CN201846236U - Constant current output control device of switch power supply - Google Patents
Constant current output control device of switch power supply Download PDFInfo
- Publication number
- CN201846236U CN201846236U CN2010205993323U CN201020599332U CN201846236U CN 201846236 U CN201846236 U CN 201846236U CN 2010205993323 U CN2010205993323 U CN 2010205993323U CN 201020599332 U CN201020599332 U CN 201020599332U CN 201846236 U CN201846236 U CN 201846236U
- Authority
- CN
- China
- Prior art keywords
- switch
- output
- current source
- degaussing
- current
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 239000003990 capacitor Substances 0.000 claims abstract description 45
- 238000001514 detection method Methods 0.000 claims description 26
- 230000002045 lasting effect Effects 0.000 claims description 7
- 230000000630 rising effect Effects 0.000 claims description 3
- 238000010586 diagram Methods 0.000 description 6
- 238000007600 charging Methods 0.000 description 5
- 238000005516 engineering process Methods 0.000 description 4
- 238000000034 method Methods 0.000 description 3
- 238000004804 winding Methods 0.000 description 2
- 230000001413 cellular effect Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000009795 derivation Methods 0.000 description 1
- 230000008520 organization Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
Images
Landscapes
- Dc-Dc Converters (AREA)
Abstract
Disclosed is a constant current output control device of a switching power supply, including: first and second current sources; first and second switches; a capacitor; the error compensation module consists of a third current source and a third switch; the positive pole of the first current source is coupled to one end of the first switch, the negative pole is coupled to the power supply voltage, and the other end of the first switch is coupled to one end of the capacitor; the negative pole of the second current source is coupled to one end of the second switch, the positive pole is coupled to the other end of the capacitor and grounded, and the other end of the second switch is coupled to the one end of the capacitor; the anode of the third current source is coupled to one end of the third switch, the cathode of the third current source is coupled to the power supply voltage, and the other end of the third switch is coupled to the one end of the capacitor. According to the utility model discloses constant current output controlling means circuit simple structure, required component figure is very few to realize easily.
Description
Technical field
The utility model relates to the power supply control technology, is specifically related to the device that the constant current output of Switching Power Supply is controlled.
Background technology
AC/DC conversion at for example battery charger and adapter etc. are used has proposed multiple power supply controlling schemes, and accurate constant voltage (CV), constant current controls such as (CC) can be provided, and obtains required supply of electric power.For example, BCD semiconductor for ManufacturingLimited has proposed multiple AC/DC power-supply controller of electric, comprise former limit control integrated circuit AP3708 (Preliminary Datasheet, Rev.1.0, in September, 2008,
Http:// www.bcdsemi.com).Fig. 1 shows the former limit of the inverse-excitation type control switching of the employing AP3708 control of simplification, comprises power-supply controller of electric AP3708, transistor Q1, current sense resistor Rcs and transformer, and this transformer is by primary coil Np, secondary coil Ns and ancillary coil N
AUXForm.
The voltage Vs at secondary coil Ns two ends is reflected in ancillary coil N
AUXOn, ancillary coil N
AUXOn voltage V
AUXFeed back on the power-supply controller of electric AP3708 by pin FB by after the electric resistance partial pressure, that is, and feedback voltage V
FBThus, power-supply controller of electric can be from feedback voltage V
FBKnow the situation of the electric current among the secondary coil Ns.
Fig. 2 shows the circuit diagram of power-supply controller of electric AP3708, is primarily aimed at constant current (Constant Current) pattern below and is described.As shown in Figure 2, power-supply controller of electric AP3708 comprises 0.1V comparator 201, Tons (Tons represents the conducting period of secondary diode D1) detector 202, first current source 203 and second current source 204, first control switch 205 and second control switch 206, electric capacity 207.
V
FBCompare with 0.1V through 0.1V comparator 201, work as V
FBDuring greater than 0.1V, 0.1V comparator 201 is output as logic low; Otherwise, be output as logic high.
0.1V the output signal of comparator 201 is imported into Tons detector 202, the conducting period that Tons detector 202 output signal Tons indicate secondary diode D1.
Signal Tons is used to control first control switch 205 and 206 pairs of electric capacity 207 of second control switch discharge and recharge.The ratio of the current value of first current source 203 and second current source 204 is constant, and the ratio that both current values have been shown among Fig. 2 is 4/3.
