CN102035370A - Charge pump circuit with current detection function and circuit unit thereof - Google Patents
Charge pump circuit with current detection function and circuit unit thereof Download PDFInfo
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- CN102035370A CN102035370A CN200910176081XA CN200910176081A CN102035370A CN 102035370 A CN102035370 A CN 102035370A CN 200910176081X A CN200910176081X A CN 200910176081XA CN 200910176081 A CN200910176081 A CN 200910176081A CN 102035370 A CN102035370 A CN 102035370A
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Abstract
The invention relates to a charge pump circuit with current detection function and a circuit unit thereof. The charge pump circuit with the current detection function comprises a charge pump circuit unit, a load circuit, a detection circuit unit and a feedback circuit unit, wherein the charge pump circuit unit comprises a controlled current source; the load circuit is electrically connected with the charge pump circuit unit and is driven by the charge pump circuit unit so as to generate a load current; the detection circuit unit is electrically connected with the load circuit and generates a feedback signal according to the load current; and the feedback circuit unit is electrically connected with the detection circuit unit, receives the feedback signal and adjusts the input current of the controlled current source according to the feedback signal. The charge pump circuit additionally comprises a protection circuit unit which can detect the feedback signal and protect the circuit according to the feedback signal.
Description
Technical field
The present invention designs a kind of circuit design of charge pump, refers to a kind of charge pump circuit and circuit unit thereof with current sense especially.
Background technology
High-luminous-efficiency, high brightness, power consumption are low because LED (Light Emitting Diode) has, long service life, safe and reliable, the characteristic that is beneficial to environmental protection and starts fast or the like, therefore many high-tech products are all used LED as light source.In general, the driving of LED is usually by the driven with current sources of a Constant Direct Current, to keep constant brightness.Particularly, for the portable equipment of battery,, be not suitable for directly driving the led light source of a plurality of series connection because the voltage that battery can provide is not high as power supply.When this means these LED of operation, need the voltage of battery be boosted, it is luminous to drive these LED smoothly.The way that battery is boosted generally is to use boost DC-DC converter, its conversion efficiency height, and still, cost is that cost and PCB area also can significantly increase.Another is to use charge pump circuit to the method that battery carries out up voltage.
The electric current that Figure 1 shows that known adjustment LED brightness changes schematic diagram.
The method of general known adjustment LED brightness, the simplest is exactly to adjust the LED electric current.Known technology is that the electric current I 1 that can produce higher brightness is adjusted into the electric current I 2 than low-light level, but can cause the luminous frequency spectrum of LED to produce drift.In some high-order product or for the responsive especially product of luminescent chromaticity, for example display etc. just can not allow that the luminous frequency spectrum of LED has such drift.
Figure 2 shows that the current switching schematic diagram of known adjustment LED brightness.
Another technology in order to improve the problem of the luminous frequency spectrum of LED drift, to develop, it utilizes human eye for passage of scintillation light the characteristic of the persistence of vision to be arranged, and the electric current that inputs to LED is done fast switched, so can be so that LED glimmers fast.
Can utilize a diverter switch that the electric current I 1 of Fig. 1 is switched fast, because human eye has the characteristic of the persistence of vision for passage of scintillation light, especially for the passage of scintillation light that is shorter than 16.67 microseconds, promptly be passage of scintillation light to switch more than the 60Hz, can't identification.Therefore, utilize this technology, be equivalent to the LED supply brightness that average current caused, and make LED can not produce the drift of luminous frequency spectrum.
Figure 3 shows that the input current waveform figure of well known charge pump circuit.
Known charge pump circuit only has elements such as several diverter switches and electric capacity, and therefore, when the diverter switch of operating charge pump circuit was charged to electric capacity, because element choked flows such as non-resistances, therefore the electric current of input can produce current spike as shown in Figure 3.Promptly be, work as switch opens, and when electric capacity charged, then input current can charge with big electric current at the beginning, then input current just rises along with capacitance voltage and reduces.Particularly, the spike of this input current can cause bad influence for portable equipment.Because portable equipment utilizes battery as the power supply supply usually, and unexpected big electric current output can cause the unexpected decline of cell voltage.In addition, but the common circuit that has several difference in functionalitys simultaneously in the portable equipment, and the while all uses this power supply to drive and operate.Therefore, other circuit that same use can be taken device battery will be subjected to the interference of current spike as shown in Figure 3, for example, produce noise etc. for the audio communication circuit.
Therefore, light-emitting devices such as LED are provided stable output current and do not disturb other circuit that uses in the portable equipment with a power supply, therefore need do further and improve charge pump circuit in order to reach.
Summary of the invention
Embodiments of the invention provide a kind of charge pump circuit and circuit unit thereof with current sense.Charge pump circuit according to the embodiment of the invention with current sense, wherein, the feedback current that produces from a load circuit can be detected in the feedback circuit unit, and can adjust the controlled current source of charge pump circuit unit according to the size of feedback current, to reach the purpose of stabling current.
