CN101500354A - Light modulation control circuit for LED - Google Patents
Light modulation control circuit for LED Download PDFInfo
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- CN101500354A CN101500354A CNA2008100086261A CN200810008626A CN101500354A CN 101500354 A CN101500354 A CN 101500354A CN A2008100086261 A CNA2008100086261 A CN A2008100086261A CN 200810008626 A CN200810008626 A CN 200810008626A CN 101500354 A CN101500354 A CN 101500354A
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Abstract
The invention provides an LED (light emitting diode) dimming control circuit which is used for driving LEDs. The LED dimming control circuit comprises an inductor, a transistor, a dimming control signal, a feedback signal, a switching control circuit, an error amplifier and an inverting amplifier. The switching control circuit is controlled by the dimming control signal and the feedback signal; the transistor is controlled by the switching control circuit; and the output end and the non-inverting input end of the error amplifier form a negative feedback path through the inverting amplifier.
Description
Technical field
The present invention relates to a kind of light modulation control circuit for LED, it is excessive and avoid the too high light modulation control circuit for LED of output voltage to relate in particular to a kind of inrush current that prevents inductance.
Background technology
Fig. 1 shows the circuit diagram of existing light modulation control circuit for LED 100.In the example of Fig. 1, light modulation control circuit for LED 100 is implemented by boost type (Boost-Type) voltage regulator, is used for input voltage V
In1Convert desired output voltage V to
O1, and then driven for emitting lights diode 19.Control switching circuit 10 comprises capacitor C
11, resistance R
11, comparator 13, oscillating circuit 14, electric current be to electric pressure converter 15, latch unit 16, current sensor 17, and drive circuit 18.Resistance R
12An end and the Coupling point of the cathode terminal of light-emitting diode 19 provide voltage as feedback signal V
Fb1 Control switching circuit 10 is in response to dimming control signal CN1, feedback signal V
Fb1, and the electric current of inductance L 1 be used for oxide-semiconductor control transistors T1.The user can be by changing the bright-dark degree that dimming control signal CN1 adjusts light-emitting diode 19.Mistake amplifier 12 comparison reference voltage V
R1With feedback signal V
Fb1Be used to produce output current I
Eo1To control switching circuit 10.When dimming control signal CN1 was high potential, light modulation control circuit for LED 100 operated in normal boost mode, and this moment, the peak current of inductance L 1 was subjected to output current I
Eo1Control.When dimming control signal CN1 was electronegative potential, light modulation control circuit for LED 100 stopped to switch, at this moment output voltage V
O1Descend, cause feedback signal V
Fb1Descend and output current I
Eo1Rise.And when dimming control signal CN1 converted high potential to by electronegative potential, the inrush current of inductance L 1 will be excessive, thereby cause output voltage V
O1Too high.
Summary of the invention
The object of the present invention is to provide a kind of light modulation control circuit for LED, can prevent that the inrush current of inductance is excessive and avoid output voltage too high.
According to purpose of the present invention, provide a kind of light modulation control circuit for LED to be used for the driven for emitting lights diode.Light modulation control circuit for LED has soft-start circuit, mistake amplifier, first switch to the, four switches, inverter, inverting amplifier, control switching circuit, inductance, transistor, diode.Inductance, transistor, and the diode coupled in common in node.Control switching circuit in response to dimming control signal, feedback signal, and the electric current of inductance be used for oxide-semiconductor control transistors.The user can adjust the bright-dark degree of light-emitting diode by changing dimming control signal.First switch and second switch are controlled by the inversion signal of dimming control signal and the 3rd switch and the 4th switch are controlled by dimming control signal.First switch is coupled between the input of the output of wrong amplifier and inverting amplifier; Second switch is coupled between the output of wrong amplifier's non-inverting and inverting amplifier; The 3rd switch is coupled between the output and wrong amplifier's non-inverting of soft-start circuit; And the 4th switch is coupled between the inverting input of the output of wrong amplifier and comparator.When dimming control signal was high potential, this moment, light modulation control circuit for LED operated in the normal current pattern.When dimming control signal was electronegative potential, light modulation control circuit for LED stopped to switch, and this moment, feedback signal descended.Because the output of wrong amplifier and non-inverting input are via the negative feedback paths of inverting amplifier formation unit gain, the voltage follow feedback signal of wrong amplifier's non-inverting is toward descending at this moment.When dimming control signal converted high potential to by electronegative potential, feedback signal can be followed the voltage of wrong amplifier's non-inverting slowly toward rising, and makes that the output current of wrong amplifier can be not excessive.Therefore, the inrush current of inductance can be not excessive, and then avoid output voltage too high.
