CN103516190B - Stream/overpower protection method, protection circuit and the Switching Power Supply excessively of a kind of Switching Power Supply - Google Patents
Stream/overpower protection method, protection circuit and the Switching Power Supply excessively of a kind of Switching Power Supply Download PDFInfo
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- CN103516190B CN103516190B CN201310479854.8A CN201310479854A CN103516190B CN 103516190 B CN103516190 B CN 103516190B CN 201310479854 A CN201310479854 A CN 201310479854A CN 103516190 B CN103516190 B CN 103516190B
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Abstract
The invention provides a kind of Switching Power Supply crosses stream/overpower-protection circuit; including: line voltage compensation circuit and excessively stream/overpower protection module; wherein; line voltage compensation circuit is for receiving first signal suitable with the dutycycle of pwm signal; and produce the scaling signal that at least two is proportional to the first signal, selection percentage signal meets the compensation signal that the scaling signal of preset rules exports as line voltage compensation circuit.Cross stream/overpower protection module and be used for receiving line voltage compensation signal and echo signal, and judge whether echo signal met stream/over-power condition according to line voltage compensation signal.Visible; by line voltage compensation circuit being arranged to the relation of the compensation electric current Icomp and sawtooth voltage Vsaw of multisection type; make Switching Power Supply in the case of low line pressure, also Switching Power Supply can be compensated, constant overcurrent protection or constant overpower protection in the range of having reached full line voltage.
Description
Technical field
The present invention relates to field of switch power, in particular, relate to a kind of Switching Power Supply crosses stream/mistake
Power guard method, protection circuit and Switching Power Supply.
Background technology
Along with developing rapidly of electronics and information industry, Switching Power Supply is widely used at computer, electric power
The fields such as equipment, instrument and meter, LED illumination, medical apparatus and instruments, military industry equipment.Generally, Switching Power Supply
It is external AC (such as civil power 220V, 380V etc.) to be converted into a galvanic current bear with supply
Carry.
Switching Power Supply has a lot of defencive function, as over-and under-voltage protection, overheat protector, overcurrent protection,
Overpower protection etc..These defencive functions avoid the integrated IC of power and the damage of whole Switching Power Supply.
Generally, overcurrent protection and overpower protection, in the range of full line voltage, do not possess constant protection value,
It is thus desirable to it is carried out line voltage compensation.And inventor finds, compensation circuit of the prior art is low
During line voltage, overcurrent protection or overpowering protection value are the lowest, it is impossible to realize invariable power protection.
Summary of the invention
In view of this, the invention provides a kind of stream/overpower protection method of crossing of Switching Power Supply, protection electricity
Road and Switching Power Supply, to overcome prior art breaker in middle power supply when low line voltage, overcurrent protection value is relatively
Low, it is impossible to the problem realizing the protection of full line voltage firm power.
For achieving the above object, the present invention provides following technical scheme:
A kind of excessively stream/overpower-protection circuit of Switching Power Supply, including:
Line voltage compensation circuit, for receiving first signal suitable with the dutycycle of pwm signal,
And produce the scaling signal that at least two is proportional to described first signal, select described scaling signal accords with
Close the compensation signal that the scaling signal of preset rules exports as described line voltage compensation circuit；
Cross stream/overpower protection module, receive described line voltage compensation signal and echo signal, and according to institute
State line voltage compensation signal and judge whether described echo signal met stream/over-power condition.
Preferably, described first signal is the sawtooth that the agitator in described switching power source control circuit produces
Type voltage signal.
Preferably, it is applied to described stream/overpower protection excessively when the output signal of described line voltage compensation circuit
The first input end of the comparator in module, when the second input of described comparator terminates first threshold voltage,
The described scaling signal of described selection meets the scaling signal of preset rules as described line voltage compensation circuit
The compensation signal of output is:
Select the minimum scaling signal in the described scaling signal corresponding to same first signal as institute
State the compensation signal of line voltage compensation circuit output.
Preferably, it is applied to described stream/overpower protection excessively when the output signal of described line voltage compensation circuit
The first input end of the comparator in module, the second input of described comparator and the Cs end of Switching Power Supply
When being connected, the described scaling signal of described selection meets the scaling signal of preset rules as described line voltage
The compensation signal compensating circuit output is:
Select the maximum scaling signal in the described scaling signal corresponding to same first signal as institute
State the compensation signal of line voltage compensation circuit output.
