CN106998134A - A kind of excellent PWM switching power source control circuits of anti-electromagnetic interference capability - Google Patents
A kind of excellent PWM switching power source control circuits of anti-electromagnetic interference capability Download PDFInfo
- Publication number
- CN106998134A CN106998134A CN201710446948.3A CN201710446948A CN106998134A CN 106998134 A CN106998134 A CN 106998134A CN 201710446948 A CN201710446948 A CN 201710446948A CN 106998134 A CN106998134 A CN 106998134A
- Authority
- CN
- China
- Prior art keywords
- module
- pipes
- electromagnetic interference
- power supply
- mode
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000001681 protective effect Effects 0.000 claims abstract description 4
- 230000005611 electricity Effects 0.000 claims description 11
- 239000004065 semiconductor Substances 0.000 claims description 11
- 238000007599 discharging Methods 0.000 claims description 9
- 230000008859 change Effects 0.000 claims description 7
- 238000005070 sampling Methods 0.000 claims description 4
- 230000003321 amplification Effects 0.000 claims description 3
- 230000001276 controlling effect Effects 0.000 claims description 3
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 3
- 230000001105 regulatory effect Effects 0.000 claims description 3
- 238000006243 chemical reaction Methods 0.000 abstract description 14
- 238000000034 method Methods 0.000 abstract description 7
- 230000009467 reduction Effects 0.000 abstract description 6
- 230000002093 peripheral effect Effects 0.000 abstract description 5
- 208000032365 Electromagnetic interference Diseases 0.000 abstract description 2
- 230000002262 irrigation Effects 0.000 abstract 1
- 238000003973 irrigation Methods 0.000 abstract 1
- 238000013461 design Methods 0.000 description 10
- 230000007423 decrease Effects 0.000 description 6
- 238000005516 engineering process Methods 0.000 description 6
- 238000001514 detection method Methods 0.000 description 5
- 238000002347 injection Methods 0.000 description 4
- 239000007924 injection Substances 0.000 description 4
- 239000003990 capacitor Substances 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 230000005855 radiation Effects 0.000 description 3
- 230000008901 benefit Effects 0.000 description 2
- 230000008878 coupling Effects 0.000 description 2
- 238000010168 coupling process Methods 0.000 description 2
- 238000005859 coupling reaction Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000001939 inductive effect Effects 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 238000005457 optimization Methods 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- 230000004913 activation Effects 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000001010 compromised effect Effects 0.000 description 1
- 230000007850 degeneration Effects 0.000 description 1
- 230000005670 electromagnetic radiation Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- NUHSROFQTUXZQQ-UHFFFAOYSA-N isopentenyl diphosphate Chemical group CC(=C)CCO[P@](O)(=O)OP(O)(O)=O NUHSROFQTUXZQQ-UHFFFAOYSA-N 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
Classifications
-
- 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
-
- 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
- H02M1/0003—Details of control, feedback or regulation circuits
-
- 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
- H02M1/0048—Circuits or arrangements for reducing losses
- H02M1/0054—Transistor switching losses
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Dc-Dc Converters (AREA)
Abstract
The invention discloses the PWM switching power source control circuits that a kind of anti-electromagnetic interference capability is excellent, its drip irrigation device is to include power supply and drive module, protection module and multi-mode control module；The power supply and drive module, including internal starting module, reference voltage module, current sampler, error amplifier, output driving module；The protection module, including overtemperature protection module, overload protection module, overvoltage protective module and overcurrent protection module；The multi-mode control module, including feedback input end, oscillator, frequency, load detecting module, zero current detecting circuit for changing switch, for realizing valley conduction pattern, the lowest point detector and mode selector, for the switching of several mode of operation, present invention employs the method for a variety of reduction electromagnetic interferences, anti-electromagnetic interference capability is preferable, peripheral circuit not only can be largely saved in actual application, moreover it is possible to greatly improve power supply conversion efficiency, reduce switching loss.
Description
Technical field
The present invention relates to integrated circuit fields, and in particular to a kind of excellent PWM Switching Power Supply controls of anti-electromagnetic interference capability
Circuit processed.
Background technology
Switching Power Supply is a kind of device for converting electric energy of high frequency, because the device that adjustment voltage stabilizing control function is played in power supply begins
Eventually so that on-off mode works and gains the name, its function is that by various forms of frameworks one reference voltage is converted into user terminal institute
The voltage or electric current of demand.Switching Power Supply main operational principle is to utilize modern power electronics technology, controlling switch pipe open and
The time ratio of shut-off, maintains stable output voltage.
