CN104470099B - Light emitting diode driving circuit - Google Patents
Light emitting diode driving circuit Download PDFInfo
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- CN104470099B CN104470099B CN201410686259.6A CN201410686259A CN104470099B CN 104470099 B CN104470099 B CN 104470099B CN 201410686259 A CN201410686259 A CN 201410686259A CN 104470099 B CN104470099 B CN 104470099B
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Abstract
A light emitting diode (LED) driving circuit comprises a feedback loop and a power tube and is characterized by further comprising a start detection resistor, a current comparator and a power-on detection circuit, wherein the start detection resistor is connected with a load LED in series, the current comparator is used for detecting a voltage drop on the start detection resistor, the power-on detection circuit is used for detecting the power-on situation of the LED driving circuit, and the output end of the current comparator and the output end of the power-on detection circuit are connected with the input end and the reset end of a trigger respectively; the output end of an either-or gating switch is connected with the input end of a PWM comparator, the power-on detection circuit is an undervoltage comparator, and power voltage and undervoltage reference voltage are input into the two input ends of the undervoltage comparator respectively. By the adoption of the LED driving circuit, the on-off state of the power tube is controlled by detecting output voltage, continuous running is conducted at a large duty ratio at the starting stage until turn-on conditions of the load LED are met, the rising speed of the output voltage is increased, and start time is shortened.
Description
Technical field
The invention belongs to IC design field, relate to Switching Power Supply, particularly a kind of LED driving circuit.
Background technology
The one of semiconductor diode, can change into luminous energy electric energy.Light emitting diode is made up of a PN junction as general-purpose diode, it may have unilateral conduction.After to light emitting diode plus forward voltage, it is injected into the hole in N district from P district and is injected into the electronics in P district by N district.
LED can only be toward direction conducting (energising), it is called forward bias (forward bias), when the current flows, electronics and hole are compound within it and send monochromatic light, this is electroluminescent effect, compared with incandescent lamp bulb and neon lamp, the feature of light emitting diode is: running voltage the lowest (the most several volts having)；Operating current the least (several milliamperes of the only zero point having can be luminous)；Shock resistance and anti-seismic performance are good, and reliability is high, and the life-span is long；The electric current power passed through by modulation can modulate the power of luminescence easily.Owing to there being these features, emitting led being illuminated is utilized to apply among scope the most widely.
In existing single-stage high-power rate factor LED illumination drive scheme, bulky capacitor (usual hundreds of microfarad) in parallel is needed to reduce the ripple of LED at LED outfan.This electric capacity initial voltage is 0V, needs to charge to tens volts of stable states of running voltage of LED.If the soft start being not added with chip internal controls, then it is susceptible to output voltage when startup and crosses punching and cause LED to have startup Transient Currents.And chip internal increases soft start and controls, then can increase the startup time being opened to LED all light from switch, be difficult to meet < the startup time needs of 0.5S.
Summary of the invention
For improving the toggle speed of LED drive circuit, the invention discloses a kind of LED driving circuit.
LED driving circuit, including feedback control loop and power tube, described feedback control loop includes error amplifier, PWM comparator, logic drive circuit, the outfan of described logic drive circuit is connected with the control end of power tube, and described error amplifier is for detecting the output voltage of LED drive circuit；
It is characterized in that, also include the startup detection resistance with load LED strip connection, and detect, to starting, the current comparator that ohmically pressure drop detects, and it being used for the power on detection circuit that testing circuit powers on, the outfan of described current comparator and power on detection circuit is connected with input and the reset terminal of trigger respectively；
The outfan of described error amplifier connects the first input end of alternative gating switch and connects, and the second input of described alternative gating switch is connected with high position reference voltage；The end that controls of described alternative gating switch is connected with the outfan of trigger,
The outfan of described alternative gating switch is connected with the input of PWM comparator；
The reference voltage value of described high position reference voltage is not less than the supply voltage of error amplifier, and described power on detection circuit is under-voltage comparator, and two inputs of described under-voltage comparator connect supply voltage and under-voltage reference voltage respectively.
Preferably, described high position reference voltage is the supply voltage of described LED driving circuit.
Preferably, also including that sample circuit, described sample circuit are the current sampling resistor being connected in load, described current sampling resistor two ends connect the different inputs of error amplifier respectively.
Preferably, it is also associated with between described error amplifier and ground compensating electric capacity.
Preferably, described trigger is rest-set flip-flop.
Use LED driving circuit of the present invention, by detecting the on off state of output voltage control power tube, startup stage with big space rate continuous service until meeting the turn-on condition of load LED, improve the rate of climb of output voltage, shortening the startup time.
Accompanying drawing explanation
Fig. 1 illustrates a kind of detailed description of the invention structural representation of the present invention.
Detailed description of the invention
Below in conjunction with the accompanying drawings, the detailed description of the invention of the present invention is described in further detail.
LED driving circuit of the present invention, including feedback control loop and power tube, described feedback control loop includes error amplifier, PWM comparator, logic drive circuit, the outfan of described logic drive circuit is connected with the control end of power tube, and described error amplifier is for detecting the output electric current of LED drive circuit.
