CN201307951Y - Light-emitting diode drive circuit - Google Patents
Light-emitting diode drive circuit Download PDFInfo
- Publication number
- CN201307951Y CN201307951Y CNU2008201403616U CN200820140361U CN201307951Y CN 201307951 Y CN201307951 Y CN 201307951Y CN U2008201403616 U CNU2008201403616 U CN U2008201403616U CN 200820140361 U CN200820140361 U CN 200820140361U CN 201307951 Y CN201307951 Y CN 201307951Y
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- current
- emitting diode
- light
- transistor switch
- led
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Abstract
The utility model provides a light-emitting diode drive circuit which is used to drive a light-emitting diode module, comprising a transistor switch and a feedback controller. The transistor switch comprises a control end, a first end and a second end; the first end is coupled with the light-emitting diode module; and the control end receives a control signal to control the current flowing through the transistor switch. The feedback controller receives reference voltage and a current detecting signal representing the current, and generates the control signal according to the reference voltage and the current detecting signal, wherein the feedback controller is connected with a drive power supply; and the potential of the drive power supply is higher than the potential of the transistor switch, so that the maximum adjustable scope of the potential of the control signal is higher than the potential of the first end of the transistor switch.
Description
Technical field
The utility model relates to a kind of LED driving circuit, particularly a kind of LED driving circuit of deciding current drives.
Background technology
Please refer to Fig. 1, is an existing light emitting diode drive device.This light emitting diode drive device comprises certain current driver 10, a power supply unit 20, a light-emitting diode (LED) module 30 and a current sense resistor R.Decide current driver 10 and comprise an error amplifier 12 and a transistor switch 14.Power supply unit 20 provide a drive current flow through light-emitting diode (LED) module 30, decide current driver 10 and resistance R, and resistance R produces the current detection signal represent the drive current size.One backward end of error amplifier 12 receives above-mentioned current detection signal, and a non-return termination is received a reference voltage Vr, and exports a drive signal according to current detection signal and reference voltage Vr.The drain D of transistor switch 14 couples light-emitting diode (LED) module 30, and source S couples resistance R, and grid G receives above-mentioned drive signal.Error amplifier 12 can be adjusted the current potential of drive signal according to current detection signal and reference voltage Vr, makes the current potential of current detection signal equal the current potential of reference voltage Vr and reaches the effect of deciding electric current with the equivalent resistance of adjusting transistor switch 14.
The power end of existing error amplifier 12 can connect the drain D of transistor switch 14, so the current potential of its output drive signal is the current potential of drain D.And be to avoid the efficient of light emitting diode drive device too poor, the current potential of drain D can be too not high, but therefore limited the lowest high-current value of transistor switch 14 conductings.When light emitting diode drive device need be with higher current drives, and the current potential of the drive signal of error amplifier 12 outputs is limited in the current potential of drain D when following, chip (DIE) size that then must increase transistor switch 14.This measure causes the increase of the cost of deciding current driver.
The utility model content
In view of the defective of prior art, the utility model improves the current potential upper limit of the drive signal of driving transistors switch in the LED driving circuit, and the lowest high-current value of transistor switch energy conducting is also risen thereupon.Compared to prior art, the die size of the transistor switch that the utility model can be less provides identical light-emitting diode drive current, therefore can effectively reduce circuit cost.
For reaching above-mentioned advantage, it is a kind of in order to drive the LED driving circuit of a light-emitting diode (LED) module that the utility model provides, and comprises transistor switch and feedback controller.Above-mentioned transistor switch has a control end, one first end and one second end, and this first end couples this light-emitting diode (LED) module, and this control end receives a control signal with the size of current of control flows through this transistor switch.Above-mentioned feedback controller receives a reference voltage and represents a current detection signal of this size of current, and produces this control signal according to this reference voltage and this current detection signal; Wherein this feedback controller connects a driving power, and the current potential of this driving power is higher than the current potential of this first end of this transistor switch, makes the maximum of the current potential adjustable range of this control signal be higher than the current potential of this first end of this transistor switch.
Compared to prior art, the driving power of feedback controller of the present utility model is coupled to another higher voltage source, but not the drain electrode of transistor switch.Therefore, but the restriction of the current potential that the lowest high-current value of transistor switch conducting is no longer drained, and can cooperate the suitable voltage source of circuit application required and external, even the driving power of feedback controller couples and can be connected directly to the contact in the light-emitting diode (LED) module that is driven and do not need to provide in addition a voltage source.
Below in conjunction with the drawings and specific embodiments the utility model is described in detail, but not as to qualification of the present utility model.
Description of drawings
Fig. 1 is an existing light emitting diode drive device;
Fig. 2 is the circuit diagram of the light emitting diode drive device of a preferred embodiment of the present utility model;
Fig. 3 is the circuit diagram of the light emitting diode drive device of another preferred embodiment of the present utility model.