Usual Switching Power Supply is by switching power source control circuit and switching tube（MOSFET）Composition.The block diagram of Switching Power Supply is for example attached
Shown in Fig. 1, the working method of switching power source control circuit has a variety of, and most common of which one kind is pulse width modulation（PWM）
Mode, the waveform of output is controlled by adjusting power MOS switch time, is adjustment power mode mos gate by the way of
Pole pwm signal dutycycle, is also a kind of mode of power adjusting so as to control the power supply of output waveform and the analog quantity of electric current.
Electromagnetic interference (Electromagnetic Interference, EMI) is interference electric signal and to reduce signal intact
The electronic noise of property, EMI is generally as produced by electromagnetic radiation occurring source.EMI presence can cause the performance of equipment to reduce.
Electromagnetic interference includes two kinds of Conduction Interference and radiation interference.Conduction Interference refers to by conducting medium a power network
Signal coupling on network（Interference）To another electric network.Radiation interference refers to that interference source couples its signal by space（It is dry
Disturb）To another electric network.In High-Speed PCB and system design, high-frequency signal line, the pin of integrated circuit, all kinds of connectors
Deng being all likely to become the radiation interference source with antenna performance, electromagnetic wave can be launched and other are influenceed in other systems or the system
The normal work of subsystem.
The anti-electromagnetic interference capability of integrated circuit has become an important symbol for weighing its performance level, and one integrated
The antijamming capability size of circuit also determines the application of the circuit, particularly with the switch applied in terms of energy conversion
It is even more so for power circuit.On the one hand, because Switching Power Supply is directly connect on the utility grids, between power-supply device and power network
There is two-way electromagnetic interference；The use condition of another aspect Switching Power Supply is generally poor, such as automotive fittings, therefore in switch
Electromagnetism interference problem is must take into consideration in the design of power supply.
The detection of the anti-electromagnetic interference capability of switching power source control circuit is generally by being applied some specific
In Switching Power Supply, special electromagnetism interference test is carried out, it can in addition contain be imitated from the switching loss of the power supply and energy conversion
Judged in rate.
Electromagnetism interference design in Switching Power Supply generally includes two parts, the antijamming capability of switching power source control circuit
Design is a wherein important part；If the antijamming capability of switching power source control circuit is weaker, complexity must be passed through
Periphery circuit design is to improve the antijamming capability of whole system.
It is that electric network source is first passed through than more typical scheme to lift global switch power supply antijamming capability by peripheral circuit
The module of electromagnetism interference, then carries out rectifying and wave-filtering again.These safeguard measures can be opened by the design lifting of peripheral circuit
The anti-electromagnetic interference capability in powered-down source, but so doing can cause the design of whole Switching Power Supply more complicated, it is necessary to increase many outer
Peripheral device, so as to cause the raising of global switch power supply cost.
As society increasingly improves to the attention rate of energy efficiency and environmental issue, reduce switching loss, improve switch electricity
The efficiency in source, so that improve Switching Power Supply anti-electromagnetic interference capability has turned into the main hair of Switching Power Supply aspect IC design
Open up direction.
The content of the invention
It is an object of the invention to provide the PWM switching power source control circuits that a kind of anti-electromagnetic interference capability is excellent, it has
Anti-electromagnetic interference capability is excellent, it is possible to increase the efficiency of Switching Power Supply, reduces the advantage of the energy loss of Switching Power Supply.
The present invention above-mentioned technical purpose technical scheme is that：
A kind of excellent PWM switching power source control circuits of anti-electromagnetic interference capability, including power supply and drive module, protection module and
Multi-mode control module；
The power supply and drive module, including it is internal starting module, reference voltage module, current sampler, error amplifier, defeated
Go out drive module；
The protection module, including overtemperature protection module, overload protection module, overvoltage protective module and overcurrent protection module；
The multi-mode control module, including feedback input end, oscillator, for change switch frequency, load detecting module,
Zero current detecting circuit, for realizing valley conduction pattern, the lowest point detector and mode selector, for several mode of operation
Switching.
By using above-mentioned technical proposal, because Switching Power Supply needs constantly to carry out charge and discharge to coil in actual applications
Electricity, the presence of this rush of current causes electromagnetic interference than more serious.Research shows that the ripple size of electric current is about V/2Lfk,
Wherein V is voltage, and L is coil inductance, fkFor switching frequency.Current ripples are directly proportional to voltage as can be seen here.
Supply voltage can not be too low in practical application, in order to reduce electromagnetic interference, and switching frequency can not be too low, that is, improve and open
Current ripples can be reduced by closing frequency, but can so increase switching loss, energy conversion efficiency reduction.Therefore switching frequency
Selection must take into consideration factors, and be compromised.The present invention uses variable switching frequency to adjust institute according to different situations
The switching frequency needed.
