CN103683900A - Control circuit and control method of power source converter - Google Patents
Control circuit and control method of power source converter Download PDFInfo
- Publication number
- CN103683900A CN103683900A CN201210364759.9A CN201210364759A CN103683900A CN 103683900 A CN103683900 A CN 103683900A CN 201210364759 A CN201210364759 A CN 201210364759A CN 103683900 A CN103683900 A CN 103683900A
- Authority
- CN
- China
- Prior art keywords
- current
- signal
- circuit
- load
- threshold
- 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.)
- Granted
Links
Images
Landscapes
- Dc-Dc Converters (AREA)
Abstract
The invention discloses a control circuit of a power source converter and a control method of the power source converter. According to an embodiment of the invention, the control circuit includes a feedback signal comparison circuit, a frequency signal generating circuit, a current peak setting circuit and a signal processing circuit; in a first time range, the current peak setting circuit fixes a current threshold value, and the frequency signal generating circuit sets the frequency of a frequency signal according to a comparison signal; and in a second time range, the current peak setting circuit reduces the current threshold value, and the frequency signal generating circuit reduces the frequency threshold value of the frequency signal. The above control circuit can not only adjust energy which is supplied to a load by the power source converter based on the situation of the load, and therefore, an energy-saving effect can be realized; and the control circuit can also reduce audio frequency noises generated by the power source converter in a low-power state, and therefore, discomfort of a user can be avoided.
Description
Technical field
The control circuit of the relevant power supply changeover device of the present invention and control method, espespecially a kind of control circuit and control method of audio frequency noise of transducer capable of reducing power source.
Background technology
In many system applies, can by power supply changeover device, convert input power to suitable voltage and electric current, load is provided to suitable electric power.In order more effectively to utilize the energy, when load is lower, power supply changeover device can reduce the energy that exports load to, and when load is higher, power supply changeover device can improve the energy that exports load to.For example, the control circuit of power supply changeover device can be by the switching frequency of controlling current switch, to adjust the energy that exports load to.Yet, when the switching frequency of current switch drops on people's audio range (audible frequency, as 20Hz～20KHz) time, the circuit elements such as the electric capacity of power supply changeover device, inductance or transformer can produce the perceptible noise of people's ear (hereinafter referred to as audio frequency noise), and cause user's discomfort.
Some power supply changeover device can be set to the audio range higher than people by switching frequency, to avoid producing audio frequency noise.Yet when the required energy of load is lower, these power supply changeover devices cannot further reduce switching frequency to reduce the energy of being exported, and can cause the waste of the energy.
In the U.S. the 8th, in 049, No. 481 patent, the control circuit of power supply changeover device can be according to the height of load, and uses respectively different modulating signal modes to produce control signal, to adjust the switching frequency of current switch and to reduce audio frequency noise.For example, the control circuit of power supply changeover device can be according to the height of load, and employing pulse width modulation (pulse width modulation, PWM), the modulating signal mode such as pulse frequency modulated (pulse frequency modulation, PFM), degree of depth pulse width modulation (deep PWM), degree of depth pulse frequency modulated (deep PFM) is carried out the control signal of generation current switch.Yet the control circuit of this type of power supply changeover device need to, by switching to produce control signal between the modulating signal mode multiple, therefore need complicated controlling mechanism, and cause the degree of difficulty of hardware designs significantly to increase.In addition, when the control circuit of power supply changeover device switches between multiple modulating signal mode, the control signal producing easily produces ripple, therefore control circuit also needs to adopt extra controlling mechanism to avoid or to reduce the generation of ripple, the usefulness that affects power supply changeover device to avoid switching the transient response problem being produced between multiple modulation mode.
Summary of the invention
In view of this, how to reduce or eliminate the audio frequency noise that power supply changeover device produces, and can utilize efficiently the energy, in fact for industry has problem to be solved.
This specification provides a kind of embodiment of control circuit of power supply changeover device, for a current switch of a power supply changeover device is set, with to a load supplying, this control circuit comprises: a feedback signal comparison circuit, for according to a feedback signal and a reference voltage to produce a comparison signal; One frequency signal produces circuit, is coupled to this feedback signal comparison circuit, for producing a frequency signal according to this comparison signal; One current peak arranges circuit, is coupled to this frequency signal and produces circuit, for producing a current threshold according to this frequency signal, and a current sensing signal and this current threshold is compared, to produce a reset signal; And a signal processing circuit, be coupled to that this frequency signal produces circuit and this current peak arranges circuit, for producing a control signal according to this frequency signal and this reset signal, so that the conducting state of this current switch to be set; Wherein in one first period, this current peak arranges circuit can fix this current threshold, and this frequency signal produces circuit can arrange according to this comparison signal the frequency of this frequency signal, and in one second period, this current peak arranges circuit can reduce this current threshold, and this frequency signal produces the frequency that circuit can reduce this frequency signal.
