CN102682714B - LED backlight source driving circuit and method for realizing soft startup - Google Patents
LED backlight source driving circuit and method for realizing soft startup Download PDFInfo
- Publication number
- CN102682714B CN102682714B CN201210126891.6A CN201210126891A CN102682714B CN 102682714 B CN102682714 B CN 102682714B CN 201210126891 A CN201210126891 A CN 201210126891A CN 102682714 B CN102682714 B CN 102682714B
- Authority
- CN
- China
- Prior art keywords
- resistance
- circuit
- driving chip
- pin
- termination
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Led Devices (AREA)
- Circuit Arrangement For Electric Light Sources In General (AREA)
- Dc-Dc Converters (AREA)
Abstract
The invention discloses an LED (light-emitting diode) backlight source driving circuit and a method for realizing soft startup. The method comprises the steps as follows: an error amplifier output pin of a control circuit driving chip is earthed by a drain resistor; when a flat television mainboard rapidly resets the driving chip by an enabling pin of the driving chip, the voltage of the driving chip error amplifier output pin is rapidly drained by the drain resistor; and when the driving chip is restarted, the voltage of the error amplifier output pin rises from zero, and the duty ratio of PWM (pulse width modulation) signal output by the driving chip is slowly increased, so that a soft startup function of the whole circuit is realized. According to the invention, the soft startup function of the driving chip can be easily realized, and the accident damage of main circuit power devices caused by over-high voltage, current and temperature stress is prevented.
Description
[technical field]
The present invention relates to flat panel TV LED backlight, particularly relate to a kind of LED backlight driving circuit and the method realizing soft start.
[background technology]
Traditional flat panel TV LED backlight driving circuit comprises main circuit and control circuit, main circuit comprises direct-flow input circuit, energy storage inductor, switching tube, RC stress absorption circuit and output rectifier and filter, and output rectifier and filter comprises commutation diode and filter capacitor.Control circuit comprises driving chip, chip power supply circuit, output voltage sampling circuit, output current sample circuit, PWM light adjusting circuit and enable circuits.
In classic flat-plate TV LED backlight driving circuit, the dutycycle of the pwm signal that driving chip (as BIT3251) exports and the output pin voltage in proportion relation of driving chip error amplifier, the voltage of error amplifier output pin is higher, and the dutycycle of pwm signal is larger.This traditional circuit has following two problems.
One: when main circuit output terminal open circuit or loose contact, current sample feedback loop does not have signals collecting to return to the error amplifier anti-phase input pin of driving chip, at this moment the anti-phase input pin voltage of error amplifier is far below the positive input pin voltage (reference voltage) of error amplifier, according to this error amount, the output voltage of error amplifier will be adjusted to mxm., if at this moment flat panel TV mainboard is by driving chip enable pin Rapid reset driving chip, within the extremely short time, the voltage of driving chip error amplifier output pin cannot be fallen, maintain the value before resetting, therefore at driving chip from when newly starting, the pwm signal dutycycle of driving chip output pin reaches maximum, control circuit loses and softly opens function, main circuit will due to superpotential, current stress causes power semiconductor device to damage.
Its two: when LED backlight driving circuit normally works, if flat panel TV mainboard is by driving chip enable pin Rapid reset driving chip, within the extremely short time, the voltage of driving chip error amplifier output pin cannot be fallen, maintain the value before resetting, therefore at driving chip from when newly starting, the pwm signal dutycycle of driving chip output pin maintains the value before resetting, control circuit loses and softly opens function, and main circuit will cause power semiconductor device to damage due to superpotential, current stress.
[summary of the invention]
The technical problem to be solved in the present invention is to provide a kind of control circuit and realizes softly opening function, makes main circuit power semiconductor device non-damageable flat panel TV LED backlight driving circuit realize the method for soft start.
Another technical matters that will solve of the present invention is to provide a kind of control circuit and realizes softly opening function, makes the non-damageable LED backlight driving circuit of main circuit power semiconductor device.
