CN207426968U - 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
- CN207426968U CN207426968U CN201720688835.XU CN201720688835U CN207426968U CN 207426968 U CN207426968 U CN 207426968U CN 201720688835 U CN201720688835 U CN 201720688835U CN 207426968 U CN207426968 U CN 207426968U
- Authority
- CN
- China
- Prior art keywords
- module
- pipes
- power supply
- electromagnetic interference
- current
- 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.)
- Active
Links
Abstract
The utility model discloses the PWM switching power source control circuits that a kind of anti-electromagnetic interference capability is excellent, its key points of the technical solution are that including 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 overheating 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 for changing switch, zero current detecting circuit, valley conduction pattern, the lowest point detector and mode selector are used to implement, for the switching of several operating mode, the utility model employs a variety of methods for reducing 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 utility model is related to integrated circuit fields, and in particular to a kind of excellent PWM switch electricity of anti-electromagnetic interference capability
Source control circuit.
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 with on-off mode works and gains the name, function is that one reference voltage is converted to user terminal institute by various forms of frameworks
The voltage or electric current of demand.Switching Power Supply main operational principle be using modern power electronics technology, control switching tube 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, there are many working methods of switching power source control circuit, and one of the most common one kind is pulse width modulation（PWM）
Mode controls the waveform of output by adjusting the switch time of power MOS, is adjustment power mode mos gate by the way of
Pole pwm signal duty cycle, so as to control the analog quantity of the power supply of output waveform and electric current and a kind of mode of power regulation.
Electromagnetic interference (Electromagnetic Interference, EMI) is interference electric signal and to reduce signal intact
The electronic noise of property, EMI is usually as caused by electromagnetic radiation occurring source.The presence of EMI can cause the reduced performance of equipment.
Electromagnetic interference includes two kinds of Conduction Interference and radiation interference.Conduction Interference refers to through conducting medium a power grid
Signal coupling on network（Interference）To another electric network.Radiation interference refers to that interference source couples its signal by space（It is dry
It disturbs）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 emitted and influence in other systems or the system other
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 range 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, since Switching Power Supply is directly connect on the utility grids, between power-supply device and power grid
There are two-way electromagnetic interferences；The use condition of another aspect Switching Power Supply is usually poor, such as automotive fittings, therefore is switching
It must take into consideration electromagnetism interference problem 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 first passes through to promote global switch power supply antijamming capability than more typical scheme by peripheral circuit
Then the module of electromagnetism interference carries out rectifying and wave-filtering again.These safeguard measures can be promoted by the design of peripheral circuit and opened
The anti-electromagnetic interference capability in powered-down source, but so doing can cause the design of entire 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 the attention rate of energy efficiency and environmental issue increasingly improves in society, reduce switching loss, improve switch electricity
The efficiency in source has become the main hair of Switching Power Supply aspect IC design so as to improve Switching Power Supply anti-electromagnetic interference capability
Open up direction.
Utility model content
The purpose of this utility model is to provide a kind of excellent PWM switching power source control circuits of anti-electromagnetic interference capability,
It is excellent with anti-electromagnetic interference capability, the advantages of the efficiency of Switching Power Supply can be improved, reduce the energy loss of Switching Power Supply.
The above-mentioned technical purpose of the utility model technical scheme is that：
The excellent PWM switching power source control circuits of a kind of anti-electromagnetic interference capability, including power supply and drive module, protection mould
Block and multi-mode control module；
The power supply and drive module, including internal starting module, reference voltage module, current sampler, error amplification
Device, output driving module；
The protection module, including overheating protection module, overload protection module, overvoltage protective module and overcurrent protection mould
Block；
The multi-mode control module, including feedback input end, oscillator, frequency, load detecting for changing switch
Module, zero current detecting circuit are used to implement valley conduction pattern, the lowest point detector and mode selector, for several work
The switching of operation mode.
