CN205946252U

CN205946252U - Led actuating device

Info

Publication number: CN205946252U
Application number: CN201620741352.7U
Authority: CN
Inventors: 何北凯
Original assignee: Shenzhen TCL New Technology Co Ltd
Current assignee: Shenzhen TCL New Technology Co Ltd
Priority date: 2016-07-13
Filing date: 2016-07-13
Publication date: 2017-02-08
Anticipated expiration: 2026-07-13

Abstract

The utility model discloses a led actuating device, this led actuating device include power interface module, power supply handle circuit, drive and control circuit, current foldback circuit and LED lamp interface, and drive and control circuit includes signal feedback end, control signal output, reference voltage output and power input end, this power input end and power interface module's first output and current foldback circuit's power input end interconnection, this reference voltage output and current foldback circuit's signal input part is connected, and this signal feedback is held and is connected with current foldback circuit's signal output part, should control signal output part and be connected with the controlled end of power supply handle circuit, power interface module's the second output and the input of power supply handle circuit are connected, the output and the LED lamp interface connection of power supply handle circuit. The utility model discloses in the time of can avoiding led actuating device unusual, the electric current of the LED lamp of flowing through exceedes its rated current upper limit value, causes the problem that the LED lamp is burnt out.

Description

LED drive device

Technical field

This utility model is related to field of LED drive, more particularly, to a kind of LED drive device.

Background technology

At present, adopt white LED lamp the backlight of the display device such as computer monitor, television set, LED is in normally electricity more When using in the range of stream, voltage, temperature equal-specification, its life-span is very long.But because thunderbolt, static discharge etc. are various former Cause, the drive circuit works easily causing LED are abnormal, and the electric current flowing through LED increases and exceedes the upper of its rated current Limit value, if circuit can not timely enter guard mode it is possible to cause the problem that LED is burned out.

Utility model content

Main purpose of the present utility model is to propose a kind of LED drive device it is intended to solve asking of being burned out of LED Topic, extends the service life of LED.

For achieving the above object, the utility model proposes a kind of LED drive device, protect including power supply interface module, excessively stream Protection circuit, drive control circuit, power supply processing circuit and LED interface, described drive control circuit includes signal feedback end, control Signal output part processed, reference voltage output terminal and power input；Described power input and the electricity of described current foldback circuit Source input is connected with the first outfan of described power supply interface module respectively, and described reference voltage output terminal is protected with described excessively stream The signal input part of protection circuit connects, and the signal output part of described current foldback circuit is connected with described signal feedback end, described Control signal outfan is connected with the controlled end of described power supply processing circuit；Second outfan of described power supply interface module and institute The input stating power supply processing circuit connects；The outfan of described power supply processing circuit is connected with described LED interface；Wherein,

Described drive control circuit, for driving described power supply processing circuit work according to internal reference voltage；

Described current foldback circuit, for detecting the reference voltage of described drive control circuit, and in described reference voltage During more than its voltage protection threshold value, output overcurrent protection signal to described drive control circuit, so that described drive control circuit Described power supply processing circuit is controlled to quit work.

Preferably, described current foldback circuit includes voltage detecting electronic circuit, error amplifies electronic circuit, first switch son electricity Road, partial pressure output electronic circuit and second switch electronic circuit, the test side of described voltage detecting electronic circuit and described drive control electricity The reference voltage output terminal on road connects, and the signal that the feedback end of described voltage detecting electronic circuit amplifies electronic circuit with described error connects Receiving end connects；The signal output part that described error amplifies electronic circuit is connected with the controlled end of described first switch electronic circuit；Described The input of first switch electronic circuit is that the power input of described current foldback circuit connects, described first switch electronic circuit Outfan is used for electrically connecting with the input of described partial pressure output electronic circuit and the controlled end of described second switch electronic circuit respectively； The outfan that described partial pressure exports electronic circuit is connected with the signal feedback end of described drive control circuit；Described second switch electricity The outfan on road is connected with the Enable Pin of described drive control circuit.

Preferably, described voltage detecting electronic circuit includes the first stabilivolt and first resistor, the moon of described first stabilivolt Pole is connected with the reference voltage output terminal of described drive control circuit, and the anode of described first stabilivolt connects through described first resistor The common port of ground, described first stabilivolt and described second resistance is the feedback end of described voltage detecting electronic circuit.

Preferably, described error amplification electronic circuit includes the first audion, second resistance, the first end of described second resistance For the signal receiving end of described drive circuit, the second end of described second resistance is connected with the base stage of the first audion；Described The colelctor electrode of one audion is connected with the controlled end of described first switch electronic circuit, the grounded emitter of described first audion.

Preferably, described first switch electronic circuit includes the second audion, 3rd resistor, the 4th resistance and the 5th resistance, The first end of described 3rd resistor is the controlled end of described first switch electronic circuit, the second end of described 3rd resistor and described the The base stage of two audions connects；The colelctor electrode of described second audion exports electronic circuit through described 5th resistance with described partial pressure Input connects, and the emitter stage of described second audion is connected with the first outfan of described power supply interface module；Described 4th Resistor coupled in parallel is connected between emitter stage and the base stage of described second audion.