In order to solve the problems of the technologies described above, the technical solution used in the present invention is, a kind of flat panel TV LED backlight driving circuit realizes the method for soft start, by the error amplifier output pin of control circuit driving chip by bleeder resistance ground connection, when driving chip is resetted by the enable pin of driving chip by flat panel TV mainboard fast, the voltage of driving chip error amplifier output pin is released fast by bleeder resistance, driving chip is when restarting, the voltage of error amplifier output pin is started from scratch rising, the dutycycle of the pwm signal that driving chip exports slowly increases, make the soft function opened of whole circuit realiration.
A kind of technical scheme of flat panel TV LED backlight driving circuit is, comprise main circuit and control circuit, main circuit comprises direct-flow input circuit, energy storage inductor, switching tube, RC stress absorption circuit and output rectifier and filter, and output rectifier and filter comprises commutation diode and filter capacitor; Control circuit comprises driving chip, chip power supply circuit, output voltage sampling circuit, output current sample circuit, PWM light adjusting circuit, enable circuits and current sample ring compensating circuit, described current sample ring compensating circuit comprises the first resistance, bleeder resistance, the first electric capacity and the second electric capacity, is connected between the error amplifier anti-phase input pin of driving chip and error amplifier output pin after the first described resistance and the first capacitances in series; The second described electric capacity is connected between the error amplifier anti-phase input pin of driving chip and error amplifier output pin; The error amplifier output pin of one termination driving chip of described bleeder resistance, other end ground connection.
Above-described flat panel TV LED backlight driving circuit, described enable circuits comprises the 3rd resistance, the 4th resistance and the 3rd electric capacity, the backlight switch signal output part of one termination TV SKD of described 3rd resistance, the enable control pin of another termination driving chip; The enable control pin of the 4th described resistance one termination driving chip, other end ground connection; The 3rd described electric capacity and the 4th resistance also connect.
Above-described flat panel TV LED backlight driving circuit, described PWM light adjusting circuit comprises the 5th resistance, the 6th resistance, the 7th resistance, the 8th resistance, the 9th resistance, the first triode and diode, the collector of the first triode connects chip power positive pole, grounded emitter by the 8th resistance; The anode of diode connects the collector of the first triode, and negative electrode connects the error amplifier anti-phase input pin of driving chip by the 9th resistance; One termination TV SKD pwm control signal output terminal of the 5th resistance, the base stage of another termination first triode; The base stage of one termination first triode of the 6th resistance, other end ground connection; One termination TV SKD pwm control signal output terminal of the 7th resistance, the collector of another termination first triode.
Above-described flat panel TV LED backlight driving circuit, described chip power supply circuit comprises linear voltage-stabilizing circuit, the direct-flow input circuit described in input termination of described linear voltage-stabilizing circuit, the supply pin of another termination driving chip.
Above-described flat panel TV LED backlight driving circuit, described linear voltage-stabilizing circuit comprises the second triode, stabilivolt, the 4th electric capacity, the tenth resistance and the 11 resistance, the emitter of the second triode connects driving chip supply pin, base stage connects the negative electrode of stabilivolt, and collector connects direct-flow input circuit positive pole by the 11 resistance; The plus earth of stabilivolt, a termination direct-flow input circuit positive pole of the tenth resistance, the base stage of another termination second triode; The emitter of one termination second triode of the 4th electric capacity, other end ground connection.
Above-described flat panel TV LED backlight driving circuit, described output current sample circuit comprises the 12 resistance and the 13 resistance, the negative pole of flat panel TV LED backlight driving circuit output terminal, by the 12 resistance eutral grounding, connects the error amplifier anti-phase input pin of driving chip by the 13 resistance.
Above-described flat panel TV LED backlight driving circuit, described voltage sampling circuit comprises the 14 resistance, the 15 resistance and the 5th electric capacity, the positive pole of one termination flat panel TV LED backlight driving circuit output terminal of the 14 resistance, the overvoltage protection pin of another termination driving chip; The overvoltage protection pin of one termination driving chip of the 15 resistance, other end ground connection, the 5th electric capacity and the 15 resistor coupled in parallel.
