CN101583216B - Driving circuit and driving method of light emitting diode (LED) - Google Patents

Driving circuit and driving method of light emitting diode (LED) Download PDF

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Publication number
CN101583216B
CN101583216B CN200810100211A CN200810100211A CN101583216B CN 101583216 B CN101583216 B CN 101583216B CN 200810100211 A CN200810100211 A CN 200810100211A CN 200810100211 A CN200810100211 A CN 200810100211A CN 101583216 B CN101583216 B CN 101583216B
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China
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voltage
emitting diode
circuit
light
output
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CN200810100211A
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Chinese (zh)
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CN101583216A (en
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王俊铠
吴劲龙
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原景科技股份有限公司
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Abstract

The invention provides a driving circuit and a driving method of a light emitting diode (LED). The driving circuit comprises a voltage conversion circuit and a reference voltage generator, wherein thereference voltage generator can generate a reference voltage according to the voltage of the cathode terminal of the LED, and the voltage conversion circuit dynamically regulates the value of the dri ving voltage of the LED according to the reference voltage to avoid unnecessary power consumption caused by overhigh driving voltage.

Description

The drive circuit of light-emitting diode and driving method

Technical field

The present invention is a kind of drive circuit and method for designing thereof, particularly relates to a kind ofly can dynamically adjusting power output, improves the drive circuit and the method for designing thereof of energy use efficiency.

Background technology

Light-emitting diode (Light Emitting Diode; LED) have functions such as power saving, switching speed be fast; From being used in the status indicator lamp of electronic installation in the past, progressive to becoming the backlight of liquid crystal display, expand to the electrical lighting and the public again and show; Like automobile-used lamp, traffic signal light, billboard message horse race lamp, large-scale video display wall, or even the illumination in the projector etc.Along with the high-order mobile phone adopts light-emitting diode behind backlight, light-emitting diode has been opened new application again.The application that following light-emitting diode is expected most is the flat-panel screens market when 7-40, in case light-emitting diode can become the backlight of flat-panel screens, its market output value will significantly be grown up.

When circuit that drives many light-emitting diode series connection or backlight module; Because it is different slightly that the technology variation can cause every light-emitting diode conducting voltage to have; Be all light-emitting diodes of conducting; Usually can output voltage be preset in higher level, big and phenomenon that can't light takes place to prevent to run into some light-emitting diode conducting voltage, but also therefore cause unnecessary power consumption.

Fig. 1 is the drive circuit according to conventional art, is made up of booster circuit (boost circuit) 100 and 140 of current source cells, to drive a plurality of light-emitting diode serial 111-119.Booster circuit 100 is according to the voltage level of duty ratio (duty cycle) the adjustment output voltage VO UT of adjustment signal SRE.When driving, as long as the duty ratio of decision input voltage VIN and adjustment signal SRE can determine the magnitude of voltage of output voltage VO UT, for making light-emitting diode serial 111~119 equal conducting electric currents (luminous), output voltage VO UT can be adjusted to the higher voltage level.Therefore, current source cell 140 just need bear more voltage drop, and causes redundant power consumption.

Summary of the invention

The present invention provides a kind of drive circuit that can dynamically adjust power output; Can drive a light-emitting diode; The present invention utilizes the cathode voltage of light-emitting diode, revises the size of output voltage automatically, to solve the problem that prior art wastes energy and shortens the loaded work piece life-span.

The present invention also provides a kind of drive circuit that can dynamically adjust power output, can drive a plurality of light-emitting diodes simultaneously, and adjusts driving voltage according to the cathode voltage of light-emitting diode, to avoid unnecessary power dissipation.

The present invention also provides a kind of drive circuit that can dynamically adjust power output, can drive a plurality of light-emitting diode serials, and adjusts driving voltage according to the cathode voltage of light-emitting diode serial, to avoid unnecessary power dissipation.

The present invention provides a kind of design of drive circuit method that can dynamically adjust power output again, utilizes the cathode terminal voltage of luminous secondary body, judges whether driving voltage is too high, and it is adjusted to the appropriate voltage level, to avoid redundant power consumption.