According to one embodiment of the invention, a kind of charge pump circuit is proposed, electrically connect with a load circuit, this load circuit produces a load current according to this driving voltage of this charge pump circuit unit, comprise: a charge pump circuit unit, produce a driving voltage, wherein the charge pump circuit unit has a controlled current source, with an input current of this charge pump circuit unit of control input; One circuit for detecting unit electrically connects with this load circuit, and produces a feedback signal according to this load current; And a feedback circuit unit, electrically connect with this circuit for detecting unit, and control the input current of this controlled current source according to this feedback signal.
According to still another embodiment of the invention, propose a kind of charge pump circuit unit, comprising: a controlled current source; One illusory path should be connected to a ground end by controlled current source; One electric capacity sees through one first switch and must establish the path electric connection with this controlled current source and this, and this controlled current source charges to this electric capacity through this first switch; And one second switch connect this electric capacity and a load circuit, and this electric capacity sees through this second switch this load circuit is discharged; Wherein this first switch and this second switch are subjected to the control of one first switching signal and a second switch signal respectively and switch in conducting and between ending, and the turn-on cycle of this first switch and this second switch staggers each other, and the electric current of this controlled current source in this first switching signal and this second switch signal be all by the time, see through this illusory path flow to the ground end, and the electric current of this controlled current source sees through this illusory path flow to the ground end when this first switching signal and this second switch signal are all electronegative potential.
Therefore, according to embodiments of the invention, a kind of charge pump circuit with detecting feedback current has been proposed, the feedback current that produces from load circuit can be detected in the feedback circuit unit of charge pump circuit, and according to feedback current adjustment is positioned at the controlled current source of charge pump circuit unit so that the current stabilization of the load circuit of flowing through; And have a protective circuit unit in addition, can detect feedback current, and carry out the protection of circuit, to avoid load circuit and charge pump circuit to be subjected to the damage of overcurrent or to protect in low current condition according to feedback current.
And,, a kind of charge pump circuit with stable input current is proposed according to embodiments of the invention.
Mechanism of the present invention and known technology are completely different, provide have current sense and have stable input current charge pump circuit, to promote industrial upgrading.
Above general introduction and ensuing detailed description and accompanying drawing all are to reach mode, means and the effect that predetermined purpose is taked in order to further specify the present invention.And relevant other purposes of the present invention and advantage will be set forth in follow-up explanation and accompanying drawing.
Description of drawings
The electric current that Figure 1 shows that known adjustment LED brightness changes schematic diagram;
Figure 2 shows that the current switching schematic diagram of known adjustment LED brightness;
Figure 3 shows that the input current waveform figure of well known charge pump circuit;
Figure 4 shows that circuit diagram according to the charge pump circuit of first embodiment of the invention;
Figure 5 shows that signal schematic representation according to first embodiment of the invention;
Figure 6 shows that oscillogram according to the input current of first embodiment of the invention;
Fig. 7 is the circuit diagram according to the charge pump circuit with illusory path (dummy path) of second embodiment of the invention;
Fig. 8 is the current waveform figure according to the input current of second embodiment of the invention;
Fig. 9 is the circuit diagram according to the charge pump circuit with illusory path (dummy path) of third embodiment of the invention.
Figure 10 shows that circuit diagram according to the charge pump circuit of fourth embodiment of the invention;
Figure 11 A and Figure 11 B are depicted as the circuit diagram according to the charge pump circuit unit of fifth embodiment of the invention;
Figure 12 A, Figure 12 B, Figure 12 C are depicted as the circuit structure diagram according to the load unit of sixth embodiment of the invention and circuit for detecting unit.
[main element description of reference numerals]
400,900,1000,1100 charge pump circuits
10 controlled current sources
11,22,23 electric capacity
12 load capacitances
13 load units
14 detecting resistance
14a detecting voltage resistance
15,28 error amplifiers
16 first comparators
17 second comparators
18 signal generators
19 processors
20 the 3rd comparators
24,25,26,30 resistance
The 21NAND gate
27 current control units
29 the 4th comparators
41,49,50 charge pump circuit unit
42 feedback circuit unit
43 protective circuit unit
44 load circuits
45 circuit overcurrent protection unit
46 low current protective circuit unit
47 circuit for detecting unit
48 current-limiting circuit unit
V
InInput voltage source
V
OutDriving voltage
S1～S14 switch
The SD dimmer switch
CLK1 first switching signal
CLK2 second switch signal
CLK3 the 3rd switching signal
I
LoadLoad current
I
FBFeedback signal
V
FBVoltage feedback signal
V
OcpThe overcurrent reference voltage
V
OVpThe overvoltage reference voltage
V
UcpThe low current reference voltage
V
iCanonical reference voltage
The DIM control signal
The illusory path of P1, P2
Embodiment
Figure 4 shows that circuit diagram according to the charge pump circuit of first embodiment of the invention.