When power-supply controller of electric AP3708 works in constant current mode, Tons/Toffs=4/3, wherein, Toffs represents the deadline of secondary diode D1, Toffs=T-Tons, the switch periods of transistor Q1 in the T presentation graphs 1.Simultaneously, ideally, under constant current mode, power supply average output current I
oSatisfy:
I
o＝1/2×n×I
pk×(Tons/T) (1)，
Wherein, I
PkBe former limit peak current, n is the turn ratio of former limit and secondary coil, so n * I
Pk=I
PksIt is the secondary peak current of considering coil ratio.
Can see, for given Switching Power Supply, n and I
PkAll fixing, therefore, be maintained fixed ratio between the conducting period (Tons) as if switch periods T and secondary diode D1, then I
oKeep constant, realize constant current output.Therefore, the key of constant current output control is to obtain the conducting period Tons of secondary diode D1, and this can realize by the zero crossing that detects electric current among the secondary coil Ns.Realize angle from circuit, zero crossing or mistake 0.1V voltage detecting circuit are easy to realize.For Switching Power Supply, common method is to detect auxiliary winding N
AUXThe time of last voltage zero-cross, obtain Tons.With reference to Fig. 1 and 2 and above description, in power-supply controller of electric AP3708, the method for employing is V
FB(situation of electric current among the reflection secondary coil Ns) cross the 0.1V voltage detecting, detect the duration of secondary current, also be the conducting period Tons of secondary diode D1.
Therefore, power-supply controller of electric can pass through feedback voltage V
FBZero crossing or cross the 0.1V point and detect the conducting period Tons (also promptly, the current duration of secondary coil) of secondary diode, thereby between the conducting period of switch periods and secondary diode Tons, be maintained fixed ratio, realize that constant current exports.
As mentioned above, in the ideal case, if Tons/T remains constant, I then
oKeep constant.Yet in actual applications, a problem of existence: after the secondary diode ended, auxiliary winding voltage will be through just can zero passage after the degaussing vibration; That is, when the electric current among the secondary coil Ns is reduced to zero, feedback voltage V
FBBecause the existence of degaussing vibration (form that has attenuation sinusoidal wave usually) also is not reduced to zero.The sequential chart of Fig. 3 shows feedback voltage V
FBWaveform, comprising the degaussing vibration that is the attenuation sinusoidal wave form.As shown in the figure, by zero crossing or cross between Tons that the 0.1V point detects and the actual Tons and have error delta T (can think that usually Δ T equals four/one-period of attenuation sinusoidal wave).Fig. 4 a shows the part of constant current output control module among the power-supply controller of electric AP3708, and Fig. 4 b shows current source and charge and discharge capacitance part in conjunction with Fig. 3.For convenience of description, the size of current with the current source among Fig. 2 203 and 204 is shown 4I and 3I.As mentioned above, in the ideal case, when power-supply controller of electric AP3708 works in constant current mode, Tons/Toffs=4/3.If consider in esse error delta T, can obtain equation (2):
3I*(Tons+ΔT)＝4I*(Toffs-ΔT) (2)
Thereby obtain output current I
o:
Wherein, L
mInductance on the expression primary coil, V
oThe output voltage (referring to Fig. 1) of expression secondary coil.As seen, owing to have degaussing vibration, actual voltage V
FBThe time point of zero passage is t
1, the electric capacity actual discharge time is Tons+ Δ T, the actual charging interval is Toffs-Δ T.N Δ TV in the equation (3)
oShow because conducting period error delta T can cause existing in the output current error, this is because output current I
oWith output voltage V
oRelevant, and output voltage V
oCan change with the variation of power source loads again, cause output current I
oCan't keep constant, thereby can't realize constant current output.
At the problems referred to above, some solutions have been proposed.For example, patent documentation (CN101552563A) has proposed to introduce time bias mechanism in the constant current output control in Switching Power Supply, the current duration of detected secondary coil is compensated for as the current duration of actual secondary coil.This patent documentation proposes joining day compensating circuit in existing constant-current control circuit, though can address the above problem, need introduce more circuit devcie in available circuit, and needs paired identical capacitor.This makes circuit complicated, and this circuit needs two capacitors, and the appearance value must guarantee accurate fixed proportion, this is unusual difficulty in reality is implemented, even can be described as and can not realize.