This specification separately provides a kind of embodiment of control circuit of power supply changeover device, for a current switch of a power supply changeover device is set, with to a load supplying, this control circuit comprises: a frequency signal produces circuit, for exporting a current output signal of this load to according to this power supply changeover device, produces a frequency signal; One threshold value produces circuit, for generation of a current threshold, when this current output signal is greater than first load threshold, this current threshold is set to one first current value, and when this current output signal is between this first load threshold and one second load threshold, this current threshold is reduced along with the reduction of this current output signal, and when this current output signal is less than this second load threshold, this current threshold is set to one second current value; One current sensor comparison circuit, is coupled to this threshold value and produces circuit, a current sensing signal and this current threshold is compared, to produce a reset signal; And a signal processing circuit, be coupled to this frequency signal and produce circuit and this current sensor comparison circuit, according to this frequency signal and this reset signal, produce a control signal, so that the conducting state of this current switch to be set; Wherein the frequency of this control signal can reduce along with the reduction of this current output signal.
This specification separately provides a kind of embodiment of control method of power supply changeover device, and for a current switch of a power supply changeover device is set, with to a load supplying, it comprises: according to a feedback signal and a reference voltage to produce a comparison signal; According to this comparison signal, produce a frequency signal; According to this frequency signal, produce a current threshold, and a current sensing signal and this current threshold are compared, to produce a reset signal; According to this frequency signal and this reset signal and produce a control signal, so that the conducting state of this current switch to be set; In one first period, fix this current threshold, and the frequency of this frequency signal is set according to this comparison signal; And in one second period, reduce this current threshold, and reduce the frequency of this frequency signal.
This specification separately provides a kind of embodiment of control method of power supply changeover device, for a current switch of a power supply changeover device is set, with to a load supplying, it comprises: according to this power supply changeover device, export a current output signal of this load to and produce a frequency signal; Produce a current threshold, and when this current output signal is greater than first load threshold, this current threshold is set to one first current value, and when this current output signal is between this first load threshold and one second load threshold, this current threshold is reduced along with the reduction of this current output signal, when this current output signal is less than this second load threshold, this current threshold is set to one second current value; One current sensing signal and this current threshold are compared, to produce a reset signal; And according to this frequency signal and this reset signal and produce a control signal, so that the conducting state of this current switch to be set.
One of advantage of above-described embodiment is to adjust according to the size of load the frequency of control signal, and in the time of can entering the mankind's audio range in the frequency of operation of power supply changeover device, Limited Current switch institute On current is to required preset value, the audio frequency noise being produced to reduce or to eliminate power supply changeover device.Another advantage of above-described embodiment is can avoid between multiple modulation mode, switching produced transient response problem, not only can promote the usefulness of power supply changeover device, can also reduce the complexity of hardware designs.Other advantages of the present invention further explain orally the following explanation of cooperation and diagram.
Accompanying drawing explanation
Fig. 1 is the functional block diagram after the flyback power converter of one embodiment of the invention is simplified.
Fig. 2 is the functional block diagram after an embodiment of the control circuit of Fig. 1 simplifies.
Fig. 3 is the sequential chart after an embodiment of the signal that produces of the control circuit in Fig. 2 simplifies.
One embodiment schematic diagram of the frequency of Fig. 4 current threshold that to be control circuit in Fig. 2 produce when different load state and frequency signal.
Fig. 5 is the sequential chart after an embodiment of the current sensing signal in Fig. 2 simplifies.
Fig. 6 is the functional block diagram after the boost type power supply changeover device of one embodiment of the invention is simplified.
Another embodiment schematic diagram of the frequency of Fig. 7 current threshold that to be control circuit in Fig. 2 produce when different load state and frequency signal.
Fig. 8 is the functional block diagram after an embodiment of the control circuit of Fig. 1 simplifies.
Embodiment
Below will coordinate relevant drawings that the present invention's embodiment is described.In these accompanying drawings, identical label represents same or similar element or flow process/step.
Fig. 1 is the functional block diagram after the flyback power converter 100 of one embodiment of the invention is simplified.Power supply changeover device 100 comprises transformer 110, current switch 130, control circuit 150, bias winding (bias winding) 170, resistance R cs, R1 and R2, capacitor C 1 and C2 and diode D.For more simple and clear being easy to of drawing illustrated, some element, signal and annexation in power supply changeover device 100 are not illustrated in Fig. 1.