Optimize the conducting of switching tube present invention employs zero current detecting circuit.At first of switching tube drain-source power supply
Position where minimum value causes the MOSFET to turn on, and can make it that the current spike of conducting is minimum.The circuit provides signal and driven
Dynamic switching tube enters open-minded when its drain terminal voltage difference is relatively low, that is, realizes valley conduction.The current spike so turned on will be most
It is small, so as to substantially reduce the electromagnetic interference of whole Switching Power Supply.
Further set：The load detecting module is connected with internal starting module, is started for starting module internally
Afterwards, detect external loading situation and electric signal is fed back into mode selector, mode selector is used for the work for changing control circuit
Operation mode.
Further set：Metal-oxide-semiconductor is connected with outside the power supply and drive module, mode of operation starts zero current detection after determining
Circuit, the lowest point detector, power supply and drive module start metal-oxide-semiconductor, produce in sampled voltage, control circuit provided with internal logic electricity
Road, sampled voltage to be compared with predetermined value, closes or opens metal-oxide-semiconductor.
Further set：The current sampler is compared output voltage with reference voltage, passes through error amplifier
Error amplification signal is converted into electric current by optocoupler, and injected in feedback input end, the size to adjust output voltage.
Further set：The oscillator uses multi-frequency generator, for constant in charging and discharging currents by changing electric capacity
In the case of regulating frequency, and can by adjust the charging and discharging currents in charging and discharging circuit change dutycycle.
By using above-mentioned technical proposal, due to the influence of inductance, electric capacity in switch power supply system, Switching Power Supply control electricity
Road can be introduced with the presence of peak value very high noise band on electric current and voltage higher harmonic components, i.e. frequency spectrum in the course of the work,
So as to produce serious electromagnetic interference.The present invention uses " frequency conversion " technology so that switching frequency is not fixed, but certain
In the range of change, so that the frequency band of each harmonic of the voltage and current in Switching Power Supply is obtained into broadening, to reduce switch electricity
Source control circuit electromagnetic interference.
Further set：The current sampling circuit for controlling switch electric current is provided with the control circuit.
By using above-mentioned technical proposal, during switching power circuit is designed, in order to reduce electromagnetic interference, simultaneously
Reduce switching loss, improve cut-off current and the load for reducing switching tube in high conversion efficiency, the present invention to a certain extent
Electric current, to reduce the loss in the course of work, improves conversion efficiency.
In summary, the invention has the advantages that：
Present invention employs the method for a variety of reduction electromagnetic interferences, the anti-of circuit is controlled after the design of multiple electromagnetism interference
Electromagnetic interference capability preferably, can application monitor/LCD TV/set top box power supply, can be used for various ac/dc power supplys
Adapter and various chargers.
Present invention Switching Power Supply frequency in external world's load change can embody the spy of " soft bending " with smoothly varying
Point, therefore reduce electromagnetic interference compared to switching loss is substantially reduced with traditional switch power supply.
By using Valley-Switching pattern, it is smaller to turn it on formed current spike, so as to reduce whole switch electricity
The electromagnetic interference in source, improves conversion efficiency.It is right in addition in addition to reduction electromagnetic interference and switching loss, improve conversion efficiency
Switching current has carried out effective control.
In actual application, the present invention not only can largely save peripheral circuit, moreover it is possible to greatly improve Power convert
Efficiency, reduces switching loss.
Brief description of the drawings
The present invention is further described below in conjunction with the accompanying drawings.
Fig. 1 is the Switching Power Supply block diagram in background technology；
Fig. 2 is the entire block diagram of the present invention；
Fig. 3 is the working mode figure of the present invention；
Fig. 4 is the working mode figure of switching tube in the present invention；
Fig. 5 is zero detection circuit structure of optimization switching tube conducting in the present invention；
Fig. 6 is the structure chart of multi-frequency generator in the present invention；
Fig. 7 is the current sampling circuit figure in the present invention.
Symbol description, AC：Alternating current source；CS：Electric current senses input；DRI：The drive output of metal-oxide-semiconductor；VIN：Direct current is defeated
Enter voltage；M1：Switching tube；CM：The drain terminal electric capacity of metal-oxide-semiconductor；NP：The number of primary turns of transformer；NS：The secondary wire of transformer
Enclose the number of turn；Lm：Mutual inductance；D：Rectifying tube；C：Filter capacitor；LPL：The leakage inductance of primary coil；EMI：Electromagnetic interference；VB：Input biasing
Voltage；DRI：Switching tube output end；Ismp：Sampled output current.
Embodiment
The embodiment to the present invention is described further below in conjunction with the accompanying drawings.
The technical solution adopted in the present invention is：
A kind of excellent PWM switching power source control circuits of anti-electromagnetic interference capability, as shown in Fig. 2 functional module include power supply and
Drive module, protection module and multi-mode control module.