Preferably, described line voltage compensation circuit includes: voltage-current converter and current-voltage conversion
Device；
Described first signal and predeterminated voltage signal are converted to first by described voltage-current converter respectively
Current proportional signal and the second current proportional signal, and by described first current proportional signal and described
Relatively small-signal in second current proportional signal is delivered to described current-voltage converter, forms voltage compensation
Signal crosses stream/overpower protection module to described.
Preferably, described voltage-current converter includes: the first voltage-current converter, the second voltage-
Current converter, the first current mirror, the second current mirror and the first current comparator；
Described first voltage-current converter gathers described first signal, described first voltage-current converter
Outfan be connected with the input of described first current mirror；Described second voltage-current converter receives institute
Stating predeterminated voltage signal, the outfan of described second voltage-current converter is defeated with described second current mirror
Enter end to be connected；
First outfan of described first current mirror is connected with the first outfan of described second current mirror, and
Public connecting end is connected with the first input end of described first current comparator；
Second outfan of described first current mirror is connected with the second outfan of described second current mirror, and
Public connecting end is connected with the second input of described first current comparator；Described first current comparator
Outfan as the outfan of described voltage-current converter, be connected with described compensation resistance.
Preferably, described current-voltage converter is for compensating resistance.
A kind of stream/overpower protection the method excessively of Switching Power Supply, is applied to Switching Power Supply, described Switching Power Supply
Including: for controlling power tube conducting and the control circuit of cut-off, described control circuit included stream/mistake merit
Rate protection module, including:
Gather first signal suitable with the dutycycle of pwm signal, and produce at least two with described
The scaling signal that first signal is proportional, selects to meet in described scaling signal the scaling signal of preset rules
As the compensation signal of output, and described compensation signal loading is crossed stream/overpower protection module to described.
Preferably, described first signal is the sawtooth that the agitator in described switching power source control circuit produces
Type voltage signal.
A kind of Switching Power Supply, it is characterised in that include the stream/overpower protection excessively described in above-mentioned any one
Circuit.
Understand via above-mentioned technical scheme, compared with prior art, the invention provides a kind of switch electricity
Stream/the overpower-protection circuit excessively in source, including: line voltage compensation circuit and excessively stream/overpower protection module,
Wherein, line voltage compensation circuit is used for receiving first signal suitable with the dutycycle of pwm signal,
And produce the scaling signal that at least two is proportional to the first signal, selection percentage signal meets and presets rule
The compensation signal that scaling signal then exports as line voltage compensation circuit.Cross stream/overpower protection module to use
In receiving line voltage compensation signal and echo signal, and judge that echo signal is according to line voltage compensation signal
No met stream/over-power condition.Visible, by line voltage compensation circuit being arranged to the compensation of multisection type
The relation of electric current Icomp and sawtooth voltage Vsaw, makes Switching Power Supply in the case of low line pressure, also can
Compensating Switching Power Supply, in the range of having reached full line voltage, constant overcurrent protection or constant overpower are protected
Protect.
Accompanying drawing explanation
In order to be illustrated more clearly that the embodiment of the present invention or technical scheme of the prior art, below will be to reality
Execute the required accompanying drawing used in example or description of the prior art to be briefly described, it should be apparent that below,
Accompanying drawing in description is only embodiments of the invention, for those of ordinary skill in the art, not
On the premise of paying creative work, it is also possible to obtain other accompanying drawing according to the accompanying drawing provided.
Fig. 1 is the circuit diagram of the switch power supply current protection circuit used in prior art；
Fig. 2 is the circuit diagram of another kind of Switching Power Supply current foldback circuit in prior art；
Fig. 3 is the compensating curve figure of prior art breaker in middle power supply overcurrent protection；
The circuit diagram of a kind of Switching Power Supply current foldback circuit that Fig. 4 provides for the embodiment of the present invention；
The compensating curve figure of the current foldback circuit that Fig. 5 provides for using the present embodiment；
The voltage-current converter that Fig. 6 provides for the embodiment of the present invention implement circuit diagram；
Fig. 7 is a kind of schematic diagram exporting result of current comparator in Fig. 6；
The circuit diagram of the another kind of Switching Power Supply current foldback circuit that Fig. 8 provides for the embodiment of the present invention；
The circuit diagram of the Voltage-voltage transducer that Fig. 9 provides for the embodiment of the present invention；
Figure 10 is a kind of schematic diagram exporting result of current comparator in Fig. 9.