In the present embodiment, one end of transformer 110 primary sides is coupled to power supply PWR and capacitor C 1, and the other end of transformer 110 primary sides is coupled to current switch 130.One end of transformer 110 secondary sides is coupled to load Z by diode D, and the other end of transformer 110 secondary sides is coupled to preset potential (for example, earth terminal).In addition, capacitor C 2 is coupled between load Z and preset potential, and resistance R c s is coupled between current switch 130 and preset potential.The end points GD of control circuit 150 is coupled to the control end of current switch 130, and for example, for example, when current switch 130 uses transistor (, MOSFET or BJT) to implement, the control end of current switch 130 can be the gate of MOSFET or the base stage of BJT etc.The end points CS of control circuit 150 is coupled to resistance R cs.One end of bias winding 170 is coupled to the end points FB of control circuit 150 by resistance R 1 and R2, and one end of the other end of bias winding 170 and resistance R 2 is all coupled to preset potential.In the embodiment in figure 1, above-mentioned preset potential is all set to earth terminal with simplified illustration, in other embodiment, also above-mentioned preset potential can be set to respectively to identical or different current potential.
In the present embodiment, the electric current I t of 130 conductings of current switch is by meeting generation current sensing signal Vcs after resistance R cs, and control circuit 150 can be estimated by end points CS the current value of transformer 110 primary side institutes conducting.
In addition, the voltage of 170 sensings of bias winding, after the dividing potential drop of resistance R 1 and R2, can produce feedback signal Vfb in the end points FB of control circuit 150.For example, in one embodiment, can the coil number of bias winding 170 and the coil number of transformer 110 secondary sides be set to identical, therefore transformer 110 secondary sides and bias winding 170 can produce identical in fact voltage, the feedback signal Vfb that control circuit 150 can provide by bias winding 170 and resistance R 1 and R2 and estimate institute's energy requirement of transformer 110 secondary sides.
Therefore, control circuit 150 can be by end points CS and end points FB received current sensing signal Vcs and feedback signal Vfb, the control end voltage of current switch 130 is set according to current sensing signal Vcs and/or feedback signal Vfb, and makes power supply changeover device 100 export required Voltage-output signal Vout and current output signal Iout to load Z.
Fig. 2 is the functional block diagram after an embodiment of the control circuit 150 of Fig. 1 simplifies, and control circuit 150 comprises that feedback signal comparison circuit 210, frequency signal produce circuit 230, current peak arranges circuit 250 and signal processing circuit 270.In the present embodiment, control circuit 150 can produce pulse frequency modulated (pulse frequency modulation) signal and be sent to the control end of current switch 130, so that the conducting state of current switch 130 to be set.
Frequency signal produces circuit 230 can produce frequency signal Vfreq accordingly according to comparison signal Vcomp, and exports respectively frequency signal Vfreq to current threshold generation circuit 250 and signal processing circuit 270.For example, in the present embodiment, frequency signal produces circuit 230 and adopts the mode of voltage control oscillating circuit (voltage controlled oscillator) to implement, frequency signal produces circuit 230 can arrange the frequency of frequency signal Vfreq according to the numerical value of comparison signal Vcomp, to produce the frequency signal Vfreq of periodic square wave.
Current peak arranges circuit 250 and comprises threshold value generation circuit 251 and current sensor comparison circuit 253, threshold value produces circuit 251 and understands according to frequency signal Vfreq generation current threshold value Vth accordingly, and current sensor comparison circuit 253 can compare the current sensing signal Vcs being received by CS end points and current threshold Vth, to produce reset signal Vreset.
Fig. 3 is the sequential chart after an embodiment of control circuit 150 the frequency signal Vfreq, the reset signal Vreset that produce and control signal Vpfm simplifies.
In the embodiments of figure 3, control circuit 150 is by end points FB receiving feedback signals Vfb, and feedback signal comparison circuit 210 can compare feedback signal Vfb and reference voltage Vref, to produce comparison signal Vcomp.Frequency signal produces circuit 230 can produce frequency signal Vfreq accordingly according to comparison signal Vcomp, in the present embodiment, frequency signal Vfreq is periodic square wave, and frequency signal generation circuit 230 is understood according to comparison signal Vcomp the frequency of the signal Vfreq that adjusts frequency accordingly, when comparison signal Vcomp raises, frequency signal produces the frequency of circuit 230 meeting rising frequency signal Vfreq, when comparison signal Vcomp reduces, frequency signal produces the frequency that circuit 230 can reduce frequency signal Vfreq.In addition the threshold value that, current peak arranges circuit 250 produce circuit 251 can be according to frequency signal Vfreq generation current threshold value Vth accordingly.
When the time of Fig. 3 S1, frequency signal Vfreq becomes high potential from electronegative potential, when the setting end S of the flip-flop 271 of signal processing circuit 270 receives the frequency signal Vfreq of high potential, the control signal Vpfm producing in output Q also can become high potential, and On current switch 130.After current switch 130 conductings, the electric current I t of institute's conducting can increase gradually, and the current sensing signal Vcs that the electric current I t that makes current switch 130 conductings produces after by resistance R cs also increases gradually.