Power supply and drive module include internal starting module, reference voltage module, current sampler, error amplifier, defeated
Go out drive module.
Protection module, including overtemperature protection module, overload protection module, overvoltage protective module and overcurrent protection module.
Multi-mode control module, including feedback input end, oscillator, for change switch frequency, load detecting module,
Zero current detecting circuit, for realizing valley conduction pattern, the lowest point detector and mode selector, for several mode of operation
Switching.
The raising of circuit anti-electromagnetic interference capability so can be realized by four kinds of modes.
1st, using multi-operation mode
The principle of multi-operation mode is：As shown in Fig. 2 after system electrification, internal activation circuitry charges to VCC ends external capacitor,
When VCC voltages rise to certain value, internal circuit is started working, and oscillator also sends trigger signal, the detection of load detecting module
External loading, mode selection circuit starts, and different working modes are respectively enterd according to different loads situation.
Zero current detecting circuit, the lowest point detector are started working afterwards, when eligible, into quasi-resonance Valley-Switching mould
Formula, metal-oxide-semiconductor is opened through drive control module.Line voltage charges to primary inductance, primary inductance electric current linear rise.
Inductive current flows through metal-oxide-semiconductor, and electric current internally produces sampled voltage on sampling resistor after mirror image in proportion, when inductive current rises
To when making sampled voltage be more than preset value, current comparator is overturn, and triggers internal logic circuit, closes metal-oxide-semiconductor.When shaking
Swing device next cycle and come interim, MOS is again turned on.
After a series of activities cycle, output voltage, which is opened, to be risen, and internal control circuit is by output voltage and benchmark
Reference voltage is compared and enlarged, and error amplification signal is converted into electric current by optocoupler, by the injection circuit of FB ports
The feed back input module in portion.
When output voltage rise, the electric current increase of FB ports injection, the pressure drop increase that the electric current is internally produced on resistance,
Current comparator overturns the pressure drop that primary inductance electric current is internally produced on resistance and reduced, i.e. primary inductance electricity
Stream reduces, and is thus relayed to the energy of secondary and will reduce, output voltage will be reduced, so as to constitute the stability series of a negative-feedback
System.Conversely, when output voltage is reduced, degeneration factor will automatically adjust the electric current of FB ends injection, raise input voltage, from
And obtain a highly stable output voltage.When the electric current of FB ends injection is close to zero, primary inductance electric current is up to
Maximum.
The mode of operation of the present invention is as shown in figure 3, in the case of full load, when the input power is low, the IC is operated in
Fixed frequency CCM（Continuous Condition Mode）Pattern, the fixed frequency is 50KHz or so；And in input power
When higher, quasi-resonant mode is operated in, at this moment low-limit frequency is clamped down in Flow；Both the above pattern can reach very high effect
Rate.
Under normal load condition, the present invention is in quasi-resonant mode（Quasi-Resonant Mode）Lower work.In order to reduce
Highest switching frequency under switching loss, quasi-resonant mode will be any limitation as, and be clamped down in this circuit in Fhigh, its value is 90KHz
Left and right, meets EMI standards.The pwm control circuit is in QR patterns, and switching tube oscillates to open-minded at first trough in power supply, opens
Beginning next cycle.By quasi-resonance mode of operation, the switching loss and EMI of system are substantially reduced.
When the load decreases, the present invention is in PFM（Pulse Frequency Modulation）Worked under pattern, to reach
Power conversion efficiency more than 90%.The present invention adjusts switching frequency, and constantly reduction according to load；In PFM stages, the lowest point
Switching characteristic remains unchanged presence, so as to obtain smooth frequency variation curve.
When loading smaller or unloaded, the present invention is in green model（Green Mode）Lower work, it is standby to reduce
Power consumption and switching loss, improve system conversion efficiency.When being operated in green model, switching frequency is Fgreen, its value is 20KHz
Left and right, and no longer reduce.It is well known that 20KHz is audiorange, by using green model, it is possible to prevente effectively from audio
The appearance of noise.
As shown in figure 3, AC the two poles of the earth are coupled with diode D1, D3 and D2, D4 positive pole, D1, D2 negative pole and V phases
Even, D3, D4 negative pole ground connection.
Resistance R1 one end is connected with Lp, another to terminate to electric capacity C1 top crowns and VCC, C1 bottom crown ground connection.
The drain electrode of M1 pipes meets LHL and electric capacity CM top crowns, and grid is connected to DRI, and source electrode is connect under CS, R2 and CM
Pole plate, R2 other end ground connection.
LS one end is connected with diode D positive poles, another to terminate to electric capacity C bottom crowns and ground, and diode D negative poles meet electric capacity C
Top crown.