Therefore, need a kind of Switching Power Supply constant current output controlling organization simple, that realize easily, the detection error of the conducting period Tons that it can cause the degaussing vibration compensates, and guarantees the accuracy of constant current output control.
Summary of the invention
In view of the above problems, proposed the constant current output control technology of Switching Power Supply, it utilizes the additional current source of controlling based on feedback voltage degaussing vibration to compensate the detection error of conducting period.
According to the utility model on the one hand, a kind of constant current output-controlling device of Switching Power Supply comprises:
First and second current sources;
First and second switches;
Capacitor; And
The error compensation module is made of the 3rd current source and the 3rd switch;
The positive pole of first current source is coupled to an end of first switch, and negative pole is coupled to supply power voltage, and the other end of first switch is coupled to an end of capacitor;
The negative pole of second current source is coupled to an end of second switch, and positive pole is coupled to the other end and the ground connection of capacitor, and the other end of second switch is coupled to a described end of capacitor;
The positive pole of the 3rd current source is coupled to an end of the 3rd switch, and negative pole is coupled to supply power voltage, and the other end of the 3rd switch is coupled to a described end of capacitor;
Wherein, control the closed and disconnected of first and second switches according to the secondary coil diode current flow period of the Switching Power Supply that detects, capacitor is charged and discharge to control first and second current sources respectively, and
Degaussing vibration according to the feedback voltage of Switching Power Supply, control the closed and disconnected of the 3rd switch, to control the 3rd current source capacitor is charged, conducting period that feasible compensation detects and the error between the actual conducting period, the output current of maintained switch power supply is constant.
According to the utility model embodiment, first current source is k with the ratio of the size of current of second current source
1/ k
2, the size of current of the 3rd current source is (k
1+ k
2)/2, k
1And k
2Be natural number.
According to the utility model embodiment, the error between the conducting period of detection and actual conducting period is Δ T, and Δ T represents the four/one-period of attenuation sinusoidal wave of the degaussing vibration of feedback voltage,
Closed second switch on the conducting period of detecting, disconnect the first and the 3rd switch, second current source discharges to capacitor, it in length closed the first and the 3rd switch on period of 2 Δ T, disconnect second switch, first and second current sources charge to capacitor, at closed first switch of switch periods Remaining Stages, disconnect the second and the 3rd switch, first current source is closed on the conducting period of detecting to the electric capacity charging.
According to the utility model embodiment, the constant current output-controlling device also comprises:
Comparator, the feedback voltage input that is connected to Switching Power Supply compares feedback voltage and reference voltage, and from output output compare result signal; And
Conducting period detector is connected to the output of comparator, receives the compare result signal of comparator, and from output output conducting period detection signal;
Wherein, the output of conducting period detector is connected to the control end of first switch via inverter, offers the control end of first switch with the inversion signal with conducting period detection signal, controls the closed and disconnected of first switch,
The output of conducting period detector is connected directly to the control end of second switch, conducting period detection signal is offered the control end of second switch, the closed and disconnected of control second switch.
According to the utility model embodiment, the constant current output-controlling device also comprises:
The degaussing oscillating detector is connected to the output of comparator and conducting period detector, receives compare result signal and conducting period detection signal, and from output output degaussing oscillator signal;
Wherein, the output of degaussing oscillating detector is connected to the control end of the 3rd switch, the degaussing oscillator signal is offered the control end of the 3rd switch, controls the closed and disconnected of the 3rd switch.
According to the utility model embodiment, the high level lasting time of degaussing oscillator signal is the two/one-period of attenuation sinusoidal wave of degaussing vibration;
The rising edge of degaussing oscillator signal triggers the 3rd switch closure, and the 3rd current source charges to capacitor on the high level lasting time of degaussing oscillator signal.
According to the utility model on the other hand, a kind of Switching Power Supply comprises aforesaid constant current output-controlling device.