When the time of Fig. 3 S2, current sensing signal Vcs is more than or equal to current threshold Vth, after current peak arranges 253 couples of current sensing signal Vcs of current sensor comparison circuit of circuit 250 and current threshold Vth and compares, can produce the reset signal Vreset of high potential.When the replacement end R of flip-flop 271 receives the reset signal Vreset of high potential, the control signal Vpfm producing in output Q also can become electronegative potential, and makes current switch 130 not conductings.
Therefore, control circuit 150 just can above-mentioned mode produce the control signal Vpfm of appropriate frequency, and transmits required energy to load Z.For example, when the period of Fig. 3 S1～S3, control circuit 150 can produce the control signal Vpfm that frequency is F1.And after time S4, control circuit 150 can be lower frequency F2 by the set of frequency of control signal Vpfm, so that lower energy output to be provided.
One embodiment of the frequency of Fig. 4 current threshold Vth that to be control circuit 150 produce when different load state and frequency signal Vfreq, Fig. 5 is the sequential chart after an embodiment of the current sensing signal Vcs that produces after by resistance R cs of the electric current I t of 130 conductings of current switch simplifies, and below will with Fig. 4 and 5, further illustrate the function mode of control circuit 150.In the present embodiment, power supply changeover device 100 can be exported fixing in fact Voltage-output signal Vout, the energy of exporting due to power supply changeover device 100 equals Voltage-output signal Vout and is multiplied by current output signal Iout, therefore can utilize the signals such as electric current I t of current output signal Iout, feedback signal Vfb and/or 130 conductings of current switch as the estimated value of load state.
When the current output signal Iout of 100 wish outputs of power supply changeover device is greater than the first load threshold Lth1 in Fig. 4, the load value that represents load Z is greater than the first preset value, control circuit 150 can be set to fix in fact by Voltage-output signal Vout, and along with the increase of load value, increase the frequency of control signal Vpfm, to increase current output signal Iout.Now, threshold value produces circuit 251 and current threshold Vth can be able to be set to the first current value I 1.
For example, in the embodiment of Fig. 5, power supply changeover device 100 is greater than the first load threshold Lth1 in Fig. 4 in the current output signal Iout of period T1 time institute wish output, control circuit 150 can produce the control signal Vpfm that frequency is F1 when period T1, and threshold value generation circuit 251 can be set to the first current value I 1 by current threshold Vth.Control circuit 150 can produce the control signal Vpfm that frequency is F1, and with intermittent On current switch 130, and current threshold Vth is set to the first current value I 1 with 130 On current It of Limited Current switch.
When period T2, it is lower to the energy of load Z that power supply changeover device 100 must provide, control circuit 150 can produce control signal Vpfm with lower frequency F2, with intermittent On current switch 130, and current threshold Vth is set to the first current value I 1 with 130 On current It of Limited Current switch.Therefore, control circuit 150 can produce according to the size of load the control signal Vpfm of appropriate frequency, with intermittent On current switch 130, and can export required current output signal Iout to load Z.
When power supply changeover device 100 wishs reduce power consumption, control circuit 150 can reduce by 130 On current It of current switches, current output signal Iout and other relevant current values, to reduce the energy that power supply changeover device 100 provided, reduces audio frequency noise.Therefore,, when the current output signal Iout of 150 wishs of control circuit output is between the first load threshold Lth1 of Fig. 4 and the second load threshold Lth2, represent that the load value of load Z is also between the first preset value and the second preset value.Control circuit 150 can be set to fix in fact by Voltage-output signal Vout, and can reduce frequency and the current threshold Vth of control signal Vpfm.When the current output signal Iout exporting when power supply changeover device 100 equals the second load threshold Lth2 in Fig. 4, threshold value produces circuit 251 can be set to the second current value I 2 by current threshold Vth, now the set of frequency of control signal Vpfm be more than or equal to the mankind audio range the upper bound (for example, 20KHz).Therefore,, when the operation frequency of power supply changeover device 100 enters the mankind's audio range, 130 On current It of current switch can be subject to the restriction of current threshold Vth, and can not produce too large audio frequency noise.
For example, in the embodiment of Fig. 5, when power supply changeover device 100 wishs reduce power consumption, control circuit 150 can reduce in period T3 the frequency of control signal Vpfm, and threshold value generation circuit 251 also can reduce current threshold Vth in period T3.Therefore, when the current output signal Iout of power supply changeover device 100 outputs equals the second load threshold Lth2, the frequency of control signal Vpfm is still more than or equal to the upper bound of the mankind's audio range, and threshold value generation circuit 251 can be set to the second current value I 2 with 130 On current It of Limited Current switch by current threshold Vth, when guaranteeing that the operation frequency of power supply changeover device 100 enters the mankind's audio range, can not produce too large audio frequency noise.