Wherein, Reference numeral
Prior art
10 decide current driver 12 error amplifiers
14 transistor switches, 20 power supply units
30 light-emitting diode (LED) module R current sense resistors
Vr reference voltage D drain electrode
S source electrode G grid
The utility model
110,210 decide current driver
112,212 feedback controllers
114,214 transistor switches
120,220 power supply units
130,230 light-emitting diode (LED) modules
216 preconditioners
240 current balancing devices
The AC AC power
The BD bridge rectifier
The Cin filter
The R current sense resistor
The Vr reference voltage
First end of D ' transistor switch
Second end of S ' transistor switch
The control end of G ' transistor switch
The C contact
Embodiment
The current formula of MOS (metal-oxide-semiconductor) transistor (MOSFET) is as follows:
Above-mentioned μ
0Be that carrier transport factor, W are the grid width of MOSFET, the grid length that L is MOSFET, specific capacitance size, the V that Cox is grid oxic horizon
GsBe the voltage difference between grid and the source electrode, and V
tIt then is critical voltage.Therefore, when electric current improves and can keep the ratio of W/L, in other words, promptly do not increase the grid width (W) of transistor chip, must improve the voltage difference Vgs between grid and the source electrode.
Please refer to Fig. 2, be the circuit diagram of the light emitting diode drive device of a preferred embodiment of the present utility model.Light emitting diode drive device comprises certain current driver 110, a power supply unit 120, a light-emitting diode (LED) module 130 and a current sense resistor R.Decide current driver 110 and comprise a feedback controller 112 and a transistor switch 114.Power supply unit 120 provide a drive current flow through light-emitting diode (LED) module 130, decide current driver 110 and resistance R, and resistance R produces the current detection signal represent the drive current size.Transistor switch 114 has a control end G ', one first end D ' and one second end S ', wherein the first end D ' couples light-emitting diode (LED) module 130, the second end S ' couples resistance R, and the control signal that control end G ' reception feedback controller 112 is produced is with the size of current of control flows warp.The electric current of light-emitting diode (LED) module 130 flow through transistor switch 114 and resistance R, and produce a current detection signal of representing size of current in the contact of transistor switch 114 and resistance R.
Moreover light emitting diode drive device of the present utility model also can be in order to drive many string light-emitting diodes.Please refer to Fig. 3, be the circuit diagram of the light emitting diode drive device of another preferred embodiment of the present utility model.Light emitting diode drive device comprises certain current driver 210, a power supply unit 220, a light-emitting diode (LED) module 230 and a current sense resistor R.Decide current driver 210 and comprise a feedback controller 212 and a transistor switch 214.Power supply unit 220 comprises an AC power AC, a bridge rectifier BD and a filter Cin, with provide a drive current flow through light-emitting diode (LED) module 230, decide current driver 210 and resistance R, and resistance R produces the current detection signal represent the drive current size.The control signal that transistor switch 214 reception feedback controllers 212 are produced is with the size of current of control flows warp.Feedback controller 212 comprises an error amplifier, and it couples resistance R and transistor switch 214, receives a reference voltage Vr and current detection signal and flows through the current stabilization of transistor switch 214 in a predetermined value to adjust the current potential of control signal in view of the above, to make.
Because light-emitting diode (LED) module 230 is made up of many strings light-emitting diode, for making each string light-emitting diode roughly the same electric current of flowing through, between transistor switch 214 and light-emitting diode (LED) module 230, a current balancing device 240 can be set, with the electric current of the many strings light-emitting diode in the balance light-emitting diode (LED) module 230.Owing to power supply unit 220 is come by the AC power rectification, can have AC signal with respect to the double frequency of AC power.For some feedback controllers 212 that the voltage stability of driving power is had relatively high expectations, one preconditioner 216 optionally is set between contact C and feedback controller 212, influences the control signal that feedback controller 212 is produced with the AC signal of avoiding power supply unit 220.
In addition, above-mentioned feedback controller 112,212 has the higher driving voltage except that coupling light-emitting diode (LED) module 130,230, also can couple other voltage source and reach identical advantage, and that reference voltage Vr also can be is external, make the scope of application more not limited.
Certainly; the utility model also can have other various embodiments; under the situation that does not deviate from the utility model spirit and essence thereof; those of ordinary skill in the art work as can make various corresponding changes and distortion according to the utility model, but these corresponding changes and distortion all should belong to the protection range of the appended claim of the utility model.
Claims (7)
1. a LED driving circuit in order to drive a light-emitting diode (LED) module, is characterized in that, comprises:
One transistor switch has a control end, one first end and one second end, and this first end couples this light-emitting diode (LED) module, and this control end receives a control signal with the size of current of control flows through this transistor switch; And
One feedback controller receives a reference voltage and represents a current detection signal of this size of current, and produces this control signal according to this reference voltage and this current detection signal; Wherein this feedback controller connects a driving power, and the current potential of this driving power is higher than the current potential of this first end of this transistor switch, makes the maximum of the current potential adjustable range of this control signal be higher than the current potential of this first end of this transistor switch.
2. LED driving circuit according to claim 1 is characterized in that wherein this driving power is provided by this light-emitting diode (LED) module.
3. LED driving circuit according to claim 1 is characterized in that, also comprises a preconditioner and is coupled between this driving power and this feedback controller.
4. LED driving circuit according to claim 1 is characterized in that, wherein second end of this transistor switch couples a resistance to produce this current detection signal.