By using above-mentioned technical proposal, since Switching Power Supply needs constantly to carry out charge and discharge to coil in practical applications
Electricity, the presence of this rush of current cause 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.It can be seen that current ripples are directly proportional to voltage.
Supply voltage cannot be too low in practical application, and in order to reduce electromagnetic interference, switching frequency cannot be too low, that is, improves and open
Current ripples can be reduced by closing frequency, but can so increase switching loss, and energy conversion efficiency reduces.Therefore switching frequency
Selection must take into consideration factors, and compromise.The utility model uses variable switching frequency with according to different situations tune
Switching frequency needed for section.
The utility model employs zero current detecting circuit to optimize the conducting of switching tube.The of switching tube drain-source power supply
Position where one minimum value causes the MOSFET to turn on, and the current spike that can cause conducting is minimum.The circuit provides letter
Number driving switch pipe into open-minded, that is, realizes valley conduction when its drain terminal voltage difference is relatively low.The current spike so turned on will
Can be minimum, so as to substantially reduce the electromagnetic interference of entire Switching Power Supply.
Further set：The load detecting module is connected with internal starting module, for starting in internal starting module
Afterwards, detect external loading situation and electric signal fed back into mode selector, mode selector for changing control circuit work
Operation mode.
Further set：Metal-oxide-semiconductor is connected with outside the power supply and drive module, operating mode starts zero current detection after determining
Circuit, the lowest point detector, power supply and drive module start metal-oxide-semiconductor, generate sampled voltage, internal logic electricity is equipped in control circuit
Road, compared with predetermined value, sampled voltage is closed or opened metal-oxide-semiconductor.
Further set：Output voltage compared with reference voltage, is passed through error amplifier by the current sampler
Error amplification signal is converted into electric current by optocoupler, and is injected in feedback input end, to adjust the size of output voltage.
Further set：The oscillator uses multi-frequency generator, and for passing through, to change capacitance constant in charging and discharging currents
In the case of adjust frequency, and duty cycle can be changed by adjusting the charging and discharging currents in charging and discharging circuit.
By using above-mentioned technical proposal, due to the influence of inductance, capacitance in switch power supply system, Switching Power Supply control electricity
Road can introduce electric current and voltage higher harmonic components during the work time, i.e., with the presence of the noise band that peak value is very high on frequency spectrum,
So as to generate serious electromagnetic interference.The utility model uses " frequency conversion " technology so that and switching frequency is not fixed, but
Variation in a certain range so as to which the frequency band of each harmonic of the voltage and current in Switching Power Supply is obtained broadening, is opened with reducing
Powered-down source control circuit electromagnetic interference.
Further set：The interior current sampling circuit for being equipped with to control switching current of the control circuit.
By using above-mentioned technical proposal, during switching power circuit designs, in order to reduce electromagnetic interference, simultaneously
Reduce switching loss, improve high conversion efficiency, reduce to a certain extent in the utility model switching tube cut-off current and
Load current to reduce the loss in the course of work, improves transfer efficiency.
In conclusion the utility model has the advantages that：
The utility model employs the method for a variety of reduction electromagnetic interferences, the control after the design of multiple electromagnetism interference
The anti-electromagnetic interference capability of circuit is preferable, can application monitor/LCD TV/set-top box power supply, can be used for it is various exchange/
DC power source adapter and various chargers.
Switching Power Supply frequency can be smoothly varying in external world's load variation for the utility model, that is, embodies " soft bending "
The characteristics of, therefore with traditional switch power supply electromagnetic interference is reduced compared to switching loss is substantially reduced.
By using Valley-Switching pattern, it is smaller to turn it on formed current spike, so as to reduce entire switch electricity
The electromagnetic interference in source improves transfer efficiency.In addition in addition to reducing electromagnetic interference and switching loss, transfer efficiency is improved, it is right
Switching current has carried out effective control.
In actual application, the utility model not only can largely save peripheral circuit, moreover it is possible to greatly improve power supply
Transfer efficiency reduces switching loss.