Description of drawings
Fig. 1 shows the circuit diagram of existing light modulation control circuit for LED;
Fig. 2 shows the circuit diagram according to light modulation control circuit for LED of the present invention.
Embodiment
Explanation hereinafter and accompanying drawing will make aforementioned and other purpose of the present invention, feature, more obvious with advantage.Now describe in detail according to a preferred embodiment of the invention with reference to the accompanying drawings.
Fig. 2 shows the circuit diagram according to light modulation control circuit for LED 200 of the present invention.
In the example of Fig. 2, light modulation control circuit for LED 200 is implemented by the boost type voltage regulator, is used for input voltage V
InConvert desired output voltage V to
o, and then driven for emitting lights diode 29.Light modulation control circuit for LED 200 comprises soft-start circuit 21, mistake amplifier 22, switch S 1 to S4, inverter 30, inverting amplifier 31, control switching circuit 20, inductance L, transistor T, diode D, resistance R
22, and output capacitance C
o, formation coupled to each other structure as shown in the figure.Inductance L, transistor T, and diode D coupled in common in node N.The anode tap of light-emitting diode 29, diode D, and output capacitance C
oCoupled in common is in another node O.Resistance R
22An end and the Coupling point of the cathode terminal of light-emitting diode 29 provide voltage as feedback signal V
Fb, feedback signal V wherein
FbBe coupled in the inverting input of wrong amplifier 22.Control switching circuit 20 is in response to dimming control signal CN, feedback signal V
Fb, and the electric current of inductance L be used for oxide-semiconductor control transistors T.The user can be by changing the bright-dark degree that dimming control signal CN adjusts light-emitting diode 29.In addition, control switching circuit 20 also comprises capacitor C
21, resistance R
21, comparator 23, oscillating circuit 24, electric current be to electric pressure converter 25, latch unit 26, current sensor 27, and drive circuit 28.Switch S 1 and S2 are controlled by the inversion signal CI of dimming control signal CN and switch S 3 and S4 are controlled by dimming control signal CN.Switch S 1 is coupled between the input of the output of wrong amplifier 22 and inverting amplifier 31; Switch S 2 is coupled between the output of the non-inverting input of wrong amplifier 22 and inverting amplifier 31; Switch S 3 is coupled between the non-inverting input of the output of soft-start circuit 21 and wrong amplifier 22; And switch S 4 is coupled between the inverting input of the output of wrong amplifier 22 and comparator 23.
When dimming control signal CN is high potential, switch S 1 and not conducting of S2 and switch S 3 and S4 conducting, this moment, light modulation control circuit for LED 200 operated in the normal current pattern.Drive circuit 28 is used for oxide-semiconductor control transistors T according to the output signal of latch unit 26.Mistake amplifier 22 is the voltage V of non-inverting input relatively
pWith feedback signal V
FbBe used to produce output current with to capacitor C
21Charge, wherein resistance R
21With capacitor C
21Form compensating circuit.The pulse signal that oscillating circuit 24 applies fixed frequency is used for turn-on transistor T to the setting end S of latch unit 26.In case transistor T conducting, the electric current of the inductance L of flowing through can begin to increase.In addition, current sensor 27 produces electric current I
STo electric current to electric pressure converter 25, wherein electric current I
SBe proportional to the electric current of inductance L.Electric current is to electric pressure converter 25 received current I
SBe used to produce output voltage V
SNon-inverting input to comparator 23.Work as output voltage V
SThe voltage V that surpasses the inverting input of comparator 23
nThe time, the replacement end R that comparator 23 promptly triggers latch unit 26 makes not conducting of transistor T.