Optocoupler OC mono- terminates FB, other end ground connection.
2nd, using Valley-Switching pattern
As shown in Fig. 2 NP、NSInductance value be respectively LP、LS, LmFor mutual inductance, for energy to be delivered into secondary, nothing from primary
Method is delivered to the magnetic flux of secondary by coupling, and its ability stored need to be discharged by other paths.And be stored in leakage inductance
Energy be switching tube shut-off be produce spike the reason for.
As shown in figure 4, switching tube is in the conduction state at the beginning, primary current is formed, its peak value is IPP, it is maximum in electric current
When turn off, leakage inductance LPLWith switching tube drain terminal electric capacity CMThe resonant tank of composition produces over-pressed spike vibration, forms resonance range one.
In resonance range one, switching tube drain-source voltage peak value can use formula（1）Represent, wherein IPAt the beginning of flowing through transformer
The direct current of level coil.
After switching tube shut-off, the mutual inductance energy of transformer is by the rectifying tube D1 formation secondary currents of conducting, and its peak value is IPS, it is right
Filter capacitor C charges, so as to transfer energy to load.Secondary current is gradually reduced in the process, when being close to zero, mutually
Feel LmWith switching tube drain terminal electric capacity CMProduce resonance range two.There are tri- points of A, B, C in oscillating curve in this section, wherein A points are
The minimum point of switching tube electrical leakage voltage, and the corresponding drain terminal voltage of C points is higher.
In resonance range two, switching tube drain-source voltage includes formula（2）Represented DC component VDDCAnd formula
（3）Represented harmonic components VDQRTwo parts, wherein RPFor transformer direct current equivalent resistance, VZFor on rectifying tube D1
Pressure drop.
When switching tube is turned on again, it can select to turn on when its drain terminal voltage is relatively low, can also select in its drain terminal voltage
Turned on when higher.Because drain terminal electric capacity CMCurrent spike can be formed during tube discharge by switching, if switching tube is in its drain terminal electricity
The higher point of pressure is opened, then will produce larger switching noise, form EMI.
, whereas if in first minimum value A point of switching tube drain terminal voltage（That is the lowest point）So that switching tube is open-minded, then
The current spike of conducting will be minimum, so as to substantially reduce the EMI of whole Switching Power Supply.The conducting of switching tube and deadline can
Formula is used respectively（4）、（5）Represent.
Optimize the open-minded of switching tube present invention employs zero current detecting circuit, zero detection circuit knot of switching tube conducting
Structure optimization is as shown in Figure 5.The circuit provides signal driving switch pipe and enters open-minded when its drain terminal voltage difference is relatively low, that is, realizes paddy
Bottom is turned on.
As shown in figure 5, the drain electrode of N0 pipes meets the I0 come from power supply, grid connects the grid of N1 pipes, and grid leak short circuit, source class connects
Ground；
The drain electrode of N1 pipes connects the drain electrode of P0 pipes, the I0 that grid connects the grid of N0 pipes and come from power supply, source class ground connection；
The drain electrode of N2 pipes connects the drain electrode of P1 pipes and the drain electrode of N4 pipes, and grid connects power supply, and source class connects drain electrode and the grid of N6 pipes of N3 pipes
Pole；
The drain electrode of N3 pipes connects the source class of N2 pipes and the grid of N6 pipes, and the I0 that grid connects the grid of N0 pipes and come from power supply, source class connects
Ground；
The drain electrode of N4 pipes connects the drain electrode missed with P1 pipes of N2 pipes, and grid connects the grid of N5 pipes, grid leak short circuit, source class ground connection；
The drain electrode of N5 pipes connects the drain electrode of P2 pipes, and grid connects the grid of N4 pipes, source class ground connection；
The drain electrode of N6 pipes connects drain electrode and the grid of P4 pipes of P3 pipes, and source class meets DRI；
The drain electrode of N7 pipes meets drain electrode and the OUT of P4 pipes, and grid meets the I0 come from power supply, source class ground connection；
The source class of P0 pipes connects power supply, and grid connects the grid of P1 pipes, and source grid short circuit, drain electrode connects the drain electrode of N1 pipes；
The source class of P1 pipes connects power supply, and grid connects the grid of P0 pipes, and drain electrode connects the drain electrode of N2 pipes and the drain electrode of N4 pipes；
The source class of P2 pipes connects power supply, and grid connects the grid of P3 pipes, and drain electrode connects the drain electrode of N5 pipes, grid leak short circuit；
The source class of P3 pipes connects power supply, and grid connects the grid of P2 pipes, and drain electrode connects drain electrode and the grid of P4 pipes of N6 pipes；
The source class of P4 pipes connects power supply, and grid connects the drain electrode of P3 pipes and the drain electrode of N6 pipes, and drain electrode meets drain electrode and the OUT of N7 pipes.