Charge pump circuit unit 41 is by an input voltage source V
InProvide certain voltage, input voltage source V
InElectrically connect with a controlled current source 10, first end of controlled 10 whiles of current source with switch S 1, S3 electrically connects, and second end of switch S 3 and first end of switch S 2 electrically connect, and second end of switch S 2 is connected to a ground end.Second end of switch S 1 is connected with first end of switch S 4 and first end of electric capacity 11 simultaneously, and second end of electric capacity 11 then electrically connects with first end of switch S 2.In addition, first end of the load unit 13 of second end of switch S 4 and first end of load capacitance 12 and load circuit 44 electrically connects, and second end of electric capacity 12 is then held with being connected to.Wherein, switch S 1, S2 are subjected to the control of one first switching signal CLK1 to open or close, and switch S 3, S4 are subjected to the control of a second switch signal CLK2 to open or close.Promptly be, electric capacity 11 sees through first switch S 1, S2 and is connected with controlled current source 10 charging, and through second switch S3, S4 electric capacity 12 and load circuit 44 is discharged, and with driving voltage point V
OutConnect.
Charge pump circuit unit 41 mainly provides 44 1 stable current sources of load circuit to drive load unit 13, and 13 drivings according to charge pump circuit unit 41 of load unit produce a load current I
Load
First end of the detecting resistance 14 of circuit for detecting unit 47 and second end of load unit 13 electrically connect, and second end of detecting resistance 14 is held with being connected to.Wherein, load circuit 44 is accepted the driving of charge pump circuit unit 41, and produces a load current I
Load, this load current of 47 detectings in circuit for detecting unit I
Load, and produce a feedback signal I according to this
FB
The feedback signal I of circuit for detecting unit 47 is accepted in feedback circuit unit 42
FB, with the load current I of monitoring stream through load unit 13
Load, and according to feedback signal I
FBSize adjust controlled current source 10 with the load current I of stable flow through load unit 13
LoadFeedback unit 42 is formed by an error amplifier 15, and the inverting terminal of error amplifier 15 is connected to first end of circuit for detecting unit 47, and the not inverting terminal of error amplifier 15 is acceptance criteria reference voltage V then
iThe output of error amplifier 15 and controlled current source 10 electrically connect, to control the current value of controlled current source 10.In addition, error amplifier 15 also receives control signal DIM, and stop or providing the electric current of controlled current source 10 according to control signal DIM, wherein, control signal DIM can be a dim signal, and error amplifier 15 is also controlled controlled current source 10 and is stopped or providing the frequency of electric current to be higher than the appreciable frequency range of people's ear, for example: the frequency that 20kHz is above, so can avoid producing low-frequency noise signal to cause the audio-frequency noise that connects other circuit of same power supplies in the above-mentioned device taken.Error amplifier 15 is also accepted the control of processor 19 to control controlled current source 10.
In addition, control signal DIM directly processor controls 19 to replace departure amplifier 15.Control signal DIM can be pulse signal or analog signal, if analog signal, processor 19 can just convert duty ratio corresponding to according to its level, stops to produce the time ratio of the first switching signal CLK1 and second switch signal CLK2 with decision, to reach dimming effect.
Protective circuit unit 43 mainly provides the protective circuit of charge pump circuit unit 41 in overcurrent/low current condition.The not inverting terminal of first comparator 16 and the inverting terminal of second comparator 17 are connected to first end of circuit for detecting unit 47, and the inverting terminal of first comparator 16 receives overcurrent reference voltage V
Ocp, the not inverting terminal of second comparator 17 receives low current reference voltage V
Ucp, and the output of first and second comparator 16,17 all is connected to processor 19.Wherein, overcurrent reference voltage V
OcpGreater than low current reference voltage V
UcpProcessor 19 electrically connects with signal generator 18, and an output of processor 19 is connected with error amplifier 15.As feedback signal I
FBGreater than current reference voltage V
OcpThe time, represent circuit abnormality to make load current I
LoadImproper rising to surpasses an overcurrent value; Perhaps feedback signal I
FBLess than current reference voltage V
UcpThe time, represent circuit abnormality to make load current I
LoadCan't rise to and surpass one and cross low current value, protective circuit unit 43 when arbitrary generations of above-mentioned two condition, through Control and Feedback circuit unit 42 to stop controlled current source 10 input currents.So can't provide electrical power to load circuit 44 in the first or temporary unexpected circuit abnormality that starts, make feedback signal I in charge pump circuit 400
FBBe lower than for the moment current reference voltage V
Ucp, protective circuit unit 43 can just stop the operation of charge pump circuit when determining that low current condition continued to surpass a scheduled time, to avoid erroneous judgement.
In addition, processor 19 also produces the first switching signal CLK1 and second switch signal CLK2 according to signal generator 18.Wherein, the frequency of signal generator 18 is a fixed frequency, so that the filtering electromagnetic interference.