In the present embodiment, when low power consumption state, the current output signal Iout of 150 wish outputs of control circuit is less than the second load threshold Lth2 of Fig. 4, and the load value of load Z is less than the second preset value.Threshold value produces circuit 251 can be set to the second current value I 2 by current threshold Vth.Control circuit 150 can be set to fix in fact by Voltage-output signal Vout, and along with the reduction of load value, reduces the frequency of control signal Vpfm, to reduce current output signal Iout.As shown in the period T4 of Fig. 5, threshold value produces circuit 251 can be set to the second current value I 2 with 130 On current It of Limited Current switch by current threshold Vth, and the frequency of control signal Vpfm can further reduce according to demand, to avoid exporting too much energy, therefore can arrive the object of reaching energy savings.
The above embodiments adopt the power supply changeover device 100 of flyback framework to describe, and in other embodiment, power supply changeover device also can adopt the power supply changeover device of boost type power supply changeover device, buck power supply changeover device or other frameworks.
For example, functional block diagram after the boost type power supply changeover device 600 that, Fig. 6 is one embodiment of the invention is simplified.Power supply changeover device 600 comprises inductance 610, current switch 130, control circuit 150, resistance R cs, R1 and R2, capacitor C 1 and C2 and diode D.For more simple and clear being easy to of drawing illustrated, some element, signal and annexation in power supply changeover device 600 are not illustrated in Fig. 6.In previous embodiment, other explanations of the execution mode of each element, function mode and associated advantages, are also applicable to the embodiment of Fig. 6, for simplicity's sake, and at this repeated description not.
Similar with the embodiment of Fig. 1, control circuit 150 can arrange by end points GD the control end voltage of current switch 130, and the electric current of 130 conductings of current switch can be set, make 100 couples of load Z of power supply changeover device export required power supply output signal Vout and current output signal Iout.In addition, control circuit 150 can be by end points CS and end points FB received current sensing signal Vcs and feedback signal Vfb, the control end voltage of current switch 130 is set according to current sensing signal Vcs and/or feedback signal Vfb, and makes power supply changeover device 100 export required Voltage-output signal Vout and current output signal Iout to load Z.
The electric current I t of 130 conductings of current switch is by meeting generation current sensing signal Vcs after resistance R cs, and control circuit 150 can be estimated by end points CS the current value of current switch institute conducting.Power supply output signal Vout passes through can produce feedback signal Vfb in the end points FB of control circuit 150 after resistance R 1 and R2.Capacitor C 1 and C2 respectively can for reducing or eliminate the high-frequency noise of power supply input signal Vin and power supply output signal Vout, and diode D can provide the functions such as rectification or protection to power supply output signal Vout.
In the embodiment of Fig. 6, control circuit 150 can adopt the execution mode of Fig. 2 equally, and comprise, feedback signal comparison circuit 210, frequency signal produce circuit 230, current peak arranges circuit 250 and signal processing circuit 270.Therefore, control circuit 150 not only can be adjusted according to the situation of load frequency and/or the current threshold Vth of control signal Vpfm, and when control circuit 150 wishs reduce power consumption state, also can be set to required preset value (as the second current value I 2 of Fig. 4) with the electric current I t of Limited Current switch institute conducting by current threshold Vth.Therefore,, when the frequency of operation of power supply changeover device 100 enters the mankind's audio range, 130 On current It of current switch can be subject to the restriction of current threshold Vth, and can not produce too large audio frequency noise.
In the embodiment of Fig. 4, when the current output signal Iout of 150 wishs of control circuit output is between the first load threshold Lth1 and the second load threshold Lth2, threshold value produces circuit 251 can reduce current threshold Vth linearly along with the reduction (or reduction of the load value of load Z) of current output signal Iout.In other embodiments, threshold value generation circuit 251 also can adopt other mode that current threshold Vth is set.For example, another embodiment of the frequency of Fig. 7 current threshold Vth that to be control circuit 150 produce when different load state and frequency signal Vfreq, in the embodiment of Fig. 7, when the current output signal Iout of 150 wishs of control circuit output is between the first load threshold Lth1 and the second load threshold Lth2, threshold value produces circuit 251 and can adopt stair-stepping mode to reduce current threshold Vth along with the reduction (or reduction of the load value of load Z) of current output signal Iout.