Description of drawings
By below in conjunction with description of drawings preferred embodiment of the present utility model, will make above-mentioned and other purpose of the present utility model, feature and advantage clearer, wherein:
Fig. 1 shows the former limit of the inverse-excitation type control switching of the employing AP3708 control of simplification;
Fig. 2 shows the circuit diagram of power-supply controller of electric AP3708;
Fig. 3 shows feedback voltage V
FBWaveform, comprising the degaussing vibration that is the attenuation sinusoidal wave form;
Fig. 4 a shows the part of constant current output control module among the power-supply controller of electric AP3708;
Fig. 4 b shows current source and charge and discharge capacitance part in conjunction with Fig. 3;
Fig. 5 shows the schematic circuit diagram according to the current source of inventive concept and charge and discharge capacitance part;
Fig. 6 shows structure and the placement according to the error compensation module of the utility model embodiment;
Fig. 7 shows the schematic block diagram according to the constant current output-controlling device of the utility model embodiment;
Fig. 8 shows the oscillogram according to signal in the constant current output-controlling device of the utility model embodiment.
Embodiment
Following with reference to accompanying drawing, example embodiment of the present utility model is described in detail, the utility model is not limited to following example embodiment.For clear description basic thought of the present utility model, only show in the accompanying drawing and the closely-related parts of the technical solution of the utility model, and omitted in the following description known technology, function or parts specific descriptions.
The present application people notices, can adopt the additional current source of controlling based on the degaussing vibration to compensate the detection error of conducting period Tons.Fig. 5 shows the schematic circuit diagram according to inventor's design, comprises the error compensation module.This error compensation module comprises the 3rd current source and the 3rd switch.For sake of convenience, the current value of the 3rd current source is expressed as 3.5I.At t
1-t
2During=2 Δ T, with the 3rd switch closure, then the 3rd current source charges to electric capacity, to compensate the detection error of the conducting period Tons that causes owing to the degaussing vibration.In conjunction with above-mentioned equation (2), can utilize additional current source 3.5I, make following equation (5) set up:
3I*(Tons+ΔT)＝4I*(Toffs-ΔT)+3.5I*2ΔT (4)
Thereby obtain
3Tons+3ΔT＝4Toffs-4ΔT+7ΔT (5)
Thus, eliminated the time error Δ T that the degaussing vibration causes in the equation (5), that is, no matter how detect error, conducting period Tons and switch periods T accurately are in fixing ratio.Thus, above-mentioned equation (3) becomes following equation (6):
That is n Δ TV in the equation (4),
oBe zero, guaranteed the precision of constant current output control thus.
When more than derivation works in constant current mode based on existing power supply controller AP3708, the example of Tons/Toffs=4/3.It will be understood by those skilled in the art that design of the present utility model is not limited to this concrete example and each concrete example parameter, and can be applied in any other switch power controller.Following equation (7) has provided the universal expression formula:
Wherein, k
1And k
2The parameter of the expression power supply corresponding respectively with power supply 3I and power supply 4I among Fig. 5, (k
1+ k
2The parameter of the current source that)/2 expression is additional, 2 Δ T can pass through V
FBThe sinusoidal wave zero crossing of degaussing vibration detect and obtain (, detecting the degaussing sinusoidal wave t that vibrates referring to Fig. 3
1Zero crossing and t constantly
2Zero crossing constantly).Certainly, also can adopt (k
1+ k
2) * Δ T replaces the (k in the equation (7)
1+ k
2)/2*2 Δ T, this just need be to V
FBThe sinusoidal wave peak point of degaussing vibration detect, implement the comparison difficulty.Therefore, in the utility model, adopt 2 Δ T and corresponding current source parameter (k
1+ k
2)/2, as shown in Figure 3.
More than the utility model design is illustrated, 6-10 with reference to the accompanying drawings, embodiment specifically describes to the utility model.
Fig. 6 shows structure and the placement according to the error compensation module of the utility model embodiment.As shown in the figure, in the constant current output-controlling device of the Switching Power Supply of conceiving substantially according to the utility model, additionally provide error compensation module 60, constituted by current source 603 and switch 606.Under the constant current mode of Switching Power Supply, degaussing vibration according to the feedback voltage V FB of Switching Power Supply, the closed and disconnected of switch 606 in the departure compensating module, and then the 603 pairs of capacitors 607 in Control current source charge, with conducting period Tons and the error between the actual conducting period that compensation detects, the output current of maintained switch power supply is constant.