Preferably, described partial pressure output electronic circuit includes the 6th resistance, the 7th resistance and isolation element, described 6th resistance First end be the input that described partial pressure exports electronic circuit, the second end of described 6th resistance is through described 7th resistance eutral grounding； Described 6th resistance is connected with the first end of described isolation element with the common port of described 7th resistance, and the of described isolation element Two ends are connected with the signal feedback end of described drive control circuit.

Preferably, described second switch electronic circuit includes the first metal-oxide-semiconductor and the first electric capacity, the grid of described first metal-oxide-semiconductor For the controlled end of described second switch electronic circuit, the drain electrode of described first metal-oxide-semiconductor is the outfan of described second switch electronic circuit, The source ground of described first metal-oxide-semiconductor；Described first electric capacity is connected in parallel between drain electrode and the source electrode of described first metal-oxide-semiconductor.

Preferably, described power supply interface module includes on-off circuit, and described on-off circuit includes the 3rd audion, second steady Pressure pipe, the second electric capacity, the 9th resistance, the tenth resistance, the 11st resistance, the first end of described 9th resistance is exported with supply voltage End connects, the second end of described 9th resistance base through described tenth resistance, described 11st resistance and described 3rd audion Pole connects；The colelctor electrode of described 3rd audion is connected with the common port of described tenth resistance and described 11st resistance, described Transmitting extremely first outfan of the 3rd audion；The negative electrode of the negative electrode of described second stabilivolt and described 3rd audion and the The first end interconnection of two electric capacity, the anode of described second stabilivolt is connected with the second end of described second electric capacity, and is grounded.

Preferably, described drive control circuit include drive control chip, the 5th electric capacity, the 6th electric capacity, the 7th electric capacity, 12 resistance, the 13rd resistance, the 14th resistance, the 16th resistance and the 17th resistance, described drive control chip includes joining Examine voltage output foot, overvoltage detection foot, enable foot, current settings foot, frequency setting foot, soft start and control loop compensate foot, Supply pin, Pulse Width Control foot, backlight illumination control input foot, the first current feedback foot, the second current feedback foot, the 3rd electric current are anti- Feed pin, the 4th current feedback foot and grounding leg；The first end of described 8th resistance is backlight start control signal receiving terminal, described Second end of the 8th resistance is connected with the enable foot of described drive control chip；Described current settings foot is through described 12nd resistance Ground connection, described frequency setting foot is through described 14th resistance eutral grounding；Described 13rd resistance is connected to described power supply processing circuit And the current detecting foot of described drive control chip between；Described 5th capacitance connection institute between described current detecting foot and ground State the 6th capacitance connection between described reference voltage output foot and ground；Described supply pin and the first of described power supply interface module Outfan connects；Described backlight illumination control input foot is connected with backlight illumination control end through described 17th resistance, described soft Start and control loop compensates foot successively through described 16th resistance and the 7th capacity earth；Described first current feedback foot, institute State the second current feedback foot, described 3rd current feedback foot and described 4th current feedback foot interface corresponding with described LED Connect.

Preferably, described power supply processing circuit includes boosting unit, over-pressed detector unit, boosting detector unit and rectification filter Ripple unit, the input of described boosting unit is the input of described power supply processing circuit, the outfan of described booster circuit with The input of described current rectifying and wave filtering circuit connects, the Pulse Width Control of the controlled end of described booster circuit and described drive control chip Foot connects, and the feedback end of described boosting unit is connected with the test side of described boosting detector unit；Described boosting detector unit Signal feedback end is connected with the current detecting foot of described drive control chip, the output head grounding of described boosting detector unit；Institute The outfan stating current rectifying and wave filtering circuit is the outfan of described power supply processing circuit, and the test side with described overvoltage detector unit Connect；The feedback output end of described overvoltage detector unit is connected with the overvoltage detection foot of described drive control chip.

This utility model LED drive device is by arranging drive control circuit come drive control power supply process circuit to through electricity The supply voltage of source interface module output is processed with lightening LED lamp, passes through to arrange current foldback circuit, this excessively stream is protected simultaneously Protection circuit passes through to detect the reference voltage of drive control circuit, when this reference voltage level is detected and reaching threshold value, will detection letter Number feed back to drive control circuit so that drive control circuit power supply processing circuit stops the power supply output to LED, this Sample, just it can be avoided that during LED drive device operation irregularity, flowing through and increased based on the LED electric current that drive control integrated circuit controls Exceed greatly its rated current higher limit, cause the problem that LED is burned out.

Brief description

Fig. 1 is the high-level schematic functional block diagram of this utility model LED drive device one embodiment；

Fig. 2 is the electrical block diagram of LED drive device shown in Fig. 1.

Drawing reference numeral explanation：

The realization of the purpose of this utility model, functional characteristics and advantage, will, and make further referring to the drawings in conjunction with the embodiments Explanation.