Detailed description of the invention
For the sake of quoting and understanding, the explanation of the technical term being used below, summary of writing a Chinese character in simplified form or abridge
As follows:
The abbreviation of OSC:oscillator, means agitator.
OCP:Over current protection, overcurrent protection.
OPP:Over power protection, overpower protection.
Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out
Clearly and completely describe, it is clear that described embodiment is only a part of embodiment of the present invention, and
It is not all, of embodiment.Based on the embodiment in the present invention, those of ordinary skill in the art are not doing
Go out the every other embodiment obtained under creative work premise, broadly fall into the scope of protection of the invention.
Referring to Fig. 1, realize circuit diagram for what switch power supply current commonly used in the prior art was protected, this is opened
The current foldback circuit (OCP) 200 closing power supply includes: diode rectifier bridge 100, filter capacitor C101,
Transformer primary side inductance Lp1, agitator 110 (OSC), logic control circuit 120, drive circuit 125,
Voltage-current converter 140, compensate resistance R115, power tube M102, current comparator 126 and
Sampling resistor R103.
Concrete, alternating voltage Vac is converted into DC voltage by diode rectifier bridge 100, and its output is just
End is connected with first end of filter capacitor C101 and the different name end of transformer primary side inductance Lp1 respectively, filter
Second end of ripple electric capacity C101 is connected and ground connection with the output negative terminal of diode rectifier bridge 100.Transformer primary
The Same Name of Ends of limit inductance Lp1 is connected with by first end of power tube M102 and sampling resistor R103, adopts
The second end ground connection of sample resistance R103.
The clock signal terminal of agitator 110 is connected with the first end of logic control circuit 120, this logic control
Second end of circuit 120 processed is connected with the control end of power tube M102 by drive circuit 125, is used for controlling
Power tube M102 processed is switched on and off.
The sawtooth signal end of agitator 110 is connected with the input of voltage-current converter 140, and voltage-
The outfan of current converter 140 respectively with compensate first end of resistance R115 and current comparator 126
First input end be connected, compensate resistance R115 the second end be connected with first end of sampling resistor R103,
This current comparator 126 second input termination predeterminated voltage Vref, its compare outfan and logic control
3rd end of circuit 120 is connected, for line voltage compensation amount is superimposed upon the electricity of the integrated IC of Switching Power Supply
On stream sampling pin CS.
In conjunction with above-mentioned annexation and Fig. 1, the operation principle of this current foldback circuit is: when former limit inductance
The electric current of Lp1 is more than after certain threshold value, and current comparator 126 controls logic control circuit 120, Jin Erguan
Disconnected power tube M102, thus limit the size of primary current, reach to protect the power conversion of Switching Power Supply
The purpose of device.
Refer to Fig. 2, for conventional Switching Power Supply circuit overcurrent protection another kind of in prior art, this electricity
Road includes: diode rectifier bridge 301, filter capacitor C306, transformer primary side inductance Lp2, agitator
310, logic control circuit 320, Voltage-voltage transducer 340, power tube M302, current comparator
328, sampling resistor R303.
The operation principle of this current foldback circuit is similar with the operation principle of the current protecting circuit in Fig. 1,
It is not described in detail in this.Except for the difference that, this circuit is that line voltage compensation amount is superimposed upon the one of current comparator
End, directly controls the threshold voltage of Switching Power Supply CS end.
In conjunction with Fig. 1 and Fig. 2, it is seen that, both of which is to utilize sawtooth waveforms upper of agitator (OSC)
Rise and along voltage Vsaw, the line voltage of current comparator (OCP) is compensated.Although two ways is table
Existing form is different, but control principle is identical, particularly as follows: at overcurrent protection (OCP) or overpower
During protection (OPP), dutycycle Duty of low line voltage correspondence PWM is relatively big, contrary high line voltage pair
Dutycycle Duty of the PWM answered is less.Sample oscillations device OSC will be carried out by dutycycle Duty for this
The rising edge voltage Vsaw of sawtooth waveforms, and the needs of line voltage compensation can be reached through suitable conversion
Value.Finally, the inductance of chip controls former limit peak point current Ipeak is rendered as with PWM duty cycle Duty
Increasing trend, reaches the purpose of line voltage compensation.