3rd, using converter technique
Due to the influence of inductance, electric capacity in switch power supply system, switching power source control circuit can introduce electric current in the course of the work
With on voltage higher harmonic components, i.e. frequency spectrum with the presence of peak value very high noise band, so as to produce serious electromagnetic interference.Drop
A kind of effective ways of low switch power control circuit electromagnetic interference are to use " frequency conversion " technology so that switching frequency is not fixed
, but change within the specific limits, so that the frequency band of each harmonic of the voltage and current in Switching Power Supply is obtained into broadening.
If frequency range is △ f, then in switching frequency excursion, broadening is △ f, two by fundamental wave bandwidth
Broadening is 2 △ f by subharmonic bandwidth, by that analogy, and broadening is n △ f by n higher hamonic waves bandwidth.It is constant in noise gross energy
Under the premise of, the amplitude of each harmonic is reduced, and higher hamonic wave amplitude reduction then becomes apparent, so as to effectively suppress system
The electromagnetic interference of system.
" frequency conversion " technology is realized present invention employs multi-frequency generator, and the structure of this oscillator is as shown in Figure 6.Electricity
It is one group of electric capacity of different sizes to hold C0, controls it whether to access the discharge and recharge of oscillator by different control signals respectively and returns
Road, these control signals are produced by frequency dividing circuit.Voltage after being charged on electric capacity C0 is Vc0, and fixed comparison voltage is Vref,
VrefWith Vc0It is compared, so as to form vibration.
Define charging current and the discharge current respectively T of the oscillatorch、Tdch, then the charge cycle T of the oscillatorch
With discharge cycle TdchFormula can be used respectively（6）、（7）Represent.
So as to which frequency of oscillation and dutycycle can use formula respectively（8）、（9）Represent.
, can be with regulating frequency in the case of charging and discharging currents are constant by changing electric capacity；And by adjusting charging and discharging circuit
On charging and discharging currents, thus it is possible to vary dutycycle.
As shown in fig. 6, the source class of P0 pipes connects power supply, grid connects the source class that Vbh. drain electrodes connect P3 pipes；
The source class of P1 pipes connects power supply, and grid meets Vbh, and drain electrode connects the drain electrode of N1 pipes；
The source class of P2 pipes connects power supply, and grid meets Vbh, and drain electrode connects C0, C1 upper step and BGR "-" interface；
The source class of P3 pipes connects P0 drain electrode, and grid connects NAND2 1 input, and drain electrode connects drain electrode and the grid of N1 pipes of N0 pipes；
The drain electrode of N0 pipes connects drain electrode and the grid of N1 pipes of P3 pipes, and the grid of N0 pipes connects the drain electrode of the grid and N3 pipes of N2 pipes, source
Level ground connection；
The drain electrode of N1 pipes connects the drain electrode of P1 pipes and NAND1 1 input, and grid connects the drain electrode of P3 pipes and the drain electrode of N0 pipes, and source electrode connects
The drain electrode of N2 pipes；
The drain electrode of N2 pipes connects the source class of N1 pipes, and grid connects drain electrode and the grid of N0 pipes of N3 pipes, source class ground connection；
The grid for missing N0 pipes and N2 pipes of N3 pipes, grid connects the output of the grid and NAND1 of P3 pipes, NAND2 1 input, source
Level ground connection；
C0 upper step connects drain electrode and the C1 upper step and BGR "-" interface of P2 pipes, bottom crown ground connection；
C1 upper step connects drain electrode and the C2 upper step and BGR "-" interface of P2 pipes, bottom crown ground connection；
NAND1 1 input connects the drain electrode of P1 pipes and the drain electrode of N1 pipes, and 2 inputs connect NAND2 output, and it is 1 defeated that output meets NAND2
Enter and P3, N3 pipe grid；
NAND2 1 input connects NAND1 output, and 2 inputs connect BGR output；Output connects NAND1 2 inputs.
4th, switching tube current control
In order to reduce electromagnetic interference, while reducing switching loss, improve in high conversion efficiency, this present invention and reduce switch as far as possible
The cut-off current and load current of pipe.It is to use current sample mode to implement, and is fed back by being formed, and keeps electric current not surpass
Go out design specification.
As shown in fig. 7, Ismp and the current in proportion relation for flowing through switch controlled pipe P4.The module operation principle is：
When switch controlled pipe P 4 is opened, P2 and P3 sample to output current, and sample rate current produces pressure on P2 channel resistance
Drop.
