CN204259231U - Possesses the LED driving circuit of start detection function - Google Patents
Possesses the LED driving circuit of start detection function Download PDFInfo
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- CN204259231U CN204259231U CN201420716180.9U CN201420716180U CN204259231U CN 204259231 U CN204259231 U CN 204259231U CN 201420716180 U CN201420716180 U CN 201420716180U CN 204259231 U CN204259231 U CN 204259231U
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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
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Abstract
Possesses the LED driving circuit of start detection function, comprise feedback control loop and power tube, it is characterized in that, also comprise the start detection resistance joined with load LED strip, and to the current comparator that the ohmically pressure drop of start detection detects, and for the power on detection circuit that testing circuit powers on, the output of described current comparator and power on detection circuit is connected with the input of trigger and reset terminal respectively; The output of described alternative gating switch is connected with the input of PWM comparator, 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.Adopt the LED driving circuit possessing start detection function described in the utility model, by detecting the on off state of output voltage control power tube, startup stage with big space rate continuous service until meet the turn-on condition of load LED, improve the rate of climb of output voltage, shorten start-up time.
Description
Technical field
The utility model belongs to integrated circuit (IC) design field, relates to Switching Power Supply, particularly a kind of LED driving circuit possessing start detection function.
Background technology
The one of semiconductor diode, can become luminous energy electric energy conversion.Light-emitting diode is the same with general-purpose diode to be made up of a PN junction, also has unilateral conduction.After adding forward voltage to light-emitting diode, be injected into the hole in N district from P district and be injected into the electronics in P district by N district.
LED can only toward a direction conducting (energising), be called forward bias (forward bias), when the current flows, electronics and hole compound and send monochromatic light within it, this is electroluminescent effect, compare with neon lamp with incandescent lamp bulb, the feature of light-emitting diode is: operating voltage very low (more several volts had); Operating current very little (the only zero point several milliamperes had can be luminous); Shock resistance and anti-seismic performance good, reliability is high, and the life-span is long; Can the power of modulated luminescence easily by modulating that the electric current that passes through is strong and weak.Owing to there being these features, utilizing and emitting ledly carry out illumination and be applied in more and more widely among scope.
In existing single-stage high-power rate factor LED illumination drive scheme, bulky capacitor in parallel (usual hundreds of microfarad) is needed to reduce the ripple of LED at LED output.This electric capacity initial voltage is 0V, needs the operating voltage tens volts of stable states charging to LED.If the soft start not adding chip internal controls, then easily there is output voltage overshoot when startup and cause LED to have startup Transient Currents.And chip internal increases soft start control, then can increase start-up time entirely bright from switch opens to LED, be difficult to needs start-up time meeting <0.5S.
Utility model content
For improving the toggle speed of LED drive circuit, the utility model discloses a kind of LED driving circuit possessing start detection function.
Possesses the LED driving circuit of start detection function, comprise feedback control loop and power tube, described feedback control loop comprises error amplifier, PWM comparator, logic drive circuit, the output 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 comprise the start detection resistance joined with load LED strip, and to the current comparator that the ohmically pressure drop of start detection detects, and for the power on detection circuit that testing circuit powers on, the output of described current comparator and power on detection circuit is connected with the input of trigger and reset terminal respectively;
The output of described error amplifier connects the first input end connection of alternative gating switch, and the second input of described alternative gating switch is connected with high position reference voltage; The described control end of alternative gating switch is connected with the output of trigger, and the output 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 for described in possess the supply voltage of the LED driving circuit of start detection function.
Preferably, also comprise sample circuit, described sample circuit is the current sampling resistor be connected in load, and described current sampling resistor two ends connect the different inputs of error amplifier respectively.
Preferably, also building-out capacitor is connected with between described error amplifier and ground.
Preferably, described trigger is rest-set flip-flop.
Adopt the LED driving circuit possessing start detection function described in the utility model, by detecting the on off state of output voltage control power tube, startup stage with big space rate continuous service until meet the turn-on condition of load LED, improve the rate of climb of output voltage, shorten start-up time.
Accompanying drawing explanation
Fig. 1 illustrates a kind of embodiment structural representation of the present utility model.
Embodiment
Below in conjunction with accompanying drawing, embodiment of the present utility model is described in further detail.
The LED driving circuit possessing start detection function described in the utility model, comprise feedback control loop and power tube, described feedback control loop comprises error amplifier, PWM comparator, logic drive circuit, the output of described logic drive circuit is connected with the control end of power tube, and described error amplifier is for detecting the output current of LED drive circuit.
Also comprise the start detection resistance joined with load LED strip, and to the current comparator that the ohmically pressure drop of start detection detects, and for the power on detection circuit that testing circuit powers on, the output of described current comparator and power on detection circuit is connected with the input of trigger and reset terminal respectively;
The output of described error amplifier connects the first input end connection of alternative gating switch, and the second input of described alternative gating switch is connected with high position reference voltage; The described control end of alternative gating switch is connected with the output of trigger, and the output 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.
Embodiment 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 charged, voltage rises gradually, under-voltage reference voltage is default system brownout threshold voltage, usually about 1.5-2.2V is arranged on, when CIN be charged to be greater than this under-voltage reference voltage time, under-voltage comparator output voltage overturns, trigger is made to export high level signal, trigger can select the simplest rest-set flip-flop formed with door by two, flipflop output signal is 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 greater than error amplifier by comparative voltage of input, PWM comparator runs with maximum duty cycle, and the maximum duty cycle exporting square wave is determined by triangular-wave generator.After logic drive circuit, the square wave driving power pipe MN1 of this maximum duty cycle runs with maximum duty cycle, and output voltage rises fast, and in FIG, high position reference voltage directly can select the supply voltage VIN inputted, and need not redesign internal module.