The present invention proposes a kind of circuit, is used to drive at least one light-emitting diode, and foregoing circuit comprises voltage conversion circuit and reference voltage generator.Wherein, voltage conversion circuit converts input voltage into output voltage, and the anode of this output voltage to above-mentioned light-emitting diode is provided, and wherein above-mentioned output voltage is corresponding to reference voltage.Then in order to produce reference voltage, above-mentioned reference voltage is corresponding to the cathode voltage of above-mentioned light-emitting diode for reference voltage generator.Above-mentioned reference voltage generator comprises detecting unit and pulse duration adjustment unit.Wherein, detecting unit is according to the cathode voltage of above-mentioned light-emitting diode, and output reference voltage, pulse duration adjustment unit are adjusted the duty ratio of signal then according to reference voltage and feedback voltage corresponding to output voltage.Wherein, if the cathode voltage of above-mentioned light-emitting diode is greater than threshold voltage, then voltage conversion circuit reduces output voltage according to the duty ratio of adjustment signal.

The present invention proposes a kind of circuit, is used to drive a plurality of light-emitting diodes, and circuit comprises voltage conversion circuit and reference voltage.Wherein, voltage conversion circuit converts an input voltage into output voltage, and the anode of this output voltage to above-mentioned light-emitting diode is provided, and wherein above-mentioned output voltage is corresponding to reference voltage.Reference voltage generator is then in order to producing reference voltage, and reference voltage is corresponding to one of them cathode voltage of above-mentioned light-emitting diode.Wherein this reference voltage generator comprises: a detecting unit, according to the minimum in the cathode voltage of above-mentioned light-emitting diode, export this reference voltage; And a pulse duration adjustment unit, according to reference voltage and a feedback voltage, adjust the duty ratio of signal corresponding to this output voltage; Wherein, greater than a threshold voltage, this voltage conversion circuit reduces this output voltage according to the duty ratio of this adjustment signal as if the minimum in the cathode voltage of above-mentioned light-emitting diode.

The present invention proposes a kind of circuit; Be used to drive a plurality of light-emitting diode serials; Each light-emitting diode serial is formed by a plurality of light-emitting diode serial connections, and this circuit comprises voltage conversion circuit and reference voltage generator, and wherein voltage conversion circuit converts an input voltage into an output voltage; And extremely first end (anode tap) of above-mentioned light emitting diode string row of this output voltage is provided, wherein above-mentioned output voltage is corresponding to reference voltage.Reference voltage generator is then in order to producing reference voltage, and reference voltage is corresponding to the voltage of second end (cathode terminal) one of in the above-mentioned light emitting diode string Xingqi.Wherein this reference voltage generator comprises: a detecting unit, according to the minimum in the cathode voltage of above-mentioned light-emitting diode serial, export this reference voltage; And a pulse duration adjustment unit, according to reference voltage and a feedback voltage, adjust the duty ratio of signal corresponding to this output voltage; Wherein, greater than a threshold voltage, this voltage conversion circuit reduces this output voltage according to the duty ratio of this adjustment signal as if the minimum in the cathode voltage of above-mentioned light-emitting diode serial.

From another viewpoint; The present invention proposes a kind of method that is used to drive a plurality of light-emitting diode serials; Each light-emitting diode serial is all formed by a plurality of light-emitting diode serial connections, and the method comprises the following steps: at first, converts an input voltage into an output voltage; And extremely first end (anode tap) of above-mentioned light emitting diode string row of output voltage is provided, wherein above-mentioned output voltage is corresponding to a reference voltage; Next, according to the minimum in the cathode voltage of above-mentioned light-emitting diode serial, produce reference voltage, this reference voltage is corresponding to the minimum in the voltage of second end (cathode terminal) of above-mentioned light-emitting diode serial.Then, according to reference voltage with corresponding to a feedback voltage of this output voltage, adjust the duty ratio of signal, thereby adjusts output voltage.Wherein, if the minimum in the cathode voltage of above-mentioned light-emitting diode serial is greater than a threshold voltage, according to the duty ratio of this adjustment signal to reduce this output voltage.