In the above-described embodiment, although some signal or function square only describe with the form of voltage or electric current, but person with usual knowledge in their respective areas should understand, the above embodiments and all can reach effect of the present invention by the suitable execution mode that converts suitable curtage to.For example, the electric current input that feedback signal comparison circuit 210 can adopt or the comparison circuit of voltage input, or also can adopt the amplifying circuit of electric current input or voltage input to implement.In other embodiments, current sensor comparison circuit 253 can adopt the comparison circuit of electric current input, and the electric current I t of 130 conductings of current switch and current threshold Vth (now can be set to current forms) are compared, and can omit resistance R cs.
In other embodiments, each function square of above-described embodiment all can carry out suitable variation, and all can reach effect of the present invention.For example, Fig. 8 is the functional block diagram after another embodiment of the control circuit 150 of Fig. 1 simplifies, similar to the embodiment of Fig. 2, control circuit 150 comprises that feedback signal comparison circuit 210, frequency signal produce circuit 230, current peak arranges circuit 250 and signal processing circuit 270, the function of these elements is with change can be with reference to above-mentioned related description, and repeats no more.Be that with the embodiment difference of Fig. 2 threshold value produces circuit 251 and changes the generation current threshold value Vth according to comparison signal Vcomp into.In another embodiment, signal processing circuit 270 also can adopt the modes such as microprocessor or logical circuit to implement the function of flip-flop 271.
In the above-described embodiment, the control circuit of power supply changeover device can be adjusted according to the size of load the frequency of control signal, makes the current switch can the suitable electric current of conducting, and exports required energy to load Z.In addition, when power supply changeover device wish reduces power consumption, the control circuit of power supply changeover device also can enter in the frequency of operation of power supply changeover device before the mankind's audio range, and Limited Current switch institute On current is to required preset value, the audio frequency noise being produced to reduce or to eliminate power supply changeover device.
In addition, in the above-described embodiment, the control circuit of power supply changeover device all adopts pulse frequency modulated signal as the control signal of current switch, therefore can avoid switching produced transient response problem between multiple modulation mode, not only the usefulness of power supply changeover device can be promoted, the complexity of hardware designs can also be reduced.
When illustrating accompanying drawing, the size of some element and relative size can be carried out amplification, so that the content of accompanying drawing can clearly be expressed.In addition, the shape of some element can be simplified to facilitate to illustrate.Therefore, the shape of each element illustrating in accompanying drawing, size and relative size, unless applicant specializes, otherwise should not be used to limit scope of the present invention.In addition, the present invention can embody by many different forms, is explaining when of the present invention, does not answer the aspect of the exemplary embodiment that limit proposes at this specification.
In specification and claims, used some vocabulary to censure specific element.Person of ordinary skill in the field should understand, and same element may be called with different nouns.This specification and claims book is not used as distinguishing the mode of element with the difference of title, but the difference in function is used as the benchmark of distinguishing with element." comprising " mentioned in specification and claims is open term, should be construed to " comprise but be not limited to ".In addition, " coupling " word comprises directly any and indirectly connects means at this.Therefore, if describe the first element in literary composition, be coupled to the second element, represent that the first element can directly be connected in the second element by signal connected modes such as electric connection or wireless transmission, optical delivery, or by other element or connection means indirectly electrically or signal be connected to the second element.
Used herein " and/or " describing mode, comprise cited one of them or the combination in any of a plurality of projects.In addition, unless in specification, specialize, the term of any odd number lattice all comprises the connotation of plural lattice simultaneously.
The foregoing is only preferred embodiment of the present invention, all equivalent variations of doing according to the claims in the present invention and modification, all should belong to covering scope of the present invention.
Claims (15)
1. a control circuit for power supply changeover device, for a current switch of a power supply changeover device is set, with to a load supplying, this control circuit comprises:
One feedback signal comparison circuit, for according to a feedback signal and a reference voltage to produce a comparison signal;
One frequency signal produces circuit, is coupled to this feedback signal comparison circuit, for producing a frequency signal according to this comparison signal;
One current peak arranges circuit, is coupled to this frequency signal and produces circuit, for producing a current threshold according to this frequency signal, and a current sensing signal and this current threshold is compared, to produce a reset signal; And
One signal processing circuit, is coupled to that this frequency signal produces circuit and this current peak arranges circuit, for producing a control signal according to this frequency signal and this reset signal, so that the conducting state of this current switch to be set;
Wherein in one first period, this current peak arranges circuit can fix this current threshold, and this frequency signal produces circuit can arrange according to this comparison signal the frequency of this frequency signal, and in one second period, this current peak arranges circuit can reduce this current threshold, and this frequency signal produces the frequency that circuit can reduce this frequency signal.
2. control circuit as claimed in claim 1, wherein, in one the 3rd period, this current peak arranges circuit can fix this current threshold, and this frequency signal produces circuit the frequency of this frequency signal can be set according to this comparison signal.
3. control circuit as claimed in claim 2, wherein, in this first period, the load value of this load is greater than one first preset value; In this second period, the load value of this load is less than this first preset value and is greater than one second preset value; And in the 3rd period, the load value of this load is less than this second preset value;
Wherein, this first preset value is greater than this second preset value.
4. control circuit as claimed in claim 1, wherein in this first period and this second period, this frequency signal produces the frequency that circuit can arrange this frequency signal to be reduced along with the reduction of the load value of this load.
5. control circuit as claimed in claim 4, wherein in this second period, this current peak arranges circuit and this current threshold can be set along with the reduction of the load value of this load, reduce linearly.
6. control circuit as claimed in claim 4, wherein in this second period, this current peak arranges circuit and this current threshold can be set along with the reduction of the load value of this load, present stepped reduction.
7. as claim 1 to 6 control circuit of any one wherein, wherein this signal processing circuit separately comprises a flip-flop, and one of this flip-flop is set end and is used for receiving this frequency signal, and the end of resetting of this flip-flop is used for receiving this reset signal.
8. a control circuit for power supply changeover device, for a current switch of a power supply changeover device is set, with to a load supplying, this control circuit comprises:
One frequency signal produces circuit, for exporting a current output signal of this load to according to this power supply changeover device, produces a frequency signal;
One threshold value produces circuit, for generation of a current threshold, when this current output signal is greater than first load threshold, this current threshold is set to one first current value, and when this current output signal is between this first load threshold and one second load threshold, this current threshold is reduced along with the reduction of this current output signal, and when this current output signal is less than this second load threshold, this current threshold is set to one second current value;
One current sensor comparison circuit, is coupled to this threshold value and produces circuit, a current sensing signal and this current threshold is compared, to produce a reset signal; And
One signal processing circuit, is coupled to this frequency signal and produces circuit and this current sensor comparison circuit, produces a control signal, so that the conducting state of this current switch to be set according to this frequency signal and this reset signal;
Wherein the frequency of this control signal can reduce along with the reduction of this current output signal.
9. control circuit as claimed in claim 8, wherein when this current output signal is between this first load threshold and one second load threshold, this current peak arranges circuit and this current threshold can be set along with the reduction of the load value of this load, reduce linearly.
10. control circuit as claimed in claim 8, wherein when this current output signal is between this first load threshold and one second load threshold, this current peak arranges circuit and this current threshold can be set along with the reduction of the load value of this load, present the multistage and reduce.
11. as claim 8 to 10 control circuit of any one wherein, and wherein this signal processing circuit separately comprises a flip-flop, and one of this flip-flop is set end and is used for receiving this frequency signal, and the end of resetting of this flip-flop is used for receiving this reset signal.
12. as claim 8 to 10 control circuit of any one wherein, separately comprises:
One feedback signal comparison circuit, for according to a feedback signal and a reference voltage to produce a comparison signal;
Wherein this threshold value produces circuit and can produce this current threshold according to this comparison signal.
13. as claim 8 to 10 control circuit of any one wherein, and wherein this threshold value produces circuit and can produce this current threshold according to this frequency signal.
The control method of 14. 1 kinds of power supply changeover devices, for a current switch of a power supply changeover device is set, with to a load supplying, it comprises:
Foundation one feedback signal and a reference voltage are to produce a comparison signal;
According to this comparison signal, produce a frequency signal;
According to this frequency signal, produce a current threshold, and a current sensing signal and this current threshold are compared, to produce a reset signal;
According to this frequency signal and this reset signal and produce a control signal, so that the conducting state of this current switch to be set;
In one first period, fix this current threshold, and the frequency of this frequency signal is set according to this comparison signal; And
In one second period, reduce this current threshold, and reduce the frequency of this frequency signal.