Specific embodiment

Below in conjunction with the accompanying drawing in this utility model embodiment, the technical scheme in this utility model embodiment is carried out Clearly and completely describe it is clear that described embodiment is only a part of embodiment of the present utility model, rather than all Embodiment.Based on the embodiment in this utility model, those of ordinary skill in the art are not making creative work premise Lower obtained every other embodiment, broadly falls into the scope of this utility model protection.

It is to be appreciated that the directional instruction (such as up, down, left, right, before and after ...) of institute in this utility model embodiment It is only used for explaining the relative position relation between each part, motion conditions etc. under a certain particular pose (as shown in drawings), such as When really this particular pose changes, then directionality instruction also correspondingly changes therewith.

In addition, the description being related to " first ", " second " etc. in this utility model is only used for describing purpose, and it is not understood that For indicating or implying its relative importance or the implicit quantity indicating indicated technical characteristic.Thus, define " first ", The feature of " second " can be expressed or implicitly include at least one this feature.In addition, the technical side between each embodiment Case can be combined with each other, but must be capable of by those of ordinary skill in the art based on, when the combination of technical scheme Will be understood that the combination of this technical scheme does not exist when appearance is conflicting or cannot realize, also do not require in this utility model Protection domain within.

The utility model proposes a kind of LED drive device.

With reference to Fig. 1, this LED drive device includes power supply interface module 10, current foldback circuit 20, power supply processing circuit 30th, drive control circuit 40 and LED interface 50, described drive control circuit 40 includes signal feedback end, control signal output End, reference voltage output terminal and power input；The power input of described drive control circuit 40 and described overcurrent protection electricity The power input on road 20 is connected with the first outfan of described power supply interface module 10 respectively, described drive control circuit 40 Reference voltage output terminal is connected with the signal input part of described current foldback circuit 20, and the signal of described current foldback circuit 20 is defeated Go out end be connected with the signal feedback end of described drive control circuit 40, the control signal outfan of described drive control circuit 40 and The controlled end of described power supply processing circuit 30 connects；Second outfan of described power supply interface module 10 processes electricity with described power supply The input on road 30 connects；The outfan of described power supply processing circuit 30 is connected with described LED interface 50.

Specifically, described power supply interface module 10, for input supply voltage, and is described power supply processing circuit 30, drives Dynamic control circuit 40 and current foldback circuit 20 energy supply；Described power supply processing circuit 30, for by described power supply interface module 10 The supply voltage of output is LED energy supply after carrying out voltage conversion process；Described drive control circuit 40, for according to internal ginseng Examine voltage to drive described power supply processing circuit 30 to work；Described current foldback circuit 20, for detecting described drive control electricity The reference voltage on road 40, and when described reference voltage is more than its voltage protection threshold value, output overcurrent protection signal to described drive Dynamic control circuit 40, so that described drive control circuit 40 controls described power supply processing circuit 30 to quit work.

When under the abnormalities such as thunderbolt, Electro-static Driven Comb, producing very big transient voltage, this voltage may pass through common ground And have influence on the reference voltage of the drive control circuit 40 of LED drive device, and so that reference voltage is raised, this reference voltage and drive The current settings foot of the drive control chip IC 1 of dynamic control circuit 40 determines the current value flowing through LED simultaneously, therefore works as reference During the impacted rising of voltage, the electric current being synchronized to LED will increase.Therefore, described drive is detected by current foldback circuit 20 The reference voltage of dynamic control circuit 40 can know whether LED will be in excessively stream in time, now, when current foldback circuit 20 is examined When measuring the reference voltage of drive control circuit and reaching threshold value, detection signal is fed back to drive control circuit 40 so that driving control Circuit 40 processed controls power supply processing circuit 30 to stop the power supply output to LED, so, just avoids LED drive device work When abnormal, flow through the LED electric current based on drive control circuit 40 controls and increase above its rated current higher limit, cause LED The problem that lamp is burned out.

With reference to Fig. 1 and Fig. 2, in a preferred embodiment, described current foldback circuit 20 include voltage detecting electronic circuit 21, Error amplifies electronic circuit 22, first switch electronic circuit 23, partial pressure output electronic circuit 24 and second switch electronic circuit 25.

Wherein, the reference voltage output terminal of the test side of described voltage detecting electronic circuit 21 and described drive control circuit 40 Connect, the signal receiving end that the feedback end of described voltage detecting electronic circuit 21 amplifies electronic circuit 22 with described error is connected；Described The signal output part that error amplifies electronic circuit 22 is connected with the controlled end of described first switch electronic circuit 23；Described first switch The input of circuit 23 is the power input of described current foldback circuit 20, and the outfan of described first switch electronic circuit 23 is used Controlled end in the input and described second switch electronic circuit 25 that export electronic circuit 24 with described partial pressure respectively electrically connects；Described The outfan that partial pressure exports electronic circuit 24 is connected with the signal feedback end of described drive control circuit 40；Described second switch electricity The outfan on road 25 is connected with the Enable Pin of described drive control circuit 40.