The idea of the present invention because of utilize feedbacking by the cathode terminal voltage of light-emitting diode, dynamically adjusted the magnitude of voltage of output voltage, avoids on current source, producing unnecessary voltage drop and causes unnecessary power consumption.

For making the above-mentioned feature and advantage of the present invention can be more obviously understandable, hereinafter is special lifts preferred embodiment, and is described with reference to the accompanying drawings as follows.

Description of drawings

Fig. 1 is the drive circuit figure according to conventional art.

Fig. 2 A is the calcspar according to the drive circuit of first embodiment of the invention.

Fig. 2 B is the drive circuit figure according to first embodiment of the invention.

Fig. 3 is the drive circuit figure according to second embodiment of the invention.

Fig. 4 is the drive circuit figure according to third embodiment of the invention.

Fig. 5 is the drive circuit figure according to fourth embodiment of the invention.

Fig. 6 is the flow chart according to the driving method of fifth embodiment of the invention.

The reference numeral explanation

100,220,320,243,343,443,543: voltage conversion circuit

200,300,400,500: drive circuit

230,330,430,530: reference voltage generator

242,252,342,352,442,452,542,552: comparator

250,350,450,550: the pulse duration adjustment unit

251,351,451,551: amplifier

210,311-319: light-emitting diode

111-119,411-419,511-519: light-emitting diode serial

240,340,440,540: detecting unit

341,441,541: selected cell

253,353,453: driver element

140,262,362,462,562: current source cell

420: the voltage conversion circuit of booster circuit

520: the voltage conversion circuit of reduction voltage circuit

553: the first driver elements

554: the second driver elements

555: inverter

S61-S63: step

Embodiment

First embodiment

Please refer to Fig. 2 A, Fig. 2 A is the calcspar according to the drive circuit that first embodiment of the invention illustrated.The drive circuit of present embodiment comprises voltage conversion circuit 220 and reference voltage generator 230.Reference voltage generator 230 is coupled between voltage conversion circuit 220 and the light-emitting diode 210, and the anode tap of light-emitting diode 210 is coupled to voltage conversion circuit 220, and its cathode terminal is coupled to current source cell 262.Voltage conversion circuit 220 converts input voltage VIN into output voltage VO UT, and output voltage VO UT is provided the anode to light-emitting diode 210, wherein the reference voltage exported corresponding to reference voltage generator 230 of output voltage VO UT.

Reference voltage generator 230 is according to the cathode voltage VD of light-emitting diode 210; Output reference voltage; Then reference voltage is converted into adjustment signal SRE and exports voltage conversion circuit 220 to; Voltage conversion circuit 220 is adjusted the magnitude of voltage of output voltage VO UT then according to the duty ratio of adjustment signal SRE.When output voltage VO UT is excessive, can produce unnecessary pressure drop at the cathode terminal of light-emitting diode 210, reference voltage generator 230 just can be adjusted the duty ratio of signal SRE in real time, to reduce output voltage VO UT, avoids redundant power consumption.

Next further specify the circuit framework and the details of operation of present embodiment, please refer to Fig. 2 B, Fig. 2 B is the drive circuit figure according to present embodiment.Drive circuit 200 comprises voltage conversion circuit 220 and reference voltage generator 230.Voltage conversion circuit 220 is responsible for converting input voltage VIN into output voltage VO UT; With driven for emitting lights diode 210; Reference voltage generator 230 is coupled between the cathode terminal and voltage conversion circuit 220 of light-emitting diode 210; And according to the cathode voltage of light-emitting diode 210, output reference voltage VRE is with adjustment output voltage VO UT, to avoid redundant power consumption.