Charge pump circuit unit 41 receives from input voltage source V through controlled current source 10
InA stable electric current.When switch S 1, S2 accept first switching signal CLK1 control and conducting and switch S 3, S4 accept second switch signal CLK2 control and not conducting, then producing a charge path charges to electric capacity 11, at this moment, load circuit 44 provides operation required electric power by electric capacity 12 (discharge).When switch S 3, S4 accept second switch signal CLK2 control and conducting, switch S 1, S2 accept first switching signal CLK1 control and not conducting then produces a discharge path and makes 11 pairs of load circuits 44 of electric capacity and electric capacity 12 discharge simultaneously.
Figure 5 shows that signal schematic representation according to first embodiment of the invention.Note, in the following explanation, represent conducting to inductive switch with high potential, electronegative potential representative is by to inductive switch, during right practical application, should look the adjustment of switch character, and for example: for P type MOS (metal-oxide-semiconductor) transistor switch, then with the electronegative potential conducting, high potential ends.
The first switching signal CLK1 and second switch signal CLK2 signal for being produced according to signal generator 18 by processor 19, and first and second switching signal CLK1, CLK2 do not overlap mutually and between a time interval Δ T is arranged, promptly be that the first switching signal CLK1 and second switch signal CLK2 are not high potential simultaneously, and the first switching signal CLK1 is that high potential and second switch signal CLK2 have a time interval Δ T between the high potential, in this time clearance delta T, first and second switching signal CLK1, CLK2 are all electronegative potential.First and second switching signal CLK1 and CLK2 difference control switch S1, S2 and switch S 3, S4.Because when switch S 1, S2 conducting, switch S 3, S4 must be not conducting, on the contrary also with, promptly switch S 1, S2 not simultaneously with switch S 3, S4 conducting.And to a time slot Δ T must be arranged between switch S 3, the S4 conducting, conducting causes electric capacity 11 improper discharges or influences the stability of FEEDBACK CONTROL when avoiding two groups of switches in switch S 1, S2 conducting.
Refer again to Fig. 4.The electric power that load circuit 44 receives the charge pump circuit unit 41 of present embodiment provides, and therefore promptly produces a load current I
LoadThe load unit 13 of flowing through.Circuit for detecting unit 47 is promptly according to this load current I
LoadProduce a feedback signal I
FB, feedback circuit unit 42 receives this feedback signal I
FB, can be according to feedback signal I
FBWith reference voltage V
iCompare, and then adjust the current value of controlled current source 10.If feedback signal I
FBOvergauge reference voltage V
i, then error amplifier 15 reduces the current value of controlled current source 10.Otherwise, feedback signal I
FBLess than canonical reference voltage V
i, error amplifier 15 increases the current value of controlled current source 10.Thereby load unit 13 is carried out current compensation, kept load current I
LoadIn a stable current value.
Figure 6 shows that oscillogram according to the input current of first embodiment of the invention.
Because the embodiment of the invention utilizes a controlled current source 10 with control input current I
InSize, therefore, when switch S 1/S2 and switch S 3/S4 respectively by the first switching signal CLK1 and second switch signal CLK2 control conducting during with not conducting, input current I
InWill have a stable input current I as shown in Figure 6
InTherefore, just can not produce current spike as shown in Figure 3 in embodiments of the invention.
Wherein,, be all not conducting, therefore can cause the input current I of current source in all switch S 1 of clearance delta T, S2, S3, S4 during this period of time because switch has time slot Δ T between switching
InInterrupt.
Fig. 7 is the circuit diagram according to the charge pump circuit with illusory path (dummy path) of second embodiment of the invention.
Fig. 8 is the current waveform figure according to the input current of second embodiment of the invention.
As mentioned above,, all be in not on-state, at this moment input current I in this time clearance delta T switch S 1, S2, S3, S4 owing to having a time clearance delta T between the first switching signal CLK1 and second switch signal CLK2
InPromptly can the vanishing electric current.
For will be with input current I
InInput current waveform become steadily, therefore a kind of embodiment with the charge pump circuit 900 in illusory path is proposed according to the present invention.Charge pump circuit 900 as shown in Figure 7 increases an illusory path P 1, and illusory path P 1 connects second end and a ground end of controlled current source 10.In addition, the circuit for detecting unit has more output voltage detecting resistance 14a.First end of detecting voltage resistance 14a and first end of load unit 13 electrically connect, and second end of detecting voltage resistance 14a holds with being connected to, and according to the driving voltage V of load unit 13
OutProduce a voltage feedback signal V
FBFirst comparator 16 of protective circuit unit 43 changes one the 3rd comparator 20 into.The not inverting terminal of the 3rd comparator 20 receives voltage feedback signal V
FB, inverting terminal receives an overvoltage reference voltage V
OvpVoltage feedback signal V
FBGreater than overvoltage reference voltage V
OvpThe time, represent circuit abnormality to make driving voltage V
OutImproper rising to surpasses an overpressure value.When protective circuit unit 43 takes place in above-mentioned overvoltage condition, see through error amplifier 15 to stop controlled current source 10 input currents.And other elements shown in Figure 7 all are as good as with Fig. 4 with being connected the pass, are not repeated at this.
