CN108512196B - A kind of overload protection fast response circuit of primary side feedback AC-DC power supply - Google Patents
A kind of overload protection fast response circuit of primary side feedback AC-DC power supply Download PDFInfo
- Publication number
- CN108512196B CN108512196B CN201810263789.8A CN201810263789A CN108512196B CN 108512196 B CN108512196 B CN 108512196B CN 201810263789 A CN201810263789 A CN 201810263789A CN 108512196 B CN108512196 B CN 108512196B
- Authority
- CN
- China
- Prior art keywords
- fast response
- overload
- overload protection
- feedback
- response circuit
- 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
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/10—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers
- H02H7/12—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers
- H02H7/125—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers for rectifiers
-
- 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
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/02—Conversion of ac power input into dc power output without possibility of reversal
- H02M7/04—Conversion of ac power input into dc power output without possibility of reversal by static converters
- H02M7/12—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/21—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M7/217—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
-
- 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
- H02M1/0025—Arrangements for modifying reference values, feedback values or error values in the control loop of a converter
Abstract
The invention discloses a kind of overload protection fast response circuits of primary side feedback AC-DC power supply, including overload protecting circuit and fast response circuit；On the basis of traditional overload protecting circuit, overload protection fast response circuit is increased；When power-supply system overload; output voltage reduction is detected by FB feedback end; ever-increasing electric current all the way is additionally provided to armature winding peak current detection end CS inside circuit; pressure allows armature winding peak point current constantly to reduce; the energy provided to power-supply system gradually decreases; output voltage rapid decrease in overload, forms positive feedback mechanism, to accelerate overload protection to respond.
Description
Technical field
The present invention relates to electronic circuit technology field, especially a kind of overload protection of primary side feedback AC-DC power supply is quick
Response circuit.
Background technique
With the development of power technology, AC-DC Switching Power Supply has been widely used in each electronic product.Green, energy conservation
Requirement put forward higher requirements for power technology；On the one hand, main control chip is for reducing cost, increasing function and optimization property
The requirement of the various aspects such as energy is also more stringent；On the other hand, miniaturization, high efficiency, heat dissipation height are increasingly becoming the market mainstream and answer
With.Compared to traditional secondary side feedback, that is, lean on the power-supply system of opto-coupled feedback, the AC-DC power supply based on primary side feedback technology
It all has a clear superiority in terms of save the cost and miniaturization, market is very widely used.
As shown in Figure 1, typical primary side feedback detection AC-DC power supply includes primary side feedback detection flyback sourse converter
Governor circuit chip, power NMOS tube, armature winding peak point current limiting resistance RCS, auxiliary winding partial pressure upper end resistance, auxiliary
Winding divides lower end resistance, transformer, output rectifier diode and VDD rectifier diode；Primary side feedback detects flyback sourse and turns
Parallel operation governor circuit chip includes tetra- input and output pins of VDD, CS, FB and PWM, and wherein VDD is power input, and the end CS is
Primary winding peak current detection input terminal, FB be output feedback input end, PWM be control power NMOS transistor conduction and
The output end of shutdown.
As shown in Fig. 2, comparator A is just in the overload protecting circuit of traditional primary side feedback detection AC-DC power supply
Fixed voltage V2 and FB are separately connected to input terminal and reverse input end, and output end connects delayer, and delayer is to logic control
Device sends overload protection signal PRO；The end FB feedback voltage is defeated when overload protection occurs compared with internal fixed voltage V2
Voltage reduces out, and the end FB voltage reduces；When being overload up to a certain degree, FB voltage is gradually reduced, only when FB voltage is lower than V2,
Comparator exports high level, and internal delay circuit is just started to work；If cancelling overload at this time, output voltage is gradually extensive
It is multiple normal, then FB voltage restores normal；Once FB voltage is greater than V2, timing can be reset；Only when FB voltage always
Lower than V2 just can timing always, after timing TIME1 terminates, pwm signal is closed and can be latched, at this moment power
MOSFET will not be opened and be needed to re-power until chip.In summary: on the one hand, when the system is overloaded, overload
Continue, output voltage continues to fall, until the voltage that FB is sampled is always below V2, ability timing；On the other hand, it is being delayed
In device TIME1 this period, power-supply system is also to be constantly in overload, while carrying starting to meet band, TIME1 when
Between again cannot be too short, it is too short if power-supply system band load do not start.