Specifically, described voltage detecting electronic circuit 21, for detecting the reference voltage output of described drive control circuit 40 The reference voltage of end output；Described error amplifies electronic circuit 22, for described drive is detected in described voltage detecting electronic circuit 21 When the reference voltage of dynamic control circuit 40 exceedes the threshold value of reference voltage, detection signal is amplified exporting to first switch Circuit 23；Described first switch electronic circuit 23, for when receiving the control signal that described error amplifies electronic circuit 22 output, Open to export detection signal；Described partial pressure exports electronic circuit 24, for after first switch electronic circuit 23 is opened, by detection letter Export to the signal feedback end of described drive control circuit 40 after number carrying out voltage division processing；Described second switch electronic circuit 25, uses In avoiding LED string to bear long overcurrent, control and close described LED drive device.

When the reference voltage that the test side of voltage detecting electronic circuit 21 detects described drive control circuit 40 exceedes reference During the threshold value of voltage, the feedback end of voltage detecting electronic circuit 21 exports detection signal to error the input amplifying electronic circuit 22 End, error is amplified letter circuit 22 and this detection signal is amplified processing after receiving detection signal, and exports and open to first Close the input of electronic circuit 23 circuit, to drive first switch electronic circuit 23 to open, thus output amplifies electronic circuit 22 through error Amplify detection signal to partial pressure export electronic circuit 24, this detection signal through partial pressure output electronic circuit 24 voltage division processing after export to The signal feedback end of described drive control circuit 40, so that drive control circuit 40 turns off drive control signal；Meanwhile, when second Switch electronic circuit 25 detects to flow through and exceedes after certain time to the overcurrent of LED, and rapid control drive control circuit 40 closes Disconnected drive control signal is to stop LED being powered, thus avoiding LED to be burned out.

With reference to Fig. 2, in being preferable to carry out one, described voltage detecting electronic circuit 21 includes the first stabilivolt ZD1 and first electricity Resistance R1, the negative electrode of described first stabilivolt ZD1 is connected with the reference voltage output terminal of described drive control circuit 40, and described first The anode of resistance R1 is grounded through described first resistor R1, and described first stabilivolt ZD1 is with described the with the common port of resistance as institute State the feedback end of voltage detecting electronic circuit 21.

When voltage detecting electronic circuit 21 detects the reference voltage of the reference voltage output terminal output of drive control circuit 40 Rise, exceed reference voltage threshold value when, the first stabilivolt ZD1 is reversed and punctures and turn on so that flowing through first resistor R1 Electric current sharply increases, and when the voltage at first resistor R1 two ends reaches certain value, this voltage is as detection signal through the first voltage stabilizing Pipe ZD1 exports to error, with the common port of described first resistor R1, the input amplifying electronic circuit 22.

With reference to Fig. 2, in a preferred embodiment, described error is amplified electronic circuit 22 and is included the first audion Q1, the second electricity Resistance R2, the first end of described second resistance R2 is the signal receiving end that described error amplifies electronic circuit 22, described second resistance R2 The second end be connected with the base stage of the first audion Q1；The colelctor electrode of described first audion Q1 and described first switch electronic circuit 23 controlled end connects, the grounded emitter of described first audion Q1.

Specifically, when the base stage of the first audion Q1 receives detection signal through second resistance R2, the first audion Q1 Triggering and conducting, and export to the controlled end of first switch electronic circuit 23 after detection signal is amplified.

With reference to Fig. 2, in a preferred embodiment, described first switch electronic circuit 23 includes the second audion Q2, the 3rd electricity Resistance R3, the 4th resistance R4 and the 5th resistance R5, the first end of described 3rd resistor R3 is being subject to of described first switch electronic circuit 23 Control end, the second end of described 3rd resistor R3 is connected with the base stage of described second audion Q2；The collection of described second audion Q2 Electrode is connected through the input that described 5th resistance R5 exports electronic circuit 24 with described partial pressure, the transmitting of described second audion Q2 Pole is connected with the first outfan VCC1 of described power supply interface module 10；Described 4th resistance R4 is connected in parallel in the described 2nd 3 Between the emitter stage of pole pipe Q2 and base stage.

Wherein, described 4th resistance R4 is used for providing bias current so that the second audion Q2 exists for the second audion Q2 Saturation conduction under certain condition, described 5th resistance R5 is delay cell, because the effect of the 5th resistance R5 is so that first switch The electric current output of electronic circuit 23 is slow.

Specifically, put through error amplification electronic circuit 22 when the base stage of described second audion Q2 receives through 3rd resistor R3 During big detection signal, the second audion Q2 triggering and conducting, complete the transmission output of detection signal.

With reference to Fig. 2, in a preferred embodiment, described partial pressure output electronic circuit 24 includes the 6th resistance R6, the 7th resistance R7 and isolation element, the first end of described 6th resistance R6 is the input that described partial pressure exports electronic circuit 24, described 6th electricity Second end of resistance R6 is through described 7th resistance R7 ground connection；The common port of described 6th resistance R6 and described 7th resistance R7 with described The first end of isolation element connects, and the second end of described isolation element is connected with the signal feedback end of described drive control circuit 40 Connect.