Also include the startup detection resistance with load LED strip connection, and detect, to starting, the current comparator that ohmically pressure drop detects, and it being used for the power on detection circuit that testing circuit powers on, the outfan of described current comparator and power on detection circuit is connected with input and the reset terminal of trigger respectively；
The outfan of described error amplifier connects the first input end of alternative gating switch and connects, and the second input of described alternative gating switch is connected with high position reference voltage；The end that controls of described alternative gating switch is connected with the outfan of trigger,
The outfan of described alternative gating switch is connected with the input of PWM comparator.
The reference voltage value of described high position reference voltage is not less than the supply voltage of error amplifier, and described power on detection circuit is under-voltage comparator, and two inputs of described under-voltage comparator connect supply voltage and under-voltage reference voltage respectively.
Detailed description of the invention as shown in Figure 1, power on detection circuit is under-voltage comparator, two inputs of described under-voltage comparator connect supply voltage and under-voltage reference voltage respectively, when powering on, input capacitance CIN is electrically charged, voltage is gradually increasing, under-voltage reference voltage is default system brownout threshold voltage, it is generally arranged at about 1.5-2.2V, when CIN is charged to more than this under-voltage reference voltage, under-voltage comparator output voltage overturns, trigger is made to export high level signal, trigger can select simplest by two rest-set flip-flops constituted with door, trigger outputs signals to single-pole double-throw switch (SPDT), control single-pole double-throw switch (SPDT) to be connected between PWM input and high position reference voltage.
Startup stage, as shown in Figure 1, two inputs of PWM comparator are connected between high position reference voltage and triangular-wave generator, high position reference voltage is higher than the supply voltage of error amplifier, PWM is made to compare the output voltage maximum being necessarily more than error amplifier by comparing voltage of input, PWM comparator runs with maximum duty cycle, and the maximum duty cycle of output square wave is determined by triangular-wave generator.After logic drive circuit, the square wave drive power tube MN1 of this maximum duty cycle runs with maximum duty cycle, and output voltage rapid increase, in FIG, high position reference voltage can directly select the supply voltage VIN of input, need not redesign internal module.
Startup stage, owing to output voltage is not enough, the load LED of cascade cannot turn on, starting does not has electric current to flow through on detection resistance RCS, two ends pressure reduction is zero, when output voltage VO UT rises to certain value, the most each load LED conducting needs 3V voltage, then 10 LED strip connection need 30V to turn on, now load LED conducting, RCS produces electric current, RCS two ends produce pressure drop, current comparator output level inverts, trigger output signal is made to reset, control alternative gating switch error amplifier output and PWM comparator input terminal to be connected, thus realize normal feedback control, startup stage big space rate promote output voltage VO UT process terminate.
The most also including current sampling circuit in detailed description of the invention shown in Fig. 1, also include that sample circuit, described sample circuit are the current sampling resistor being connected in load, described current sampling resistor two ends connect the different inputs of error amplifier respectively.Output electric current can be converted into voltage signal and process by which.
Preferably, connect between outfan and the ground of described error amplifier and have compensation electric capacity C2, can be to control loop to provide a dominant pole, the stability that reinforcing feedback controls.Switching Power Supply topology in Fig. 1 is BOOST structure, including inductance and commutation diode, collectively forms BOOST framework with power tube MN1.
Use LED driving circuit of the present invention, by detecting the on off state of output voltage control power tube, startup stage with big space rate continuous service until meeting the turn-on condition of load LED, improve the rate of climb of output voltage, shortening the startup time.
Previously described each preferred embodiment for the present invention, preferred implementation in each preferred embodiment is if not the most contradictory or premised on a certain preferred implementation, each preferred implementation can arbitrarily stack combinations use, design parameter in described embodiment and embodiment is merely to clearly state the invention proof procedure of inventor, and it is not used to limit the scope of patent protection of the present invention, the scope of patent protection of the present invention is still as the criterion with its claims, the equivalent structure change that the description of every utilization present invention and accompanying drawing content are made, in like manner should be included in protection scope of the present invention.
Claims (3)
1. LED driving circuit, including feedback control loop and power tube, described feedback control loop includes error amplifier, PWM
Comparator, logic drive circuit, the outfan of described PWM comparator is connected with the input of described logic drive circuit,
The outfan of described logic drive circuit is connected with the control end of power tube, and described error amplifier is used for detecting LED and drives
The output voltage on galvanic electricity road；
It is characterized in that, also include the startup detection resistance with load LED strip connection, and detect ohmically pressure drop to starting
Carry out the current comparator detected, and the power on detection circuit powered on for testing circuit, described current comparator and upper
The outfan of power detection circuit is connected with input and the reset terminal of trigger respectively；
The outfan of described error amplifier connects the first input end of alternative gating switch and connects, described alternative gating switch
The second input be connected with high position reference voltage；The outfan controlling end and trigger of described alternative gating switch is even
Connecing, the outfan of described alternative gating switch is connected with the input of PWM comparator；
The reference voltage value of described high position reference voltage is not less than the supply voltage of error amplifier, and described power on detection circuit is deficient
Pressure comparator, two inputs of described under-voltage comparator connect supply voltage and under-voltage reference voltage respectively；
Wherein, described high position reference voltage is the supply voltage of described LED driving circuit, and described trigger is that RS touches
Send out device.