The most above-mentioned current foldback circuit limits the maximum current value of the former limit inductance of Switching Power Supply, thus
Limit former limit and be transferred to the peak power of secondary, protect Switching Power Supply and the heat of output loading element
Damage.
But, the compensation circuit used in prior art, its compensation dosage Vcomp or Icomp are by shaking
Swing sawtooth waveforms (Vsaw) signal in device OSC circuit to generate, and compensation dosage Vcomp or Icomp are
It it is the once linear function of voltage Vsaw.As it is shown on figure 3, the compensation circuit of routine is when low line voltage,
Overcurrent protection or overpowering protection value are the lowest, it is impossible to realize invariable power protection, be difficult to meet some requirements
The needs of strict clients.
In order to solve prior art breaker in middle power supply when low line voltage, overcurrent protection value is relatively low, it is impossible to real
The problem of existing full line voltage firm power protection, the invention provides a kind of Switching Power Supply current foldback circuit
And Switching Power Supply.
Referring to accompanying drawing 4, a kind of Switching Power Supply provided for the present invention crosses stream/overpower-protection circuit 400,
It is applied to Switching Power Supply, including: line voltage compensation circuit and excessively stream/overpower protection module, wherein,
Cross stream/overpower protection module to include: logic controller 420, voltage-current converter 500, compensate electricity
Resistance R415, drive circuit 425, cross stream comparator 426.
In conjunction with Fig. 4, the annexation of foregoing circuit element is described:
Alternating voltage Vac is converted into DC voltage by diode rectifier bridge 401, its output plus terminal respectively with
First end of filter capacitor C411 and the different name end of transformer primary side inductance Lp4 are connected, filter capacitor
Second end of C411 is connected and ground connection with the output negative terminal of diode rectifier bridge 401.Transformer primary side inductance
The Same Name of Ends of Lp4 is connected with by first end of power tube M402 and sampling resistor R403, sampling resistor
The second end ground connection of R403.
The clock signal terminal of agitator 410 is connected with the first end of logic controller 420, this logic control
Second end of device 420 is connected with the control end of power tube M402 by drive circuit 425, is used for controlling merit
Rate pipe M402 is switched on and off.
The sawtooth signal end of agitator 410 is connected with the input of voltage-current converter 500, and voltage-
The outfan of current converter 500 respectively with compensate first end of resistance R415 and current comparator 426
First input end be connected, compensate resistance R415 the second end be connected with second end of sampling resistor R403,
This current comparator 426 second input termination predeterminated voltage Vref, its compare outfan and logic control
3rd end of device 420 is connected, for line voltage compensation amount is superimposed upon the electric current of the integrated IC of Switching Power Supply
On sampling pin CS.
Wherein, line voltage compensation circuit, for receiving one suitable with the dutycycle of pwm signal first
Signal, and produce the scaling signal that at least two is proportional to above-mentioned first signal, select aforementioned proportion letter
The compensation signal that the scaling signal of preset rules exports is met as above-mentioned line voltage compensation circuit in number；
Cross stream/overpower protection module and be used for receiving above-mentioned line voltage compensation signal and echo signal, and according to
Above-mentioned line voltage compensation signal judges whether above-mentioned echo signal met stream/over-power condition.
It should be noted that in the line voltage compensation circuit of the present embodiment offer and prior art, the first is opened
Close power protecting circuit compare understand, the voltage-current converter in the present embodiment unlike the prior art,
Other components and parts are similar.In view of the problems such as circuit hardware consumption, the voltage-to-current that the present embodiment provides
Transducer 500 uses the relation of the compensation electric current Icomp and sawtooth voltage Vsaw of two-part, and each
Segmentation, the relation compensating electric current Icomp and voltage Vsaw is still linear functional relation, but between segmentation
Linear gradient different.And when same voltage Vsaw, choose the value of less compensation circuit I comp,
As shown in Figure 7.So, the compensation circuit (the present embodiment) after improvement, crossing of switch power supply system is flowed
The curve of protection and overpower protection is transformed into Line2 from Line1, constant in the range of having reached full line voltage
OCP or constant OPP protects, as shown in Figure 5.