Due to the complexity of power-supply system application, input (90V/60Hz~264V/50 Hz) condition is exchanged in gamut
Under, under the conditions of transformer different parameters, under different load conditions, it should guarantee that Maximum Power Output is with higher consistent
Property, also require output overloading protection point as small as possible with power difference corresponding to recovery point, while to output overloading protection
More stringent requirements are proposed for response speed.
Summary of the invention
Goal of the invention of the invention is: in view of the above problems, providing a kind of mistake of primary side feedback AC-DC power supply
It carries protection fast response circuit and increases overload protection fast response circuit, effectively on the basis of traditional overload protecting circuit
The response speed for improving overload protecting circuit.
The technical solution adopted by the invention is as follows:
A kind of overload protection fast response circuit of primary side feedback AC-DC power supply of the present invention, including overload protecting circuit, institute
Stating overload protecting circuit includes comparator A and comparator B, and the positive input of comparator A is connected and fixed voltage V2, reversed to input
End connection FB, output end connect delayer, and delayer sends overload protection signal PRO, logic controller hair to logic controller
PWM out；The positive input of comparator B is connected and fixed voltage V1, and reverse input end connects CS, and output end connects logic control
Device；
It further include fast response circuit, the fast response circuit includes operational amplifier OP1, the operational amplifier
The positive input of OP1 terminates FB, and negative input end connects feedback resistance R2, the grid end of output termination PMOS tube M1, the drain terminal of PMOS tube M1
Connecting resistance R1, R1 connecting resistance R2, R1 connect the negative input end of operational amplifier OP1, R2 resistance eutral grounding；The operational amplifier OP1
Output end be also connected with the grid end of PMOS tube M2, the drain terminal of PMOS tube M2 meets internal fixed bias current IB, on the drain terminal of M2 also
The grid end and drain terminal of PMOS tube M3 are connected, the grid end of M4 is connected in the grid end of M3, and the drain terminal of M4 is output end, is connected to the end CS
On mouth；The source of described PMOS tube M1, M2, M3 and M4 are separately connected input current IA, IC, ID and IE.
Preferably, the size and output voltage of IA electric current are directly proportional when feedback end FB detects output voltage.
Preferably, the M1 and M2 are mirrored into current source；The M3 and M4 are mirrored into current source.
Preferably, the electric current of the internal fixed bias IB is greater than IC current maxima.
In conclusion by adopting the above-described technical solution, the beneficial effects of the present invention are: the present invention is in traditional overload
It protects on circuit base, increases overload protection fast response circuit；When power-supply system overload, can be detected by FB feedback end
It is reduced to output voltage, is supplied to the ever-increasing electric current IE in the end CS, when IE electric current increases, armature winding peak point current is reduced,
The energy that whole system is supplied to output in overload is reduced, and output voltage declines faster, forms positive feedback mechanism, is added to realize
Fast overload protection response.
Detailed description of the invention
Examples of the present invention will be described by way of reference to the accompanying drawings, in which:
Fig. 1 is that typical primary side feedback detects AC-DC power supply application structure block diagram.
Component labelling in figure: 101: typical primary side feedback detects flyback sourse converter governor circuit
102: power NMOS tube
103: armature winding peak point current limiting resistance RCS
104: auxiliary winding divides upper end resistance
105: auxiliary winding divides lower end resistance
106: transformer
107: output rectifier diode
108:VDD rectifier diode
Fig. 2 is traditional overload protecting circuit figure.
Fig. 3 is fast response circuit figure of the present invention.
Specific embodiment
All features disclosed in this specification or disclosed all methods or in the process the step of, in addition to mutually exclusive
Feature and/or step other than, can combine in any way.
Any feature disclosed in this specification (including any accessory claim, abstract), unless specifically stated,
It is replaced by other equivalent or with similar purpose alternative features.That is, unless specifically stated, each feature is a series of
An example in equivalent or similar characteristics.