In the present embodiment, described isolation element preferably employs diode D1, and this isolation element is used for realizing detection signal Unidirectional output.

Specifically, the 6th resistance R6 and the 7th resistance R7 pass through connect partial pressure, by detection signal through isolation element export to The signal feedback end of drive control circuit 40, completes the output of signal.

With reference to Fig. 2, in a preferred embodiment, described second switch electronic circuit 25 includes the first metal-oxide-semiconductor QW1 and first electricity Hold C1, the grid of described first metal-oxide-semiconductor QW1 is the controlled end of described second switch electronic circuit 25, described first metal-oxide-semiconductor QW1's The outfan draining as described second switch electronic circuit, the source ground of described first metal-oxide-semiconductor QW1；Described first electric capacity C1 is simultaneously Connection is connected between the drain electrode of described first metal-oxide-semiconductor QW1 and the source electrode of described first metal-oxide-semiconductor QW1.

Wherein, there is interelectrode capacity between the inside drain electrode of the first metal-oxide-semiconductor QW1 and source electrode, this electric capacity and the 5th resistance R5 Constitute RC delay unit, by resistance and the grid source capacitance Cgs of regulation the 5th resistance R5 thus controlling second switch The conducting delay time of circuit 25.

Specifically, when the grid of the first metal-oxide-semiconductor QW1 receives the Continuity signal of first switch electronic circuit 23, through grid source After the delay unit time delay certain time of interelectrode capacity Cgs and the 5th resistance R5 composition, the conducting of the first metal-oxide-semiconductor QW1 is so that drive The Enable Pin of dynamic control circuit 40 is pulled low and so that described drive control circuit 40 is quit work, thus stopping output driving control Signal, and maintain over-voltage locking state, in this manner it is possible to avoid the electric current flowing through LED to increase above its rated current upper limit During value, LED is caused to be burned out the continuous action of LED.

In conjunction with Fig. 2 and above-described embodiment, the physical circuit principle of this utility model current foldback circuit 20 is as follows：

When the reference voltage that voltage detecting electronic circuit 21 detects described drive control circuit 40 is increased to preset value, the One stabilivolt ZD1 is reversed and punctures and turn on so that the electric current flowing through first resistor R1 sharply increases, when first resistor R1 two ends Voltage when reaching certain value, this voltage public warp through the first stabilivolt ZD1 and described first resistor R1 as detection signal Second resistance R2 exports, and drives the first audion Q1 triggering and conducting to the base stage of the first audion Q1, and the first audion Q1 will Detection signal exports to the controlled end of first switch electronic circuit 23 after amplifying, and the base stage of the second audion Q2 connects through 3rd resistor R3 Receive and amplify, through error, the detection signal that electronic circuit 22 amplifies and trigger the second audion Q2 conducting, and export detection signal to the Six resistance R6, the 6th resistance R6 and the 7th resistance R7, after partial pressure of connecting, detection signal are exported to described through isolation element The signal feedback end of drive control circuit 40, completes the output of signal.

It is understood that when the enable foot ENA of drive control chip IC 1 is in the backlight starting-up signal receiving outside During BL_ON, the voltage of this foot is high level, when the grid of the first metal-oxide-semiconductor QW1 receives the conducting letter of first switch electronic circuit 23 After number, after the delay unit time delay certain time through grid source capacitance Cgs and the 5th resistance R5 composition, the first metal-oxide-semiconductor QW1's Conducting is so that the level of the enable foot ENA of drive control chip IC 1 is pulled low and closes drive control chip IC 1, thus stopping Output driving control signal, and maintain over-voltage locking state.

To sum up, using the current foldback circuit 20 of the present embodiment, it is to avoid LED in LED drive device operation irregularity, The reference voltage causing drive control chip IC 1 raises and passes through LED electric current and increase above its rated current higher limit, Cause the problem that LED is burned out, extend the service life of LED.

In above-described embodiment, described power supply interface module 10 also includes on-off circuit 11, and described on-off circuit 11 includes Three audion Q3, the second stabilivolt ZD2, the second electric capacity C2, the 9th resistance R9, the tenth resistance R10, the 11st resistance R11, described The first end of the 9th resistance R9 is connected with supply voltage outfan, and second end of described 9th resistance R9 is through described tenth resistance R10, described 11st resistance R11 are connected with the base stage of described 3rd audion Q3；The colelctor electrode of described 3rd audion Q3 with The common port of the 11st resistance R11 described in described tenth resistance R10 connects, and the transmitting extremely power supply of described 3rd audion Q3 connects First outfan VCC1 of mouth module 10；The negative electrode of the negative electrode of described second stabilivolt ZD2 and described 3rd audion Q3 and the The first end interconnection of two electric capacity C2, the anode of described second stabilivolt ZD2 is connected with second end of described second electric capacity C2, and connects Ground.