It should be noted that the voltage-current converter of present invention offer compensates electric current Icomp and sawtooth
The relation of wave voltage Vsaw can be two ends formula piecewise function, it is also possible to for multisection type function, or is
MathCAD model calculates the curve that display compensating curve is a Curvature varying, does not limits herein.
Preferably, present embodiments provide a kind of voltage-current converter implements circuit, such as Fig. 6
Shown in, this voltage-current converter 500 includes: first voltage-current converter the 560, second voltage-
Current converter the 550, first current mirror the 520, second current mirror 540 and the first current comparator 530.
Wherein, the first voltage-current converter 560 gathers the sawtooth voltage Vsaw of agitator, its output
End is connected with the input of the first current mirror 520.Second voltage-current converter 550 receives predeterminated voltage
Vref, the input of its outfan and the second current mirror 540 is connected.First output of above-mentioned first current mirror
End is connected with the first outfan of the second current mirror, and public connecting end and the first current comparator 530
First input end is connected.Second outfan of the first current mirror and the second outfan of the second current mirror are connected,
And the second input of public connecting end and the first current comparator 530 is connected.First current comparator 530
Outfan as the outfan of this voltage-current converter, be connected with compensating resistance R415.
The operation principle of the voltage-current converter 500 that the present embodiment provides is:
The electricity of the sawtooth waveforms with wired information of voltage that first voltage-current converter 560 reception oscillator produces
Pressure Vsaw, and voltage Vsaw is changed into electric current Isaw.Concrete, Isaw=Vsaw/R1.Wherein
Resistance R1 is the resistance in the first voltage-current converter 560, does not draw in figure.Afterwards, produce
Raw electric current Isaw processes through the first current mirror 520, produces image current or is multiplied by suitable coefficient
Electric current, wherein, coefficient can be n1 and n2.
Equally, Reference voltage Vref is converted into electric current Iref through the second voltage-current converter.It
After, the electric current Iref of generation processes through the second current mirror 540, produce image current or be multiplied by suitable
The electric current of coefficient, wherein, coefficient can be n3 and n4.
In conjunction with the annexation of Fig. 6, can obtain:
Ia=n1 (Vsaw/R1) n3 (Vref/R2)
Ib=n2 (Vsaw/R1) n4 (Vref/R2)
The compensation dosage that switch power supply system needs: Icomp=k Choose (Ia, Ib), in the present embodiment,
The smaller value in Ia and Ib chosen by this current comparator 530.The graph of a relation of itself Icomp and Vsaw i.e. is such as
Shown in Fig. 7, when a certain voltage Vsaw, choose the smaller value of electric current Icomp, or at a certain electric current
During Icomp, choose less voltage Vsaw, such as the bold portion in Fig. 7.It should be noted that figure
In 7, the determination of the intersection point of two straight lines can be to be obtained, in a certain Switching Power Supply by modeling repeatedly
In, once set at the value of this intersection point, then after Switching Power Supply is dispatched from the factory, the value of this intersection point no longer changes.
Visible, the present embodiment provide voltage-current converter use two-part compensation electric current Icomp with
The relation of sawtooth voltage Vsaw, make the overcurrent protection of switch power supply system and the curve of overpower protection from
Line1 in Fig. 5 is transformed into Line2, i.e. in the case of low line pressure, also can carry out Switching Power Supply
Compensate, constant overcurrent protection or constant overpower protection in the range of having reached full line voltage.
Embodiment two
Referring to accompanying drawing 8, the another kind of Switching Power Supply provided for the present invention crosses stream/overpower-protection circuit
600, it is applied to Switching Power Supply, including: diode rectifier bridge 601, filter capacitor C611, transformer primary
Limit inductance Lp6, agitator 610, logic control circuit 620, drive circuit 625, Voltage-voltage is changed
Device 800, power tube M602, current comparator and sampling resistor R603.
Wherein, alternating voltage Vac is converted into DC voltage by diode rectifier bridge 601, its output plus terminal
It is connected with first end of filter capacitor C611 and the different name end of transformer primary side inductance Lp6 respectively, filtering
Second end of electric capacity C611 is connected and ground connection with the output negative terminal of diode rectifier bridge 601.Transformer primary side
The Same Name of Ends of inductance Lp6 is connected with by first end of power tube M602 and sampling resistor R603, sampling
The second end ground connection of resistance R603.