Description of the drawings
The utility model is further illustrated 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 utility model；
Fig. 3 is the working mode figure of the utility model；
Fig. 4 is the working mode figure of switching tube in the utility model；
Fig. 5 is the zero detection circuit structure for optimizing switching tube conducting in the utility model；
Fig. 6 is the structure chart of multi-frequency generator in the utility model；
Fig. 7 is the current sampling circuit figure in the utility model.
Symbol description, AC：Alternating current source；CS：Electric current senses input terminal；DRI：The drive output of metal-oxide-semiconductor；VIN：Direct current is defeated
Enter voltage；M1：Switching tube；CM：The drain terminal capacitance 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 terminal；Ismp：Sampled output current.
Specific embodiment
Specific embodiment of the present utility model is described further below in conjunction with the accompanying drawings.
Technical solution is used by the utility model：
The excellent PWM switching power source control circuits of a kind of anti-electromagnetic interference capability, as shown in Fig. 2, function module includes supplying
Electricity 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 overheating protection module, overload protection module, overvoltage protective module and overcurrent protection module.
Multi-mode control module, including feedback input end, oscillator, frequency, load detecting module for changing switch,
Zero current detecting circuit is used to implement valley conduction pattern, the lowest point detector and mode selector, for several operating mode
Switching.
So it can realize the raising of circuit anti-electromagnetic interference capability 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 is filled to VCC ends external capacitor
Electricity, when VCC voltages rise to certain value, internal circuit is started to work, and oscillator also sends trigger signal, the inspection of load detecting module
External loading is surveyed, 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 to work afterwards, when eligible, into quasi-resonance Valley-Switching mould
Formula opens metal-oxide-semiconductor 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 generates sampled voltage after mirror image on internal sampling resistor in proportion, when inductive current rises
To when sampled voltage being made to be more than preset value, current comparator is overturn, and triggers internal logic circuit, closes metal-oxide-semiconductor.When shaking
It swings device next cycle to come temporarily, 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 raises, the electric current increase of FB ports injection, the pressure drop which generates on internal resistance increases,
Current comparator is overturn so that the pressure drop that primary inductance electric current generates on internal resistance reduces, i.e., primary inductance is electric
Stream reduces, and being thus relayed to secondary energy will reduce, and output voltage will reduce, so as to form the stability series of a negative-feedback
System.Conversely, when output voltage reduces, 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 operating mode of the utility model is as shown in figure 3, in full load, when the input power is low, the IC works
Make in fixed frequency CCM（Continuous Condition Mode）Pattern, the fixed frequency are 50KHz or so；And it is inputting
When power is 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
Efficiency.
Under normal load condition, the utility model is in quasi-resonant mode（Quasi-Resonant Mode）Lower work.In order to
Switching loss is reduced, the highest switching frequency under quasi-resonant mode will be any limitation as, and be clamped down in this circuit in Fhigh, value is
90KHz or so meets EMI standards.The pwm control circuit is oscillated at first trough in power supply and opened in QR patterns, switching tube
It is logical, start next cycle.By quasi-resonance operating mode, the switching loss and EMI of system substantially reduce.
When the load decreases, the utility model is in PFM（Pulse Frequency Modulation）It works under pattern, with
Reach more than 90% power conversion efficiency.The utility model according to load come adjusting switch frequency, and constantly reduce；In PFM ranks
Section, the lowest point switching characteristic still exists, so as to obtain smooth frequency variation curve.
When loading smaller or unloaded, this practicality is newly in green model（Green Mode）Lower work, is treated to reduce
Machine power consumption and switching loss improve system transfer efficiency.When being operated in green model, switching frequency Fgreen, value is
20KHz or so, and no longer reduce.It is well known that 20KHz is audiorange, by using green model, it is possible to prevente effectively from
The appearance of audio-frequency noise.
As shown in figure 3, the two poles of the earth of AC are coupled with the anode of diode D1, D3 and D2, D4, cathode and the V phases of D1, D2
Even, D3, D4 cathode ground connection.