Startup stage, because output voltage is not enough, the load LED of cascade cannot conducting, start detection resistance RCS does not have electric current to flow through, two ends pressure reduction is zero, when output voltage VO UT rises to certain value, such as each load LED conducting needs 3V voltage, then 10 LED strip connection need 30V to get final product conducting, now load LED conducting, generation current on RCS, RCS two ends produce pressure drop, current comparator output level reverses, flipflop output signal is reset, control alternative gating switch error amplifier output is connected with PWM comparator input terminal, thus realize normal FEEDBACK CONTROL, startup stage big space rate promote output voltage VO UT process and terminate.
Also comprise current sampling circuit in embodiment shown in Fig. 1, also comprise sample circuit, described sample circuit is the current sampling resistor be connected in load, and described current sampling resistor two ends connect the different inputs of error amplifier respectively.Which can convert output current to voltage signal and process.
Preferably, between the output of described error amplifier and ground, be connected with building-out capacitor C2, a dominant pole can be provided for control loop, the stability that reinforcing feedback controls.Switching Power Supply topology in Fig. 1 is BOOST structure, comprises inductance and rectifier diode, jointly forms BOOST framework with power tube MN1.
Adopt the LED driving circuit possessing start detection function described in the utility model, by detecting the on off state of output voltage control power tube, startup stage with big space rate continuous service until meet the turn-on condition of load LED, improve the rate of climb of output voltage, shorten start-up time.
Previously described is each preferred embodiment of the present utility model, preferred implementation in each preferred embodiment is if not obviously contradictory or premised on a certain preferred implementation, each preferred implementation can stack combinations use arbitrarily, design parameter in described embodiment and embodiment is only the utility model proof procedure in order to clear statement utility model people, and be not used to limit scope of patent protection of the present utility model, scope of patent protection of the present utility model is still as the criterion with its claims, the equivalent structure change that every utilization specification of the present utility model and accompanying drawing content are done, in like manner all should be included in protection range of the present utility model.
Claims (5)
1. possesses the LED driving circuit of start detection function, comprise feedback control loop and power tube, described feedback control loop comprises error amplifier, PWM comparator, logic drive circuit, the output 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 comprise the start detection resistance joined with load LED strip, and to the current comparator that the ohmically pressure drop of start detection detects, and for the power on detection circuit that testing circuit powers on, the output of described current comparator and power on detection circuit is connected with the input of trigger and reset terminal respectively;
The output of described error amplifier connects the first input end connection of alternative gating switch, and the second input of described alternative gating switch is connected with high position reference voltage; The described control end of alternative gating switch is connected with the output of trigger, and the output 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.
2. possess the LED driving circuit of start detection function as claimed in claim 1, it is characterized in that, described high position reference voltage for described in possess the supply voltage of the LED driving circuit of start detection function.
3. possesses the LED driving circuit of start detection function as claimed in claim 1, it is characterized in that, also comprise sample circuit, described sample circuit is the current sampling resistor be connected in load, and described current sampling resistor two ends connect the different inputs of error amplifier respectively.
4. possess the LED driving circuit of start detection function as claimed in claim 1, it is characterized in that, between described error amplifier and ground, be also connected with building-out capacitor.
5. possess the LED driving circuit of start detection function as claimed in claim 1, it is characterized in that, described trigger is rest-set flip-flop.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420716180.9U CN204259231U (en) | 2014-11-26 | 2014-11-26 | Possesses the LED driving circuit of start detection function |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420716180.9U CN204259231U (en) | 2014-11-26 | 2014-11-26 | Possesses the LED driving circuit of start detection function |
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| CN204259231U true CN204259231U (en) | 2015-04-08 |
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| CN201420716180.9U Active CN204259231U (en) | 2014-11-26 | 2014-11-26 | Possesses the LED driving circuit of start detection function |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104470099A (en) * | 2014-11-26 | 2015-03-25 | 成都岷创科技有限公司 | Light emitting diode driving circuit |
| CN104780684A (en) * | 2015-04-20 | 2015-07-15 | 成都岷创科技有限公司 | DC conversion LED drive circuit |
-
2014
- 2014-11-26 CN CN201420716180.9U patent/CN204259231U/en active Active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104470099A (en) * | 2014-11-26 | 2015-03-25 | 成都岷创科技有限公司 | Light emitting diode driving circuit |
| CN104470099B (en) * | 2014-11-26 | 2017-01-11 | 上海晶丰明源半导体有限公司 | Light emitting diode driving circuit |
| CN104780684A (en) * | 2015-04-20 | 2015-07-15 | 成都岷创科技有限公司 | DC conversion LED drive circuit |
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Legal Events
| Date | Code | Title | Description |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C41 | Transfer of patent application or patent right or utility model | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20160517 Address after: 201204 Zhang Heng road Shanghai, Pudong New Area Zhangjiang hi tech Park Lane 666 No. 2 floor 504-511 room 5 Patentee 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 Patentee before: Chengdu Minchuang Science & Technology Co., Ltd. |
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| CP03 | Change of name, title or address | ||
| CP03 | Change of name, title or address |
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. |