When above-mentioned time slot Δ T, cutoff switch S1, S4 and actuating switch S2, S3.At this moment, input current I
InCan see through switch S 2, illusory path P that S3 formed 1 flows to the ground end, so input current I
InCan't produce violent current fluctuation.So, input current I
InInput current waveform figure that can be as shown in Figure 8 has an input current stably.
Fig. 9 is the circuit diagram according to the charge pump circuit with illusory path (dummy path) of third embodiment of the invention.
Charge pump circuit 1100 according to the embodiment of the invention increases an illusory path P 2, illusory path P 2 connects second end and a ground end of controlled current source 10, and a switch S 5 is set on illusory path P 2, first end of switch S 5 and second end of controlled current source 10 electrically connect, and second end of switch S 5 then is connected to a ground end.In addition, charge pump circuit 1100 increases by a dimmer switch SD, be coupled between load unit 13 and the detecting resistance 14, and according to control signal DIM conducting, end.Compared to Fig. 4 and enforcement circuit shown in Figure 7, the enforcement circuit of Fig. 9 replaces error amplifier 15 with dimmer switch SD and receives control signal DIM, can avoid discharge and recharge the time delay light modulation that caused in of load capacitance 12, so can make the brightness adjustment control can be more accurate in the light modulation process.Other elements shown in Figure 9 all are as good as with Fig. 7 with being connected the pass, are not repeated at this.One NAND gate 21 is arranged in addition, and its input receives the first switching signal CLK1 and second switch signal CLK2 respectively, and produces one the 3rd signal CLK3, and the 3rd switching signal CLK3 is opening and closing of control switch S5.Promptly be that when the first switching signal CLK1 and second switch signal CLK2 were all an electronegative potential, the NAND gate promptly produced the 3rd switching signal CLK3, and is a high potential.Therefore switch S 5 can be according to this 3rd signal CLK3 and conducting, input current I
InCan see through illusory path P 2 and switch S 5 flow direction ground ends.Therefore, output current I
InStill can keep a plateau.So, input current I
InInput current waveform figure that can be as shown in Figure 8 has an input current stably.
Figure 10 shows that circuit diagram according to the charge pump circuit of fourth embodiment of the invention.
Charge pump circuit 1000 has a controlled current source 10, and wherein controlled current source 10 is composed in series by a resistance 30 and a switch S 14, in addition, and the not inverting terminal input feedback signal I of the error amplifier 15 of feedback circuit unit 42
FBAnd inverting terminal input canonical reference voltage V
i, and the output in feedback circuit unit 42 connects a current-limiting circuit unit 48, and wherein, current-limiting circuit unit 48 is made up of an error amplifier 28 and one the 4th comparator 29, and switch S 14 is a PMOS transistor switch in present embodiment.First end of resistance 30 and input voltage V
InConnect, first end of transistor switch S14 then is to be connected with second end of resistance 30 and the inverting terminal of error amplifier 28 and the 4th comparator 29, grid then is to be connected with the output of error amplifier 28, and second end then is first end that is connected to switch S 1, S3.The not inverting terminal of the not inverting terminal of error amplifier 28 and the 4th comparator 29 is connected with the output of error amplifier 15, and error amplifier 28 receives the output signal of the 4th comparator 29, and operates or close according to the output signal of the 4th comparator 29.Except that dimming mode with Fig. 9 is identical, other element with and connected mode all identical with Fig. 4.
The load current I that is detected when circuit for detecting unit 47
LoadThe feedback signal I of Chan Shenging hour, then
FBThen can be lower than canonical reference voltage V
i, this moment, the output-voltage levels of feedback circuit unit 42 error amplifier 15 descended with the cut-off current that increases current-limiting circuit unit 48 (promptly the point that is triggered of the 4th comparator 29 moves to higher current value), otherwise, as feedback signal I
FBBe higher than canonical reference voltage V
i, then the output-voltage levels of error amplifier 15 rises to reduce the cut-off current of current-limiting circuit unit 48.Current-limiting circuit unit 48 is the current limliting reference value with the output signal of error amplifier 15, when the electric current of the resistance 30 of flowing through less, then the current potential of second end of resistance 30 generation is higher than the current limliting reference value that error amplifier 15 is exported, 29 output of the 4th comparator, one electronegative potential.Error amplifier 28 receives the electronegative potential of the 4th comparator 29 outputs and decommissions, and its output signal makes switch S 14 remain in minimum conduction impedance in low level.Otherwise, if the higher current potential of second end generation of resistance 30 that makes of the electric current of the resistance 30 of flowing through is lower than the current limliting reference value, 29 output of the 4th comparator, one high potential, and error amplifier 28 receptions come into operation than high potential.At this moment, the paraphase terminal voltage level of error amplifier 28 is lower than the voltage level of not paraphase end, and then the voltage level rising of error amplifier 28 outputs makes the voltage level of paraphase end keep identical with the voltage level of not paraphase end.The electric current of resistance 30 of just flowing through this moment is clamped on the predetermined strangulation current value, and this predetermined strangulation current value is according to feedback signal I
FBAnd determine.