Resistance R1 one end is connected with Lp, another to terminate to capacitance C1 top crowns and VCC, C1 bottom crown ground connection.
The drain electrode of M1 pipes meets LHL and capacitance CM top crowns, and grid is connected to DRI, and source electrode is connect under CS, R2 and CM
Pole plate, the other end ground connection of R2.
LS one end is connected with diode D anodes, another to terminate to capacitance C bottom crowns and ground, and diode D cathode meet capacitance 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 transferred to secondary from primary,
Secondary magnetic flux can not be transferred to by coupling, the ability of storage need to be discharged by other paths.And it is stored in leakage inductance
In energy be switching tube shut-off be generate spike the reason for.
As shown in figure 4, switching tube is in the conduction state at the beginning, primary current, peak value I are formedPP, it is maximum in electric current
When turn off, leakage inductance LPLWith switching tube drain terminal capacitance CMThe resonant tank of composition generates over-pressed spike vibration, forms resonance range one.
In resonance range one, switching tube drain-source voltage peak value can use formula（1）It represents, wherein IPAt the beginning of flowing through transformer
The direct current of grade coil.
After switching tube shut-off, the mutual inductance energy of transformer forms secondary current, peak value I by the rectifying tube D1 of conductingPS,
It charges to filter capacitor C, so as to transfer energy to load.Secondary current continuously decreases in the process, when being close to zero,
Mutual inductance LmWith switching tube drain terminal capacitance CMGenerate resonance range two.There are tri- points of A, B, C, wherein A points in oscillating curve in this section
It is 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 turns on again, it can select to turn on when its drain terminal voltage is relatively low, can also select in its drain terminal
It is turned on when voltage is higher.Because drain terminal capacitance CMCurrent spike can be formed during by switching tube discharge, if switching tube is leaked at it
The higher point of terminal voltage is opened, then will generate larger switching noise, forms 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 entire Switching Power Supply.The conducting of switching tube and deadline can
Formula is used respectively（4）、（5）It represents.
The utility model employs zero current detecting circuit to optimize the open-minded of switching tube, zero detection electricity of switching tube conducting
Line structure optimization is as shown in Figure 5.The circuit provides signal driving switch pipe when its drain terminal voltage difference is relatively low into open-minded, i.e. reality
Existing valley conduction.
As shown in figure 5, the drain electrode of N0 pipes meets the I0 to come from power supply, grid connects the grid of N1 pipes, grid leak short circuit, and source level 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 comes from power supply, source level 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 level connects the drain electrode of N3 pipes and N6 pipes
Grid；
The drain electrode of N3 pipes connects the source level of N2 pipes and the grid of N6 pipes, the I0 that grid connects the grid of N0 pipes and comes from power supply, source
Grade ground connection；
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, and source level connects
Ground；
The drain electrode of N5 pipes connects the drain electrode of P2 pipes, and grid connects the grid of N4 pipes, source level ground connection；
The drain electrode of N6 pipes connects the drain electrode of P3 pipes and the grid of P4 pipes, source level meet DRI；
The drain electrode of N7 pipes meets drain electrode and the OUT of P4 pipes, and grid connects the I0 come from power supply, source level ground connection；
The source level of P0 pipes connects power supply, and grid connects the grid of P1 pipes, source grid short circuit, and drain electrode connects the drain electrode of N1 pipes；
The source level 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 level 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 level of P3 pipes connects power supply, and grid connects the grid of P2 pipes, and drain electrode connects the drain electrode of N6 pipes and the grid of P4 pipes；
The source level 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, capacitance in switch power supply system, switching power source control circuit can introduce during the work time
Electric current and voltage higher harmonic components with the presence of the noise band that peak value is very high that is, on frequency spectrum, are done so as to generate serious electromagnetism
It disturbs.A kind of effective ways for reducing switching power source control circuit electromagnetic interference are to use " frequency conversion " technology so that switching frequency is not
It is fixed, but changes within the specific limits, so as to which the frequency band of each harmonic of the voltage and current in Switching Power Supply is obtained
To broadening.