When dimming control signal CN was electronegative potential, light modulation control circuit for LED 200 stopped to switch, at this moment output voltage V
oDescend, cause feedback signal V
FbDescend.This moment switch S 1 and S2 conducting and switch S 3 and not conducting of S4, voltage V
pControlled by soft-start circuit 21.Because the output of wrong amplifier 22 and non-inverting input form the negative feedback paths of unit gains (Unit Gain), voltage V at this moment via inverting amplifier 31
pFollow feedback signal V
FbToward descending.
When dimming control signal CN converts high potential to by electronegative potential, the reference voltage V of soft-start circuit 21 outputs
rSlowly past the rising, and rise to predetermined voltage V
AAfter be maintained at this predetermined voltage V
ASince switch S 3 conductings, voltage V
pEqual reference voltage V
rAnd slowly toward rising.This moment, light modulation control circuit for LED 200 operated in normal current pattern, feedback signal V
FbCan follow voltage V
pSlowly, make that the output current of wrong amplifier 22 can be not excessive toward rising.Therefore, the inrush current of inductance L can be not excessive, and then avoid output voltage V
oToo high.
Though the present invention is illustrated as illustration by preferred embodiment, should be noted that: the invention is not restricted to the embodiment that this is disclosed.On the contrary, this invention is intended to contain tangible to those skilled in the art various modifications and similar configuration.Therefore, the scope of claim should be according to the widest explanation, and this type of is revised and similar configuration to contain all.
Claims (12)
1, a kind of adjusting control circuit is used for the driven for emitting lights diode, and described adjusting control circuit comprises:
Inductance, wherein said inductance flows through first electric current;
Transistor, wherein said inductance and described transistor coupled in common are in node;
Dimming control signal;
Feedback signal;
Control switching circuit, wherein said control switching circuit are controlled by described dimming control signal and described feedback signal, and described transistor is controlled by described control switching circuit;
Mistake amplifier, described wrong amplifier have first non-inverting input, first inverting input, reach first output; And
Inverting amplifier, described inverting amplifier have second input and second output;
Wherein said first output and described first non-inverting input form negative feedback paths via described inverting amplifier.
2, adjusting control circuit as claimed in claim 1 also comprises diode, and an end of wherein said diode is coupled in described node.
3, adjusting control circuit as claimed in claim 1 also comprises:
First switch, described first switch are coupled between described first output and described second input; And
Second switch, described second switch are coupled between described first non-inverting input and described second output.
4, adjusting control circuit as claimed in claim 3, wherein said first switch and described second switch are controlled by the inversion signal of described dimming control signal.
5, adjusting control circuit as claimed in claim 4 also comprises:
The 3rd switch; And
The 4th switch;
Wherein said the 3rd switch and described the 4th switch are controlled by described dimming control signal.
6, adjusting control circuit as claimed in claim 5, wherein:
Described control switching circuit comprises:
Current sensor is used to provide second electric current, and described second electric current is proportional to described first electric current;
Comparator, described comparator have the 3rd non-inverting input, the 3rd inverting input, reach the 3rd output, and wherein said the 3rd inverting input is coupled in compensating circuit;
Electric current receives described second electric current to electric pressure converter, is used to produce first voltage to described the 3rd non-inverting input;
Oscillating circuit, described oscillating circuit has the 4th output;
Latch unit, described latch unit have the end of replacement, set end, reach first output signal, and wherein said replacement end is coupled in described the 3rd output and described setting end is coupled in described the 4th output; And
Drive circuit according to described dimming control signal and described first output signal, is used to control described transistor.