In this, if the input voltage of the inverting terminal of the 4th comparator 29 is during near cut-off current, promptly the electric current of resistance 30 changes because noise effect is flowed through easily, the input voltage of inverting terminal that causes the 4th comparator 29 is near the variation of the flow valuve of rationing the power supply, make comparator export high potential or electronegative potential continually along with the variation of input voltage, cause the signal of error amplifier 28 receptions the 4th comparator 29 and carry out frequent running or the switching of closing.Therefore, the incoming signal level of the not paraphase end of the 4th comparator 29 preferably a little more than the incoming signal level of the not paraphase end of error amplifier 28, causes error amplifier frequently to switch to avoid noise.
Figure 11 A and Figure 11 B are depicted as the circuit diagram according to the charge pump circuit unit of fifth embodiment of the invention.
Please refer to Figure 11 A, for the present invention is applied to the circuit diagram of 0.5 multiplication of voltage charge pump circuit unit 49, comprising a controlled current source 10, switch S 6～S10 and electric capacity 12,22,23.Input voltage source V
InProvide voltage to charge pump circuit unit 49.First end of controlled current source 10 and input voltage source V
InBe connected, second end then electrically connects with first end of switch S 6; Second end of switch S 6 electrically connects with first end of switch S 9 with electric capacity 22 simultaneously; Second end while of electric capacity 22 electrically connects with first end of switch S 7 and switch S 8; Second end of switch S 7 then electrically connects with first end of switch S 10 and electric capacity 23; Second end of switch S 8 and second end of electric capacity 23 then are connected respectively to a ground end; At last, the driving voltage V of second end of switch S 9 and switch S 10 and electric capacity 12 and load unit 13
OutPoint electrically connects.
Wherein, switch S 6, switch S 7 are subjected to the control of the first switching signal CLK1, and switch S 8, S9, S10 all are subjected to the control of second switch signal CLK2.Therefore, when switch S 6, S7 are subjected to first switching signal CLK1 control and conducting, switch S 8, S9, S10 then are not conducting input voltage source V then simultaneously
In Electric capacity 22,23 is charged.Next, switch S 8, S9, S10 are subjected to the control of second switch signal CLK2 and conducting, and switch S 6, S7 then are not conducting simultaneously, and then second end of electric capacity 22 then can be held with being connected to.So the current potential of electric capacity 22 and electric capacity 23 then can see through switch S 9 and switch S 10 exports electric capacity 12 and load unit 13 to.Therefore see through the circuit of present embodiment, can be flexibly with input current potential V
InChange into the highest 0.5 times the input current potential with driving voltage to load unit 13.
Charge pump circuit unit 50 shown in Figure 11 B, wherein included element is similar to Figure 11 A, has only deleted switch S 8, and has increased switch S 11, S12, S13.Wherein, the connection of controlled current source 10, electric capacity 12,22,23 and switch S 6, S7, S9, S10 is closed all identical with Figure 11 A.First end of first end of switch S 12, S13 and second end of controlled current source 10 and switch S 6 electrically connects; Second end of first end of switch S 11 and electric capacity 23 and switch S 12 electrically connects; And second end of switch S 11 is held with being connected to; Second end of switch S 13 then electrically connects with second end of electric capacity 22 and first end of switch S 7.
Wherein, switch S 6, S7, S11 are subjected to the control of the first switching signal CLK1, and switch S 9, S10, S12, S13 all are subjected to the control of second switch signal CLK2.Therefore, control and conducting when switch S 6, S7, S11 are subjected to the first switching signal CLK1, switch S 9, S10, S12, S13 then are not conducting simultaneously, then input voltage source V
InElectric capacity 22,23 is charged.Next, switch S 9, S10, S12, S13 are subjected to the control of second switch signal CLK2 and conducting, and switch S 6, S7, S11 then be not conducting simultaneously, and then second end of electric capacity 22 then can be connected to input voltage source V through switch 13
InCurrent potential, and second end of electric capacity 23 also sees through switch 12 and is connected to input voltage source V
InCurrent potential.So the current potential of electric capacity 22 and electric capacity 23 then can see through switch S 9 and switch S 10 respectively and export electric capacity 12 and load unit 13 to.Therefore see through the circuit of present embodiment, can be flexibly with driving voltage V
OutChange the highest 1.5 times of input current potential V into
InTo export load circuit 44 to.
Figure 12 A, Figure 12 B, Figure 12 C are depicted as the circuit structure diagram according to the load unit of sixth embodiment of the invention and circuit for detecting unit.
