CN206585480U - A kind of low common-mode noise switching power circuit - Google Patents
A kind of low common-mode noise switching power circuit Download PDFInfo
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- CN206585480U CN206585480U CN201621221429.4U CN201621221429U CN206585480U CN 206585480 U CN206585480 U CN 206585480U CN 201621221429 U CN201621221429 U CN 201621221429U CN 206585480 U CN206585480 U CN 206585480U
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- switching power
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- mode noise
- low common
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Abstract
The utility model is related to switching power circuit technical field, more particularly to a kind of low common-mode noise switching power circuit.Voltage change ratio and current changing rate during by controlling noise channel, reducing the work of Switching Power Supply high-speed switch using snubber circuit, so as to reduce the noise that magnetic field is produced with electric field, succinct circuit reduces stray inductance and parasitic capacitance, and winding structure of transformer is optimized, the number of plies of Transformer Winding is reduced to reduce layer capacitance between Transformer Winding, set the coiling of the same number of turns to make screen layer in armature winding and secondary windings respectively in addition, reduce the primary coefficient of coup with secondary.This low common-mode noise switching power circuit no Y capacitance is without common mode inductance, Switching Power Supply can be made to be operated under relatively low common-mode noise, realize the purpose for reducing common-mode noise, ensure the normal transmission of data in equipment, and circuit structure is simple, the circuit space of occupancy is small, effectively alleviates product cost pressure.
Description
Technical field
The utility model is related to switching power circuit technical field, more particularly to a kind of low common-mode noise switch power supply
Road.
Background technology
With the growth requirement of modernization, big screen intelligent mobile phone, tablet personal computer, laptop computer, ADSL, set top box, nothing
One of the digital products such as line router are widely used, and Switching Power Supply is originated as the main power supply of each class of electronic devices, various
The different Switching Power Supply product of style arises at the historic moment., all can be in civil power during most Switching Power Supply design to meet various countries' EMC standards
The Y capacitance of common mode inductance and the primary dead point access suppression common mode interference with secondary wire is sealed in incoming line, this was both accounted for
Cost on product is added again with a large amount of place on line.Meanwhile, be equipped with such as ADSL of the equipment with phonetic function, set top box,
Also be present higher power frequency root and common-mode noise in wireless router product, and exist higher when using the Switching Power Supply of Y capacitance
The Switching Power Supply of common-mode noise can influence the normal use of equipment and easily cause loss of data.
The content of the invention
The purpose of this utility model is to avoid above-mentioned weak point of the prior art and providing one kind can be reduced altogether
The switching power circuit of mode noise, so that Switching Power Supply is operated under relatively low common-mode noise, it is ensured that data are being just in equipment
Often transmission.
The purpose of this utility model is achieved through the following technical solutions：
It is whole there is provided a kind of low common-mode noise switching power circuit, including the civil power incoming line, the primary side that are sequentially connected
Flow filter circuit and switch transformed circuit, the switch transformed circuit includes transformer T1, switch transformed circuit passes through all the way
Transformer T1 is connected with secondary side output rectifier and filter, and another road is connected with primary side feedback control circuit, the primary side
Current rectifying and wave filtering circuit includes double LC filter circuits, and the switch transformed circuit includes in parallel after electric capacity, resistance and diode concatenation
Snubber circuit at transformer T1 two ends.
Wherein, the transformer T1 is flat surface transformer.
Wherein, there is the screen layer of same number of turns coiling on the armature winding and secondary windings of the transformer T1 respectively.
Wherein, the primary side current rectifying and wave filtering circuit includes bridge heap BD1；Described pair of LC filter circuit is connected to after bridge heap BD1
End, including inductance L1, L2, electric capacity C1, C2 and the resistance R1 in parallel with inductance L1.