Fig. 6 also shows other relevant elements, comprising: first and second current sources 601,602, first and second switch 604,605 and the capacitors 607.The positive pole of first current source 601 is coupled to an end of first switch 604, and negative pole is coupled to supply power voltage VDD, and the other end of first switch 604 is coupled to an end of capacitor 607.The negative pole of second current source 602 is coupled to an end of second switch 605, and positive pole is coupled to the other end and the ground connection of capacitor 607, and the other end of second switch 605 is coupled to a described end of capacitor 607.The positive pole of the 3rd current source 603 is coupled to an end of the 3rd switch 606, and negative pole is coupled to supply power voltage VDD, and the other end of the 3rd switch 606 is coupled to a described end of capacitor 607.
With reference to above-mentioned explanation, it will be understood by those skilled in the art that if suppose the ratio of the size of current of first current source 601 and second current source 602 be k to the utility model design
1/ k
2(this current ratio is fixed), then the size of current of the 3rd current source 606 is (k
1+ k
2)/2, k
1And k
2Be natural number.
Under the constant current mode of Switching Power Supply, control the closed and disconnected of first and second switches 604,605 according to the secondary coil diode current flow period Tons of the Switching Power Supply that detects, charge and discharge to control 601,602 pairs of capacitors 607 of first and second current sources respectively.For example, first and second switches 604,605 can be PMOS transistor, nmos pass transistor or bipolar transistor.For example under the nmos pass transistor situation, on the high level lasting time of the signal of indicating conducting period Tons, during closed second switch 605, disconnect the first and the 3rd switch 604 and 607 discharges of 602 pairs of capacitors of 606, the second current sources.
In addition, according to the feedback voltage V of Switching Power Supply
FBDegaussing vibration, control the closed and disconnected of the 3rd switch 606, charge to control 603 pairs of capacitors 607 of the 3rd current source.Equally, the 3rd switch 606 also can be PMOS transistor, nmos pass transistor or bipolar transistor.In conjunction with Fig. 3 and above explanation to the utility model design, it will be understood by those skilled in the art that the conducting period Tons of detection and the error between the actual conducting period are Δ T, Δ T is generally feedback voltage V
FBFour/one-period of attenuation sinusoidal wave of degaussing vibration.Thus, when closed second switch 605 on the conducting period Tons of detection, disconnect the first and the 3rd switch 604 and 607 discharges of 602 pairs of capacitors of 606, the second current sources.Closed the first and the 3rd switch 604 and 606 on 2 Δ T periods, disconnect second switch 605, the first and the 3rd current source 601 and 603 pairs of capacitor 607 chargings, at closed first switch 604 of switch periods Remaining Stages, disconnect 601 pairs of capacitor chargings of the second and the 3rd switch 605 and 606, the first current sources.Thus, satisfy the requirement of above equation (7), make n Δ TV in the equation (4)
oBe zero, guaranteed output current and output voltage V
oIrrelevant, thus irrelevant with power source loads, improved the precision of constant current output control.
Fig. 7 shows the schematic block diagram according to the constant current output-controlling device 70 of the utility model embodiment.For among Fig. 7 with Fig. 6 components identical, adopt identical Reference numeral, and omit detailed description.As shown in Figure 7, constant current output-controlling device 70 comprises comparator 701, and the feedback voltage input that is connected to Switching Power Supply is with feedback voltage V
FBCompare with reference voltage, and from output output compare result signal Comp.As shown in Figure 7, consider technical error margin, reference voltage adopts 0.1V but not 0V detects feedback voltage V
FBZero crossing.Feedback voltage V
FBInput to the negative-phase input '-' of comparator 701, normal phase input end '+' connects reference voltage 0.1V.
Constant current output-controlling device 70 also comprises conducting period detector 702, is connected to the output of comparator 701, receives the compare result signal Comp of comparator, and from output output conducting period detection signal Tons.Though it will be understood by those skilled in the art that not shownly, Switching Power Supply can adopt trigger to carry out the conducting period and detect.This is uncorrelated with the utility model, saves detailed description at this.The output of conducting period detector 702 is connected to the control end of first switch 604 via inverter, offers the control end of first switch 604 with the inversion signal Tons ' with conducting period detection signal Tons.Simultaneously, the output of conducting period detector 702 is connected directly to the control end of second switch 605, conducting period detection signal Tons is offered the control end of second switch 605.