Figure 12 A is the circuit of a plurality of LED series connection, and resistance 14 is detected in series connection one behind these LED.Because therefore the uniformity of LED when making cause often to have different threshold voltage V between a plurality of LED
Th, for example: 3.2～3.6V.Therefore, if these are had different threshold voltages V
ThLED be cascaded, the driving voltage that then needs to provide higher can drive and reach predetermined luminosity smoothly to guarantee these LED.With the present embodiment is example, for example: reach the driving voltage of setting luminosity and have (corresponding different threshold voltage V such as 10.8V (3.6V*3), 10.2V (3.4V*3), 9.6V (3.2V*3)
ThDuring state), this moment is driving voltage V
OutBeing set in 12V just can guarantee and can drive.But the driving efficient of the charge pump circuit unit 41 of this moment also can become relatively poor.From above example (9.6V (3.2V*3)), charge pump circuit unit 41 minimum driving efficient are 9.6V/12V=80%.But,, utilize feedback circuit unit 42 detecting feedback signal I if according to the embodiment of the invention
FBMode then can significantly increase the driving efficient of charge pump circuit unit 41.Supposing needs cross-pressure 0.5V on the detecting resistance 14, therefore only needs in driving voltage V
OutDrive with 10.1V, and, the same current because these LED flow through, so these LED can have roughly the same brightness.At this moment, the efficient of charge pump circuit unit 41 is 9.6V/ (9.6V+0.5V)=95%.This is that charge pump circuit unit 41 uses detecting feedback signal I
FBA major reason.
Figure 12 B is that several LED connect with a resistance and form one group of LED serial circuit, and in parallel with array LED serial circuit, again the circuit of connecting with a detecting resistance 14.In these LED serial circuits, the resistance 24,25,26 of all connecting.These resistance 24,25,26 mainly are that to carry out balanced balanced current be purpose.Because aforesaid LED regular meeting has different threshold voltage V
Th, therefore be cascaded as these LED, can cause the difference on the electric current with other groups LED serial circuit because of the difference of threshold voltage vt h.Therefore for the electric current of each group LED serial circuit of balance, add that a resistance is to reduce these LED because of having different V
ThInfluence on the electric current that causes.So, if the threshold voltage V of these LED
ThDifference more little, then the resistance value of required series connection also just can be more little.
Figure 12 C is that array LED connection in series-parallel is connected with a current control unit 27 and formed one group of LED series-parallel circuit, again the circuit of connecting with a detecting resistance 14.Approximate with Figure 12 B, but in present embodiment, utilize a current control unit 27 to control the electric current of each group LED serial circuit, therefore promptly can reach the electric current of each group LED serial circuit of balance.
But; the above; only be the detailed description and the accompanying drawing of specific embodiments of the invention; be not in order to restriction the present invention; all scope Ying Yiying of the present invention are as the criterion with claim; any those of ordinary skill in the field of the invention, can think easily and variation or revise all can be encompassed in the claim protection range of the present invention.
Claims (13)
1. a charge pump circuit electrically connects with a load circuit, and this load circuit produces a load current according to this driving voltage of this charge pump circuit unit, it is characterized in that, comprising:
One charge pump circuit unit produces a driving voltage, and wherein this charge pump circuit unit has a controlled current source, with an input current of this charge pump circuit unit of control input;
One circuit for detecting unit electrically connects with this load circuit, and produces a feedback signal according to this load current; And
One feedback circuit unit electrically connects with this circuit for detecting unit, and controls this input current of this controlled current source according to this feedback signal.
2. charge pump circuit as claimed in claim 1 is characterized in that, this charge pump circuit unit comprises this controlled current source; One electric capacity sees through one first switch and electrically connect with this controlled current source, and this controlled current source charges to this electric capacity through this first switch; One second switch connects this electric capacity, and this electric capacity discharges through this second switch; Wherein this first switch and this second switch are subjected to the control of one first switching signal and a second switch signal respectively and switch in conducting and between ending, and the turn-on cycle of this first switch and this second switch staggers each other.
3. charge pump circuit as claimed in claim 1 is characterized in that, more comprises a protective circuit unit, and this protective circuit unit comprises a circuit overcurrent protection unit, an overvoltage crowbar unit or a low current protective circuit unit.
4. charge pump circuit as claimed in claim 3 is characterized in that, this feedback signal is detected in this circuit overcurrent protection unit, and when this feedback signal is higher than an overcurrent reference voltage or is lower than a low current reference voltage, stops the operation of this charge pump circuit.
5. charge pump circuit as claimed in claim 3 is characterized in that, this feedback signal is detected in this low current protective circuit unit, and when continuing a scheduled time in this feedback signal in a low current reference voltage, stops the operation of charge pump circuit.
6. charge pump circuit as claimed in claim 3 is characterized in that, this feedback signal is detected in this overvoltage crowbar unit, and the driving voltage in this charge pump circuit unit stops the operation of charge pump circuit when being higher than an overpressure value.
7. charge pump circuit as claimed in claim 1 is characterized in that, this charge pump circuit unit more stops with a light modulating frequency according to a dim signal and provides this input current, this light modulating frequency to be higher than the appreciable frequency range of people's ear.
8. charge pump circuit as claimed in claim 1, it is characterized in that, this illusory path comprises that more one the 3rd switch is connected between this controlled current source and this ground end, and the 3rd switch is subjected between one the 3rd switching signal is controlled in conducting and ends, and the turn-on cycle of the turn-on cycle of the 3rd switch and this first switch and this second switch staggers.