If frequency range is △ f, then in switching frequency excursion, broadening is △ f by fundamental wave bandwidth, two
Broadening is 2 △ f by subharmonic bandwidth, and so on, 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 inhibit to be
The electromagnetic interference of system.
The utility model employs multi-frequency generator to realize " frequency conversion " technology, structure such as 6 institute of attached drawing of this oscillator
Show.Capacitance C0 is one group of capacitance of different sizes, controls whether it accesses the charge and discharge of oscillator by different control signals respectively
Electrical circuit, these control signals are generated by frequency dividing circuit.Voltage after charging on capacitance C0 is Vc0, and fixed comparison voltage is
Vref, VrefWith Vc0It is compared, so as to form vibration.
It is respectively T to define the charging current of the oscillator and discharge currentch、Tdch, then the charge cycle T of the oscillatorch
With discharge cycle TdchFormula can be used respectively（6）、（7）It represents.
So as to which frequency of oscillation and duty cycle can use formula respectively（8）、（9）It represents.
By changing capacitance, frequency can be adjusted in the case that charging and discharging currents are constant；And by adjusting charging and discharging circuit
On charging and discharging currents, thus it is possible to vary duty cycle.
As shown in fig. 6, the source level of P0 pipes connects power supply, grid connects the source level that Vbh. drain electrodes connect P3 pipes；
The source level of P1 pipes connects power supply, and grid meets Vbh, and drain electrode connects the drain electrode of N1 pipes；
The source level of P2 pipes connects power supply, and grid meets Vbh, and drain electrode connects C0, the upper step of C1 and the "-" interface of BGR；
The source level of P3 pipes connects the drain electrode of P0, and grid connects 1 input of NAND2, and drain electrode connects the drain electrode of N0 pipes and the grid of N1 pipes；
The drain electrode of N0 pipes connects the drain electrode of P3 pipes and the grid of N1 pipes, the grid of N0 pipes connect the leakage of the grid and N3 pipes of N2 pipes
Pole, source level ground connection；
The drain electrode of N1 pipes connects the drain electrode of P1 pipes and 1 input of NAND1, and grid connects the drain electrode of P3 pipes and the drain electrode of N0 pipes, source
Pole connects the drain electrode of N2 pipes；
The drain electrode of N2 pipes connects the source level of N1 pipes, and grid connects the drain electrode of N3 pipes and the grid of N0 pipes, source level ground connection；
The grid for missing N0 pipes and N2 pipes of N3 pipes, grid connect the output of the grid and NAND1 of P3 pipes, and the 1 of NAND2 is defeated
Enter, source level ground connection；
The upper step of C0 connects the drain electrode of P2 pipes and the upper step of C1 and the "-" interface of BGR, bottom crown ground connection；
The upper step of C1 connects the drain electrode of P2 pipes and the upper step of C2 and the "-" interface of BGR, bottom crown ground connection；
1 input of NAND1 connects the drain electrode of P1 pipes and the drain electrode of N1 pipes, and 2 inputs connect the output of NAND2, and output connects NAND2's
1 input and the grid of P3, N3 pipe；
1 input of NAND2 connects the output of NAND1, and 2 inputs connect the output of BGR；Output connects 2 inputs of NAND1.
4th, switching tube current control
In order to reduce electromagnetic interference, while reduce switching loss, improve high conversion efficiency, subtract as far as possible in this utility model
The small cut-off current and load current of switching tube.Specific implementation is to use current sample mode, and passes through and to form feedback, is kept
Electric current is without departing from 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 output current, and sample rate current generates pressure on the channel resistance of P2
Drop.