The clock signal terminal of agitator 610 is connected with the first end of logic controller 620, this logic control
Second end of device 620 is connected with the control end of power tube M602 by drive circuit 625, is used for controlling merit
Rate pipe M802 is switched on and off.
The sawtooth signal end of agitator 610 is connected with the input of Voltage-voltage transducer 800, and voltage-
The outfan of electric pressure converter 800 is applied directly to an input of current comparator, and current ratio is relatively
First end of another input termination sampling resistor R603 of device, the outfan of current comparator and logic control
3rd end of circuit 620 processed is connected, for line voltage compensation amount is superimposed upon the integrated IC's of Switching Power Supply
On current sample pin CS.
Embodiment one is that compensation dosage is superimposed upon CS leads ends, and the present embodiment is that compensation dosage is superimposed upon OCP
One input of comparator, its operation principle is similar with embodiment one.Voltage-voltage in the present embodiment
Transducer is also adopted by the relation of Vcomp Yu Vsaw of multisection type, and its operation principle is similar with embodiment one.
Preferably, what the present embodiment additionally provided a kind of Voltage-voltage transducer implements circuit, such as figure
Shown in 9, including: tertiary voltage-current converter the 830, the 4th voltage-current converter the 840, the 3rd
Current mirror the 820, the 4th current mirror the 810, second current comparator 850 and current-voltage converter 860.
The annexation of the most each prototype part is:
Tertiary voltage-current converter gathers the sawtooth voltage Vsaw of agitator, its outfan and the 3rd electricity
The input of stream mirror is connected.4th voltage-current converter receives predeterminated voltage Vref, its outfan and the
The input of four current mirrors is connected.First outfan of the 3rd current mirror and the first output of the 4th current mirror
End is connected, and the first input end of public connecting end and the second current comparator is connected.3rd current mirror
Second outfan of the second outfan and the 4th current mirror is connected, and public connecting end and the second current ratio are relatively
Second input of device is connected.The outfan of the second current comparator and the input of current-voltage converter
Being connected, the outfan of above-mentioned current-voltage converter is as the outfan of this voltage-current converter.
In the present embodiment, switch power supply system needs the voltage compensation curve realized shown in Figure 10, to this end,
The second current comparator 850 in Fig. 9 needs the higher value in selection Ia and Ib and is multiplied by coefficient k.And
It is compensated voltage Vcomp=Vref+Icomp R8 by current-voltage converter 860, wherein,
Vref and R8 is some parameters in current-voltage converter 860.
The Voltage-voltage transducer that the present embodiment provides uses compensation voltage Vcomp and the sawtooth of two-part
The relation of wave voltage Vsaw, makes Switching Power Supply in the case of low line pressure, also can mend Switching Power Supply
Repay, constant overcurrent protection or constant overpower protection in the range of having reached full line voltage.
Being not difficult to draw from embodiment one and embodiment two, above-mentioned first signal is that above-mentioned Switching Power Supply controls
The sawtooth pattern voltage signal that agitator in circuit produces.And when the output letter of above-mentioned line voltage compensation circuit
Number it is applied to the first input end of the above-mentioned comparator crossed in stream/overpower protection module, above-mentioned comparator
During the second input termination first threshold voltage, select at the aforementioned proportion signal corresponding to same first signal
In the compensation signal that exports as above-mentioned line voltage compensation circuit of minimum scaling signal.When above-mentioned line electricity
Pressure compensates the output signal of circuit and is applied to the first defeated of the above-mentioned comparator crossed in stream/overpower protection module
Enter end, when the second input of above-mentioned comparator is connected with the Cs end of Switching Power Supply, select same first
The scaling signal of the maximum in the aforementioned proportion signal corresponding to signal is defeated as above-mentioned line voltage compensation circuit
The compensation signal gone out.
On the basis of above-described embodiment, the stream/overpower of crossing that present invention also offers a kind of Switching Power Supply is protected
Maintaining method, is applied to above-mentioned Switching Power Supply, and above-mentioned Switching Power Supply includes: be used for controlling power tube conducting and
The control circuit of cut-off, above-mentioned control circuit included stream/overpower protection module, and the method includes:
Gather first signal suitable with the dutycycle of pwm signal, and produce at least two with above-mentioned
The scaling signal that first signal is proportional, selects to meet in aforementioned proportion signal the scaling signal of preset rules
As the compensation signal of output, and above-mentioned compensation signal loading is crossed stream/overpower protection module to above-mentioned.