As mentioned above, according to the utility model embodiment, require feedback voltage V according to Switching Power Supply
FBDegaussing vibration, control the closed and disconnected of the 3rd switch 606, charge to control 603 pairs of capacitors 607 of the 3rd current source.Thus, need be according to the feedback voltage V of Switching Power Supply
FBDegaussing vibration, the signal that the 3rd switch 606 is controlled is provided.
For this reason, constant current output-controlling device 70 also comprises degaussing oscillating detector 703, be connected to the output of comparator 701 and conducting period detector 702, receive compare result signal Comp and conducting period detection signal Tons, and from output output degaussing oscillator signal Tring.The output of degaussing oscillating detector 703 is connected to the control end of the 3rd switch 606, degaussing oscillator signal Tring is offered the control end of the 3rd switch 606, controls the closed and disconnected of the 3rd switch 606.Degaussing oscillating detector 703 can provide degaussing oscillator signal Tring according to compare result signal Comp that receives and conducting period detection signal Tons.For example, degaussing oscillating detector 703 can be subjected to the triggering of the trailing edge of conducting period detection signal Tons, make degaussing oscillator signal Tring become high level, subsequently in the low duration of conducting period detection signal Tons, be subjected to the following triggering that rises the edge of compare result signal Comp, make degaussing oscillator signal Tring become low level.Thus, the high level lasting time of degaussing oscillator signal Tring is the two/one-period of attenuation sinusoidal wave of degaussing vibration, that is, and and 2 Δ T.The rising edge of degaussing oscillator signal Tring triggers the 3rd switch 606 closures, thereby the 3rd current source 603 charges to capacitor 607 on the high level lasting time 2 Δ T of degaussing oscillator signal.
Fig. 8 shows the oscillogram according to signal in the constant current output-controlling device 70 of the utility model embodiment, comprises feedback voltage V
FB, conducting period detection signal Tons, degaussing oscillator signal Tring and electric capacity 607 two ends voltage Vcap.
As can be seen from Figure 8, on the period 801, conducting period detection signal Tons is a low level, and degaussing oscillator signal Tring is a high level, first switch 604 and the 3rd switch 606 closures, and first current source 601 and 603 pairs of capacitors 607 of the 3rd current source charge; On the period 802, degaussing oscillator signal Tring becomes low level, and the 3rd switch 606 disconnects, and 607 chargings of 601 pairs of capacitors of first current source are only arranged; On the period 803, first switch 604 disconnects, second switch 605 closures, and second current source 602 begins capacitor 607 discharges.Oscillogram shown in Figure 8 only is an example, and the utility model is not limited thereto.For example, can adopt the switch of other types, make switch conduction when signal is low level, and switch disconnects when high level.For example also can adopting, assembly such as inverter makes up any other circuit structure that those skilled in the art can be susceptible to.
Thus, by error compensation module 60 (current source 603 with switch 606) additionally is provided, and under the constant current mode of Switching Power Supply, according to the feedback voltage V of Switching Power Supply
FBDegaussing vibration, the closed and disconnected of control switch 606, and then the 603 pairs of capacitors 607 in Control current source charge, thus compensated the conducting period Tons and the error between the actual conducting period that detect.Thus, satisfy the requirement of above equation (7), make n Δ TV in the equation (4)
oBe zero, guaranteed output current and output voltage V
oIrrelevant, thus irrelevant with power source loads, improved the precision of constant current output control.
Switching Power Supply can comprise above-mentioned constant current output-controlling device according to the utility model embodiment, to realize accurate more constant current output.
Below specifically described constant current output-controlling device in conjunction with the accompanying drawings according to the utility model embodiment, it is by being provided with the error compensation module that is made of power supply and switch simply, and it is controlled according to the degaussing of feedback voltage vibration, compensated the conducting period of detection and the error between the actual conducting period, guaranteed that the output current of Switching Power Supply is constant.Constant current output-controlling device circuit structure according to the utility model embodiment is simple, and required component number seldom and is realized easily.
Apparatus and method according to the utility model preferred embodiment have more than been described.In above description, only in the mode of example, show preferred embodiment of the present utility model, but and do not mean that the utility model is confined to above-mentioned steps and cellular construction.Under possible situation, can adjust, accept or reject and make up step and unit as required.In addition, some step and unit are not to implement the necessary element of overall invention thought of the present utility model.Therefore, the necessary technical characterictic of the utility model only is subject to the minimum requirements that can realize overall invention thought of the present utility model, and is not subjected to the restriction of above instantiation.