7, adjusting control circuit as claimed in claim 1, wherein said feedback signal is coupled in the cathode terminal of described light-emitting diode.
8, adjusting control circuit as claimed in claim 6, also comprise soft-start circuit, wherein said soft-start circuit is used to produce reference voltage according to predetermined voltage, and described soft-start circuit has the 5th output, and the voltage of wherein said the 5th output equals described reference voltage.
9, adjusting control circuit as claimed in claim 8, wherein said the 3rd switch are coupled between described the 5th output and described first non-inverting input, and described the 4th switch is coupled between described first output and described the 3rd inverting input.
10, adjusting control circuit as claimed in claim 2, the other end of wherein said diode is coupled in the anode tap of described light-emitting diode.
11, adjusting control circuit as claimed in claim 1, wherein said feedback signal are coupled in described first inverting input.
12, adjusting control circuit as claimed in claim 1, wherein said control switching circuit are controlled by described first electric current.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA2008100086261A CN101500354A (en) | 2008-02-01 | 2008-02-01 | Light modulation control circuit for LED |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA2008100086261A CN101500354A (en) | 2008-02-01 | 2008-02-01 | Light modulation control circuit for LED |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN101500354A true CN101500354A (en) | 2009-08-05 |
Family
ID=40947166
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA2008100086261A Pending CN101500354A (en) | 2008-02-01 | 2008-02-01 | Light modulation control circuit for LED |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101500354A (en) |
Cited By (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102014540A (en) * | 2010-03-04 | 2011-04-13 | 凹凸电子（武汉）有限公司 | Drive circuit and controller for controlling electric power of light source |
| CN102695325A (en) * | 2011-03-22 | 2012-09-26 | 登丰微电子股份有限公司 | Drive circuit and control circuit |
| US8330388B2 (en) | 2008-12-12 | 2012-12-11 | O2Micro, Inc. | Circuits and methods for driving light sources |
| US8339067B2 (en) | 2008-12-12 | 2012-12-25 | O2Micro, Inc. | Circuits and methods for driving light sources |
| US8378588B2 (en) | 2008-12-12 | 2013-02-19 | O2Micro Inc | Circuits and methods for driving light sources |
| US8508150B2 (en) | 2008-12-12 | 2013-08-13 | O2Micro, Inc. | Controllers, systems and methods for controlling dimming of light sources |
| US8698419B2 (en) | 2010-03-04 | 2014-04-15 | O2Micro, Inc. | Circuits and methods for driving light sources |
| CN104066235A (en) * | 2013-03-19 | 2014-09-24 | Nxp股份有限公司 | Multi-channel Led Driver Arrangements |
| US8866398B2 (en) | 2012-05-11 | 2014-10-21 | O2Micro, Inc. | Circuits and methods for driving light sources |
| US9030122B2 (en) | 2008-12-12 | 2015-05-12 | O2Micro, Inc. | Circuits and methods for driving LED light sources |
| US9232591B2 (en) | 2008-12-12 | 2016-01-05 | O2Micro Inc. | Circuits and methods for driving light sources |
| US9253843B2 (en) | 2008-12-12 | 2016-02-02 | 02Micro Inc | Driving circuit with dimming controller for driving light sources |
| US9386653B2 (en) | 2008-12-12 | 2016-07-05 | O2Micro Inc | Circuits and methods for driving light sources |
