CN201403226Y - LED backlight driving device - Google Patents
LED backlight driving device Download PDFInfo
- Publication number
- CN201403226Y CN201403226Y CN2009201310921U CN200920131092U CN201403226Y CN 201403226 Y CN201403226 Y CN 201403226Y CN 2009201310921 U CN2009201310921 U CN 2009201310921U CN 200920131092 U CN200920131092 U CN 200920131092U CN 201403226 Y CN201403226 Y CN 201403226Y
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
- Y02B20/40—Control techniques providing energy savings, e.g. smart controller or presence detection
Abstract
An LED backlight driving device comprises an LM 3404/04HV single-chip voltage-reducing switch regulator, the VIN pin of the regulator inputs a power supply, an SW pin output end of the regulator outputs Vf through an electric inductance L1, is connected with one end of a backlight LED and drives the LED to emit light, the other end of the backlight LED is connected to a current feedback pin CS ofthe voltage-reducing switch regulator and forms a current stabilization circuit, the current feedback pin CS is further connected with an output current adjusting resistance Rsns which is used for adjusting the output current and enabling the output current to be always in a constant current state, the device further comprises a voltage adjusting resistance Ron which is connected between the Ron pin of the voltage-reducing switch regulator and the VIN pin and is used for outputting the Vf value. The device can support super-wide power supply input (6V-42V), can realize big current output without external compensation, can realize the independent PWM DIMMING light modulation control through a built-in big power MOSFET pipe, has the under-voltage and overheating automatic protection functionand the independent functions of outputting voltage and adjusting current, can obtain the converting efficiency which is more than 95%, and has better energy-saving effect.
Description
Technical field
The utility model relates to drive circuit, is specifically related to a kind of LED-backlit drive unit.
Background technology
The LED-backlit unit is used to LCD to show light source is provided, the LED-backlit drive circuit of prior art, and the power utilization rate is not high, and is unfavorable to energy-saving and emission-reduction.
Summary of the invention
The technical problems to be solved in the utility model provides a kind of LED-backlit drive unit, and it is compared with existing LED-backlit, can improve the utilance of power supply greatly, reaches more purpose of energy saving.
The above-mentioned technical problem of the utility model solves like this, construct a kind of LED-backlit drive unit and comprise that a model is the step-down switching regulator of the single-chip of LM3404/04HV, the VIN pin input power supply of this step-down switching regulator, SW pin output connect an end that drives LED backlight through inductance L 1 output Vf makes it luminous; The other end of described LED backlight is connected to the current feedback pin CS of step-down switching regulator, forms the loop of a current stabilization; Current feedback pin CS also is connected with and is used to regulate the output current adjusting resistance R sns that output current makes it to work in all the time constant current state, also comprises a voltage-regulation resistance R on who is connected the Vf value that is used to export between step-down switching regulator Ron pin and the VIN pin.
In above-mentioned LED-backlit drive unit, comprise that also capacitor C F is connected between step-down switching regulator VCC and the ground.
In above-mentioned LED-backlit drive unit, comprise that also capacitor C B is connected between step-down switching regulator BOOT pin and the SW pin.
Implement the LED-backlit drive unit that the utility model provides, can support super wide power input (6V-42V), need not the external compensation circuit, can realize that the big electric current of 1.2A is exported; The built-in high-power MOSFET tube of this drive unit; can realize independently PWM DIMMING brightness adjustment control; can adjust comfortable brightness easily by the duty ratio of regulating the DIM pin; have under-voltage, overheated automatic protection functions and output voltage independently simultaneously; the Current Regulation function; aspect energy-conservation, more can obtain up to the conversion efficiency more than 95%, energy-saving effect is better.
Description of drawings
Fig. 1 is the circuit theory diagrams of the utility model LED-backlit drive unit embodiment;
Fig. 2 is the logic diagram of the used LM3404/04HV integrated circuit of the utility model;
Embodiment
Shown in Figure 1, comprise that at the utility model LED-backlit drive unit a model is the integrated circuit of LM3404/04HV; This LM3404/LM3404HV is a kind of step-down switching regulator of single-chip, can be high-power LED constant drive current is provided, the high-end N-MOSFET switch of this built-in chip type, its internal circuit as shown in Figure 2, can export the electric current of driving up to 1A, and feedback voltage Vfb can be low to moderate 200MV, thereby can significantly reduce the power consumption of current sensing resistor, reduces the power consumption purpose thereby reach; The feedback voltage that is low to moderate 200MV simultaneously also can obtain higher conversion efficiency.As shown in Figure 1, power supply is handled from the output of SW pin through internal circuit from the input of VIN pin, and is luminous through inductance L 1 output Vf driving LED from the SW pin; Through entering the loop that feedback pin CS forms a current stabilization behind the LED.(workflow is seen shown in Fig. 1 black arrow).The CS pin is the current feedback pin, and the feedback regulation output by this pin makes circuit work in constant current state all the time, and Rsns is that output current is provided with pin, changes the electric current that this resistance is regulated output, the VF value that the resistance of change Ron can be regulated output.