The control method of 15. 1 kinds of power supply changeover devices, for a current switch of a power supply changeover device is set, with to a load supplying, it comprises:
According to this power supply changeover device, export a current output signal of this load to and produce a frequency signal;
Produce a current threshold, and when this current output signal is greater than first load threshold, this current threshold is set to one first current value, and when this current output signal is between this first load threshold and one second load threshold, this current threshold is reduced along with the reduction of this current output signal, when this current output signal is less than this second load threshold, this current threshold is set to one second current value;
One current sensing signal and this current threshold are compared, to produce a reset signal; And
According to this frequency signal and this reset signal and produce a control signal, so that the conducting state of this current switch to be set.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210364759.9A CN103683900B (en) | 2012-09-26 | 2012-09-26 | The control circuit of power supply changeover device and control method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210364759.9A CN103683900B (en) | 2012-09-26 | 2012-09-26 | The control circuit of power supply changeover device and control method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103683900A true CN103683900A (en) | 2014-03-26 |
| CN103683900B CN103683900B (en) | 2016-01-20 |
Family
ID=50320483
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210364759.9A Expired - Fee Related CN103683900B (en) | 2012-09-26 | 2012-09-26 | The control circuit of power supply changeover device and control method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103683900B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110048387A (en) * | 2019-04-28 | 2019-07-23 | 深圳市华星光电技术有限公司 | Current foldback circuit and display panel |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110196430B (en) * | 2019-05-15 | 2021-05-14 | 深圳市速腾聚创科技有限公司 | Temperature compensation circuit and method applied to single photon array sensor |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101521456A (en) * | 2008-02-22 | 2009-09-02 | 崇贸科技股份有限公司 | Switching controller capable of reducing acoustic noise for power converters |
| CN101552560A (en) * | 2009-01-13 | 2009-10-07 | 成都芯源系统有限公司 | Switch voltage stabilizing circuit and control method thereof |
| US20100157631A1 (en) * | 2008-12-18 | 2010-06-24 | Infineon Technologies Ag | Audible noise reduction in a power supply transfomer |
| CN101867295A (en) * | 2010-03-16 | 2010-10-20 | 成都芯源系统有限公司 | Circuit and control method |
| JP2010268657A (en) * | 2009-05-18 | 2010-11-25 | Funai Electric Co Ltd | Switching power supply circuit |
| CN102201738A (en) * | 2011-05-18 | 2011-09-28 | 上海新进半导体制造有限公司 | Noise control circuit of power converter and method thereof |
-
2012
- 2012-09-26 CN CN201210364759.9A patent/CN103683900B/en not_active Expired - Fee Related
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101521456A (en) * | 2008-02-22 | 2009-09-02 | 崇贸科技股份有限公司 | Switching controller capable of reducing acoustic noise for power converters |
| US20100157631A1 (en) * | 2008-12-18 | 2010-06-24 | Infineon Technologies Ag | Audible noise reduction in a power supply transfomer |
| CN101552560A (en) * | 2009-01-13 | 2009-10-07 | 成都芯源系统有限公司 | Switch voltage stabilizing circuit and control method thereof |
| JP2010268657A (en) * | 2009-05-18 | 2010-11-25 | Funai Electric Co Ltd | Switching power supply circuit |
| CN101867295A (en) * | 2010-03-16 | 2010-10-20 | 成都芯源系统有限公司 | Circuit and control method |
| CN102201738A (en) * | 2011-05-18 | 2011-09-28 | 上海新进半导体制造有限公司 | Noise control circuit of power converter and method thereof |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110048387A (en) * | 2019-04-28 | 2019-07-23 | 深圳市华星光电技术有限公司 | Current foldback circuit and display panel |
| US11223197B2 (en) | 2019-04-28 | 2022-01-11 | Tcl China Star Optoelectronics Technology Co., Ltd. | Overcurrent protective circuit and display panel |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103683900B (en) | 2016-01-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9577543B2 (en) | Constant on time (COT) control in isolated converter | |
| US6728118B1 (en) | Highly efficient, tightly regulated DC-to-DC converter | |
| US9954455B2 (en) | Constant on time COT control in isolated converter | |
| US20160294296A1 (en) | Universal System Structure for Low Power Adapters | |
| EP2355327A2 (en) | Switching power-supply apparatus | |
| US20100225289A1 (en) | Two-stage switching power supply | |
| CN203056977U (en) | Boost isolation type DC-DC converter | |
| US10651750B2 (en) | Constant on-time (COT) control in isolated converter | |
| CN101807856A (en) | Dc-dc converter and switching control circuit | |
| JP2006296186A (en) | Switching converter | |
| CN102130613B (en) | Power converter having a switch coupled between windings | |
| US10250116B2 (en) | Control circuit for reducing power loss of LLC resonant converter during light-load or no-load operation | |
| CN102801314A (en) | Constant on-time switching regulator implementing dual control loops | |
| CN101951151A (en) | Dual-mode fully-integrated high-frequency reduction voltage power supply with high light load efficiency | |
| CN208424332U (en) | Power inverter and its control circuit | |
| TWI327421B (en) | Method for stabling voltage, pulse frequency modulating circuit and power supply using the same | |
| CN108512538A (en) | Power inverter and its control circuit and control method | |
| CN105337492A (en) | Power switch driving method | |
| CN101964599B (en) | Switching power conversion circuit and applicable power supply therefor | |
| CN101834527B (en) | Two-stage switching power supply conversion circuit | |
| US9548667B2 (en) | Constant on-time (COT) control in isolated converter | |
| US9577542B2 (en) | Constant on-time (COT) control in isolated converter | |
| CN101071991A (en) | Switch power for reducing output ripple | |
| CN103683900B (en) | The control circuit of power supply changeover device and control method | |
| KR20140091477A (en) | Switching regulator including charge pump |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20160120 Termination date: 20210926 |