Above-described flat panel TV LED backlight driving circuit, comprises the 16 resistance, the positive pole of direct-flow input circuit described in the first termination of energy storage inductor, and the second termination connects the first end of switching tube; Second end ground connection of switching tube, the control pole of switching tube connects the output terminal of driving chip by the 16 resistance; The anode of commutation diode connects the first end of switching tube, and negative electrode connects the positive pole of flat panel TV LED backlight driving circuit output terminal; The negative electrode of one termination commutation diode of filter capacitor, other end ground connection, the grounding leg ground connection of driving chip.
Above-described flat panel TV LED backlight driving circuit, described RC stress absorption circuit comprises the 17 resistance and the 6th electric capacity, and after the 17 resistance and the 6th capacitances in series, a termination connects the first end of switching tube, other end ground connection.
LED backlight driving circuit of the present invention can realize driving chip soft start function smoothly, prevents main circuit power device because of the excessive and accidental damage of voltage, electric current, temperature stress.
[accompanying drawing explanation]
Below in conjunction with the drawings and specific embodiments, the present invention is further detailed explanation.
Fig. 1 is the schematic diagram of flat panel TV LED backlight driving circuit embodiment of the present invention.
[embodiment]
As shown in Figure 1, the flat panel TV LED backlight driving circuit of the embodiment of the present invention comprises main circuit and control circuit, main circuit comprises direct-flow input circuit, energy storage inductor L5, switching tube Q29, RC stress absorption circuit and output rectifier and filter, and output rectifier and filter comprises commutation diode D14 and filter capacitor C32 and EC18.Control circuit comprises driving chip IC6 (model BIT3251), chip power supply circuit, output voltage sampling circuit, output current sample circuit, PWM light adjusting circuit, enable circuits and current sample ring compensating circuit.
The driving chip of the present embodiment is that LED constant current pwm chip BIT3251, chip BIT3251 peripheral circuit is simple, device is less, cost performance is high, can realize high precision constant current mode and carry out driving LED backlit operation.
The positive pole (+24V or+12V) of the first termination direct-flow input circuit of energy storage inductor L5, the second termination connects the first end of switching tube Q29.The second end ground connection of switching tube Q29, the control pole of switching tube Q29 connects the output terminal (the 8th pin OUT) of driving chip IC6 by resistance R120.The anode of commutation diode D14 connects the first end of switching tube Q29, and negative electrode meets the positive pole LED+ of flat panel TV LED backlight driving circuit output terminal.The negative electrode of the one termination commutation diode D14 of filter capacitor C32 and EC18, other end ground connection, grounding leg (the 7th pin GND) ground connection of driving chip IC6.
RC stress absorption circuit comprises resistance R117 and electric capacity C34, and after resistance R117 and electric capacity C34 connects, a termination connects the first end of switching tube Q29, other end ground connection.
Current sample ring compensating circuit is connected across between the error amplifier output pin (the 3rd pin CMP) of driving chip IC6 and the error amplifier anti-phase input pin (the 4th pin INN) of IC6.
Current sample ring compensating circuit comprises resistance R23, bleeder resistance R23B, electric capacity C27 and electric capacity C26, and resistance R23 is connected on after connecting with electric capacity C27 between the error amplifier output pin (the 3rd pin CMP) of driving chip IC6 and the error amplifier anti-phase input pin (the 4th pin INN) of IC6.Electric capacity C26 is connected between the error amplifier output pin (the 3rd pin CMP) of driving chip IC6 and the error amplifier anti-phase input pin (the 4th pin INN) of IC6.The error amplifier output pin (the 3rd pin CMP) of the one termination driving chip IC6 of bleeder resistance R23B, other end ground connection.