Wherein, the snubber circuit by resistance R5 it is in parallel with electric capacity C4 after series resistor R6 and diode D1 constitute,
The diode D1 is the diode of 1N4007 models, and anode connects transformer T1 armature winding end, negative electrode connecting resistance R6.
Wherein, the primary side feedback control circuit includes the control chip U1, the transformer T1 for being built-in with switching tube MOS
According to the conduction and cut-off storage energy of the switching tube MOS/release energy.
Wherein, the GND pin of the control chip U1 are connected to the head end of transformer T1 armature windings, electrochemical capacitor through resistance
After C3 and ceramic disc capacitor C6 is in parallel, the node in the middle of the GND pin and resistance of a termination control chip U1, one end ground connection.
Wherein, the control chip U1 is model SOP-7 OB2500N control chip.
The beneficial effects of the utility model：This low common-mode noise switching power circuit, by controlling noise channel, using slow
Voltage change ratio and current changing rate when rushing absorbing circuit to reduce the work of Switching Power Supply high-speed switch, so as to reduce magnetic field and electricity
The noise that field is produced, succinct circuit reduces stray inductance and parasitic capacitance, and winding structure of transformer is optimized,
Reduce the number of plies of Transformer Winding to reduce layer capacitance between Transformer Winding, set respectively in armature winding and secondary windings in addition
Screen layer is made in the coiling for putting the same number of turns, reduces the primary coefficient of coup with secondary.This low common-mode noise switching power circuit
No Y capacitance can be such that Switching Power Supply is operated under relatively low common-mode noise without common mode inductance, realize the mesh for reducing common-mode noise
, it is ensured that the normal transmission of data in equipment, and circuit structure is simple, and the circuit space of occupancy is small, effectively alleviates production
Product cost pressure.
Brief description of the drawings
This low common-mode noise switching power circuit is described further using accompanying drawing.
Fig. 1 is the theory diagram of low common-mode noise switching power circuit；
Fig. 2 is the circuit diagram of low common-mode noise switching power circuit；
Fig. 3 is the circuit diagram of switch transformed circuit；
Fig. 4 is the circuit diagram that primary side feedback controls circuit；
Fig. 5 is the circuit diagram of secondary side output rectifier and filter；
Include in Fig. 1：1 --- civil power incoming line, 2 --- primary side current rectifying and wave filtering circuit, 21 --- double LC filtering
--- primary side feedback control circuit, 4 --- switch transformed circuit, 41 --- snubber circuit, 5 --- secondary side is defeated for circuit, 3
Go out current rectifying and wave filtering circuit.
Embodiment
Low common-mode noise switching power circuit is further described with the following Examples.
As shown in Fig. 1 ~ 5, the low common-mode noise switching power circuit in the present embodiment is primary side feedback（PSR）Control formula is opened
Powered-down source circuit, charges for smart mobile phone or is powered to other communication apparatus, including the civil power incoming line being sequentially connected
1st, primary side current rectifying and wave filtering circuit 2 and switch transformed circuit 4.Switch transformed circuit 4 passes through flat surface transformer T1 and two all the way
Secondary side output rectifier and filter 5 is connected, and the voltage of flat surface transformer T1 outputs is by the rectification of secondary side output rectifier and filter 5
Power supply to the device is exported after filtering；Another road controls the control chip U1 of circuit 3 to be connected with primary side feedback.
Civil power incoming line 1 provides the defeated of 100 ~ 240V by fuse resistance F1 and current-limiting resistance NTC1 for Switching Power Supply
Enter voltage, the piezo-resistance VZ1 having for anti-lightning strike protection is bridged in civil power input side.Primary side current rectifying and wave filtering circuit 2 includes
Bridge heap BD1 and the double LC filter circuits 21 for being connected to bridge heap BD1 rear ends, double LC filter circuits 21 include colour loop inductance L1, paster electricity
Feel L2, electrochemical capacitor C1, C2 and the resistance R1 in parallel with colour loop inductance L1, primary side current rectifying and wave filtering circuit 2 is civil power input line
The alternating voltage that road 1 is inputted is converted into smooth DC voltage, is that following stage switch transformed circuit 4 provides energy.Pass through bridge heap
BD1 and double composition of LC filter circuits 21 current rectifying and wave filtering circuit, it is not necessary in circuit plus common mode inductance, makes circuit structure simpler
It is single, and reduce stray inductance and parasitic capacitance.