When output current increases, the current potential decline of W3 causes the current potential of W2 to decline, since P5 with P6 grid potentials are identical, P6
Source potential（W2）Decline reduces P6 electric currents, and W4 current potentials is caused to decline, and W4 is connected to the grid of P7, increases P7 electric currents, makes
W1 current potentials decline, and P5 electric currents is caused to decline, and N0 is constant-current source, and the grid potential of P5 will be pulled low, i.e. the grid of P6 is pulled low,
P6 electric currents increase, and W4 rises make this feedback control loop reach stable state, so as to limit switch tube current.By to power on
Stream sample circuit causes switching current to be restricted.
Referring to Fig. 7, the source level of P0 pipes connects power supply, grounded-grid, and drain electrode connects the source level of P5 pipes and P7 pipes；
The source level of P1 pipes connects the drain electrode of P2 pipes and the source level of P3 pipes, grounded-grid, and drain electrode connects the source level of P6 pipes；
The source level of P2 pipes connects power supply, grounded-grid, and drain electrode connects the source level of P1 pipes and the source level of P3 pipes；
The source level of P3 pipes connects the drain electrode of P2 pipes and the source level of P1 pipes, grounded-grid, and drain electrode meets drain electrode and the DRI of P4 pipes；
The source level of P4 pipes connects power supply, grounded-grid, and drain electrode meets drain electrode and the DRI of P3 pipes；
The source level of P5 pipes connects the drain electrode of P0 pipes and the source level of P7 pipes, and grid connects the grid of P6 pipes, and drain electrode connects the drain of N0 pipes,
Grid and drain electrode short circuit；
The source level 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 level of P7 pipes connects the drain electrode of P0 pipes and the source level of P5 pipes, and grid connects the drain electrode of P6 pipes and the drain of N1 pipes, drain electrode
Meet Ismp；
The drain of N0 pipes connects the drain electrode of P5 pipes, and grid connects Vb, source electrode ground connection；
The drain of N1 pipes connects the drain electrode of P6 pipes and the grid of P7 pipes, and grid connects Vb, source electrode ground connection.
The above are the preferred embodiments of the utility model, not make limitation in any form to the utility model,
It is every according to the technical essence of the utility model to any simple modification, equivalent change and modification made for any of the above embodiments,
Belong in the range of utility model technical solution.
Claims (5)
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 internal starting module, reference voltage module, current sampler, error amplifier, defeated
Go out drive module；
The protection module, including overheating 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 for changing switch,
Zero current detecting circuit is used to implement valley conduction pattern, the lowest point detector and mode selector, for several operating mode
Switching；
The power supply and drive module are electrically connected respectively with protection module and multi-mode control module, load detecting module and inside
Starting module connects, for after the startup of internal starting module, detecting external loading situation and electric signal being fed back to pattern choosing
Select device, mode selector for changing control circuit operating mode.
2. a kind of excellent PWM switching power source control circuits of anti-electromagnetic interference capability according to claim 1, feature exist
In：Metal-oxide-semiconductor is connected with outside the power supply and drive module, operating mode starts zero current detecting circuit, the lowest point detector after determining,
Power supply and drive module start metal-oxide-semiconductor, generate sampled voltage, internal logic circuit are equipped in control circuit, will sample electricity
Pressure closes or opens metal-oxide-semiconductor compared with predetermined value.
3. a kind of excellent PWM switching power source control circuits of anti-electromagnetic interference capability according to claim 2, feature exist
In：Error amplification signal compared with reference voltage, is led to output voltage by the current sampler by error amplifier
It crosses optocoupler and is converted into electric current, and inject in feedback input end, to adjust the size of output voltage.
4. a kind of excellent PWM switching power source control circuits of anti-electromagnetic interference capability according to claim 1, feature exist
In：The oscillator uses multi-frequency generator, changes capacitance for passing through and adjusts frequency in the case that charging and discharging currents are constant, and
Duty cycle can be changed by adjusting the charging and discharging currents in charging and discharging circuit.