Preferably, above-mentioned first signal is the sawtooth that the agitator in above-mentioned switching power source control circuit produces
Type voltage signal.
The operation principle of this guard method sees above-described embodiment, is not repeated at this to discuss.Except this, this
Embodiment additionally provides a kind of Switching Power Supply, including any one line voltage compensation electricity in above-described embodiment
Road.
The most above-mentioned:
The invention provides a kind of Switching Power Supply crosses stream/overpower-protection circuit, including: line voltage compensation
Circuit and excessively stream/overpower protection module, wherein, line voltage compensation circuit is for receiving one and PWM
The first signal that the dutycycle of signal is suitable, and produce the ratio that at least two is proportional to the first signal
Signal, meets what the scaling signal of preset rules exported as line voltage compensation circuit in selection percentage signal
Compensate signal.Cross stream/overpower protection module and be used for receiving line voltage compensation signal and echo signal, and root
Judge whether echo signal met stream/over-power condition according to line voltage compensation signal.Visible, by by line
Voltage compensating circuit is arranged to the relation of the compensation electric current Icomp and sawtooth voltage Vsaw of multisection type, makes
Switching Power Supply, in the case of low line pressure, also can be compensated by Switching Power Supply, has reached full line voltage model
Enclose interior constant overcurrent protection or constant overpower protection.
In this specification, each embodiment uses the mode gone forward one by one to describe, and each embodiment stresses
Being the difference with other embodiments, between each embodiment, identical similar portion sees mutually.
For the device that embodiment provides, owing to it is corresponding with the method that embodiment provides, so describing
Fairly simple, relevant part sees method part and illustrates.
Described above to the embodiment provided, makes professional and technical personnel in the field be capable of or uses
The present invention.Multiple amendment to these embodiments will be aobvious and easy for those skilled in the art
See, generic principles defined herein can without departing from the spirit or scope of the present invention,
Realize in other embodiments.Therefore, the present invention is not intended to be limited to the embodiments shown herein,
And it is to fit to the widest scope consistent with principle provided in this article and features of novelty.
Claims (10)
1. stream/the overpower-protection circuit excessively of a Switching Power Supply, it is characterised in that including:
Line voltage compensation circuit, for receiving first signal suitable with the dutycycle of pwm signal,
And produce the scaling signal that at least two is proportional to described first signal, select described scaling signal accords with
Close the compensation signal that the scaling signal of preset rules exports as described line voltage compensation circuit；
Cross stream/overpower protection module, receive described line voltage compensation signal and echo signal, and according to institute
State line voltage compensation signal and judge whether described echo signal met stream/over-power condition.
Stream/overpower-protection circuit excessively the most according to claim 1, it is characterised in that described first
Signal is the sawtooth pattern voltage signal that the agitator in described switching power source control circuit produces.
Stream/overpower-protection circuit excessively the most according to claim 1, it is characterised in that when described line
The output signal of voltage compensating circuit is applied to the first of the described comparator crossed in stream/overpower protection module
Input, when the second input of described comparator terminates first threshold voltage, the described ratio of described selection is believed
Meeting the compensation signal that the scaling signal of preset rules exports as described line voltage compensation circuit in number is:
Select the minimum scaling signal in the described scaling signal corresponding to same first signal as institute
State the compensation signal of line voltage compensation circuit output.
Stream/overpower-protection circuit excessively the most according to claim 1, it is characterised in that when described line
The output signal of voltage compensating circuit is applied to the first of the described comparator crossed in stream/overpower protection module
Input, when the second input of described comparator is connected with the Cs end of Switching Power Supply, described in described selection
Scaling signal meets the compensation letter that the scaling signal of preset rules exports as described line voltage compensation circuit
Number be:
Select the maximum scaling signal in the described scaling signal corresponding to same first signal as institute
State the compensation signal of line voltage compensation circuit output.
Stream/overpower-protection circuit excessively the most according to claim 1, it is characterised in that described line electricity
Pressure compensates circuit and includes: voltage-current converter and current-voltage converter；
Described first signal and predeterminated voltage signal are converted to first by described voltage-current converter respectively
Current proportional signal and the second current proportional signal, and by described first current proportional signal and described
Relatively small-signal in second current proportional signal is delivered to described current-voltage converter, forms voltage compensation
Signal crosses stream/overpower protection module to described.