When output current increases, W3 current potential, which declines, causes W2 current potential to decline, because P5 with P6 grid potentials are identical, P6
Source potential（W2）Decline reduces P6 electric currents, causes W4 current potentials to decline, and W4 is connected to P7 grid, increases P7 electric currents, makes
W1 current potentials decline, and cause P5 electric currents to decline, and N0 is constant-current source, and P5 grid potential will be pulled low, i.e. P6 grid is pulled low,
P6 electric currents increase, W4 rises, this feedback control loop is reached stable state, so as to limit switch tube current.The electricity more than
Stream sample circuit causes switching current to be restricted.
Referring to Fig. 7, the source class of P0 pipes connects power supply, grounded-grid, and drain electrode connects the source class of P5 pipes and P7 pipes；
The source class of P1 pipes connects drain electrode and the source class of P3 pipes of P2 pipes, and grounded-grid, drain electrode connects the source class of P6 pipes；
The source class of P2 pipes connects power supply, and grounded-grid, drain electrode connects the source class of P1 pipes and the source class of P3 pipes；
The source class of P3 pipes connects drain electrode and the source class of P1 pipes of P2 pipes, and grounded-grid, drain electrode meets drain electrode and the DRI of P4 pipes；
The source class of P4 pipes connects power supply, and grounded-grid, drain electrode meets drain electrode and the DRI of P3 pipes；
The source class of P5 pipes connects drain electrode and the source class of P7 pipes of P0 pipes, and grid connects the grid of P6 pipes, and drain electrode connects the drain of N0 pipes, grid
With drain electrode short circuit；
The source class of P6 pipes connects the drain electrode of O1 pipes, and grid connects the grid of P5 pipes, and drain electrode connects the drain of N1 pipes and the grid of P7 pipes；
The source class of P7 pipes connects drain electrode and the source class of P5 pipes of P0 pipes, and grid connects drain electrode and the drain of N1 pipes of P6 pipes, and drain electrode connects
Ismp；
The drain of N0 pipes connects the drain electrode of P5 pipes, and grid meets Vb, source ground；
The drain of N1 pipes connects drain electrode and the grid of P7 pipes of P6 pipes, and grid meets Vb, source ground.
Above is presently preferred embodiments of the present invention, not makees any formal limitation, every foundation to the present invention
The technical spirit of the present invention belongs to inventive technique to any simple modification made for any of the above embodiments, equivalent variations and modification
In the range of scheme.
Claims (6)
1. a kind of excellent PWM switching power source control circuits of anti-electromagnetic interference capability, it is characterised in that：Including powering and driving mould
Block, protection module and multi-mode control module；
The power supply and drive module, including it is internal starting module, reference voltage module, current sampler, error amplifier, defeated
Go out drive module；
The protection module, including overtemperature protection module, overload protection module, overvoltage protective module and overcurrent protection module；
The multi-mode control module, including feedback input end, oscillator, for change switch frequency, load detecting module,
Zero current detecting circuit, for realizing valley conduction pattern, the lowest point detector and mode selector, for several mode of operation
Switching.
2. a kind of excellent PWM switching power source control circuits of anti-electromagnetic interference capability according to claim 1, its feature exists
In：The load detecting module is connected with internal starting module, after starting for starting module internally, detects external loading feelings
Electric signal is simultaneously fed back to mode selector by condition, and mode selector is used for the mode of operation for changing control circuit.
3. a kind of excellent PWM switching power source control circuits of anti-electromagnetic interference capability according to claim 2, its feature exists
In：Metal-oxide-semiconductor is connected with outside the power supply and drive module, mode of operation starts zero current detecting circuit, the lowest point detector after determining,
Power supply and drive module, which start in metal-oxide-semiconductor, generation sampled voltage, control circuit, is provided with internal logic circuit, to the electricity that will sample
Pressure is compared with predetermined value, closes or open metal-oxide-semiconductor.
4. a kind of excellent PWM switching power source control circuits of anti-electromagnetic interference capability according to claim 3, its feature exists
In：The current sampler is compared output voltage with reference voltage, is led to error amplification signal by error amplifier
Cross optocoupler and be converted into electric current, and inject in feedback input end, the size to adjust output voltage.
5. a kind of excellent PWM switching power source control circuits of anti-electromagnetic interference capability according to claim 1, its feature exists
In：The oscillator uses multi-frequency generator, for by changing electric capacity regulating frequency in the case of charging and discharging currents are constant, and
Dutycycle can be changed by adjusting the charging and discharging currents in charging and discharging circuit.