So far in conjunction with the preferred embodiments the utility model is described.Should be appreciated that those skilled in the art can carry out various other change, replacement and interpolations under the situation that does not break away from spirit and scope of the present utility model.Therefore, scope of the present utility model is not limited to above-mentioned specific embodiment, and should be limited by claims.
Claims (7)
1. the constant current output-controlling device of a Switching Power Supply comprises:
First and second current sources;
First and second switches;
Capacitor; And
The error compensation module is made of the 3rd current source and the 3rd switch;
The positive pole of first current source is coupled to an end of first switch, and negative pole is coupled to supply power voltage, and the other end of first switch is coupled to an end of capacitor;
The negative pole of second current source is coupled to an end of second switch, and positive pole is coupled to the other end and the ground connection of capacitor, and the other end of second switch is coupled to a described end of capacitor;
The positive pole of the 3rd current source is coupled to an end of the 3rd switch, and negative pole is coupled to supply power voltage, and the other end of the 3rd switch is coupled to a described end of capacitor;
Wherein, control the closed and disconnected of first and second switches according to the secondary coil diode current flow period of the Switching Power Supply that detects, capacitor is charged and discharge to control first and second current sources respectively, and
Degaussing vibration according to the feedback voltage of Switching Power Supply, control the closed and disconnected of the 3rd switch, to control the 3rd current source capacitor is charged, conducting period that feasible compensation detects and the error between the actual conducting period, the output current of maintained switch power supply is constant.
2. constant current output-controlling device according to claim 1, wherein, first current source is k with the ratio of the size of current of second current source
1/ k
2, the size of current of the 3rd current source is (k
1+ k
2)/2, k
1And k
2Be natural number.
3. constant current output-controlling device according to claim 1, wherein, the error between the conducting period of detection and actual conducting period is Δ T, Δ T represents the four/one-period of attenuation sinusoidal wave of the degaussing vibration of feedback voltage,
Closed second switch on the conducting period of detecting, disconnect the first and the 3rd switch, second current source discharges to capacitor, it in length closed the first and the 3rd switch on period of 2 Δ T, disconnect second switch, first and second current sources charge to capacitor, at closed first switch of switch periods Remaining Stages, disconnect the second and the 3rd switch, first current source charges to electric capacity.
4. constant current output-controlling device according to claim 1 also comprises:
Comparator, the feedback voltage input that is connected to Switching Power Supply compares feedback voltage and reference voltage, and from output output compare result signal; And
Conducting period detector is connected to the output of comparator, receives the compare result signal of comparator, and from output output conducting period detection signal;
Wherein, the output of conducting period detector is connected to the control end of first switch via inverter, offers the control end of first switch with the inversion signal with conducting period detection signal, controls the closed and disconnected of first switch,
The output of conducting period detector is connected directly to the control end of second switch, conducting period detection signal is offered the control end of second switch, the closed and disconnected of control second switch.
5. constant current output-controlling device according to claim 4 also comprises:
The degaussing oscillating detector is connected to the output of comparator and conducting period detector, receives compare result signal and conducting period detection signal, and from output output degaussing oscillator signal;
Wherein, the output of degaussing oscillating detector is connected to the control end of the 3rd switch, the degaussing oscillator signal is offered the control end of the 3rd switch, controls the closed and disconnected of the 3rd switch.
6. constant current output-controlling device according to claim 5, wherein, the high level lasting time of degaussing oscillator signal is the two/one-period of attenuation sinusoidal wave of degaussing vibration;
The rising edge of degaussing oscillator signal triggers the 3rd switch closure, and the 3rd current source charges to capacitor on the high level lasting time of degaussing oscillator signal.