Stream/overpower-protection circuit excessively the most according to claim 5, it is characterised in that described voltage
-current converter includes: the first voltage-current converter, the second voltage-current converter, the first electric current
Mirror, the second current mirror and the first current comparator；
Described first voltage-current converter gathers described first signal, described first voltage-current converter
Outfan be connected with the input of described first current mirror；Described second voltage-current converter receives institute
Stating predeterminated voltage signal, the outfan of described second voltage-current converter is defeated with described second current mirror
Enter end to be connected；
First outfan of described first current mirror is connected with the first outfan of described second current mirror, and
Public connecting end is connected with the first input end of described first current comparator；
Second outfan of described first current mirror is connected with the second outfan of described second current mirror, and
Public connecting end is connected with the second input of described first current comparator；Described first current comparator
Outfan as the outfan of described voltage-current converter, be connected with described compensation resistance.
Stream/overpower-protection circuit excessively the most according to claim 5, it is characterised in that described electric current
-electric pressure converter is for compensating resistance.
8. a stream/overpower protection method excessively for Switching Power Supply, is applied to Switching Power Supply, described switch electricity
Source includes: for controlling power tube conducting and the control circuit of cut-off, described control circuit included stream/mistake
Power protection module, it is characterised in that including:
Gather first signal suitable with the dutycycle of pwm signal, and produce at least two with described
The scaling signal that first signal is proportional, selects to meet in described scaling signal the scaling signal of preset rules
As the compensation signal of output, and described compensation signal loading is crossed stream/overpower protection module to described.
Stream/overpower protection method excessively the most according to claim 8, it is characterised in that described first
Signal is the sawtooth pattern voltage signal that the agitator in described switching power source control circuit produces.
10. a Switching Power Supply, it is characterised in that include as described in any one in claim 1-7
Cross stream/overpower-protection circuit.
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| CN201310479854.8A CN103516190B (en) | 2013-10-14 | 2013-10-14 | Stream/overpower protection method, protection circuit and the Switching Power Supply excessively of a kind of Switching Power Supply |
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| CN103516190B true CN103516190B (en) | 2016-08-10 |
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| CN106208647B (en) * | 2015-05-04 | 2020-05-05 | 中兴通讯股份有限公司 | Overcurrent protection method and device |
| CN106961094B (en) * | 2017-03-30 | 2019-05-24 | 昂宝电子（上海）有限公司 | The system of input undervoltage and overvoltage protection is provided for supply convertor |
| CN111211668B (en) * | 2020-01-13 | 2022-08-26 | 深圳市能效电气技术有限公司 | Constant power regulation method for digital switching power supply output |
| CN111600470B (en) * | 2020-06-10 | 2023-08-29 | 杰华特微电子股份有限公司 | Switching power supply control circuit and control method |
| CN116093893B (en) * | 2023-04-07 | 2023-07-07 | 深圳市联明电源有限公司 | Constant-current driving protection circuit, laser pumping system and constant-current driving protection method |
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| CN202009331U (en) * | 2011-05-05 | 2011-10-12 | 上海新进半导体制造有限公司 | Circuit for controlling constant current output in switch power source |
| CN102324843A (en) * | 2011-05-17 | 2012-01-18 | 浙江大学 | High-precision sectional type linear slope compensation circuit |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN101964589A (en) * | 2009-07-22 | 2011-02-02 | Bcd半导体制造有限公司 | Method and device for controlling output current of convertor |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202009331U (en) * | 2011-05-05 | 2011-10-12 | 上海新进半导体制造有限公司 | Circuit for controlling constant current output in switch power source |
| CN102324843A (en) * | 2011-05-17 | 2012-01-18 | 浙江大学 | High-precision sectional type linear slope compensation circuit |
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Effective date of registration: 20210125 Address after: No. 1600, Zixing Road, Minhang District, Shanghai 200241 Patentee after: BCD (SHANGHAI) MICRO-ELECTRONICS Ltd. Address before: 800 Yishan Road, Xuhui District, Shanghai Patentee before: BCD Semiconductor Manufacturing Ltd. |
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