Switch transformed circuit 4 receives the energy of prime supply and supplies flat surface transformer T1, primary side feedback control circuit 3
Switching tube MOS inside control chip U1 always works in the conduction and cut-off recurrent state of a high speed, switching tube MOS conductings
When flat surface transformer T1 storage energies, flat surface transformer T1 releases energy when switching tube MOS ends, so as to export whole for secondary side
Stream filter circuit 5 provides the conducting voltage of forward direction.It is wound with respectively on flat surface transformer T1 armature winding and secondary windings
Screen layer is made in the coiling of the same number of turns, is reducing the flat surface transformer T1 winding number of plies, and armature winding and secondary windings are close
After coupling, the layer capacitance between winding can be substantially reduced, so that common-mode noise when reducing Switching Power Supply work.Meanwhile,
Flat surface transformer T1 front ends be parallel with resistance R5 it is in parallel with ceramic disc capacitor C4 after be sequentially connected in series resistance R6 and diode D1 composition
Snubber circuit 41, diode D1 is the diode of 1N4007 models, and anode connects flat surface transformer T1 armature winding end,
Negative electrode connecting resistance R6.Flat surface transformer T1 is in storage energy/release energy circulation work, and snubber circuit 41 can reduce
Its voltage change ratio and current changing rate, so that reduce the noise that magnetic field is produced with electric field, and during flat surface transformer T1 work
The buffered absorbing circuit 41 of leakage current of generation absorbs, it is to avoid larger ac leakage flows through secondary side output rectifier and filter
5 export to charging equipment.
Primary side feedback control circuit 3 by flat surface transformer T1 transformer feedback winding, control chip U1, diode D2,
Resistance R2, R7~R10 and electric capacity C3, C5, C6 composition.The transformer that control chip U1 DRAN pin meet flat surface transformer T1 is anti-
Present the end of winding, the switching tube MOS conduction and cut-offs inside control chip U1 so as to control plane transformer T1 storage energies/
Release energy, control chip U1 GND pin connect the head end of flat surface transformer T1 armature windings through resistance R4, R3.Control chip U1
By the change of the sensing of transformer feedback winding and secondary windings, the in real time DC voltage and current of detection secondary windings output,
And the working frequency and dutycycle for the control chip U1 controlling switch pipes MOS for passing through model SOP-7 OB2500N, make plane
The voltage x current that transformer T1 remains stable is exported to secondary side output rectifier and filter 5.Electrochemical capacitor C3 and ceramics
After electric capacity C6 is in parallel, the node in the middle of the GND pin and resistance R4 of a termination control chip U1, one end ground connection, with electrochemical capacitor C3
Ceramic disc capacitor C6 in parallel is while filtering, it is possible to reduce the leakage current that flat surface transformer T1 is produced when working.
Secondary side output rectifier and filter 5 is the voltage sensed from flat surface transformer T1 secondary windings through secondary rectification
It is changed into the DC DC voltages of the desired smooth steady of charging equipment.Secondary side output rectifier and filter 5 includes model
It is in parallel with diode D3 after HSB3T60 diode D3, electric capacity C7 and resistance R12 concatenation, in addition to it is connected in parallel on voltage output end
Electric capacity C8, C9, resistance R13 between positive pole OUT ﹢ and negative pole OUT ﹣.
This low common-mode noise switching power circuit no Y capacitance can be operated in Switching Power Supply relatively low without common mode inductance
Under common-mode noise, the purpose for reducing common-mode noise is realized, it is ensured that the normal transmission of data in equipment, and circuit structure letter
Single, the circuit space of occupancy is small, effectively alleviates product cost pressure.
Claims (8)
1. a kind of low common-mode noise switching power circuit, including civil power incoming line, the primary side rectifying and wave-filtering electricity being sequentially connected
Road and switch transformed circuit, the switch transformed circuit include transformer T1, and switch transformed circuit passes through transformer T1 all the way
Be connected with secondary side output rectifier and filter, another road is connected with primary side feedback control circuit, it is characterised in that it is described once
Side current rectifying and wave filtering circuit includes double LC filter circuits, and the switch transformed circuit is included after electric capacity, resistance and diode concatenation simultaneously
It is associated in the snubber circuit at transformer T1 two ends.
2. a kind of low common-mode noise switching power circuit according to claim 1, it is characterised in that the transformer T1 is
Flat surface transformer.
3. a kind of low common-mode noise switching power circuit according to claim 1 or 2, it is characterised in that the transformer
There is the screen layer of same number of turns coiling on T1 armature winding and secondary windings respectively.
4. a kind of low common-mode noise switching power circuit according to claim 1, it is characterised in that the primary side rectification
Filter circuit includes bridge heap BD1；Described pair of LC filter circuit is connected to bridge heap BD1 rear ends, including inductance L1, L2, electric capacity C1, C2 and
The resistance R1 in parallel with inductance L1.
5. a kind of low common-mode noise switching power circuit according to claim 1, it is characterised in that the snubber electricity
Series resistor R6 and diode D1 compositions after routing resistance R5 is in parallel with electric capacity C4, the diode D1 is the two of 1N4007 models
Pole pipe, anode connects transformer T1 armature winding end, negative electrode connecting resistance R6.
6. a kind of low common-mode noise switching power circuit according to claim 1, it is characterised in that the primary side feedback control
Circuit processed includes being built-in with switching tube MOS control chip U1, the transformer T1 according to the conducting of the switching tube MOS/cut
Only storage energy/release energy.
7. a kind of low common-mode noise switching power circuit according to claim 6, it is characterised in that the control chip U1
GND pin be connected to the head ends of transformer T1 armature windings through resistance, electrochemical capacitor C3 and ceramic disc capacitor C6 it is in parallel after, a termination
Node in the middle of control chip U1 GND pin and resistance, one end ground connection.
8. a kind of low common-mode noise switching power circuit according to claim 1, it is characterised in that the control chip U1
It is model SOP-7 OB2500N control chip.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201621221429.4U CN206585480U (en) | 2016-11-14 | 2016-11-14 | A kind of low common-mode noise switching power circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201621221429.4U CN206585480U (en) | 2016-11-14 | 2016-11-14 | A kind of low common-mode noise switching power circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN206585480U true CN206585480U (en) | 2017-10-24 |
Family
ID=60109082
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201621221429.4U Expired - Fee Related CN206585480U (en) | 2016-11-14 | 2016-11-14 | A kind of low common-mode noise switching power circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN206585480U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109861561A (en) * | 2018-12-29 | 2019-06-07 | 深圳日辉达电源股份有限公司 | A kind of Switching Power Supply |
| WO2021000364A1 (en) * | 2019-07-01 | 2021-01-07 | 苏州纳芯微电子股份有限公司 | Isolated power supply chip |
-
2016
- 2016-11-14 CN CN201621221429.4U patent/CN206585480U/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109861561A (en) * | 2018-12-29 | 2019-06-07 | 深圳日辉达电源股份有限公司 | A kind of Switching Power Supply |
| WO2021000364A1 (en) * | 2019-07-01 | 2021-01-07 | 苏州纳芯微电子股份有限公司 | Isolated power supply chip |
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| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20171024 Termination date: 20181114 |
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| CF01 | Termination of patent right due to non-payment of annual fee |