5. a kind of excellent PWM switching power source control circuits of anti-electromagnetic interference capability according to claim 1, feature exist
In：The interior current sampling circuit for being equipped with to control switching current of the control circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720688835.XU CN207426968U (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 |
|---|---|---|---|
| CN201720688835.XU CN207426968U (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 |
|---|---|
| CN207426968U true CN207426968U (en) | 2018-05-29 |
Family
ID=62398990
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201720688835.XU Active CN207426968U (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) | CN207426968U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106998134A (en) * | 2017-06-14 | 2017-08-01 | 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 |
| CN111964855A (en) * | 2019-12-31 | 2020-11-20 | 苏州苏试试验集团股份有限公司 | Automatic magnetic flux leakage control method for electric vibration table |
-
2017
- 2017-06-14 CN CN201720688835.XU patent/CN207426968U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106998134A (en) * | 2017-06-14 | 2017-08-01 | 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 |
| CN111964855A (en) * | 2019-12-31 | 2020-11-20 | 苏州苏试试验集团股份有限公司 | Automatic magnetic flux leakage control method for electric vibration table |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102904448B (en) | Control chip of switch power supply and switch power supply | |
| CN102523406B (en) | Power circuit structure and LED liquid crystal television | |
| CN103208934B (en) | A kind of pulse width modulating switch power source controller and Switching Power Supply | |
| CN101710786B (en) | Switch voltage stabilizing circuit and method | |
| CN104734510B (en) | Switch power supply and control chip thereof | |
| CN202435294U (en) | Pulse width modulation switch power supply controller and switch power supply | |
| CN102055313B (en) | Power factor correction control device in fixed frequency constant on time current make-and-break mode | |
| CN102468747A (en) | Charge pump control circuit | |
| CN103187864B (en) | Buck active power factor correction device | |
| CN108173434A (en) | Switching power circuit | |
| Chen et al. | Latest advances of LLC converters in high current, fast dynamic response, and wide voltage range applications | |
| CN105871192A (en) | Power supply circuit, control chip, switch power supply system and power supply method | |
| CN209233522U (en) | A kind of compound voltage reducing formula solar energy movable power supply | |
| CN103384117B (en) | A kind of variable mode transducer and regulate and control method thereof | |
| CN207426968U (en) | A kind of excellent PWM switching power source control circuits of anti-electromagnetic interference capability | |
| CN106998134A (en) | A kind of excellent PWM switching power source control circuits of anti-electromagnetic interference capability | |
| CN103414323B (en) | Reduce the circuit of service time in current-control type switching regulators | |
| CN110829846A (en) | Zero-voltage switch control circuit and method applied to switching power supply | |
| CN104795984A (en) | Power converter | |
| CN203466720U (en) | Circuit reducing opening time in current control type switching regulating system | |
| CN105792447B (en) | The LED drive circuit and its high power factor correction device of no electrolytic capacitor | |
| CN104124862B (en) | High PFC constant-current control devices and voltage changer without loop compensation | |
| CN204578367U (en) | A kind of Switching Power Supply of BOOST circuit topological structure | |
| CN205566097U (en) | Supply circuit , control chip , switching power supply system | |
| Liu et al. | Dual-current pump module for transient improvement of step-down DC–DC converters |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20210812 Address after: No.88, East Zhongtong Road, Shuofang, Xinwu District, Wuxi City, Jiangsu Province, 214000 Patentee after: WUXI ROUM SEMICONDUCTOR TECHNOLOGY Co.,Ltd. Address before: 214000 No.1 qianou Road, Wuxi City, Jiangsu Province Patentee before: JIANGSU VOCATIONAL College OF INFORMATION TECHNOLOGY |
|
| CP01 | Change in the name or title of a patent holder | ||
| CP01 | Change in the name or title of a patent holder |
Address after: No.88, East Zhongtong Road, Shuofang, Xinwu District, Wuxi City, Jiangsu Province, 214000 Patentee after: Jiangsu Donghai Semiconductor Co.,Ltd. Address before: No.88, East Zhongtong Road, Shuofang, Xinwu District, Wuxi City, Jiangsu Province, 214000 Patentee before: WUXI ROUM SEMICONDUCTOR TECHNOLOGY Co.,Ltd. |