Wherein, the second stabilivolt ZD2 and the second electric capacity C2 is over-voltage protection element, is used for preventing from flowing through the 3rd audion Q3 Voltage excessive when, damage the 3rd audion Q3.

Specifically, when the base stage of the 3rd audion Q3 receives start letter through the tenth resistance R10 and the 9th resistance R9 successively Number when, triggering the 3rd audion Q3 conducting is to export corresponding voltage for current foldback circuit 20 and drive control chip IC 1 Running voltage is provided.

In above-described embodiment, drive control circuit 40 include drive control chip IC 1, the 5th electric capacity C5, the 6th electric capacity C6, 7th electric capacity C7, the 8th resistance R8, the 12nd resistance R12, the 13rd resistance R13, the 14th resistance R14, the 15th resistance R15, the 16th resistance R16, the 17th resistance R17, described drive control chip IC 1 also includes current settings foot ISET, frequency Setting foot RT, soft start and control loop compensation foot SSTCMP, supply pin VIN, Pulse Width Control foot LDR, backlight illumination control defeated Enter foot PWM, the first current feedback foot ISEN1, the second current feedback foot ISEN2, the 3rd current feedback foot ISEN3, the 4th electric current Feedback foot ISEN4, running status output pin STATUS, grounding leg GND；The first end of described 8th resistance R8 is started shooting for backlight and is controlled Signal BL_ON receiving terminal processed, second end of described 8th resistance R8 is connected with the enable foot ENA of described drive control chip IC 1； The described current settings foot ISET flowing through LED interface 50 current value for setting is grounded through described 12nd resistance R12, described For setting the frequency setting foot RT of boosting component frequency through described 14th resistance R14 ground connection；Described 13rd resistance R13 is even It is connected between described power supply processing circuit 30 and the current detecting foot ISW of described drive control chip IC 1；Described 5th electric capacity C5 It is connected to described between described current detecting foot and ground, the 6th electric capacity C6 is connected to described reference voltage output foot VREF and ground Between；Described supply pin VIN is connected with the first outfan of described power supply interface module 10；Described backlight illumination control input foot PWM is connected with connecing backlight illumination control end through described 17th resistance R17, and described soft start and control loop compensate foot SSTCMP It is grounded through described 16th resistance R16 and the 7th electric capacity C7 successively；Described first current feedback foot ISEN1, described second electric current Feedback foot ISEN2, described 3rd current feedback foot ISEN3, described 4th current feedback foot ISEN4 respectively with described LED pair The LED interface 50 answered connects.

Wherein, the control input signal of described backlight illumination control input foot PWM input can adjust P_DIN or electricity for pulse Pressure adjustment signal A_DIM；Drive control chip IC 1 also has running status output pin STATUS, this running status output pin STATUS is used for exporting the operating state signal STA of described LED drive device through the 15th resistance R15.

In above-described embodiment, described power supply processing circuit 30 includes boosting unit 31, boosting detector unit 32, rectifying and wave-filtering Unit 33 and over-pressed detector unit 34, the input of described boosting unit is the input of described power supply processing circuit 30, described The outfan of boosting unit 31 is connected with the input of described rectification filtering unit 33, the controlled end of described boosting unit 31 and institute State Pulse Width Control foot LDR connection, the feedback end of described boosting unit 31 and the described boosting detector unit of drive control chip IC 1 32 test side connects；The signal feedback end of described boosting detector unit 32 and the current detecting of described drive control chip IC 1 Foot ISW connects, the output head grounding of described boosting detector unit 32；The outfan of described rectification filtering unit 33 is described power supply The outfan of process circuit 30, and be connected with the test side of described overvoltage detector unit 34；Described overvoltage detector unit 34 anti- Feedback outfan is connected with the overvoltage detection foot OVP of described drive control chip IC 1.

Wherein, described boosting unit 31 has the 8th electric capacity C8 and first electricity for filtering alternating component in supply voltage Sense L1, the second metal-oxide-semiconductor QW2, the 18th resistance R18 and the 19th resistance R19 for controlling for the first inductance L1 charging interval, the The first end of eight electric capacity C8 is interconnected with the first end of the first inductance L1 and the second outfan of power supply interface module 10, the 8th electric capacity The second end ground connection of C8；Second end of the first inductance is mutual with the drain electrode of the second metal-oxide-semiconductor QW2 and the input of rectification filtering unit 33 Even；The first end interconnection of the first end of the grid of the second metal-oxide-semiconductor QW2 and 18 resistance R18 and the 19th resistance R19, the 2nd MOS The source electrode of pipe QW2 is connected with the signal feedback end of boosting detector unit 32；Described boosting detector unit 32 has the 20th resistance The first end of R20, the 20th resistance R20 is the signal feedback end of boosting detector unit, second termination of the 20th resistance R20 Ground；Described rectification filtering unit 33 has commutation diode D2 and the 9th electric capacity C9, and the anode of commutation diode D2 is filtered for rectification The test side interconnection of the input of ripple unit 33, the negative electrode of commutation diode D2 and the 9th electric capacity C9 and over-pressed detector unit 34； Described overvoltage detector unit 34 has the tenth electric capacity C10, the 21st resistance R21, the 22nd resistance R22 and the 23rd electricity Resistance R23, the first end of the 21st resistance R21 is the test side of over-pressed detector unit 34, and the 21st resistance R21 is successively through the 22 resistance R22 and the 23rd resistance R23 ground connection；Tenth electric capacity C10 and the 23rd resistance R23 is connected in parallel.