5. LED driving circuit according to claim 1 is characterized in that wherein this feedback controller comprises an error amplifier.
6. LED driving circuit according to claim 1 is characterized in that, wherein this light-emitting diode (LED) module is formed by many string light-emitting diodes.
7. LED driving circuit according to claim 6 is characterized in that wherein this transistor switch couples a current balancing device, with this light-emitting diode (LED) module of balance each the string light-emitting diode electric current.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008201403616U CN201307951Y (en) | 2008-11-12 | 2008-11-12 | Light-emitting diode drive circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008201403616U CN201307951Y (en) | 2008-11-12 | 2008-11-12 | Light-emitting diode drive circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201307951Y true CN201307951Y (en) | 2009-09-09 |
Family
ID=41100416
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNU2008201403616U Expired - Fee Related CN201307951Y (en) | 2008-11-12 | 2008-11-12 | Light-emitting diode drive circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201307951Y (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101866622A (en) * | 2010-06-22 | 2010-10-20 | 鸿富锦精密工业（深圳）有限公司 | LED display device capable of controlling current balance and control method thereof |
| CN101950535A (en) * | 2010-08-12 | 2011-01-19 | 友达光电股份有限公司 | Luminous device and related driving method |
| CN102065603A (en) * | 2009-11-18 | 2011-05-18 | 登丰微电子股份有限公司 | Load drive circuit and multi-load feedback circuit |
| CN102088815A (en) * | 2009-12-07 | 2011-06-08 | 登丰微电子股份有限公司 | Tube driving device and displacement driving circuit |
| CN102348311A (en) * | 2010-08-02 | 2012-02-08 | 艾笛森光电股份有限公司 | Light-emitting diode (LED) driving circuit |
| CN102695326A (en) * | 2011-03-22 | 2012-09-26 | 登丰微电子股份有限公司 | Controller with protection function and light emitting diode driving circuit |
| CN103037569A (en) * | 2011-09-30 | 2013-04-10 | 朗捷科技股份有限公司 | Shunting type alternating current LED drive circuit |
| CN102123536B (en) * | 2010-01-12 | 2013-10-30 | 冠捷投资有限公司 | Light-emitting diode driving circuit |
| CN103546143A (en) * | 2012-07-09 | 2014-01-29 | 登丰微电子股份有限公司 | Feedback detection circuit |
| CN114141203A (en) * | 2021-12-03 | 2022-03-04 | Tcl华星光电技术有限公司 | Backlight driving circuit and display device |
-
2008
- 2008-11-12 CN CNU2008201403616U patent/CN201307951Y/en not_active Expired - Fee Related
Cited By (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102065603B (en) * | 2009-11-18 | 2014-03-05 | 登丰微电子股份有限公司 | Load drive circuit and multi-load feedback circuit |
| CN102065603A (en) * | 2009-11-18 | 2011-05-18 | 登丰微电子股份有限公司 | Load drive circuit and multi-load feedback circuit |
| CN102088815A (en) * | 2009-12-07 | 2011-06-08 | 登丰微电子股份有限公司 | Tube driving device and displacement driving circuit |
| CN102123536B (en) * | 2010-01-12 | 2013-10-30 | 冠捷投资有限公司 | Light-emitting diode driving circuit |
| CN101866622A (en) * | 2010-06-22 | 2010-10-20 | 鸿富锦精密工业（深圳）有限公司 | LED display device capable of controlling current balance and control method thereof |
| CN102348311A (en) * | 2010-08-02 | 2012-02-08 | 艾笛森光电股份有限公司 | Light-emitting diode (LED) driving circuit |
| CN101950535B (en) * | 2010-08-12 | 2012-06-27 | 友达光电股份有限公司 | Luminous device and related driving method |
| CN101950535A (en) * | 2010-08-12 | 2011-01-19 | 友达光电股份有限公司 | Luminous device and related driving method |
| CN102695326A (en) * | 2011-03-22 | 2012-09-26 | 登丰微电子股份有限公司 | Controller with protection function and light emitting diode driving circuit |
| US8872441B2 (en) | 2011-03-22 | 2014-10-28 | Green Solution Technology Co., Ltd. | Controller and LED driving circuit with protection function |
| CN102695326B (en) * | 2011-03-22 | 2015-04-01 | 登丰微电子股份有限公司 | Controller with protection function and light emitting diode driving circuit |
| CN103037569A (en) * | 2011-09-30 | 2013-04-10 | 朗捷科技股份有限公司 | Shunting type alternating current LED drive circuit |
| CN103546143A (en) * | 2012-07-09 | 2014-01-29 | 登丰微电子股份有限公司 | Feedback detection circuit |
| CN103546143B (en) * | 2012-07-09 | 2016-05-18 | 登丰微电子股份有限公司 | Feedback sense circuit |
| CN114141203A (en) * | 2021-12-03 | 2022-03-04 | Tcl华星光电技术有限公司 | Backlight driving circuit and display device |
| CN114141203B (en) * | 2021-12-03 | 2023-04-07 | Tcl华星光电技术有限公司 | Backlight driving circuit and display device |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20090909 Termination date: 20121112 |