Reference voltage generator 230 comprises detecting unit 240 and pulse duration adjustment unit 250.Wherein, detecting unit 240 also comprises comparator 242 and voltage conversion circuit 243, and pulse duration adjustment unit 250 then comprises amplifier 251, comparator 252 and driver element 253.Detecting unit 240 is coupled to the cathode terminal of light-emitting diode 210, and according to the cathode voltage VD between light-emitting diode 210 and the current source cell 212, adjustment reference voltage VRE.250 of pulse duration adjustment units change the duty ratio of adjustment signal SRE according to reference voltage VRE and feedback voltage VFB corresponding to output voltage VO UT.That is to say, as the cathode voltage VD of light-emitting diode 210 during (that is the predeterminated voltage VSET in Fig. 2 detecting unit 240, can decide) according to design requirement greater than a threshold voltage value.Reference voltage generator 230 can change the duty ratio of adjustment signal SRE, to reduce output voltage VO UT, avoids too high output voltage VO UT to cause redundant power consumption.

In detecting unit 240, comparator 242 is exported a comparative voltage VCOM to voltage conversion circuit 243 according to cathode voltage VD and predeterminated voltage VSET.According to comparative voltage VCOM and preset adjustment voltage VPR, output reference voltage VRE is to pulse duration adjustment unit 250 again for voltage conversion circuit 243.Voltage conversion circuit 243 main functions are the adjustment mechanism according to pulse duration adjustment unit 250, and the reference voltage VRE of output corresponding voltage value is with the duty ratio of adjustment adjustment signal SRE.

In pulse duration adjustment unit 250, amplifier 251 is according to reference voltage VRE and feedback voltage VFB, and voltage VTN is adjusted in output, and wherein adjusting voltage VTN is the difference gain of reference voltage VRE and feedback voltage VFB.According to the comparative result of adjustment voltage VTN and triangular signal VTRI, signal SRE is adjusted in output to comparator 252 again, and when the voltage level of adjustment voltage VTN changed, the duty ratio of adjustment signal SRE just can change thereupon.Driver element 253 then is coupled between comparator 252 and the voltage conversion circuit 220, is used for strengthening the driving force of adjustment signal SRE.

Voltage conversion circuit 220 can be a booster circuit (boost circuit) or reduction voltage circuit in the present embodiment, among Fig. 2 B is the example explanation with the booster circuit, and the output voltage VO UT that this booster circuit is exported can decide with the duty ratio of adjustment signal SRE.This booster circuit mainly is made up of switch S 1, inductance L 1, first resistance R 1, second resistance R 2, capacitor C 1 and diode D1.Inductance L 1 is coupled between input voltage VIN and the switch S 1, and the other end of switch S 1 is coupled to earth terminal GND.Diode D1 is coupled between inductance L 1 and the output voltage VO UT, and capacitor C 1 is coupled between output voltage VO UT and the earth terminal GND.

In addition, first resistance R 1 and second resistance R 2 are series between output voltage VO UT and the earth terminal GND, and the feedback voltage VFB that on its shared node, is produced is the dividing potential drop of output voltage VO UT.The control end of switch S 1 is couple to adjustment signal SRE, and booster circuit is exactly recently to adjust output voltage VO UT with driven for emitting lights diode 210 according to the duty of adjustment signal SRE.Current source 262 is coupled between the cathode terminal and earth terminal GND of light-emitting diode 210, is mainly used in the electric current of restricted passage light-emitting diode 210, with the brightness of protection light-emitting diode 210 and adjustment light-emitting diode 210.

In the present embodiment, the duty ratio of adjustment signal SRE is to determine according to the voltage VD between light-emitting diode 210 and the current source cell 212.When output voltage VO UT is too high; Light-emitting diode 210 can produce voltage drop with the shared node of current source cell 262; Cathode voltage VD just; Drive circuit 200 promptly utilizes the change in voltage of cathode voltage VD to judge whether output voltage VO UT is too high, with the voltage level of adjustment output voltage VO UT.In other words, as the cathode voltage VD of light-emitting diode 210 during greater than a threshold voltage (predeterminated voltage VSET), voltage conversion circuit 220 can reduce output voltage VO UT according to the duty ratio of adjustment signal SRE, to reduce redundant power consumption.