7. a Switching Power Supply comprises according to the described constant current output-controlling device of one of claim 1 to 6.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010205993323U CN201846236U (en) | 2010-11-04 | 2010-11-04 | Constant current output control device of switch power supply |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010205993323U CN201846236U (en) | 2010-11-04 | 2010-11-04 | Constant current output control device of switch power supply |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201846236U true CN201846236U (en) | 2011-05-25 |
Family
ID=44041112
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2010205993323U Expired - Fee Related CN201846236U (en) | 2010-11-04 | 2010-11-04 | Constant current output control device of switch power supply |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201846236U (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102064703A (en) * | 2010-11-04 | 2011-05-18 | 成都芯源系统有限公司 | Constant current output control device and method for switching power supply |
| CN103001494A (en) * | 2012-12-12 | 2013-03-27 | 杭州士兰微电子股份有限公司 | Switching power supply and controller controlling constant output current of switching power supply |
| CN103580491A (en) * | 2012-07-12 | 2014-02-12 | 艾沃特有限公司 | Configurable power controller with combination input |
| CN106208692A (en) * | 2016-08-31 | 2016-12-07 | 杰华特微电子（杭州）有限公司 | The control method of on-off circuit, control circuit and switch circuit devices |
-
2010
- 2010-11-04 CN CN2010205993323U patent/CN201846236U/en not_active Expired - Fee Related
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102064703A (en) * | 2010-11-04 | 2011-05-18 | 成都芯源系统有限公司 | Constant current output control device and method for switching power supply |
| CN102064703B (en) * | 2010-11-04 | 2013-11-06 | 成都芯源系统有限公司 | Constant current output control device and method for switching power supply |
| CN103580491A (en) * | 2012-07-12 | 2014-02-12 | 艾沃特有限公司 | Configurable power controller with combination input |
| CN103580491B (en) * | 2012-07-12 | 2016-04-13 | 戴乐格半导体公司 | There is the configurable power controller of combinatorial input |
| CN103001494A (en) * | 2012-12-12 | 2013-03-27 | 杭州士兰微电子股份有限公司 | Switching power supply and controller controlling constant output current of switching power supply |
| CN103001494B (en) * | 2012-12-12 | 2015-07-08 | 杭州士兰微电子股份有限公司 | Switching power supply and controller controlling constant output current of switching power supply |
| CN106208692A (en) * | 2016-08-31 | 2016-12-07 | 杰华特微电子（杭州）有限公司 | The control method of on-off circuit, control circuit and switch circuit devices |
| CN106208692B (en) * | 2016-08-31 | 2020-05-22 | 杰华特微电子（杭州）有限公司 | Control method of switching circuit, control circuit and switching circuit device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102064703B (en) | Constant current output control device and method for switching power supply | |
| TWI599160B (en) | Flyback power converter and controller and driver thereof | |
| CN101552563B (en) | Device and method for controlling constant-current output in switch power supply | |
| US9362833B2 (en) | Constant voltage constant current control circuits and methods with improved load regulation | |
| CN106341053B (en) | Flyback-based power conversion device | |
| CN101924471B (en) | Method for constantly outputting current and device thereof | |
| US20150280578A1 (en) | Isolated power converter and switching power supply using the same | |
| US7777467B2 (en) | Voltage rising/falling type switching regulator and operation control method thereof | |
| CN201022180Y (en) | First side feedback controlled exchange power supplier | |
| US20090021968A1 (en) | Switching power supply apparatus and power supply control semiconductor integrated circuit | |
| US8120340B2 (en) | Control device for an interleaving power factor corrector | |
| CN106664022B (en) | Switching power supply device | |
| CN113746347B (en) | Flyback switching power supply and sampling control circuit, sampling control method and chip thereof | |
| CN102761275B (en) | A kind of former limit feedback AC-DC Switching Power Supply tremble control system frequently | |
| CN201846236U (en) | Constant current output control device of switch power supply | |
| CN107317491A (en) | Switching power source chip and the switching power circuit including it | |
| US20240097573A1 (en) | Methods and Circuits for Sensing Isolated Power Converter Output Voltage Across the Isolation Barrier | |
| TW201902103A (en) | Power control device and power control system | |
| KR102143254B1 (en) | Pwm controlling apparatus for flyback converter | |
| CN115940944A (en) | Current signal sampling method, sampling circuit and switching power supply | |
| CN103378726B (en) | Switched power supply and control circuit thereof and control method | |
| TWI520469B (en) | Control circuit applicable to power converter and operation method thereof | |
| CN103248246A (en) | Off-line AC-DC (alternating current-direct current) control circuit and switching circuit comprising control circuit | |
| CN102368667A (en) | Offline type AC-DC (Alternating Current-Direct Current) control circuit and converting circuit comprising same | |
| CN103269059A (en) | Switching circuit improving overvoltage protection precision |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 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: 20110525 Termination date: 20161104 |