Specifically, boosting unit 31 is controlled based on drive control chip IC 1, and the supply voltage of input is boosted, and Export to rectification filtering unit 33, rectification filtering unit 33 exports after rectified for input voltage Filtering Processing to LED interface 50, think LED interface 50 energy supply, meanwhile, after over-pressed detector unit 34 detects rectified filter unit 33 and processes Voltage exceed LED rated voltage when, by detection signal feed back to drive control chip IC 1 overvoltage detection foot OVP, with Drive control chip IC 1 is made to export corresponding control signal thus adjusting the voltage exporting to LED interface 50, boosting detection is single Unit 32, when boosting unit 31 output current is detected and exceeding pre-value, detection signal is exported to the electricity of drive control chip IC 1 Stream detection foot is to adjust output current.

Specifically, when drive control circuit 40 receives backlight start control signal BL_ON, control power supply processing circuit 30 work, the supply voltage exporting through power supply interface module 10 is carried out boosting by power supply processing circuit 30, rectification and Filtering Processing After export and think LED energy supply to LED interface 50, additionally, when drive control circuit 40 controls letter receiving brightness regulation Number when, output pwm control signal to control to adjust the output voltage of power supply processing circuit 30.

It is understood that due to above-mentioned current foldback circuit 20 being employed on this utility model LED drive device, therefore Avoiding the overvoltage producing because LED is burned out being likely to result in the short circuit of LED lamp circuit the two poles of the earth causes control device long-time High power work and make driving means temperature anomaly raise problem, improve the safety of LED drive device.

The foregoing is only preferred embodiment of the present utility model, not thereby limit the scope of the claims of the present utility model, Equivalent structure or equivalent flow conversion that every utilization this utility model description and accompanying drawing content are made, or direct or indirect transport Used in other related technical fields, all include in the same manner in scope of patent protection of the present utility model.

Claims

1. a kind of LED drive device it is characterised in that include power supply interface module, power supply processing circuit, drive control circuit, Current foldback circuit and LED interface, described drive control circuit includes signal feedback end, control signal outfan, reference electricity Pressure outfan and power input；The power input of described power input and described current foldback circuit respectively with described electricity First outfan of source interface module connects, and described reference voltage output terminal is connected with the signal input part of described current foldback circuit Connect, the signal output part of described current foldback circuit is connected with described signal feedback end, described control signal outfan with described The controlled end of power supply processing circuit connects；Second outfan of described power supply interface module and the input of described power supply processing circuit End connects；The outfan of described power supply processing circuit is connected with described LED interface；

Wherein, described drive control circuit, for driving described power supply processing circuit work according to internal reference voltage；

Described current foldback circuit, for detecting the reference voltage of described drive control circuit, and is more than in described reference voltage During its voltage protection threshold value, output overcurrent protection signal to described drive control circuit, so that described drive control circuit Described power supply processing circuit quits work.

2. LED drive device as claimed in claim 1 is it is characterised in that described current foldback circuit includes voltage detecting Circuit, error amplify electronic circuit, first switch electronic circuit, partial pressure output electronic circuit and second switch electronic circuit, described voltage inspection Survey electronic circuit test side be connected with the reference voltage output terminal of described drive control circuit, described voltage detecting electronic circuit anti- The signal receiving end that electronic circuit is amplified with described error in feedback end is connected；Described error amplify the signal output part of electronic circuit with described The controlled end of first switch electronic circuit connects；The input of described first switch electronic circuit is the power supply of described current foldback circuit Input, the outfan of described first switch electronic circuit is used for exporting respectively the input of electronic circuit and described the with described partial pressure The controlled end electrical connection of two switch electronic circuits；Described partial pressure exports the outfan of electronic circuit and the signal of described drive control circuit Feedback end connects；The signal receiving end of described second switch electronic circuit be used for receive backlight start control signal, described second The outfan of switch electronic circuit is connected with the Enable Pin of described drive control circuit.

3. LED drive device as claimed in claim 2 is it is characterised in that described voltage detecting electronic circuit includes the first voltage stabilizing Pipe and first resistor, the negative electrode of described first stabilivolt drives the reference voltage output terminal controlling circuit to be connected with described, and described the The anode of one stabilivolt is grounded through described first resistor, and described first stabilivolt is described electricity with the common port of described first resistor The feedback end of pressure detection electronic circuit.