Second embodiment

Please refer to Fig. 3, Fig. 3 is the driving circuit structure figure of one preferred embodiment according to the present invention.The drive circuit 300 of present embodiment can be used for driving a plurality of light-emitting diodes 311~319, and this drive circuit 300 is the selected cell 341 in the detecting unit 330 with the main difference of above-mentioned Fig. 2 B.Minimum among the cathode voltage VD1~VD9 of selected cell 341 selections and output light emitting diode.Comparator 342 is in order to minimum among the cathode voltage VD1~VD9 of more above-mentioned light-emitting diode 311~319 and predeterminated voltage VSET, and generation comparative voltage VCOM.And voltage conversion circuit 343 is according to comparative voltage VCOM and preset adjustment voltage VPR, output reference voltage VRE.Then, output voltage VO UT then can become along with reference voltage VRE.

Because the technology variation, 311~319 other conducting voltage of light-emitting diode may have difference slightly.Therefore, the light-emitting diode that conducting voltage is less, its cathode voltage will be bigger.As output voltage VO UT during greater than light-emitting diode 311~319 needed conducting voltage, current source cell 362 just must bear the unnecessary pressure drop of output voltage VO UT, also just causes unnecessary power consumption.

In the driving process, as long as output voltage VO UT is greater than conducting voltage maximum in the light-emitting diode 311~319, so can judge by the minimum among the cathode voltage VD1~VD9 of light-emitting diode 311~319 whether output voltage VO UT is excessive.In other words, as long as keep minimum among cathode voltage VD1~VD9 greater than a predeterminated voltage VSET, all light-emitting diodes 311~319 can whole conductings.

Therefore; In the present embodiment; Output voltage VO UT promptly adjusts to the minimum among the cathode voltage VD1~VD9 of light-emitting diode 311~319; When the minimum among the cathode voltage VD1~VD9 of light-emitting diode 311~319 during greater than predeterminated voltage VSET, voltage conversion circuit 320 just reduces output voltage VO UT, and the minimum in the cathode voltage VD1~VD9 of light-emitting diode 311~319 is less than predeterminated voltage VSET.All the other details of operations of present embodiment have been specified in the embodiment explanation of above-mentioned Fig. 2 B all, have common knowledge the knowledgeable in the present technique field, all can know by inference easily, do not add tired stating at this.

The 3rd embodiment

Please refer to Fig. 4, Fig. 4 is drive circuit figure according to another embodiment of the present invention.The drive circuit 400 of present embodiment can be used for driving a plurality of light-emitting diode serials 411~419; Each light-emitting diode serial 411~419 is formed by a plurality of light-emitting diode serial connections; The circuit framework of drive circuit 400 is identical with Fig. 3 embodiment; Voltage conversion circuit 420 converts input voltage VIN into output voltage VO UT, and output voltage VO UT is provided first end (anode tap) to above-mentioned light emitting diode string row 411~419, and wherein above-mentioned output voltage VO UT is corresponding to reference voltage VRE.Reference voltage generator 440 according to the cathode voltage VD1~VD9 of second end of light-emitting diode serial 411~419 one of them, output reference voltage VPR.

Please, in like manner analogize, as long as find out the minimum among cathode voltage VD1~VD9, just can know the maximum light-emitting diode serial 411~419 of conducting voltage by inference with reference to the explanation of Fig. 3.And voltage conversion circuit 420 is adjusted the magnitude of voltage of output voltage VO UT just according to the minimum among the cathode voltage VD1~VD9 of light-emitting diode serial 411~419.When the minimum among the cathode voltage VD1~VD9 of light-emitting diode serial 411~419 is excessive (greater than predeterminated voltage VSET), reduce output voltage VO UT immediately, to avoid redundant power consumption.All the other details of operations of present embodiment are identical with above-mentioned Fig. 3 embodiment, do not add tired stating at this.