This circuit, except current sample feedback loop have employed traditional first order pole, simple zero compensation, is also connected to bleeder resistance R23B to ground at the error amplifier output pin (the 3rd pin CMP) of driving chip IC6.Open a way at main circuit output terminal, under the states such as loose contact or normal work, when driving chip IC6 is resetted by the enable pin of driving chip IC6 by flat panel TV mainboard fast, by this resistance, the voltage of driving chip IC6 error amplifier output pin (the 3rd pin CMP) can be released fast, driving chip IC6 is when restarting, the voltage of error amplifier output pin (the 3rd pin CMP) slowly rises from zero, the dutycycle of the pwm signal that driving chip IC6 exports slowly increases, thus make the soft function opened of whole circuit realiration, avoid power semiconductor device due to superpotential, current stress and puncturing.
Enable circuits comprises resistance R24, resistance R23A and electric capacity C24, the backlight switch signal output part (BK/ON) of a termination flat panel TV mainboard of resistance R24, the enable control pin (the 2nd pin EA) of another termination driving chip IC6.The enable control pin (the 2nd pin EA) of resistance R23A mono-termination driving chip IC6, other end ground connection.Electric capacity C24 and resistance R23A also connects.R23A R24, C24 constitute switch (BK/ON) control circuit of backlight.According to the sequential of flat panel TV mainboard reality, regulate the resistance of R23A R24 can regulate the startup sequential of driving chip IC6, reach and avoid televisor to produce flower screen and mosaic phenomenon when switching on and shutting down.
PWM light adjusting circuit comprise resistance R1, resistance R101, resistance R59, resistance R22, resistance R74, NPN triode Q28 and diode D11, NPN triode Q28 collector connect chip power positive pole (VCC1) by resistance R22, grounded emitter.The anode of diode D11 connects the collector of NPN triode Q28, and negative electrode connects the error amplifier anti-phase input pin (the 4th pin INN) of the IC6 of driving chip IC6 by resistance R74.The one termination TV SKD pwm control signal output terminal of resistance R1, the base stage of another termination NPN triode Q28.The base stage of the one termination NPN triode Q28 of resistance R101, other end ground connection.The one termination TV SKD pwm control signal output terminal of resistance R59, the collector of another termination NPN triode Q28.When flat panel TV mainboard by light modulation pin (ADJ) send PWM dim signal come time, the triode Q28 of PWM light adjusting circuit is under the driving of PWM dim signal, be operated on off state, the collector of triode Q28 is made to produce pwm signal, this signal arrives the error amplifier anti-phase input pin of driving chip IC6 through diode D11 resistance R74, the output pin voltage follow of error amplifier is made dim signal change by the voltage of departure amplifier anti-phase input pin, also the dutycycle namely controlling the output pwm signal of driving chip IC6 follows dim signal change, thus reach the function regulating main circuit output current.
Chip power supply circuit comprises linear voltage-stabilizing circuit, linear voltage-stabilizing circuit comprises NPN triode Q1, stabilivolt Z1, electric capacity C18, resistance R16 and resistance R15, the emitter of NPN triode Q1 connects driving chip I C6 supply pin (the 1st pin VDD), base stage connects the negative electrode of stabilivolt Z1, and collector connects direct-flow input circuit positive pole (+24V or+12V) by resistance R15.The plus earth of stabilivolt Z1, a termination direct-flow input circuit positive pole (+24V or+12V) of resistance R16, the base stage of another termination NPN triode Q1.The emitter of the one termination NPN triode Q1 of electric capacity C18, other end ground connection.Direct-flow input circuit (+24V or+12V) by this circuit for driving chip IC6 provides stable operating voltage.
Output current sample circuit comprises resistance R166 and resistance R122, the negative pole LED-of flat panel TV LED backlight driving circuit output terminal by resistance R168 ground connection, and connects the error amplifier anti-phase input pin (the 4th pin INN) of the IC6 of driving chip IC6 by resistance R122.The output current of resistance R168 sampling main circuit, sampled signal is sent to the anti-phase input pin of driving chip IC6 error amplifier by resistance R122, when the output current of main circuit has deviation, the voltage (reference signal) of sampled signal and error amplifier positive input pin produces error signal, output pin through error amplifier regulates the dutycycle of driving chip IC6 output pin pwm signal, makes the constant output current of main circuit at preset value.