4. LED drive device as claimed in claim 2 includes the one or three pole it is characterised in that described error amplifies electronic circuit Pipe, second resistance, the first end of described second resistance is the signal receiving end of described drive circuit, the second of described second resistance End is connected with the base stage of the first audion；The colelctor electrode of described first audion is connected with the controlled end of described first switch electronic circuit Connect, the grounded emitter of described first audion.

5. LED drive device as claimed in claim 3 is it is characterised in that described first switch electronic circuit includes the two or three pole Pipe, 3rd resistor, the 4th resistance and the 5th resistance, the first end of described 3rd resistor is the controlled of described first switch electronic circuit End, the second end of described 3rd resistor is connected with the base stage of described second audion；The colelctor electrode of described second audion is through institute The input stating the 5th resistance with described partial pressure output electronic circuit is connected, and the emitter stage of described second audion is defeated with described first Go out end to connect；Described 4th resistor coupled in parallel is connected between emitter stage and the base stage of described second audion.

6. LED drive device as claimed in claim 5 it is characterised in that described partial pressure output electronic circuit include the 6th resistance, 7th resistance and isolation element, the first end of described 6th resistance is the input that described partial pressure exports electronic circuit, the described 6th Second end of resistance is through described 7th resistance eutral grounding；Described 6th resistance is first with described isolation with the common port of described 7th resistance The first end of part connects, and the second end of described isolation element is connected with the signal feedback end of described drive control circuit.

7. LED drive device as claimed in claim 6 is it is characterised in that described second switch electronic circuit includes the first metal-oxide-semiconductor And first electric capacity, the grid of described first metal-oxide-semiconductor is the controlled end of described second switch electronic circuit, the leakage of described first metal-oxide-semiconductor The outfan of extremely described second switch electronic circuit, the source ground of described first metal-oxide-semiconductor；Described first electric capacity is connected in parallel in Between the drain electrode of described first metal-oxide-semiconductor and source electrode.

8. LED drive device as claimed in claim 7 is it is characterised in that described power supply interface module includes on-off circuit, institute State on-off circuit and include the 3rd audion, the second stabilivolt, the second electric capacity, the 9th resistance, the tenth resistance, the 11st resistance, institute The first end stating the 9th resistance is connected with supply voltage outfan, and the second end of described 9th resistance is through described tenth resistance, institute The base stage stating the 11st resistance with described 3rd audion is connected；The colelctor electrode of described 3rd audion and described tenth resistance and The common port of described 11st resistance connects, transmitting extremely first outfan of described 3rd audion；Described second stabilivolt The negative electrode of negative electrode and described 3rd audion and the second electric capacity first end interconnection, the anode of described second stabilivolt with described Second end of the second electric capacity connects, and is grounded.

9. LED drive device as claimed in claim 1 is it is characterised in that described drive control circuit includes drive control core Piece, the 5th electric capacity, the 6th electric capacity, the 7th electric capacity, the 8th resistance, the 12nd resistance, the 13rd resistance, the 14th resistance, the tenth Six resistance and the 17th resistance, described drive control chip includes reference voltage output foot, overvoltage detection foot, enables foot, electric current Set foot, frequency setting foot, soft start and control loop and compensate foot, supply pin, Pulse Width Control foot, backlight illumination control input Foot, the first current feedback foot, the second current feedback foot, the 3rd current feedback foot, the 4th current feedback foot and grounding leg；Described The first end of eight resistance is backlight start control signal receiving terminal, the second end of described 8th resistance and described drive control chip Enable foot connect；, through described 12nd resistance eutral grounding, described frequency setting foot is through the described 14th electricity for described current settings foot Resistance ground connection；Described 13rd resistance be connected to described power supply processing circuit and described drive control chip current detecting foot it Between；Described 5th capacitance connection between described current detecting foot and ground described 6th capacitance connection in described reference voltage output Between foot and ground；Described supply pin is connected with the first outfan of described power supply interface module；Described backlight illumination control input Foot is connected with backlight illumination control end through described 17th resistance, and described soft start and control loop compensate foot successively through described the 16 resistance and the 7th capacity earth；Described first current feedback foot, described second current feedback foot, described 3rd current feedback Foot and described 4th current feedback foot interface corresponding with described LED connect.

10. LED drive device as claimed in claim 9 it is characterised in that described power supply processing circuit include boosting unit, Over-pressed detector unit, boosting detector unit and rectification filtering unit, the input of described boosting unit is that described power supply processes electricity The input on road, the outfan of described booster circuit is connected with the input of described current rectifying and wave filtering circuit, described booster circuit Controlled end is connected with the Pulse Width Control foot of described drive control chip, and the feedback end of described boosting unit is single with described boosting detection The test side of unit connects；The signal feedback end of described boosting detector unit is with the current detecting foot of described drive control chip even Connect, the output head grounding of described boosting detector unit；The outfan of described current rectifying and wave filtering circuit is described power supply processing circuit Outfan, and be connected with the test side of described overvoltage detector unit；The feedback output end of described overvoltage detector unit and described drive The overvoltage detection foot of dynamic control chip connects.