The 4th embodiment

In another embodiment of the present invention, voltage conversion circuit can be reduction voltage circuit (buck circuit), and Fig. 5 is drive circuit figure according to another embodiment of the present invention.Voltage conversion circuit 520 among Fig. 5 is a reduction voltage circuit.This reduction voltage circuit comprises first switch S 1, second switch S2, inductance L 1, first resistance R 1, second resistance R 2 and capacitor C 1.First resistance R 1 is connected with second resistance R 2, and an end is coupled to light-emitting diode serial 511~519, and the other end is received earthed voltage GND.First resistance R 1 and second resistance R 2 couple the place, can record a feedback voltage VFB, and feedback voltage VFB are exactly the fixed partial pressure of output voltage VO UT.Inductance L 1, one end is coupled to the common joint of first switch S 1 and second switch S2, and the other end is couple to a plurality of light-emitting diode serials 511~519.Above-mentioned first switch S, 1 other end is coupled to input voltage VIN, and the other end of second switch S2 is received earthed voltage GND.Capacitor C 1 one ends are coupled to a plurality of light-emitting diode serials 511~519, and the other end is coupled to earthed voltage GND.

Aspect pulse duration adjustment unit 550, the difference of present embodiment and above-mentioned Fig. 4 mainly is inverter 555, first driver element 553 and second driver element 554.Because the output voltage VO UT of voltage conversion circuit 520 is decided by first switch S 1 and the ON time of second switch S2, the duty ratio that therefore changes adjustment signal SRE just can be adjusted the magnitude of voltage of output voltage VO UT.In the driving process, the ON time of first switch S 1 and second switch S2 needs opposite each other, so adjustment signal SRE can be via exporting second switch S2 behind the inverter 555 again to.

In the present embodiment; Reference voltage generator 530 can be adjusted reference voltage VRE according to the minimum among the cathode voltage VD1~VD9 of light-emitting diode serial 511~519 equally; And then change the duty ratio of adjusting signal SRE, with the magnitude of voltage of adjustment output voltage VO UT.UT is too high when output voltage VO; And when light-emitting diode serial 511~519 forms too high voltage drop with current source cell 562; Reference voltage generator 530 just can change the duty ratio of adjustment signal SRE to reduce the magnitude of voltage of output voltage VO UT, avoids redundant power consumption.Have common knowledge the knowledgeable in the present technique field,, should know all the other details of operations and the application mode of present embodiment easily by inference, do not add tired stating at this via the announcement of present embodiment.

The 5th embodiment

From another perspective, present embodiment proposes a kind of driving method of driven for emitting lights diode, can effectively reduce power consumption.Fig. 6 is the driving method flow chart according to present embodiment.The driving method of present embodiment can be used for driving a plurality of light-emitting diode serials; Each light-emitting diode serial is all formed by a plurality of light-emitting diode serial connections; This driving method comprises the following steps: at first; Step S61 converts an input voltage into output voltage, and first end (anode tap) of this output voltage to above-mentioned light emitting diode string row is provided, and wherein output voltage is corresponding to a reference voltage.Then, step S62 produces (adjustment) reference voltage according to second terminal voltage (cathode terminal voltage) one of in the light emitting diode string Xingqi.Then, step S63 adjusts output voltage according to reference voltage.Because in the present embodiment, between output voltage and the reference voltage dynamic equilibrium, the change of output voltage can influence reference voltage, and reference voltage can influence the magnitude of voltage of output voltage, and is too high and cause redundant power consumption to avoid output voltage.And in the present embodiment,,, do not add tired stating at this all to be specified in the explanation of above-mentioned Fig. 2 to Fig. 5 embodiment about all the other correlative details of driving method.

Claims (21)