Voltage sampling circuit comprises resistance R160, resistance R164 and the 5th electric capacity C36; the positive pole LED+ of the one termination flat panel TV LED backlight driving circuit output terminal of resistance R160, the overvoltage protection pin (the 5th pin OVP) of another termination driving chip IC6.The overvoltage protection pin (the 5th pin OVP) of the one termination driving chip IC6 of resistance R164, other end ground connection, the 5th electric capacity C36 and resistance R164 is in parallel.Resistance R160 and resistance R164 is to the defeated voltage scale dividing potential drop of main circuit and carry out through C36 the overvoltage protection pin (the 5th pin OVP) delivering to driving chip IC6 after filtering, and when main circuit output terminal is opened a way, the voltage of output terminal will rise rapidly.After reaching the overvoltage protection thresholding of driving chip IC6 the 5th pin, will trigger driving chip IC6 and close output, protection main circuit avoids superpotential impact.
Claims (10)
1. a flat panel TV LED backlight driving circuit realizes the method for soft start, it is characterized in that, by the error amplifier output pin of control circuit driving chip by bleeder resistance ground connection, when driving chip is resetted by the enable pin of driving chip by flat panel TV mainboard fast, the voltage of driving chip error amplifier output pin is released fast by bleeder resistance, driving chip is when restarting, the voltage of error amplifier output pin is started from scratch rising, the dutycycle of the pwm signal that driving chip exports slowly increases, and makes the soft function opened of whole circuit realiration.
2. a flat panel TV LED backlight driving circuit, comprise main circuit and control circuit, main circuit comprises direct-flow input circuit, energy storage inductor, switching tube, RC stress absorption circuit and output rectifier and filter, and output rectifier and filter comprises commutation diode and filter capacitor; Control circuit comprises driving chip, chip power supply circuit, output voltage sampling circuit, output current sample circuit, PWM light adjusting circuit and enable circuits, it is characterized in that, comprise current sample ring compensating circuit, described current sample ring compensating circuit comprises the first resistance, bleeder resistance, the first electric capacity and the second electric capacity, is connected between the error amplifier anti-phase input pin of driving chip and error amplifier output pin after the first described resistance and the first capacitances in series; The second described electric capacity is connected between the error amplifier anti-phase input pin of driving chip and error amplifier output pin; The error amplifier output pin of one termination driving chip of described bleeder resistance, other end ground connection.
3. flat panel TV LED backlight driving circuit according to claim 2, it is characterized in that, described enable circuits comprises the 3rd resistance, the 4th resistance and the 3rd electric capacity, the backlight switch signal output part of one termination TV SKD of described 3rd resistance, the enable control pin of another termination driving chip; The enable control pin of the 4th described resistance one termination driving chip, other end ground connection; The 3rd described electric capacity and the 4th resistance also connect.
4. flat panel TV LED backlight driving circuit according to claim 2, it is characterized in that, described PWM light adjusting circuit comprises the 5th resistance, the 6th resistance, the 7th resistance, the 8th resistance, the 9th resistance, the first triode and diode, the collector of the first triode connects chip power positive pole, grounded emitter by the 8th resistance; The anode of diode connects the collector of the first triode, and negative electrode connects the error amplifier anti-phase input pin of driving chip by the 9th resistance; One termination TV SKD pwm control signal output terminal of the 5th resistance, the base stage of another termination first triode; The base stage of one termination first triode of the 6th resistance, other end ground connection; One termination TV SKD pwm control signal output terminal of the 7th resistance, the collector of another termination first triode.
5. flat panel TV LED backlight driving circuit according to claim 2, it is characterized in that, described chip power supply circuit comprises linear voltage-stabilizing circuit, the direct-flow input circuit described in input termination of described linear voltage-stabilizing circuit, the supply pin of another termination driving chip.