A kind of overload protection fast response circuit of primary side feedback AC-DC power supply of the present invention, including overload protecting circuit, such as
Shown in Fig. 2, the overload protecting circuit includes comparator A and comparator B, and the positive input of comparator A is connected and fixed voltage
V2, reverse input end connect FB, and output end connects delayer, and delayer sends overload protection signal PRO to logic controller, patrols
It collects controller and issues PWM；The positive input connection Cycle by Cycle peak point current of comparator B limits voltage V1, and reverse input end connects
CS is met, output end connects logic controller；
It further include fast response circuit, as shown in figure 3, the fast response circuit includes operational amplifier OP1；The fortune
The positive input for calculating amplifier OP1 terminates FB, and negative input end connects feedback resistance R2, the grid end of output termination PMOS tube M1, PMOS tube
Drain terminal connecting resistance R1, R1 the connecting resistance R2, R1 of M1 connects the negative input end of operational amplifier OP1, R2 resistance eutral grounding；The operation is put
The output end of big device OP1 is also connected with the grid end of PMOS tube M2, and the drain terminal of PMOS tube M2 connects internal fixed bias current IB, the leakage of M2
The grid end and drain terminal of PMOS tube M3 are also connected on end, the grid end of M4 is connected in the grid end of M3, and the drain terminal of M4 is output end, connection
Onto the port CS；The source of described PMOS tube M1, M2, M3 and M4 are separately connected input current IA, IC, ID and IE.
During the power NMOS tube shutdown of primary side feedback detection AC-DC power supply, output electricity is sampled by FB feedback end
Pressure, generates electric current IA all the way according to the size of output voltage, the size and output voltage of IA electric current are directly proportional, defeated on R1 resistance
Voltage is bigger out, and FB voltage is bigger, and IA is bigger；It is on the contrary then smaller.
In fast response circuit, M1 with the M2 size is identical, is mirrored into current source, and IA electric current is identical with IC electric current；
The size of the M3 and M4 is identical, is mirrored into current source, and IE electric current is equal to ID electric current；Because IA electric current is identical with IC electric current；FB
The maximum value sampled obtains IA current maxima divided by resistance R2；Then IC electric current is obtained most to IC by mirroring ratios
Big value, so IC current maxima is necessarily less than equal to fixed bias current IB.
The output end of operational amplifier is connected to the grid end of M1 and M2, by mirror current source, IA electric current and IC electric current phase
Together, no doubt, ID electric current subtracts IC electric current equal to IB electric current, so ID electric current is also equal to IB electric current and subtracts IA electric current；Because M3 and
M4 is mirrored into current source, and IE electric current is equal to ID electric current, so IE electric current is also equal to IB electric current and subtracts IA electric current；When feedback end FB is examined
Output voltage is measured, the size and output voltage of IA electric current are directly proportional, and output voltage is bigger, and FB voltage is bigger, and IA is bigger；So
IE electric current and feedback end FB detect that output voltage is inversely proportional, and output voltage is bigger, and FB voltage is bigger, and IA is bigger, and IE is with regard to smaller；
Output voltage is smaller, and FB voltage is smaller, and IA is smaller, and IE is bigger.
When power-supply system overload, output voltage reduction can be detected by FB feedback end, IE increases, and IE electric current flows through inspection
Measuring resistance RCS, VCS=VRCS+ Δ V, Δ V=IE*RCS, so VCS=(Ipeak+IE) * RCS, since Cycle by Cycle peak point current limits
Voltage V1 processed is a fixed value, and VCS is a definite value, and when IE electric current increases, armature winding peak point current Ipeak can only be reduced；With
System overload degree deepen, armature winding peak point current Ipeak can gradually decrease, that is, whole system is allowed to mention in overload
The energy of supply output is reduced, then output voltage can reduce faster, output voltage accelerates drop, and FB voltage reduces as soon as possible
To V2 voltage is less than, delayer is clocked into, and overload protection, Lai Shixian quick response are opened after timing.
The invention is not limited to specific embodiments above-mentioned.The present invention, which expands to, any in the present specification to be disclosed
New feature or any new combination, and disclose any new method or process the step of or any new combination.
Claims (4)
1. a kind of overload protection fast response circuit of primary side feedback AC-DC power supply, including overload protecting circuit, the overload is protected
Protection circuit includes comparator A and comparator B, and the positive input of comparator A is connected and fixed voltage V2, and reverse input end connection is anti-
End FB is presented, output end connects delayer, and delayer sends overload protection signal PRO to logic controller, and logic controller issues
PWM；The positive input connection Cycle by Cycle peak point current of comparator B limits voltage V1, and reverse input end connects CS, and output end connects
Connect logic controller；
It is characterized by comprising fast response circuit, the fast response circuit includes operational amplifier OP1, and the operation is put
The positive input terminal of big device OP1 meets feedback end FB, and negative input end meets feedback resistance R2, the grid end of output termination PMOS tube M1, PMOS
One end drain terminal connecting resistance R1 of pipe M1, the one end another terminating resistor R2 of R1, the negative input of another termination operational amplifier OP1 of R1
End, R2 resistance other end ground connection；The output end of the operational amplifier OP1 is also connected with the grid end of PMOS tube M2, PMOS tube M2's
Drain terminal meets internal fixed bias current IB, and the grid end and drain terminal of PMOS tube M3 are also connected on the drain terminal of M2, and the grid end of M4 is connected to
In the grid end of M3, the drain terminal of M4 is output end, is connected on the port CS；The source of described PMOS tube M1, M2, M3 and M4 connect respectively
Meet input current IA, IC, ID and IE.