1. a circuit is used to drive at least one light-emitting diode, and foregoing circuit comprises:
One voltage conversion circuit converts an input voltage into an output voltage, and the anode of this output voltage to above-mentioned light-emitting diode is provided, and wherein above-mentioned output voltage is corresponding to a reference voltage; And
One reference voltage generator produces this reference voltage, and this reference voltage is corresponding to the cathode voltage of above-mentioned light-emitting diode, and wherein this reference voltage generator comprises: a detecting unit, according to the cathode voltage of above-mentioned light-emitting diode, export this reference voltage; And a pulse duration adjustment unit, according to reference voltage and a feedback voltage, adjust the duty ratio of signal corresponding to this output voltage; Wherein, if the cathode voltage of above-mentioned light-emitting diode is greater than a threshold voltage, this voltage conversion circuit reduces this output voltage according to the duty ratio of this adjustment signal.
2. circuit as claimed in claim 1, wherein this detecting unit comprises:
One comparator in order to the cathode voltage and a predeterminated voltage of more above-mentioned light-emitting diode, and produces a comparative voltage; And
One voltage conversion circuit according to this comparative voltage and a preset adjustment voltage, is exported this reference voltage.
3. circuit as claimed in claim 1, wherein this pulse duration adjustment unit comprises:
One amplifier, according to this reference voltage and this feedback voltage, output one adjustment voltage;
One comparator according to this an adjustment voltage and a triangular signal, is adjusted the duty ratio of this adjustment signal.
4. circuit as claimed in claim 3, wherein this pulse duration adjustment unit comprises a driver element, is coupled between this comparator and this voltage conversion circuit, in order to strengthen the driving force of this adjustment signal.
5. circuit as claimed in claim 1 also comprises a plurality of resistance, is coupled between this output voltage and the earth terminal, produces this feedback voltage with the dividing potential drop mode.
6. circuit as claimed in claim 1, wherein this voltage conversion circuit comprises a booster circuit or a reduction voltage circuit.
7. a circuit is used to drive a plurality of light-emitting diodes, and this circuit comprises:
One voltage conversion circuit converts an input voltage into an output voltage, and the anode of this output voltage to above-mentioned light-emitting diode is provided, and wherein above-mentioned output voltage is corresponding to a reference voltage; And
One reference voltage generator; Produce this reference voltage, this reference voltage is corresponding to one of them cathode voltage of above-mentioned light-emitting diode, and wherein this reference voltage generator comprises: a detecting unit; According to the minimum in the cathode voltage of above-mentioned light-emitting diode, export this reference voltage; And a pulse duration adjustment unit, according to reference voltage and a feedback voltage, adjust the duty ratio of signal corresponding to this output voltage; Wherein, greater than a threshold voltage, this voltage conversion circuit reduces this output voltage according to the duty ratio of this adjustment signal as if the minimum in the cathode voltage of above-mentioned light-emitting diode.
8. circuit as claimed in claim 7, wherein this detecting unit comprises:
The minimum in the cathode voltage of above-mentioned light-emitting diode is selected and exported to one selected cell;
One comparator in order to a minimum in the cathode voltage of more above-mentioned light-emitting diode and a predeterminated voltage, and produces a comparative voltage; And
One voltage conversion circuit according to this comparative voltage and a preset adjustment voltage, is exported this reference voltage.
9. circuit as claimed in claim 7, wherein this pulse duration adjustment unit comprises:
One amplifier, according to this reference voltage and this feedback voltage, output one adjustment voltage;
One comparator according to this an adjustment voltage and a triangular signal, is adjusted the duty ratio of this adjustment signal.
10. circuit as claimed in claim 9, wherein this pulse duration adjustment unit comprises driver element, is coupled between this comparator and this voltage conversion circuit, in order to strengthen the driving force of this adjustment signal.
11. circuit as claimed in claim 7 also comprises a plurality of resistance, is coupled between this output voltage and the earth terminal, produces this feedback voltage with the dividing potential drop mode.
12. circuit as claimed in claim 7, wherein voltage conversion circuit comprises a booster circuit or a reduction voltage circuit.
13. circuit as claimed in claim 7, wherein this reference voltage is corresponding to the minimum in the cathode voltage of above-mentioned light-emitting diode.
14. a circuit is used to drive a plurality of light-emitting diode serials, each said light-emitting diode serial is formed by a plurality of light-emitting diode serial connections, and this circuit comprises:
One voltage conversion circuit converts an input voltage into an output voltage, and the anode of this output voltage to above-mentioned light emitting diode string row is provided, and wherein above-mentioned output voltage is corresponding to a reference voltage; And
One reference voltage generator; Produce this reference voltage; This reference voltage is corresponding to the cathode voltage one of in the above-mentioned light emitting diode string Xingqi; Wherein this reference voltage generator comprises: a detecting unit, according to the minimum in the cathode voltage of above-mentioned light-emitting diode serial, export this reference voltage; And a pulse duration adjustment unit, according to reference voltage and a feedback voltage, adjust the duty ratio of signal corresponding to this output voltage; Wherein, greater than a threshold voltage, this voltage conversion circuit reduces this output voltage according to the duty ratio of this adjustment signal as if the minimum in the cathode voltage of above-mentioned light-emitting diode serial.
15. circuit as claimed in claim 14, wherein this detecting unit comprises:
The minimum in the cathode voltage of above-mentioned light-emitting diode serial is selected and exported to one selected cell;
One comparator in order to a minimum in the cathode voltage of more above-mentioned light-emitting diode serial and a predeterminated voltage, and produces a comparative voltage; And
One voltage conversion circuit according to this comparative voltage and a preset adjustment voltage, is exported this reference voltage.
16. circuit as claimed in claim 14, wherein this pulse duration adjustment unit comprises:
One amplifier, according to this reference voltage and this feedback voltage, output one adjustment voltage;
One comparator according to this an adjustment voltage and a triangular signal, is adjusted the duty ratio of this adjustment signal.
17. circuit as claimed in claim 16, wherein this pulse duration adjustment unit comprises driver element, is coupled between this comparator and this voltage conversion circuit, in order to strengthen the driving force of this adjustment signal.
18. circuit as claimed in claim 14 also comprises a plurality of resistance, is coupled between this output voltage and the earth terminal, produces this feedback voltage with the dividing potential drop mode.
19. circuit as claimed in claim 14, wherein voltage conversion circuit comprises a booster circuit or a reduction voltage circuit.
20. circuit as claimed in claim 14, wherein this reference voltage is corresponding to the minimum in the cathode voltage of above-mentioned light-emitting diode serial.
21. a method that is used to drive a plurality of light-emitting diode serials, each said light-emitting diode serial are all formed by a plurality of light-emitting diode serial connections, this method comprises the following steps:
Convert an input voltage into an output voltage, and the anode of this output voltage to above-mentioned light emitting diode string row is provided, wherein above-mentioned output voltage is corresponding to a reference voltage;
Cathode voltage according to one of in the above-mentioned light emitting diode string Xingqi produces this reference voltage, and wherein this reference voltage is corresponding to the minimum in the cathode voltage of above-mentioned light-emitting diode serial; And
According to this reference voltage with corresponding to a feedback voltage of this output voltage, adjust the duty ratio of signal, thereby adjust this output voltage,
Wherein, if the minimum in the cathode voltage of above-mentioned light-emitting diode serial is greater than a threshold voltage, according to the duty ratio of this adjustment signal to reduce this output voltage.
CN200810100211A 2008-05-16 2008-05-16 Driving circuit and driving method of light emitting diode (LED) CN101583216B (en)

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TWI452937B (en) 2012-06-25 2014-09-11 Richtek Technology Corp Led control device for phase cut dimming system and control method thereof
CN103517499B (en) * 2012-06-27 2015-06-03 立锜科技股份有限公司 Light emitting diode control devices and related control methods
CN103547013A (en) * 2012-07-12 2014-01-29 新能微电子股份有限公司 Light-emitting diode driving device and method
CN103582223B (en) * 2012-08-07 2017-06-16 欧司朗股份有限公司 Lighting device
TWI527497B (en) * 2014-08-13 2016-03-21 wen-qin Xiao Light - emitting diode drive system and control module
CN106163027B (en) * 2015-03-26 2018-12-04 苏州璨宇光学有限公司 Light source drive device and light source driving method

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101093639A (en) * 2006-06-22 2007-12-26 Lg.菲利浦Lcd株式会社 Organic light-emitting diode display device and driving method thereof

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101093639A (en) * 2006-06-22 2007-12-26 Lg.菲利浦Lcd株式会社 Organic light-emitting diode display device and driving method thereof

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