9. charge pump circuit as claimed in claim 1 is characterized in that this load unit comprises a light-emitting diode (LED) module, and this light-emitting diode (LED) module comprises at least one light-emitting diode, and the electric current of each light-emitting diode of flowing through is roughly the same.
10. charge pump circuit as claimed in claim 1 is characterized in that, more comprises a current-limiting circuit unit, in order to this controlled current source of control this input current is prepended within the predetermined strangulation electric current, and this predetermined strangulation electric current is according to the feedback signal adjustment.
11. charge pump circuit as claimed in claim 1 is characterized in that, more comprises a dimmer switch, connects with this load circuit, this dimmer switch is more controlled this load current this load circuit of whether flowing through according to a dim signal.
12. a charge pump circuit unit is characterized in that, comprising:
One controlled current source;
One illusory path should be connected to a ground end by controlled current source;
One electric capacity sees through one first switch and must establish the path electric connection with this controlled current source and this, and this controlled current source charges to this electric capacity through this first switch; And
One second switch connects this electric capacity and a load circuit, and this electric capacity discharges to this load circuit through this second switch;
Wherein this first switch and this second switch are subjected to the control of one first switching signal and a second switch signal respectively and switch in conducting and between ending, and the turn-on cycle of this first switch and this second switch staggers each other, and the electric current of this controlled current source in this first switching signal and this second switch signal be all by the time, see through this illusory path flow to the ground end.
13. charge pump circuit as claimed in claim 12 unit, it is characterized in that, more comprise a current-limiting circuit unit, flow through an input current of this controlled current source within a predetermined strangulation electric current in order to strangulation, this predetermined strangulation electric current is according to the electric current adjustment of this load circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200910176081.XA CN102035370B (en) | 2009-09-28 | 2009-09-28 | Charge pump circuit with current detection function and circuit unit thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200910176081.XA CN102035370B (en) | 2009-09-28 | 2009-09-28 | Charge pump circuit with current detection function and circuit unit thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102035370A true CN102035370A (en) | 2011-04-27 |
| CN102035370B CN102035370B (en) | 2013-10-09 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN200910176081.XA Expired - Fee Related CN102035370B (en) | 2009-09-28 | 2009-09-28 | Charge pump circuit with current detection function and circuit unit thereof |
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| Country | Link |
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| CN (1) | CN102035370B (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103095127A (en) * | 2013-01-22 | 2013-05-08 | 上海艾为电子技术有限公司 | Charge pump circuit and electronic equipment |
| CN104049670A (en) * | 2013-03-14 | 2014-09-17 | 飞思卡尔半导体公司 | Voltage regulator with current limiter |
| TWI499348B (en) * | 2011-08-19 | 2015-09-01 | Green Solution Tech Co Ltd | Load driving circuit with charge spike protection |
| CN110602820A (en) * | 2019-08-09 | 2019-12-20 | 漳州立达信光电子科技有限公司 | Fast start system without voltage detection |
| CN111240386A (en) * | 2020-02-20 | 2020-06-05 | 重庆邮电大学 | Self-compensating current-steering charge pump circuit |
| CN111316189A (en) * | 2017-11-03 | 2020-06-19 | 德州仪器公司 | High-voltage grid drive current source |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007202316A (en) * | 2006-01-27 | 2007-08-09 | Rohm Co Ltd | Charge pump circuit and electrical equipment with the same |
| JP2008017596A (en) * | 2006-07-05 | 2008-01-24 | Matsushita Electric Ind Co Ltd | Semiconductor integrated circuit |
| CN101414784A (en) * | 2007-10-16 | 2009-04-22 | 瑞昱半导体股份有限公司 | Charge pump |
-
2009
- 2009-09-28 CN CN200910176081.XA patent/CN102035370B/en not_active Expired - Fee Related
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI499348B (en) * | 2011-08-19 | 2015-09-01 | Green Solution Tech Co Ltd | Load driving circuit with charge spike protection |
| CN103095127A (en) * | 2013-01-22 | 2013-05-08 | 上海艾为电子技术有限公司 | Charge pump circuit and electronic equipment |
| CN104049670A (en) * | 2013-03-14 | 2014-09-17 | 飞思卡尔半导体公司 | Voltage regulator with current limiter |
| CN111316189A (en) * | 2017-11-03 | 2020-06-19 | 德州仪器公司 | High-voltage grid drive current source |
| CN110602820A (en) * | 2019-08-09 | 2019-12-20 | 漳州立达信光电子科技有限公司 | Fast start system without voltage detection |
| CN110602820B (en) * | 2019-08-09 | 2022-01-11 | 漳州立达信光电子科技有限公司 | Fast start system without voltage detection |
| CN111240386A (en) * | 2020-02-20 | 2020-06-05 | 重庆邮电大学 | Self-compensating current-steering charge pump circuit |
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|---|---|
| CN102035370B (en) | 2013-10-09 |
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