6. flat panel TV LED backlight driving circuit according to claim 5, it is characterized in that, described linear voltage-stabilizing circuit comprises the second triode, stabilivolt, the 4th electric capacity, the tenth resistance and the 11 resistance, the emitter of the second triode connects driving chip supply pin, base stage connects the negative electrode of stabilivolt, and collector connects direct-flow input circuit positive pole by the 11 resistance; The plus earth of stabilivolt, a termination direct-flow input circuit positive pole of the tenth resistance, the base stage of another termination second triode; The emitter of one termination second triode of the 4th electric capacity, other end ground connection.
7. flat panel TV LED backlight driving circuit according to claim 2, it is characterized in that, described output current sample circuit comprises the 12 resistance and the 13 resistance, the negative pole of flat panel TV LED backlight driving circuit output terminal, by the 12 resistance eutral grounding, connects the error amplifier anti-phase input pin of driving chip by the 13 resistance.
8. flat panel TV LED backlight driving circuit according to claim 2, it is characterized in that, described voltage sampling circuit comprises the 14 resistance, the 15 resistance and the 5th electric capacity, the positive pole of one termination flat panel TV LED backlight driving circuit output terminal of the 14 resistance, the overvoltage protection pin of another termination driving chip; The overvoltage protection pin of one termination driving chip of the 15 resistance, other end ground connection, the 5th electric capacity and the 15 resistor coupled in parallel.
9. the flat panel TV LED backlight driving circuit according to claim arbitrary in claim 2 to 8, is characterized in that, comprise the 16 resistance, the positive pole of direct-flow input circuit described in the first termination of energy storage inductor, and the second termination connects the first end of switching tube; Second end ground connection of switching tube, the control pole of switching tube connects the output terminal of driving chip by the 16 resistance; The anode of commutation diode connects the first end of switching tube, and negative electrode connects the positive pole of flat panel TV LED backlight driving circuit output terminal; The negative electrode of one termination commutation diode of filter capacitor, other end ground connection, the grounding leg ground connection of driving chip.
10. flat panel TV LED backlight driving circuit according to claim 9, it is characterized in that, described RC stress absorption circuit comprises the 17 resistance and the 6th electric capacity, and after the 17 resistance and the 6th capacitances in series, a termination connects the first end of switching tube, other end ground connection.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210126891.6A CN102682714B (en) | 2012-04-27 | 2012-04-27 | LED backlight source driving circuit and method for realizing soft startup |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210126891.6A CN102682714B (en) | 2012-04-27 | 2012-04-27 | LED backlight source driving circuit and method for realizing soft startup |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102682714A CN102682714A (en) | 2012-09-19 |
| CN102682714B true CN102682714B (en) | 2015-04-15 |
Family
ID=46814541
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210126891.6A Active CN102682714B (en) | 2012-04-27 | 2012-04-27 | LED backlight source driving circuit and method for realizing soft startup |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102682714B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103295548B (en) * | 2013-05-20 | 2015-05-20 | 合肥京东方光电科技有限公司 | Backlight module driving circuit and display device |
| CN106373500B (en) * | 2016-11-04 | 2023-05-30 | 上海控易电子科技有限公司 | Liquid crystal display screen |
| CN106683621B (en) * | 2016-12-30 | 2024-03-29 | 厦门厦华科技有限公司 | LED backlight driving circuit and method for realizing soft start |
| CN107277985B (en) * | 2017-08-15 | 2023-10-24 | 合肥惠科金扬科技有限公司 | LED dimming circuit and LED display device |