The power supply input is imported from the VIN pin; the magnitude of voltage of the feedback voltage Vfb pin of the current stabilization chip of traditional LED is about 1.25V; cause the loss ratio of itself bigger at driving high-power LED backlight; according to law of conservation of energy; the mode that the power of this part loss can only be converted to heat energy discharges; chip design in more and more littler encapsulation now proposes higher requirement in heat radiation, and present on the other hand energy crisis more let us will be considered purpose of energy saving to greatest extent in design.To recently describing, is 1A if need the electric current I f of driving LED with for example, the loss power of general current stabilization chip: (pressing Vfb=1.25V)
According to computing formula: P=UI
Can calculate the power P=1.25 * 1=1.25w of loss
And the loss power when adopting the LM3404 chip according to the utility model is:
P＝0.2×1＝0.2w
At the chip of equal encapsulation, under the same radiating condition, the temperature rise meeting of scheme of the present utility model is much lower, and the ultrathin design space for LCD television set and other use the electrical equipment of LCD demonstration provides reliable and stable operational environment.
Claims (3)
1, a kind of LED-backlit drive unit, it is characterized in that, comprise that a model is the step-down switching regulator of the single-chip of LM3404/04HV, the VIN pin input power supply of this step-down switching regulator, SW pin output connect an end that drives LED backlight through inductance L 1 output Vf makes it luminous; The other end of described LED backlight is connected to the current feedback pin CS of step-down switching regulator, forms the loop of a current stabilization; Current feedback pin CS also is connected with and is used to regulate the output current adjusting resistance R sns that output current makes it to work in all the time constant current state, also comprises a voltage-regulation resistance R on who is connected the Vf value that is used to export between step-down switching regulator Ron pin and the VIN pin.
2, according to the described LED-backlit drive unit of claim 1, it is characterized in that, comprise that also capacitor C F is connected between step-down switching regulator VCC and the ground.
3, according to the described LED-backlit drive unit of claim 1, it is characterized in that, comprise that also capacitor C B is connected between step-down switching regulator BOOT pin and the SW pin.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009201310921U CN201403226Y (en) | 2009-04-27 | 2009-04-27 | LED backlight driving device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009201310921U CN201403226Y (en) | 2009-04-27 | 2009-04-27 | LED backlight driving device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201403226Y true CN201403226Y (en) | 2010-02-10 |
Family
ID=41663025
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2009201310921U Expired - Lifetime CN201403226Y (en) | 2009-04-27 | 2009-04-27 | LED backlight driving device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201403226Y (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101825266A (en) * | 2010-04-30 | 2010-09-08 | 福建捷联电子有限公司 | LED light tube power panel applied to liquid crystal display |
| CN101835312A (en) * | 2010-05-10 | 2010-09-15 | 海洋王照明科技股份有限公司 | LED drive control circuit |
| CN103002627A (en) * | 2011-09-15 | 2013-03-27 | 海洋王照明科技股份有限公司 | LED drive circuit with function of time delay and LED lamp |
| CN111583864A (en) * | 2020-06-11 | 2020-08-25 | 京东方科技集团股份有限公司 | Display driving circuit, driving method thereof and display device |
-
2009
- 2009-04-27 CN CN2009201310921U patent/CN201403226Y/en not_active Expired - Lifetime
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101825266A (en) * | 2010-04-30 | 2010-09-08 | 福建捷联电子有限公司 | LED light tube power panel applied to liquid crystal display |
| CN101825266B (en) * | 2010-04-30 | 2013-08-21 | 福建捷联电子有限公司 | LED light tube power panel applied to liquid crystal display |
| CN101835312A (en) * | 2010-05-10 | 2010-09-15 | 海洋王照明科技股份有限公司 | LED drive control circuit |
| CN101835312B (en) * | 2010-05-10 | 2014-03-26 | 海洋王照明科技股份有限公司 | LED drive control circuit |
| CN103002627A (en) * | 2011-09-15 | 2013-03-27 | 海洋王照明科技股份有限公司 | LED drive circuit with function of time delay and LED lamp |
| CN103002627B (en) * | 2011-09-15 | 2015-04-01 | 海洋王照明科技股份有限公司 | LED drive circuit with function of time delay and LED lamp |
| CN111583864A (en) * | 2020-06-11 | 2020-08-25 | 京东方科技集团股份有限公司 | Display driving circuit, driving method thereof and display device |
| CN111583864B (en) * | 2020-06-11 | 2021-09-03 | 京东方科技集团股份有限公司 | Display driving circuit, driving method thereof and display device |
| WO2021249137A1 (en) * | 2020-06-11 | 2021-12-16 | 京东方科技集团股份有限公司 | Display driving circuit, driving method therefor, and display device |
| US11875742B2 (en) | 2020-06-11 | 2024-01-16 | Beijing Boe Display Technology Co., Ltd. | Display drive circuit and drive method thereof, and display device |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term | ||
| CX01 | Expiry of patent term |
Granted publication date: 20100210 |