2. LED driving circuit as claimed in claim 1, it is characterised in that also include sample circuit, described sample circuit
For the current sampling resistor being connected in load, the difference that described current sampling resistor two ends connect error amplifier respectively is defeated
Enter end.
3. LED driving circuit as claimed in claim 1, it is characterised in that also connect between described error amplifier and ground
It is connected to compensate electric capacity.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410686259.6A CN104470099B (en) | 2014-11-26 | 2014-11-26 | Light emitting diode driving circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410686259.6A CN104470099B (en) | 2014-11-26 | 2014-11-26 | Light emitting diode driving circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104470099A CN104470099A (en) | 2015-03-25 |
| CN104470099B true CN104470099B (en) | 2017-01-11 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201410686259.6A Active CN104470099B (en) | 2014-11-26 | 2014-11-26 | Light emitting diode driving circuit |
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Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104768292A (en) * | 2015-03-27 | 2015-07-08 | 绵阳豪迈电子科技有限公司 | Drive circuit applied to intelligent cell system |
| CN104767362A (en) * | 2015-03-27 | 2015-07-08 | 绵阳豪迈电子科技有限公司 | Parking lot management system drive circuit |
| CN104780684A (en) * | 2015-04-20 | 2015-07-15 | 成都岷创科技有限公司 | DC conversion LED drive circuit |
| CN106160712B (en) * | 2016-07-08 | 2019-04-12 | 深圳市博巨兴实业发展有限公司 | A kind of por circuit of band LVR function |
| CN109302777B (en) * | 2018-12-06 | 2024-03-15 | 深圳市德信创微电子有限公司 | LED dimming device and dimming system |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102088808A (en) * | 2010-11-30 | 2011-06-08 | 南京微盟电子有限公司 | Contact current LED driving circuit of snap switch |
| CN102510619A (en) * | 2011-10-27 | 2012-06-20 | 上海晶丰明源半导体有限公司 | Quick start-up device of LED (light-emitting diode) driving power supply |
| CN102802318A (en) * | 2012-08-28 | 2012-11-28 | 绍兴光大芯业微电子有限公司 | Flyback-type quick-start LED (Light-Emitting Diode) drive circuit structure |
| US8629631B1 (en) * | 2011-07-21 | 2014-01-14 | Cooper Technologies Company | Method and system for improving start-up time of a light emitting diode (LED) driver at reduced input voltage |
| CN204259231U (en) * | 2014-11-26 | 2015-04-08 | 成都岷创科技有限公司 | Possesses the LED driving circuit of start detection function |
-
2014
- 2014-11-26 CN CN201410686259.6A patent/CN104470099B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102088808A (en) * | 2010-11-30 | 2011-06-08 | 南京微盟电子有限公司 | Contact current LED driving circuit of snap switch |
| US8629631B1 (en) * | 2011-07-21 | 2014-01-14 | Cooper Technologies Company | Method and system for improving start-up time of a light emitting diode (LED) driver at reduced input voltage |
| CN102510619A (en) * | 2011-10-27 | 2012-06-20 | 上海晶丰明源半导体有限公司 | Quick start-up device of LED (light-emitting diode) driving power supply |
| CN102802318A (en) * | 2012-08-28 | 2012-11-28 | 绍兴光大芯业微电子有限公司 | Flyback-type quick-start LED (Light-Emitting Diode) drive circuit structure |
| CN204259231U (en) * | 2014-11-26 | 2015-04-08 | 成都岷创科技有限公司 | Possesses the LED driving circuit of start detection function |
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| Publication number | Publication date |
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| CN104470099A (en) | 2015-03-25 |
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Effective date of registration: 20160419 Address after: 201204 Zhang Heng road Shanghai, Pudong New Area Zhangjiang hi tech Park Lane 666 No. 2 floor 504-511 room 5 Applicant after: Shanghai Bright Power Semiconductor Co.,Ltd. Address before: West high tech Zone Fucheng Road in Chengdu city of Sichuan province 610000 399 No. 6 Building 1 unit 10 floor No. 2 Applicant before: Chengdu Minchuang Science & Technology Co., Ltd. |
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Address after: 5 room 504-511, room 2, Lane 666, Zhang Heng Road, Pudong New Area, China (Shanghai) free trade zone, Shanghai, China () Patentee after: Shanghai semiconducto Limited by Share Ltd Address before: 201204 Zhang Heng road Shanghai, Pudong New Area Zhangjiang hi tech Park Lane 666 No. 2 floor 504-511 room 5 Patentee before: Shanghai Bright Power Semiconductor Co.,Ltd. |