| CN112886807B (en) * | 2021-02-07 | 2023-06-20 | 上海空间电源研究所 | Device and method for realizing soft start |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1417767A (en) * | 2001-11-09 | 2003-05-14 | 三洋电机株式会社 | Display with function of initializing brightness data of optical elements |
| CN201388310Y (en) * | 2008-12-30 | 2010-01-20 | 深圳市中联数源电子有限公司 | LED constant current drive circuit |
| CN201667742U (en) * | 2010-01-22 | 2010-12-08 | 青岛海信电器股份有限公司 | LED backlight driving device of light emitting diode and liquid crystal display |
| CN201877108U (en) * | 2010-12-15 | 2011-06-22 | 深圳市启欣科技有限公司 | Light-emitting diode (LED) screen backlight drive circuit |
| CN102149235A (en) * | 2010-02-09 | 2011-08-10 | 深圳市新超亮特种显示设备有限公司 | PWM (pulse-width modulation) duty ratio adjusting and LED (light-emitting diode) indicating circuit |
| CN202634777U (en) * | 2012-04-27 | 2012-12-26 | 深圳麦格米特电气股份有限公司 | LED backlight source drive circuit |
-
2012
- 2012-04-27 CN CN201210126891.6A patent/CN102682714B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1417767A (en) * | 2001-11-09 | 2003-05-14 | 三洋电机株式会社 | Display with function of initializing brightness data of optical elements |
| CN201388310Y (en) * | 2008-12-30 | 2010-01-20 | 深圳市中联数源电子有限公司 | LED constant current drive circuit |
| CN201667742U (en) * | 2010-01-22 | 2010-12-08 | 青岛海信电器股份有限公司 | LED backlight driving device of light emitting diode and liquid crystal display |
| CN102149235A (en) * | 2010-02-09 | 2011-08-10 | 深圳市新超亮特种显示设备有限公司 | PWM (pulse-width modulation) duty ratio adjusting and LED (light-emitting diode) indicating circuit |
| CN201877108U (en) * | 2010-12-15 | 2011-06-22 | 深圳市启欣科技有限公司 | Light-emitting diode (LED) screen backlight drive circuit |
| CN202634777U (en) * | 2012-04-27 | 2012-12-26 | 深圳麦格米特电气股份有限公司 | LED backlight source drive circuit |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102682714A (en) | 2012-09-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102682714B (en) | LED backlight source driving circuit and method for realizing soft startup | |
| CN103501031B (en) | A kind of super capacitor charging control circuit | |
| CN202634777U (en) | LED backlight source drive circuit | |
| CN103219893B (en) | Switch power controller and switching power circuit | |
| CN102970791B (en) | Light-emitting diode (LED) constant current driving circuit and LED lamp | |
| CN203301611U (en) | Direct-current switching circuit and switching power source | |
| CN102013802A (en) | BOOST circuit with short circuit protection function | |
| CN103346538A (en) | Short-circuit protection circuit for APF high-power IGBT | |
| CN104374986A (en) | Novel current sampling circuit and electronic controller of breaker | |
| CN203445592U (en) | High-side output circuit with short-circuit protection | |
| CN101179185B (en) | USB interface short-circuit protection circuit and power supply with USB interface short-circuit protection function | |
| CN203368003U (en) | Dual protection device for Boost circuit | |
| CN202906437U (en) | Input undervoltage protection circuit | |
| CN103037558B (en) | Over-current protection circuit of light-emitting diode (LED) constant-current driving circuit | |
| CN101771338A (en) | Switching power supply module with high reliability and low power consumption | |
| CN203233312U (en) | Switch power supply controller and switch power supply device | |
| US20160205731A1 (en) | Hot plug module and driver for illuminating device and illuminating device | |
| CN201156786Y (en) | Energy saving television synchronous switch | |
| CN101916991A (en) | Absorption circuit for restraining impact current | |
| CN204347107U (en) | The electronic controller of New type of current sample circuit and isolating switch | |
| CN204376695U (en) | With the power starting circuit of fictitious load and the electronic controller of circuit breaker | |
| CN204068684U (en) | For the current foldback circuit of power device | |
| CN203691701U (en) | Device for controlling input surge current of LED module | |
| CN201946974U (en) | Overvoltage buffer circuit, overvoltage protection circuit and television | |
| CN203691703U (en) | Device for controlling surge current of LED module |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |