terminal 1 are located at the identical side of the toroidal core, 4 He of the first output end
Second input terminal 2 is located at the identical other side of the toroidal core；The first input end 3 and first differential mode inductance
One end of L1 is connected, and the second output terminal 1 is connected with one end of the second differential mode inductance L2, the first differential mode inductance L1
The other end connected with the other end of the second differential mode inductance L2 by the first capacitor C1；First output end 4 with
Second input terminal 2 is connected by the second capacitor C2；Between the first differential mode inductance L1 and the first capacitor C1
Equipped with input port VDC, output port Vout is equipped between first output end 4 and the second capacitor C2；Described first
The GND indirectly of capacitor C1 and the second differential mode inductance L2, also connect between the second capacitor C2 and second input terminal 2
Ground GND.
As preferred and non-limiting, the first coil is identical with second coil dimension, and the number of turns is identical.
As preferred and non-limiting, the first capacitor C1 and the second capacitor C2 are patch capacitor.
It please refers to shown in Figure of description 2.
A kind of principle of noise reduction of noise reduction filtering circuit provided by the present invention is as follows:
Power supply is connect with input port VDC, after power supply flows through the first differential mode inductance L1, then from the of common mode inductance CM1
One input terminal 3 flows into, and the outflow of the first output end 4 flows through the second capacitor C2；GND loop current is defeated from the second of common mode inductance CM1
Enter end 2 to flow into, second output terminal 1 flows out, then returns to the ground connection GND of input terminal by the second differential mode inductance L2.
First differential mode inductance L1 can hinder the conduction noise of power supply, and conduction noise is made to flow to ground connection from first capacitor C1
The end GND filters.Common mode inductance CM1 provides balanced impedance, i.e., provides identical impedance to source and loop line, further filter out noise.
Conduction noise on the circuit GND can be hindered, make it through first capacitor C1 and flow back to input port by the second differential mode inductance L2
VDC greatly reduces influence of the conduction noise to late-class circuit.
It please refers to shown in Figure of description 3, attached drawing 4 and attached drawing 5.
In the present embodiment, Fig. 3, Fig. 4 and Fig. 5 are obtained after carrying out EMC test to three kinds of different Dolby circuits respectively
EMC Test Drawing.EMC test, which is called, does electromagnetic compatibility test, refers to interfering electronic product in terms of electromagnetic field size and resist
The Comprehensive Assessment of interference performance is one of most important index of product quality.EMC test purpose is produced by detection electric equipment products
Influence of the electromagnetic radiation to the electric equipment products of human body, public electric wire net and other normal works.Using survey customary in the art
Amount method passes through wave detector, frequency spectrum such as conduction interference peak limit value-voltage method and conduction interference average value limit value-voltage method
The equipment such as analyzer, scanning radio measure three kinds of different Dolby circuits, it can be seen that most in spectrum analyzer
Whole measurement result.By observation spectrum analyzer waveform diagram at different frequencies, and by itself and GBT18655-2010
The standard value of Class3 compares, and can intuitively find out the technical effect of noise reduction.The mark of 2010 Class3 of GBT18655-
It is quasi- as follows.
2010 Class3_PK peaks demand of GBT18655-is exemplified below:
LW wave band (0.15~0.3MHz) is 90dB (μ V), and MW wave band (0.53~1.8MHz) is 70dB (μ V), SW wave band
(5.9~6.2MHz) is 65dB (μ V), and FM wave band (76~108MHz) is 50dB (μ V), and TV frequency range I wave band (41~88MHz) is
46dB (μ V), VHF wave band (30~54MHz) are 56dB (μ V).
2010 Class3_AV average value of GBT18655-requires to be exemplified below:
LW wave band (0.15~0.3MHz) is 70dB (μ V), and MW wave band (0.53~1.8MHz) is 50dB (μ V), SW wave band
(5.9~6.2MHz) is 45dB (μ V), and FM wave band (76~108MHz) is 30dB (μ V), and TV frequency range I wave band (41~88MHz) is
36dB (μ V), VHF wave band (30~54MHz) are 36dB (μ V).
Analysis result after test is as follows.
Basic filter circuit in the prior art, be by common mode inductance CM1, the first differential mode inductance L1, first capacitor C1 and
Second capacitor C2 is constituted.Common mode inductance CM1 and the second capacitor C2 filtering common mode noise.First differential mode inductance L1 and first capacitor C1
Filter out differential mode noise.EMC test is carried out using this basic filter circuit, test result is as shown in figure 3, numerical value expression in figure
It is the abscissa and ordinate at corresponding inverted triangle, i.e. the average value of frequency and measurement, concrete example is as follows: in 200kHz frequency
The average value measured under rate is 81.809dB (μ V), and the average value of LW wave band corresponding higher than its requires 70dB (μ V), admittedly it is not inconsistent
Close the standard of GBT18655-2010 Class3_AV；Similarly, it can be seen that in 530kHz, 39.8MHz, 87.55MHz frequency
The average value of lower measurement is respectively 65.33dB (μ V), 66.491dB (μ V), 71.955dB (μ V), respectively higher than its correspondence wave band
Average value requirement, admittedly do not comply with the standard of GBT18655-2010 Class3_AV.(experimental result can also directly observe ratio
Compared with average value/peak value measured waveform figure and standard value waveform diagram, the part that measured waveform is higher by standard value waveform is not meet
Wave band) test result shows that its noise reduction effect is undesirable.
Filter capacitor is added in the front and back of basic filter circuit in the above prior art, and noise reduction effect is without significant change.
Its EMC test result is as shown in figure 4, what numerical value indicated in figure is abscissa and ordinate at corresponding inverted triangle, i.e. frequency
With the peak value of measurement, concrete example is as follows: the peak value measured under 270kHz frequency is 95.584dB (μ V), and it is corresponding to be higher than its
The peaks demand 90dB (μ V) of LW wave band, admittedly do not meet the standard of GBT18655-2010 Class3_PK.Similarly, it can see
Out, the peak value measured under 535kHz, 39.7MHz, 84.2MH frequency be respectively 81.894dB (μ V), 61.129dB (μ V),
58.196dB (μ V), respectively higher than its peaks demand for corresponding to wave band, admittedly do not comply with GBT18655-2010 Class3_PK
Standard.Test result shows that its noise reduction effect is still undesirable.
EMC test is carried out using a kind of noise reduction filtering circuit provided by the present invention, test result is as shown in figure 5, institute
There is average value/peak value measured waveform of wave band below standard value waveform, i.e., measured value is respectively less than standard value, Gu all make an uproar
Sound tests the standard for meeting GBT18655-2010 Class3_AV Yu 2010 Class3_PK of GBT18655-, noise reduction effect
Fruit is obviously.
To sum up, a kind of noise reduction filtering circuit provided by the present invention, either theoretically still actual test result
From the point of view of, it is owned by significant noise reduction effect.
Above specific embodiment is only the preferred embodiment of this creation, all in this wound not to limit this creation
Any modification, equivalent substitution, improvement and etc. done within the spirit and principle of work, should be included in this creation protection scope it
It is interior.
Claims (3)
1. a kind of noise reduction filtering circuit, it is characterised in that: including common mode inductance, the first differential mode inductance, the second differential mode inductance, first
Capacitor and the second capacitor；The common mode inductance includes toroidal core, first coil and the second coil；The first coil and described
Second coil is symmetrically wound on the toroidal core, and coiling is contrary；The first coil includes the first input
End and the first output end, second coil include the second input terminal and second output terminal, the first input end and described the
Two output ends are located at the identical side of the toroidal core, and first output end and second input terminal are located at the annular
The identical other side of magnetic core；The first input end is connected with one end of first differential mode inductance, the second output terminal with
One end of second differential mode inductance is connected, the other end of the other end of first differential mode inductance and second differential mode inductance
It is connected by the first capacitor；First output end is connected with second input terminal by second capacitor；It is described
It is equipped with input port between first differential mode inductance and the first capacitor, is set between first output end and second capacitor
There is output port；The first capacitor and second differential mode inductance indirectly, second capacitor and second input
It is also grounded between end.
2. a kind of noise reduction filtering circuit according to claim 1, it is characterised in that: the first coil and second line
Circle size is identical, and the number of turns is identical.
3. a kind of noise reduction filtering circuit according to claim 1, it is characterised in that: the first capacitor and second electricity
Appearance is patch capacitor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910461246.1A CN110212752A (en) | 2019-05-30 | 2019-05-30 | A kind of noise reduction filtering circuit |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910461246.1A CN110212752A (en) | 2019-05-30 | 2019-05-30 | A kind of noise reduction filtering circuit |
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| Publication Number | Publication Date |
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| CN110212752A true CN110212752A (en) | 2019-09-06 |
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ID=67789561
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| CN201910461246.1A Pending CN110212752A (en) | 2019-05-30 | 2019-05-30 | A kind of noise reduction filtering circuit |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023045604A1 (en) * | 2021-09-27 | 2023-03-30 | 尹伟明 | Filtering apparatus, filter device, and transmission apparatus |
| CN117060873A (en) * | 2023-08-16 | 2023-11-14 | 上海凌世电磁技术有限公司 | Multistage common-differential mode hybrid filtering electric fast transient pulse group decoupling network |
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| CN201138785Y (en) * | 2007-11-29 | 2008-10-22 | 上海美多通信设备有限公司 | Wave filter circuit for switch power supply |
| CN105099165A (en) * | 2014-05-19 | 2015-11-25 | 北京东土科技股份有限公司 | EMC protection and filtering device and method of high voltage power supply |
| CN206237299U (en) * | 2016-12-13 | 2017-06-09 | 佛山市顺德区美的电热电器制造有限公司 | The control device and household electrical appliance of electromagnetic compatibility filter circuit, Electromagnetic Heating household electrical appliances |
| CN208767971U (en) * | 2018-09-05 | 2019-04-19 | 贵州浪潮英信科技有限公司 | A kind of device improving power supply conducting power |
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2019
- 2019-05-30 CN CN201910461246.1A patent/CN110212752A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201138785Y (en) * | 2007-11-29 | 2008-10-22 | 上海美多通信设备有限公司 | Wave filter circuit for switch power supply |
| CN105099165A (en) * | 2014-05-19 | 2015-11-25 | 北京东土科技股份有限公司 | EMC protection and filtering device and method of high voltage power supply |
| CN206237299U (en) * | 2016-12-13 | 2017-06-09 | 佛山市顺德区美的电热电器制造有限公司 | The control device and household electrical appliance of electromagnetic compatibility filter circuit, Electromagnetic Heating household electrical appliances |
| CN208767971U (en) * | 2018-09-05 | 2019-04-19 | 贵州浪潮英信科技有限公司 | A kind of device improving power supply conducting power |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023045604A1 (en) * | 2021-09-27 | 2023-03-30 | 尹伟明 | Filtering apparatus, filter device, and transmission apparatus |
| CN117060873A (en) * | 2023-08-16 | 2023-11-14 | 上海凌世电磁技术有限公司 | Multistage common-differential mode hybrid filtering electric fast transient pulse group decoupling network |
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Application publication date: 20190906 |
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