| CN106068045A (en) * | 2015-04-21 | 2016-11-02 | Lg伊诺特有限公司 | Electric supply installation for LED |
| CN107343344A (en) * | 2017-09-04 | 2017-11-10 | 矽力杰半导体技术(杭州)有限公司 | For the control circuit of LED driver, integrated circuit and LED driver |
| CN110740555A (en) * | 2019-10-24 | 2020-01-31 | 苏州锐联芯半导体有限公司 | full-integrated electric vehicle flasher driving chip |
-
2008
- 2008-02-01 CN CNA2008100086261A patent/CN101500354A/en active Pending
Cited By (25)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9386653B2 (en) | 2008-12-12 | 2016-07-05 | O2Micro Inc | Circuits and methods for driving light sources |
| US8339067B2 (en) | 2008-12-12 | 2012-12-25 | O2Micro, Inc. | Circuits and methods for driving light sources |
| US9232591B2 (en) | 2008-12-12 | 2016-01-05 | O2Micro Inc. | Circuits and methods for driving light sources |
| US9030122B2 (en) | 2008-12-12 | 2015-05-12 | O2Micro, Inc. | Circuits and methods for driving LED light sources |
| US8378588B2 (en) | 2008-12-12 | 2013-02-19 | O2Micro Inc | Circuits and methods for driving light sources |
| US8508150B2 (en) | 2008-12-12 | 2013-08-13 | O2Micro, Inc. | Controllers, systems and methods for controlling dimming of light sources |
| US9253843B2 (en) | 2008-12-12 | 2016-02-02 | 02Micro Inc | Driving circuit with dimming controller for driving light sources |
| US8330388B2 (en) | 2008-12-12 | 2012-12-11 | O2Micro, Inc. | Circuits and methods for driving light sources |
| US8339063B2 (en) | 2010-03-04 | 2012-12-25 | O2Micro Inc | Circuits and methods for driving light sources |
| US8698419B2 (en) | 2010-03-04 | 2014-04-15 | O2Micro, Inc. | Circuits and methods for driving light sources |
| CN102014540A (en) * | 2010-03-04 | 2011-04-13 | 凹凸电子（武汉）有限公司 | Drive circuit and controller for controlling electric power of light source |
| US8664895B2 (en) | 2010-03-04 | 2014-03-04 | O2Micro, Inc. | Circuits and methods for driving light sources |
| US8890440B2 (en) | 2010-03-04 | 2014-11-18 | O2Micro, Inc. | Circuits and methods for driving light sources |
| CN102695325A (en) * | 2011-03-22 | 2012-09-26 | 登丰微电子股份有限公司 | Drive circuit and control circuit |
| CN102695325B (en) * | 2011-03-22 | 2015-02-04 | 登丰微电子股份有限公司 | Drive circuit and feedback control circuit |
| US8866398B2 (en) | 2012-05-11 | 2014-10-21 | O2Micro, Inc. | Circuits and methods for driving light sources |
| US9185757B2 (en) | 2013-03-19 | 2015-11-10 | Nxp B.V. | Multi-channel LED driver arrangements |
| CN104066235B (en) * | 2013-03-19 | 2016-06-22 | Nxp股份有限公司 | Multi-channel led driver |
| CN104066235A (en) * | 2013-03-19 | 2014-09-24 | Nxp股份有限公司 | Multi-channel Led Driver Arrangements |
| CN106068045A (en) * | 2015-04-21 | 2016-11-02 | Lg伊诺特有限公司 | Electric supply installation for LED |
| CN106068045B (en) * | 2015-04-21 | 2019-11-01 | Lg伊诺特有限公司 | Power supply unit for LED light |
| CN107343344A (en) * | 2017-09-04 | 2017-11-10 | 矽力杰半导体技术(杭州)有限公司 | For the control circuit of LED driver, integrated circuit and LED driver |
| CN107343344B (en) * | 2017-09-04 | 2019-11-22 | 矽力杰半导体技术(杭州)有限公司 | For the control circuit of LED driver, integrated circuit and LED driver |
| CN110740555A (en) * | 2019-10-24 | 2020-01-31 | 苏州锐联芯半导体有限公司 | full-integrated electric vehicle flasher driving chip |
| CN110740555B (en) * | 2019-10-24 | 2021-04-30 | 苏州锐联芯半导体有限公司 | Full-integrated electric vehicle flasher driving chip |
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Open date: 20090805 |