6. a kind of excellent PWM switching power source control circuits of anti-electromagnetic interference capability according to claim 1, its feature exists
In：The current sampling circuit for controlling switch electric current is provided with the control circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710446948.3A CN106998134A (en) | 2017-06-14 | 2017-06-14 | A kind of excellent PWM switching power source control circuits of anti-electromagnetic interference capability |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710446948.3A CN106998134A (en) | 2017-06-14 | 2017-06-14 | A kind of excellent PWM switching power source control circuits of anti-electromagnetic interference capability |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN106998134A true CN106998134A (en) | 2017-08-01 |
Family
ID=59436555
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710446948.3A Pending CN106998134A (en) | 2017-06-14 | 2017-06-14 | A kind of excellent PWM switching power source control circuits of anti-electromagnetic interference capability |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106998134A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109450257A (en) * | 2018-12-12 | 2019-03-08 | 西安矽力杰半导体技术有限公司 | Isolated form switch converters and its control circuit and control method |
| CN109765955A (en) * | 2018-12-07 | 2019-05-17 | 中电科仪器仪表(安徽)有限公司 | A kind of Voltage Feedback control circuit |
| CN112564480A (en) * | 2020-11-24 | 2021-03-26 | 西安交通大学 | Zero current detection circuit and KY converter with wide load range |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103023330A (en) * | 2012-12-18 | 2013-04-03 | 深圳市明微电子股份有限公司 | Switching power supply and self-adaption multi-mode control circuit |
| CN207426968U (en) * | 2017-06-14 | 2018-05-29 | 江苏信息职业技术学院 | A kind of excellent PWM switching power source control circuits of anti-electromagnetic interference capability |
-
2017
- 2017-06-14 CN CN201710446948.3A patent/CN106998134A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103023330A (en) * | 2012-12-18 | 2013-04-03 | 深圳市明微电子股份有限公司 | Switching power supply and self-adaption multi-mode control circuit |
| CN207426968U (en) * | 2017-06-14 | 2018-05-29 | 江苏信息职业技术学院 | A kind of excellent PWM switching power source control circuits of anti-electromagnetic interference capability |
Non-Patent Citations (1)
| Title |
|---|
| 赵晨光 等: "一种具有频率扩展功能的低温漂振荡器设计", 《微电子学与计算机》 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109765955A (en) * | 2018-12-07 | 2019-05-17 | 中电科仪器仪表(安徽)有限公司 | A kind of Voltage Feedback control circuit |
| CN109450257A (en) * | 2018-12-12 | 2019-03-08 | 西安矽力杰半导体技术有限公司 | Isolated form switch converters and its control circuit and control method |
| CN109450257B (en) * | 2018-12-12 | 2019-08-27 | 西安矽力杰半导体技术有限公司 | Isolated form switch converters and its control circuit and control method |
| CN112564480A (en) * | 2020-11-24 | 2021-03-26 | 西安交通大学 | Zero current detection circuit and KY converter with wide load range |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103208934B (en) | A kind of pulse width modulating switch power source controller and Switching Power Supply | |
| CN104734510B (en) | Switch power supply and control chip thereof | |
| CN101710786B (en) | Switch voltage stabilizing circuit and method | |
| CN103580470B (en) | For the mixed self-adapting power factor correction scheme of switching power converter | |
| CN203368317U (en) | High PFC constant current control device without loop compensation and voltage converter | |
| CN104578800B (en) | Control circuit of switch power supply and switch power supply provided with control circuit | |
| CN202435294U (en) | Pulse width modulation switch power supply controller and switch power supply | |
| US8581561B2 (en) | DC-DC boost converter circuit with an output stabilization circuit and method for driving the same | |
| CN102055313B (en) | Power factor correction control device in fixed frequency constant on time current make-and-break mode | |
| CN103187864B (en) | Buck active power factor correction device | |
| CN103095135A (en) | Switch converter and slope compensation circuit thereof | |
| CN102468747A (en) | Charge pump control circuit | |
| CN103036418A (en) | Buck power factor correction system | |
| CN103384117B (en) | A kind of variable mode transducer and regulate and control method thereof | |
| CN106998134A (en) | A kind of excellent PWM switching power source control circuits of anti-electromagnetic interference capability | |
| CN103281829B (en) | A kind of LED drive circuit | |
| CN203278655U (en) | control circuit and switching power supply | |
| CN102545552B (en) | Matching circuit and large-power pulse power supply using same | |
| CN103414323A (en) | Circuit for reducing turn-on time of current control type switch adjusting system | |
| CN207426968U (en) | A kind of excellent PWM switching power source control circuits of anti-electromagnetic interference capability | |
| CN203135724U (en) | Switch converter and slope compensation circuit thereof | |
| CN204578367U (en) | A kind of Switching Power Supply of BOOST circuit topological structure | |
| CN201846229U (en) | Soft start circuit | |
| CN102386773B (en) | Switch power supply | |
| CN202178706U (en) | AC-DC power conversion chip and power conversion circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20170801 |