2. the overload protection fast response circuit of primary side feedback AC-DC power supply as described in claim 1, it is characterised in that: when
When feedback end FB detects output voltage, the size and output voltage of IA electric current are directly proportional.
3. the overload protection fast response circuit of primary side feedback AC-DC power supply as described in claim 1, it is characterised in that: institute
It states M1 and M2 is mirrored into current source；The M3 and M4 are mirrored into current source.
4. the overload protection fast response circuit of primary side feedback AC-DC power supply as described in claim 1, it is characterised in that: institute
The electric current for stating internal fixed bias current IB is greater than the maximum current of IC.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810263789.8A CN108512196B (en) | 2018-03-28 | 2018-03-28 | A kind of overload protection fast response circuit of primary side feedback AC-DC power supply |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810263789.8A CN108512196B (en) | 2018-03-28 | 2018-03-28 | A kind of overload protection fast response circuit of primary side feedback AC-DC power supply |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108512196A CN108512196A (en) | 2018-09-07 |
| CN108512196B true CN108512196B (en) | 2019-10-15 |
Family
ID=63378967
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810263789.8A Active CN108512196B (en) | 2018-03-28 | 2018-03-28 | A kind of overload protection fast response circuit of primary side feedback AC-DC power supply |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108512196B (en) |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH09138247A (en) * | 1995-11-16 | 1997-05-27 | Nissan Motor Co Ltd | Overcurrent detection circuit |
| CN101165983B (en) * | 2006-10-16 | 2010-06-09 | 安凯(广州)微电子技术有限公司 | Current limiting short circuit protection circuit |
| CN101924362B (en) * | 2009-06-16 | 2014-11-05 | 快捷半导体有限公司 | Over-current protection circuit with foldback capability |
| CN101976962B (en) * | 2010-09-20 | 2015-11-25 | 北京中星微电子有限公司 | A kind of AC-DC power supply change-over circuit and method for repairing and regulating thereof |
-
2018
- 2018-03-28 CN CN201810263789.8A patent/CN108512196B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN108512196A (en) | 2018-09-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9077248B2 (en) | Start-up circuit for a power adapter | |
| US8953347B2 (en) | Capacitor discharging circuit and power converter | |
| EP2618443B1 (en) | Dynamic damper and lighting driving circuit comprising the dynamic damper | |
| CN103887984A (en) | Isolating converter and switching power supply comprising same | |
| WO2019169904A1 (en) | Low-cost input anti-overvoltage protection circuit | |
| CN103746566A (en) | Primary side controlled switching power supply and control method thereof | |
| CN105245112B (en) | A kind of adaptive high-accuracy and constant current circuit and Switching Power Supply | |
| US20030184266A1 (en) | Inrush current suppressing device | |
| TWI523382B (en) | Power conversion apparatus and protection method thereof while feedback current signal abnormal | |
| CN105471242A (en) | Novel power-on surge current suppression circuit | |
| WO2019178935A1 (en) | Self-adjustment method for bleeder current and led silicon-controlled light adjusting circuit | |
| CN109450417A (en) | A kind of starting overshoot suppression circuit for LDO | |
| CN208656639U (en) | Control circuit and switch converters for switch converters | |
| CN110768537A (en) | Bilateral feedback and control DSR framework | |
| CN111342436B (en) | Surge current suppression circuit and method | |
| TW201526511A (en) | Power conversion apparatus and control chip thereof | |
| CN111564973A (en) | DC-DC adaptive power supply and conversion control method thereof | |
| CN108512196B (en) | A kind of overload protection fast response circuit of primary side feedback AC-DC power supply | |
| WO2018163413A1 (en) | Electronic circuit breaker | |
| CN104411035A (en) | LED drive circuit without auxiliary winding for power supply | |
| TWI499348B (en) | Load driving circuit with charge spike protection | |
| TWI699082B (en) | Power supply device | |
| CN109617385B (en) | Capacitor precharge circuit | |
| CN218244229U (en) | Automatic heat abstractor of heavy current device of current control | |
| CN204168139U (en) | The buffer circuit of power input |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |