CN106132025B

CN106132025B - A kind of LED constant current driving chip, device and LED

Info

Publication number: CN106132025B
Application number: CN201610672126.2A
Authority: CN
Inventors: 胡渊
Original assignee: Limited Co Of Fu Man Electronics Group Of Shenzhen
Current assignee: Fuman Microelectronics Group Co ltd
Priority date: 2016-08-15
Filing date: 2016-08-15
Publication date: 2018-03-16
Anticipated expiration: 2036-08-15
Also published as: CN106132025A

Abstract

The invention belongs to LED drive controls field, there is provided a kind of LED constant current driving chip, device and LED.The present invention is by using including lower electro-detection module, cycle counter, coding and decoding module, pulse width modulation module, the LED constant current driving chip of first constant-current driven module and the second constant-current driven module, reach default maximum ON time in the ON time for detecting switching tube by lower electro-detection module, and the turn-off time of switching tube be less than preset overpressure protection the shut-in time when, judge electricity under power switch and control cycle counter to shift, by coding and decoding module according to shift result, power switch again on it is electric when, corresponding LED string is controlled to light, to realize that colour temperature is adjusted, corresponding LED string is driven to light with predetermined current by pulse width modulation module, to realize brightness regulation, so that LED constant current driving chip performs colour temperature regulation and brightness regulation to LED string exactly under the control of power switch.

Description

A kind of LED constant current driving chip, device and LED

Technical field

The invention belongs to LED Drive Control Techniques field, more particularly to a kind of LED constant current driving chip, device and LED Lamp.

Background technology

Existing LED light modulation color-temperature regulating system be by LED constant current driving chip detect the lower electric number of power switch come Colour temperature regulation and brightness regulation are carried out to LED string.As shown in figure 1, when electric under power switch, the bus capacitor after rectifier bridge CL voltage can decline, and cause the voltage of the supply pin of LED constant current driving chip to decline, pass through the low pressure in LED constant current chip The voltage of the supply pin of detection module detection LED constant current chip, when the voltage for the supply pin for detecting LED constant current driving chip is small When preset voltage value, low pressure detection module judges under power switch electricity and exports corresponding control signal, when power switch again When secondary electric, control module controls cold light LED control circuit and/or warm light LED control circuit to perform phase according to the control signal The colour temperature regulation answered and brightness regulation.

However, because LED dims color-temperature regulating system when in overvoltage protection or overcurrent protection state, can also pull down The voltage of the supply pin of LED constant current driving chip and trigger low pressure detection module, therefore, come in this way to power switch Lower electric number detected it is not accurate enough；Also, if the voltage of driving LED string is higher, under power switch after electricity, bus The energy of electric capacity CL storages can by starting resistance RST again by the voltage high of the supply pin of LED constant current driving chip, so as to There is the phenomenon that power switch principal repeatedly triggers low pressure detection module, cause the colour temperature of LED string to adjust and adjusted with brightness Section is not controlled by power switch.

In summary, there is lower electricity of the LED constant current driving chip to power switch in existing LED light modulations color-temperature regulating system The problem of number detection inaccurately causes not controlled the colour temperature regulation of LED string and brightness regulation by power switch.

The content of the invention

It is an object of the invention to provide a kind of LED constant current driving chip, drive device and LED, it is intended to solves existing LED light modulations color-temperature regulating system LED constant current driving chip be present and the lower electric number of power switch detected inaccurate and caused pair The problem of colour temperature regulation of LED string and brightness regulation are not controlled by power switch.

The present invention is achieved in that a kind of LED constant current driving chip, with the first switch in cold light LED control circuit Pipe connects with the second switch pipe in warm light LED control circuit, and the LED constant current driving chip is by controlling the first switch The break-make of pipe and/or the second switch pipe is with to the cold light LED lamp string and/or warm light LED string progress constant current control System, the cold light LED control circuit and the warm light LED control circuit are under the control of power switch, respectively to cold light LED lamp String and warm light LED string perform colour temperature regulation and brightness regulation, it is characterised in that the LED constant current driving chip includes：First Lower electro-detection module, second time electro-detection module, cycle counter, coding and decoding module, pulse width modulation module, the first constant current are driven Dynamic model block and the second constant-current driven module；

The test side of first time electro-detection module and the test side of second time electro-detection module respectively with it is described The drive control end of first constant-current driven module connects with the drive control end of second constant-current driven module, the circulation meter The first control terminal, the second control terminal and the output end of number the devices output end with first time electro-detection module, described the respectively The input connection of the output end and the coding and decoding module of two times electro-detection modules, the first of the coding and decoding module are defeated Go out end, the second output end and the 4th output end the first control terminal with first constant-current driven module, second perseverance respectively Flow the first control terminal of drive module and the control terminal connection of the pulse width modulation module, the 3rd of the coding and decoding module are defeated Go out end to be connected with the second control terminal of first constant-current driven module and the second control terminal of second constant-current driven module, The output end of the pulse width modulation module drives with the 3rd control terminal of first constant-current driven module and second constant current The 3rd control terminal connection of module, the detection of the test side of first constant-current driven module and second constant-current driven module End is connected with the cold end of the first switch pipe and the cold end of the second switch pipe respectively；

First time electro-detection module detects ON time and the turn-off time of the first switch pipe, when detecting The ON time for stating first switch pipe reaches default maximum ON time, and the turn-off time of the first switch pipe is less than default During the overvoltage protection shut-in time, first time electro-detection module judges electricity under the power switch and exports shift control letter Number；Second time electro-detection module detects ON time and the turn-off time of the second switch pipe, when detecting described the The ON time of two switching tubes reaches default maximum ON time, and the turn-off time of the second switch pipe is less than preset overpressure When protecting the shut-in time, second time electro-detection module judges electricity under the power switch and exports shift control signal；Institute Cycle counter is stated to carry out cyclic shift according to the shift control signal and export shift result；The coding and decoding module will The shift result is converted to corresponding state control signal, and the power switch again on it is electric when, according to the state Control signal controls first constant-current driven module and/or second constant-current driven module to drive the cold light LED control Circuit and/or the warm light LED control circuit perform the colour temperature regulation；The pulse width modulation module is receiving the coding During the state control signal of decoding module output, first constant-current driven module and institute are controlled according to the state control signal State the second constant-current driven module makes the cold light LED control circuit and the warm light LED control circuit control with predetermined current respectively Make the cold light LED lamp string and the warm light LED string lights according to predetermined luminance.

Present invention also offers a kind of LED constant current drive device, is connect with cold light LED lamp string and warm light LED series winding, described LED constant current drive device includes power switch, rectification module, the first bus capacitor, cold light LED control circuit and warm light LED controls Circuit processed, the LED constant current drive device also include above-mentioned LED constant current driving chip；

The first end of the power switch and the second end connect respectively AC power output end and the rectification module it is defeated Enter to hold, the supply pin of the first output termination LED constant current driving chip of the rectification module, the second of the rectification module Output end, the input of the cold light LED lamp string, the first control terminal of the cold light LED control circuit, the warm light LED The input of string, the first control terminal of the warm light LED control circuit are connected to the positive pole of first bus capacitor altogether, and described The negative pole ground connection of one bus capacitor, the of the second control terminal of the cold light LED control circuit and the warm light LED control circuit Two control terminals connect the output end of the cold light LED lamp string and the output end of the warm light LED string respectively；

The cold light LED control circuit include first switch pipe, the first load capacitance, the first load resistance, the first inductance, First fly-wheel diode and the first crest voltage detection resistance；The warm light LED control circuit includes second switch pipe, second negative Carry electric capacity, the second load resistance, the second inductance, the second fly-wheel diode and the second crest voltage detection resistance；

The positive pole of first load capacitance, the first end of first load resistance and first fly-wheel diode Negative electrode connects the first control terminal as the cold light LED control circuit altogether, the negative pole of first load capacitance, described first negative Second end of load resistance and the first end of first inductance connect the second control terminal as the cold light LED control circuit altogether, The anode of second end of first inductance and first fly-wheel diode is connected to the hot end of the first switch pipe altogether, The control terminal and cold end of the first switch pipe control pin and the with the first grid of the LED constant current driving chip respectively The control pin connection of one source electrode, the first end of the first crest voltage detection resistance and the first of the LED constant current driving chip Crest voltage detection pin connection, the second end ground connection of the first crest voltage detection resistance；Second load capacitance is just The negative electrode of pole, the first end of second load resistance and second fly-wheel diode connects altogether to be controlled as the warm light LED First control terminal of circuit, the negative pole of second load capacitance, the second end of second load resistance and second electricity The first end of sense connects the second control terminal as the warm light LED control circuit altogether, the second end of second inductance with it is described The anode of second fly-wheel diode is connected to the hot end of the second switch pipe altogether, the control terminal of the second switch pipe and low Potential end controls pin and the second source electrode control pin to be connected with the second grid of the LED drive chip respectively, second peak value The first end of voltage detection resistances is connected with the second crest voltage detection pin of the LED constant current driving chip, second peak The second end ground connection of threshold voltage detection resistance.

Present invention also offers a kind of LED, including cold light LED lamp string and warm light LED string, the LED also to include LED constant current drive device described above.

The present invention translates by using including first time electro-detection module, second time electro-detection module, cycle counter, coding Code module, pulse width modulation module, the LED constant current driving chip of the first constant-current driven module and the second constant-current driven module, by the Once electro-detection module reaches default maximum ON time in the ON time for detecting first switch pipe, and first switch pipe When turn-off time is less than the preset overpressure protection shut-in time, judges electricity under power switch and export shift control signal, by second Lower electro-detection module reaches default maximum ON time, and the pass of second switch pipe in the ON time for detecting second switch pipe When the disconnected time is less than the preset overpressure protection shut-in time, judges electricity under power switch and export shift control signal, counted by circulation Number device carries out cyclic shift according to shift control signal and exports shift result, is converted to shift result by coding and decoding module Corresponding state control signal, and power switch again on it is electric when, control corresponding constant current to drive according to state control signal Module works, and to drive corresponding LED string to be lighted, and then realizes the purpose of colour temperature regulation, and by pulse width modulation module When receiving state control signal, corresponding constant-current driven module is controlled to drive corresponding LED string to carry out with predetermined current It is luminous, and then the purpose of brightness regulation is realized, so that LED constant current driving chip is right exactly under the control of power switch LED string performs colour temperature regulation and brightness regulation.

Brief description of the drawings

Fig. 1 is the structural representation for the LED constant current driving chip that prior art provides；

Fig. 2 is the modular structure schematic diagram of LED constant current driving chip provided in an embodiment of the present invention；

Fig. 3 is the modular structure schematic diagram of LED constant current driving chip provided in an embodiment of the present invention；

Fig. 4 is the electrical block diagram of first time electro-detection module provided in an embodiment of the present invention；

Fig. 5 is the electrical block diagram of second time electro-detection module provided in an embodiment of the present invention；

Fig. 6 is the electrical block diagram of LED constant current drive device provided in an embodiment of the present invention.

Embodiment

In order to make the purpose , technical scheme and advantage of the present invention be clearer, it is right below in conjunction with drawings and Examples The present invention is further elaborated.It should be appreciated that the specific embodiments described herein are merely illustrative of the present invention, and It is not used in the restriction present invention.

The embodiment of the present invention by using including first time electro-detection module, second time electro-detection module, cycle counter, Coding and decoding module, pulse width modulation module, the LED constant current driving core of the first constant-current driven module and the second constant-current driven module Piece, reach default maximum ON time, and first in the ON time for detecting first switch pipe by first time electro-detection module When the turn-off time of switching tube is less than the preset overpressure protection shut-in time, judges electricity under power switch and export shift control letter Number, reach default maximum ON time, and second in the ON time for detecting second switch pipe by second time electro-detection module When the turn-off time of switching tube is less than the preset overpressure protection shut-in time, judges electricity under power switch and export shift control letter Number, cyclic shift is carried out according to shift control signal by cycle counter and exports shift result, will be moved by coding and decoding module Position result is converted to corresponding state control signal, and power switch again on it is electric when, phase is controlled according to state control signal The constant-current driven module work answered, to drive corresponding LED string to be lighted, and then realizes the purpose of colour temperature regulation, and by Pulse width modulation module controls corresponding constant-current driven module corresponding with predetermined current driving when receiving state control signal LED string is lighted, and then realizes the purpose of brightness regulation, so that control of the LED constant current driving chip in power switch Perform colour temperature regulation and brightness regulation under system to LED string exactly.

Fig. 2 shows the modular structure of LED constant current driving chip provided in an embodiment of the present invention, for convenience of description, only The part related to the embodiment of the present invention is shown, details are as follows：

A kind of LED constant current driving chip 1, controlled with the first switch pipe 31 in cold light LED control circuit 3 and warm light LED Second switch pipe 41 in circuit 4 connects, and LED constant current driving chip 1 is by controlling first switch pipe 31 and/or second switch pipe 41 break-make is with to cold light LED lamp string 5 and/or the progress current constant control of warm light LED string 6, cold light LED control circuit 3 and warm light LED control circuit 4 under the control of power switch, cold light LED lamp string 5 and warm light LED string 6 are performed respectively colour temperature regulation and Brightness regulation, LED constant current driving chip 1 include：First time electro-detection module 10, second time electro-detection module 16, cycle count Device 11, coding and decoding module 12, pulse width modulation module 13, the first constant-current driven module 14 and the second constant-current driven module 15.

Wherein, the test side of first time electro-detection module 10 and the test side of second time electro-detection module 16 are respectively with first The drive control end of constant-current driven module 14 connects with the drive control end of the second constant-current driven module 15, cycle counter 11 First control terminal, the second control terminal and the output end output end with first time electro-detection module 10, second time electro-detection mould respectively The input connection of the output end and coding and decoding module 12 of block 16, the first output end of coding and decoding module 12, the second output The first control terminal with the first constant-current driven module 14, the first of the second constant-current driven module 15 are controlled respectively for end and the 4th output end The control terminal of end processed and pulse width modulation module 13 connects, the 3rd output end and the first constant-current driven module of coding and decoding module 12 14 the second control terminal and the connection of the second control terminal of the second constant-current driven module 15, the output end of pulse width modulation module 15 and the 3rd control terminal of one constant-current driven module 14 and the 3rd control terminal connection of the second constant-current driven module 15, the first constant current driving The test side of module 14 and the test side of the second constant-current driven module 15 respectively with the cold end of first switch pipe 31 and second The cold end connection of switching tube 41.

First time electro-detection module 10 detects ON time and the turn-off time of first switch pipe 31, when detecting that first opens The ON time for closing pipe 31 reaches default maximum ON time, and the turn-off time of first switch pipe 31 is protected less than preset overpressure During the shut-in time, first time electro-detection module 10 judges electricity under power switch and exports shift control signal；Second time electro-detection Module 16 detects ON time and the turn-off time of second switch pipe 41, when the ON time for detecting second switch pipe 41 reaches Maximum ON time is preset, and when the turn-off time of second switch pipe 41 is less than the preset overpressure protection shut-in time, second time electric Detection module 16 judges electricity under power switch and exports shift control signal；Cycle counter 11 is carried out according to shift control signal Cyclic shift simultaneously exports shift result；Shift result is converted to corresponding state control signal by coding and decoding module 12, and When power switch is upper electric again, the first constant-current driven module 14 and/or the second constant current is controlled to drive mould according to state control signal Block 15 drives cold light LED control circuit 3 and/or warm light LED control circuit 4 to perform colour temperature regulation；Pulse width modulation module 13 is connecing When receiving the state control signal of the output of coding and decoding module 12, the first constant-current driven module 14 is controlled according to state control signal Make with predetermined current cold light LED control circuit 3 respectively with the second constant-current driven module 15 and warm light LED control circuit 4 control it is cold Light LED string 5 and warm light LED string 6 light according to predetermined luminance, to realize the purpose of brightness regulation.

In embodiments of the present invention, it is the first switch pipe 31 and second switch pipe pre-set to preset maximum ON time 41 maximum ON time, when the ON time of first switch pipe 31 reaches default maximum ON time, the first constant current driving Module 14 controls first switch pipe 31 to turn off, when the ON time of second switch pipe 41 reaches default maximum ON time, the Two constant-current driven modules 15 control second switch pipe 41 turns off.In embodiments of the present invention, as cold light LED lamp string 5 or warm light LED When the voltage at the both ends of lamp string 6 is higher than the maximum voltage of the LED string pre-set, the overvoltage protection of system can be triggered, and is triggered The shut-in time of system is the overvoltage protection shut-in time during overvoltage protection.

In embodiments of the present invention, first time electro-detection module 10 and second time electro-detection module 16 by detecting respectively The ON time and turn-off time of one switching tube 31 and second switch pipe 41 judge the whether lower electricity of power switch.Specifically, work as When LED constant current driving chip 1 drives the work of cold light LED control circuit 3, first time electro-detection mould 10 detects first switch pipe 31 ON time and turn-off time, when the ON time for detecting first switch pipe 31 reaches default maximum ON time, and first When the turn-off time of switching tube is less than the preset overpressure protection shut-in time, first time electro-detection module 10 is judged under power switch Electricity；When LED constant current driving chip 1 drives warm light LED control circuit 4 to work, second time detection of electro-detection module 16 second is opened ON time and the turn-off time of pipe 41 are closed, when the ON time for detecting second switch pipe 41 reaches default maximum conducting Between, and the turn-off time of second switch pipe 41 be less than preset overpressure protection the shut-in time when, second time electro-detection module 16 judges It is electric under power switch；When LED constant current driving chip 1 drives cold light LED control circuit 3 and warm light LED control circuit 4 to work simultaneously When, first time electro-detection module 10 and second time electro-detection module 16 detect first switch pipe 31 and second switch pipe respectively simultaneously 41 ON time and turn-off time, when first time electro-detection mould 10 detects that the ON time of first switch pipe 31 reaches default Maximum ON time, and the turn-off time of first switch pipe 31 be less than the preset overpressure protection shut-in time, or when second time it is electric Detection module 16 detects that the ON time of second switch pipe 41 reaches default maximum ON time, and the pass of second switch pipe 41 When the disconnected time is less than the preset overpressure protection shut-in time, then it is assumed that it is electric under power switch, it is achieved thereby that to electric under power switch The accurate detection of number.When electric under power switch, first time electro-detection module 10 or second time electro-detection module 16 export height To cycle counter 11, cycle counter 11 carries out cyclic shift when receiving high level signal and exports displacement level signal As a result, shift result is converted to corresponding state control signal by the coding and decoding circuit of coding and decoding module 12, and by state control Signal processed is stored, and when power switch is upper electric again, coding and decoding module 12 is corresponding defeated from it by state control signal Go out end to be exported.

In embodiments of the present invention, the circulation digit of cycle counter 11 is controlled with cold light LED control circuit 3 and warm light LED The total working status number of circuit 4 processed is equal.For example, work as 4 a total of three kinds of cold light LED control circuit 3 and warm light LED control circuit (cold light LED control circuit 3 works working condition, and warm light LED control circuit 4 does not work；Cold light LED control circuit 3 does not work, Warm light LED control circuit 4 works；Cold light LED control circuit 3 and warm light LED control circuit 4 work simultaneously) when, cycle counter 11 circulation digit is 3.

In embodiments of the present invention, cycle counter 11 can use existing the following as core using trigger and gate circuit Inner loop counter.

In embodiments of the present invention, coding and decoding module 12 can use existing by encoder, decoder and memory group Into coding and decoding circuit.

In embodiments of the present invention, pulse width modulation module can use the existing arteries and veins using oscillator and frequency divider as core Wide modulation circuit, it obtains the modulated signal of certain dutycycle by the output signal of gate level circuit combination frequency divider.

Fig. 3 shows the modular structure of LED constant current driving chip provided in an embodiment of the present invention, for convenience of description, only The part related to the embodiment of the present invention is shown, details are as follows：

As shown in figure 3, as one embodiment of the invention, first time electro-detection module 10 includes：First ON time detects Unit 100, the first turn-off time detection unit 102 and the first displacement control unit 101.

The input and first of the input of first ON time detection unit 100, the first turn-off time detection unit 102 Second input of displacement control unit 101 connects the test side as first time electro-detection module 10, the inspection of the first ON time altogether Survey unit 100 output end and the first turn-off time detection end unit 102 output end respectively with the first displacement control unit 101 First input end and the 3rd input connection, the output end of the first displacement control unit 101 is first time electro-detection module 10 Output end.

When the ON time for detecting first switch pipe 31 reaches default maximum ON time, the detection of the first ON time Unit 100 exports high level signal to the first input end of the first displacement control unit 101；When detecting first switch pipe 31 When turn-off time is less than the preset overpressure protection shut-in time, the first turn-off time detection unit 102 exports high level to the first shifting 3rd input of position control unit 101；When the first input end of the first displacement control unit 101 is high level and the first displacement When second input of control unit 101 is changed into low level from high level, the first displacement control unit 101 output shift control letter Number.

In embodiments of the present invention, when the normal work of cold light LED control circuit 3 (i.e. the normally of first switch pipe 31 and Shut-off) when, the first ON time detection unit 100 and the first turn-off time detection unit 102 export low level signal, now First displacement control unit 101 output low level signal to cycle counter 11, cycle counter 11 does not shift.Specifically, work as When LED constant current driving chip 1 drives the work of cold light LED control circuit 3, the first ON time detection unit 100 and the first shut-off Time detecting unit 102 detects ON time and the turn-off time of first switch pipe 31 respectively, when first switch pipe 31 is normally led (ON time of first switch pipe 31 is less than default maximum ON time and the turn-off time protects not less than preset overpressure for logical and shut-off Protect the shut-in time) when, the first ON time detection unit 100 and the first turn-off time detection unit 101 export low level, this When the first displacement control unit 101 output low level signal, cycle counter 11 do not shift, and when the detection of the first ON time is single Member 100 detects that the ON time of first switch pipe 31 reaches default maximum ON time, and the first turn-off time detection unit 102 when detecting that turn-off time of first switch pipe 31 is less than the preset overpressure protection shut-in time, and the detection of the first ON time is single The turn-off time detection unit 102 of member 100 and first exports high level, now, when the second end of the first displacement control unit 101 By high level upset be low level when, the first displacement control unit output high level, cycle counter 11 progress cyclic shift.

As one embodiment of the invention, second time electro-detection module 16 includes：Second ON time detection unit 160, Two turn-off time detection units 162 and the second displacement control unit 161.

The input and second of the input of second ON time detection unit 160, the second turn-off time detection unit 162 Second input of displacement control unit 161 connects the test side as second time electro-detection module 16, the inspection of the second ON time altogether Survey unit 160 output end and the first turn-off time detection end unit 102 output end respectively with the second displacement control unit 161 First input end and the 3rd input connection, the output end of the second displacement control unit 161 is second time electro-detection module 16 Output end.

When the ON time for detecting second switch pipe 41 reaches default maximum ON time, the detection of the second ON time Unit 160 exports high level signal to the first input end of the second displacement control unit 161；When detecting second switch pipe 41 When turn-off time is less than the preset overpressure protection shut-in time, the second turn-off time detection unit 162 exports high level to the second shifting 3rd input of position control unit 161；When the first input end of the second displacement control unit 161 is high level and the second displacement When second input of control unit 161 is changed into low level from high level, the second displacement control unit 161 output shift control letter Number.

In embodiments of the present invention, when the normal work of warm light LED control circuit 4 (i.e. the normally of second switch pipe 41 and Shut-off) when, the second ON time detection unit 160 and the second turn-off time detection unit 162 export low level signal, now Second displacement control unit 161 output low level signal to cycle counter 11, cycle counter 11 does not shift.Specifically, work as When LED constant current driving chip 1 drives the work of warm light LED control circuit 4, the second ON time detection unit 160 and the second shut-off Time detecting unit 162 detects ON time and the turn-off time of second switch pipe 41 respectively, when second switch pipe 41 is normally led (ON time of second switch pipe 41 is less than default maximum ON time and the turn-off time protects not less than preset overpressure for logical and shut-off Protect the shut-in time) when, the second ON time detection unit 160 and the first turn-off time detection unit 101 export low level, this When the second displacement control unit 161 output low level signal, cycle counter 11 do not shift, and when the detection of the second ON time is single Member 160 detects that the ON time of second switch pipe 41 reaches default maximum ON time, and the second turn-off time detection unit 162 when detecting that turn-off time of second switch pipe 41 is less than the preset overpressure protection shut-in time, and the detection of the second ON time is single The turn-off time detection unit 162 of member 160 and second exports high level, now, when the second end of the second displacement control unit 161 By high level upset be low level when, the first displacement control unit output high level, cycle counter 11 progress cyclic shift.

As one embodiment of the invention, the first constant-current driven module 14 includes the demagnetization detection of the first control unit 140, first Unit 141, the first crest voltage detection unit 142 and the 3rd switching tube 143, the first control terminal of the first control unit 140, Two control terminals and the 3rd control terminal are respectively the first control terminal, the second control terminal and the 3rd control of the first constant-current driven module 14 End, the unlatchings control terminal of the first control unit 140 and turn off control terminal demagnetized respectively with first detection unit 141 output end and The output end connection of first crest voltage detection unit 142, the input of the first demagnetization detection unit 141, the first control unit The hot end with the 3rd switching tube 143, the control respectively of the input of 140 output end and the first crest voltage detection unit 142 End processed and cold end connection, the output end of the first control unit 140 are the drive control end of the first constant-current driven module 14.

In actual applications, the first crest voltage detection unit 142 also external first crest voltage detection resistance RCS1 First end, and the first crest voltage detection resistance RCS1 the second end ground connection (as shown in Figure 6)；The control terminal of first switch pipe 31 The supply pin VCC of LED constant current driving chip 1 is met by the resistance inside LED constant current driving chip 1, i.e. first switch pipe 31 exists Normal open state is under normal circumstances；The hot end of first switch pipe 31 is connected by the first inductance L1 with power switch.

In embodiments of the present invention, the first demagnetization detection unit 141 detects the voltage of the cold end of first switch pipe 31, When the electric current for flowing through the first inductance L1 drops to zero, the voltage of the cold end of first switch pipe 31 declines and produces mutation, When detecting that the voltage of cold end of first switch pipe 31 declines and when producing mutation, the first demagnetization detection unit 141 exports Opening control signal to the first control unit 140, the first control unit 140 controls the 3rd switching tube according to opening control signal 143 conductings, and then control first switch pipe 31 to turn on.First crest voltage detection unit 142 detects the detection of the first crest voltage The voltage of resistance RCS1 first end, when first switch pipe 31 turns on, flow through the first crest voltage detection resistance RCS1 electricity Stream can rise, and therefore, the voltage of the first crest voltage detection resistance RCS1 first end can rise, when detect the first peak value electricity When the voltage of pressure detection resistance RCS1 first end rises to pre-set peak value voltage, the first crest voltage detection unit 142 exports Turn off control signal to the first control unit 140, the first control unit 140 and the 3rd switching tube is controlled according to shut-off control signal 143 shut-offs, and then control first switch pipe 31 to turn off.

In embodiments of the present invention, the first demagnetization detection unit 141 uses the detection circuit using comparator as core, that is, compares Compared with device by the voltage of the cold end of first switch pipe 31 compared with the voltage of the supply pin of LED constant current driving chip 1, when The voltage of the cold end of first switch pipe 31 drops to smaller than the voltage of the supply pin of LED constant current driving chip 1 one default electricity During pressure value, it is high level that the output end of comparator is overturn by low level, and the first control unit 140 is receiving the first demagnetization detection During the high level signal that unit 141 exports, the 3rd switching tube 143 of control turns on, and then controls first switch pipe 31 to turn on.Its In, preset voltage value can be configured according to actual conditions, be not limited herein.

First crest voltage detection unit 142 uses the detection circuit using comparator as core, i.e. comparator is by first peak Threshold voltage detection resistance RCS1 voltages are compared with pre-set peak value voltage, when the first of the first crest voltage detection resistance RCS1 When the voltage at end reaches pre-set peak value voltage, the first crest voltage detection unit 142 output high level, the first control unit 140 When receiving the high level signal of the first crest voltage detection unit 142 output, the 3rd switching tube 143 of control turns off, and then Control first switch pipe 31 turns off.

First control unit 140 uses the existing control circuit using logic gates as core.

As one embodiment of the invention, the second constant-current driven module 15 includes the demagnetization detection of the second control unit 150, second Unit 151, the second crest voltage detection unit 152 and the 4th switching tube 153, the first control terminal of the second control unit 150, Two control terminals and the 3rd control terminal are respectively the first control terminal, the second control terminal and the 3rd control of the second constant-current driven module 15 End, the unlatchings control terminal of the second control unit 150 and turn off control terminal demagnetized respectively with second detection unit 151 output end and The output end connection of second crest voltage detection unit 152, the input of the second demagnetization detection unit 151, the second control unit The hot end with the 4th switching tube 153, the control respectively of the input of 150 output end and the second crest voltage detection unit 152 End processed and cold end connection, the output end of the second control unit 150 are the drive control end of the second constant-current driven module 15.

In actual applications, the second crest voltage detection unit 152 also external second crest voltage detection resistance RCS2 First end, and the second crest voltage detection resistance RCS2 the second end ground connection (as shown in Figure 6)；The control terminal of second switch pipe 41 The supply pin VCC of LED constant current driving chip 1 is met by the resistance inside LED constant current driving chip 1, i.e. second switch pipe 41 exists Normal open state is under normal circumstances；The hot end of second switch pipe 41 is connected by the second inductance L2 with power switch.

In embodiments of the present invention, the second demagnetization detection unit 151 detects the voltage of the cold end of second switch pipe 41, When the electric current for flowing through the second inductance L1 drops to zero, the voltage of the cold end of second switch pipe 41 declines and produces mutation, When detecting that the voltage of cold end of second switch pipe 41 declines and when producing mutation, the second demagnetization detection unit 151 exports Opening control signal to the second control unit 150, the second control unit 150 controls the 4th switching tube according to opening control signal 153 conductings, and then control second switch pipe 41 to turn on.Second crest voltage detection unit 152 detects the detection of the second crest voltage The voltage of resistance RCS2 first end, when second switch pipe 41 turns on, flow through the second crest voltage detection resistance RCS2 electricity Stream can rise, and therefore, the voltage of the second crest voltage detection resistance RCS2 first end can also rise, when detecting the second peak value When the voltage of voltage detection resistances RCS2 first end rises to pre-set peak value voltage, the second crest voltage detection unit 152 is defeated Go out to turn off control signal to the second control unit 150, the second control unit 150 and the 4th switching tube is controlled according to shut-off control signal 153 shut-offs, and then control second switch pipe 41 to turn off.

In embodiments of the present invention, the second demagnetization detection unit 151 uses the detection circuit using comparator as core, that is, compares Compared with device by the voltage of the cold end of second switch pipe 41 compared with the voltage of the supply pin of LED constant current driving chip 1, when The voltage of the cold end of second switch pipe 41 drops to smaller than the voltage of the supply pin of LED constant current driving chip 1 one default electricity During pressure value, it is high level that the output end of comparator is overturn by low level, and the second control unit 150 is receiving the second demagnetization detection During the high level signal that unit 151 exports, the 4th switching tube 153 of control turns on, and then controls second switch pipe 41 to turn on.Its In, preset voltage value can be configured according to actual conditions, be not limited herein.

Second crest voltage detection unit 152 uses the detection circuit using comparator as core, i.e. comparator is by the second peak The voltage of threshold voltage detection resistance RCS2 first end is compared with pre-set peak value voltage, when the second crest voltage detection resistance When the voltage of RCS2 first end reaches pre-set peak value voltage, the second crest voltage detection unit 152 output high level, the second control Unit 150 processed controls the 4th switching tube 153 when receiving the high level signal of the second crest voltage detection unit 152 output Shut-off, and then control second switch pipe 41 to turn off.

Second control unit 150 uses the existing control circuit using logic gates as core.

In the present embodiment, first switch pipe 31 and second switch pipe 41 are high-voltage power pipe, the He of the 3rd switching tube 143 4th switching tube 153 is low pressure and low power pipe.

Fig. 4 shows the circuit structure of first time electro-detection module 10 provided in an embodiment of the present invention, for convenience of description, The part related to the embodiment of the present invention is illustrate only, details are as follows：

As shown in figure 4, the first ON time detection unit 100 includes the first NMOS tube N1, the second NMOS tube N2, first PMOS P1, the second PMOS P2, the first electric capacity C1 and first comparator U1.

Wherein, the first NMOS tube N1 grid and the first PMOS P1 grid connect altogether detects list as the first ON time The input of member 100, the grid of the first NMOS tube N1 drain electrode, the first PMOS P1 drain electrode and the second NMOS tube N2 are connected to altogether Second PMOS P2 grid, the positive pole of the second NMOS tube N2 drain electrode, the second PMOS P2 drain electrode and the first electric capacity C1 are total to First comparator U1 in-phase input end is connected to, first comparator U1 anti-phase input terminates the first reference voltage source 1000, the One PMOS P1 source electrode and the second PMOS P2 source electrode are connected to power supply VCC, the first NMOS tube N1 source electrode, the 2nd NMOS altogether Pipe N2 source electrode and the first electric capacity C1 negative pole are connected to ground altogether, and first comparator U1 output end is single for the detection of the first ON time The output end of member 100.

First displacement control unit 101 includes the first rest-set flip-flop U3, the first phase inverter U4 and the first controlling switch S1.

Wherein, the first rest-set flip-flop U3 set end S and reset terminal R is respectively the first of the first displacement control unit 101 Input and the second input, the first phase inverter U4 input and the output end in-phase output end with the first rest-set flip-flop respectively Q and the first controlling switch S1 control terminal connect, and the first controlling switch S1 first end and the second end are respectively the first displacement control The 3rd input and output end of unit 101 processed.

First turn-off time detection unit 102 includes the 5th NMOS tube N5, the first bias current sources IP1, the second electric capacity C2 And the second comparator U2.

Wherein, the 5th NMOS tube N5 grid be the first turn-off time detection unit 102 input, the 5th NMOS tube N5 Drain electrode, the second electric capacity C2 positive pole and the second comparator U2 current input be connected to the of the first bias current sources IP1 altogether One end, the first bias current sources IP1 the second termination power VCC, the second comparator U2 anti-phase input terminate the second benchmark electricity Potential source 1020, the 5th NMOS tube N5 source electrode and the second electric capacity C2 negative pole are connected to ground altogether, and the second comparator U2 output end is The output end of first turn-off time detection unit 102.

In embodiments of the present invention, when the control terminal of the 3rd switching tube 143 is high level, the 3rd switching tube 143 turns on, First switch pipe 31 turns on, now, the input of the first ON time detection unit 100, the first turn-off time detection unit 102 Input and the second input of the first displacement control unit 101 be high level, the first NMOS tube N1 and the second PMOS P2 is turned on, and power supply VCC charges to the first electric capacity C1, because in cold light LED 3 normal work of control circuit, first switch The ON time of pipe 31 is not up to default maximum ON time, and therefore, the first electric capacity C1 positive pole be (i.e. first comparator U1's In-phase input end) voltage be not more than the voltage of the first reference voltage source 1000, therefore, first comparator U1 exports low electricity It is flat, the first rest-set flip-flop U3 in-phase input end Q output low levels, the first phase inverter U4 output high level, the first controlling switch S1 is in normally off, the first displacement control unit 101 output low level, and cycle counter 11 does not shift, meanwhile, the 5th NMOS Pipe N5 is turned on, and the electric current on the first bias current sources IP1 flows to ground by the 5th NMOS tube N5, and the second comparator U2 exports low electricity It is flat；And when the ON time of first switch pipe 31 reaches default maximum ON time, the voltage of the first electric capacity C1 positive pole is big In the voltage of the first reference voltage source 1000, first comparator U1 output high level, now the first control unit 140 control the 3rd Switching tube 143 is turned off, and then controls first switch pipe 31 to turn off, and the input of the first ON time detection unit 100, first are closed The input of disconnected time detecting unit 102 and the second input of the first displacement control unit 101 are overturn to be low by high level Level, now, the 5th NMOS tube N5 shut-offs, power supply VCC charge to the second electric capacity C2, the second comparator U2 output high level Signal, the first rest-set flip-flop U3 set end S is high level, and reset terminal R is low level, and the first rest-set flip-flop U3 same phase exports Hold Q output high level, the first phase inverter U4 output low levels, the first controlling switch S1 conductings, the first turn-off time detection unit The high level signal of 102 outputs is transmitted to cycle shift unit 11, cycle shift unit 11 by the first controlling switch S1 to be carried out Cyclic shift.

Fig. 5 shows the circuit structure of second time electro-detection module 16 provided in an embodiment of the present invention, for convenience of description, The part related to the embodiment of the present invention is illustrate only, details are as follows：

As shown in figure 5, the second ON time detection unit 160 includes the 3rd NMOS tube N3, the 4th NMOS tube N4, the 3rd PMOS P3, the 4th PMOS P4, the 3rd electric capacity C3 and the 3rd comparator U5.

Wherein, the 3rd NMOS tube N3 grid and the 3rd PMOS P3 grid connect altogether detects list as the second ON time The input of member 160, the 3rd NMOS tube N3 drain electrode, the 3rd PMOS P3 drain electrode and the 4th NMOS tube N4 grid are connected to altogether 4th PMOS P4 grid, the 4th NMOS tube N4 drain electrode, the 4th PMOS P4 drain electrode and the 3rd electric capacity C3 positive pole are total to The 3rd comparator U5 in-phase input end is connected to, the 3rd comparator U5 anti-phase input terminates the first reference voltage source 1000, the Three PMOS P3 source electrode and the 4th PMOS P4 source electrode are connected to power supply VCC, the 3rd NMOS tube N3 source electrode, the 4th NMOS altogether Pipe N4 source electrode and the 3rd electric capacity C3 negative pole are connected to ground altogether, and the 3rd comparator U5 output end is single for the detection of the second ON time The output end of member 160.

Second displacement control unit 161 includes the second rest-set flip-flop U7, the second phase inverter U8 and the second controlling switch S2.

Wherein, the second rest-set flip-flop U7 set end S and reset terminal R is respectively the first of the second displacement control unit 161 Input and the second input, the second phase inverter U8 input and the output end in-phase output end with the first rest-set flip-flop respectively Q and the second controlling switch S2 control terminal connect, and the second controlling switch S2 first end and the second end are respectively the second displacement control The 3rd input and output end of unit 161 processed.

Second turn-off time detection unit 162 includes the 6th NMOS tube N6, the second bias current sources IP2, the 4th electric capacity C4 And the 4th comparator U6.

Wherein, the 6th NMOS tube N6 grid be the second turn-off time detection unit 162 input, the 6th NMOS tube N6 Drain electrode, the 4th electric capacity C4 positive pole and the 4th comparator U6 current input be connected to the of the second bias current sources IP2 altogether One end, the second bias current sources IP2 the second termination power VCC, the 4th comparator U6 anti-phase input terminate the second benchmark electricity Potential source 1020, the 6th NMOS tube N6 source electrode and the 4th electric capacity C4 negative pole are connected to ground altogether, and the 4th comparator U6 output end is The output end of second turn-off time detection unit 162.

In embodiments of the present invention, when the control terminal of the 4th switching tube 153 is high level, the 4th switching tube 153 turns on, Second switch pipe 41 turns on, now, the input of the second ON time detection unit 160, the second turn-off time detection unit 162 Input and the second input of the second displacement control unit 161 be high level, the 3rd NMOS tube N3 and the 4th PMOS P4 is turned on, and power supply VCC charges to the 3rd electric capacity C3, because in warm light 4 normal work of LED control circuit, second switch The ON time of pipe 41 is not up to default maximum ON time, and therefore, the 3rd electric capacity C3 positive pole be (i.e. the 3rd comparator U5's In-phase input end) voltage be not more than the voltage of the first reference voltage source 1000, therefore, the 3rd comparator U5 exports low electricity It is flat, the second rest-set flip-flop U7 in-phase input end Q output low levels, the second phase inverter U8 output high level, the second controlling switch S2 is in normally off, the second displacement control unit 161 output low level, and cycle counter 11 does not shift, meanwhile, the 6th NMOS Pipe N6 is turned on, and the electric current on the second bias current sources IP2 flows to ground by the 6th NMOS tube N6, and the 4th comparator U6 exports low electricity Ordinary mail number；And when the ON time of second switch pipe 41 reaches default maximum ON time, the electricity of the 3rd electric capacity C3 positive pole Pressure is more than the voltage of the first reference voltage source 1000, and the 3rd comparator U5 exports high level, and now the second control unit 150 controls 4th switching tube 153 turns off, and then controls second switch pipe 41 to turn off, the input of the second ON time detection unit 160, the Second input of the input of two turn-off time detection units 162 and the second displacement control unit 161 is overturn by high level For low level, now, the 6th NMOS tube N6 shut-offs, power supply VCC charges to the 4th electric capacity C4, and the 4th comparator U6 outputs are high Level signal, the second rest-set flip-flop U7 set end S are high level, and reset terminal R is low level, the second rest-set flip-flop U7 same phase Output end Q exports high level, the second phase inverter U8 output low levels, the second controlling switch S2 conductings, the detection of the second turn-off time The high level signal that unit 162 exports is transmitted to cycle shift unit 11, cycle shift unit 11 by the second controlling switch S2 Carry out cyclic shift.

The embodiment of the present invention additionally provides a kind of LED constant current drive device, and Fig. 6 shows provided in an embodiment of the present invention The circuit structure of LED constant current drive device, for convenience of description, the part related to the embodiment of the present invention is illustrate only, be described in detail It is as follows：

A kind of LED constant current drive device, it is connected with cold light LED lamp string 5 and warm light LED string 6, LED constant current drive device Including power switch 2, rectification module 7, the first bus capacitor C1, cold light LED control circuit 3 and warm light LED control circuit 4, LED Constant current driving device also includes above-mentioned LED constant current driving chip.

Wherein, the first end of power switch 2 and the second end connect the input of AC power 8 and rectification module 7, rectification respectively The supply pin VCC of first output termination LED constant current driving chip 1 of module 7, the second output end, the cold light LED of rectification module 7 The input of lamp string 5, the first control terminal of cold light LED control circuit 3, the input of warm light LED string 6, warm light LED control electricity First control terminal on road 4 is connected to the first bus capacitor C1 positive pole, the first bus capacitor C1 negative pole ground connection, cold light LED control altogether Second control terminal of circuit 3 processed and the second control terminal of warm light LED control circuit 4 connect respectively cold light LED lamp string 5 output end and The output end of warm light LED string 6.

Cold light LED control circuit 3 includes first switch pipe 31, the first load capacitance C1L, the first load resistance R1L, first Inductance L1, the first sustained diode 1 and the first crest voltage detection resistance RCS1；Warm light LED control circuit 4 is opened including second Close pipe 41, the second load capacitance C2L, the second load resistance R2L, the second inductance L2, the second sustained diode 2 and the second peak value Voltage detection resistances RCS2.

Wherein, the first load capacitance C1L positive pole, the first load resistance R1L first end and the first sustained diode 1 Negative electrode connect the first control terminal as cold light LED control circuit 3, the first load capacitance C1L negative pole, the first load resistance altogether R1 the second end and the first inductance L1 first end meet the second control terminal as cold light LED control circuit 3, the first inductance L1 altogether The anode of the second end and the first sustained diode 1 be connected to the hot end of first switch pipe 31, the control of first switch pipe 31 altogether End processed and cold end control pin GATE1 and the first source electrode control pin OUT1 with the first grid of LED constant current driving chip 1 respectively Connection, the first crest voltage detection resistance RCS1 first end and the first crest voltage detection pin of LED constant current driving chip 1 CS1 connections, the first crest voltage detection resistance RCS1 the second end ground connection；Second load capacitance C2L positive pole, the second load electricity The negative electrode of the first end and the second sustained diode 2 that hinder R2L connects the first control terminal as warm light LED control circuit 4 altogether, the The first end of two load capacitance C2L negative pole, the second load resistance R2L the second end and the second inductance L2 connects as warm light altogether Second control terminal of LED control circuit 4, the second inductance L2 the second end and the anode of the second sustained diode 2 are connected to second altogether The hot end of switching tube 41, the control terminal and cold end of second switch pipe 41 second grid with LED drive chip 1 respectively Control pin GATE2 and the control pin OUT2 connections of the second source electrode, the second crest voltage detection resistance RCS2 first end and LED constant current The second crest voltage detection pin CS2 connections of driving chip 1, the second crest voltage detection resistance RCS2 the second end ground connection.

As one embodiment of the invention, first switch pipe 31 is NMOS tube M1, and NMOS tube M1 grid is first switch pipe 31 control terminal, NMOS tube M1 drain electrode is the hot end of first switch pipe 31, and NMOS tube M1 source electrode is first switch pipe 31 cold end.

As one embodiment of the invention, second switch pipe 41 is NMOS tube M2, and NMOS tube M2 grid is second switch pipe 41 control terminal, NMOS tube M2 drain electrode is the hot end of second switch pipe 41, and NMOS tube M2 source electrode is second switch pipe 41 cold end.

As one embodiment of the invention, rectification module 7 includes rectifier bridge 70, starts resistance RST and start-up capacitance CS.Rectification The input of bridge 70 is the input of rectification module 7, and the output end of rectifier bridge 70 connects conduct altogether with starting resistance RST first end Second output end of rectification module 7, start resistance RST the second end and connect altogether as rectification module 7 with start-up capacitance CS positive pole The first output end, start-up capacitance CS negative pole ground connection.

As one embodiment of the invention, cold light LED control circuit 3 also includes the first overvoltage protection resistance ROVP1, warm light LED control circuit 4 also includes the second overvoltage protection resistance ROVP2.

Wherein, the first overvoltage protection resistance ROVP1 first end and the second overvoltage protection resistance ROVP2 first end difference It is connected with the first overvoltage protection pin OVP1 and the second overvoltage protection pin OVP2 of LED constant current driving chip 1, the first overvoltage protection electricity ROVP1 the second end and the second overvoltage protection resistance ROVP2 the second end is hindered to be grounded.

In embodiments of the present invention, the Schema control pin MODE and lower margin GND of LED constant current driving chip are connected to ground altogether.

The embodiment of the present invention additionally provides a kind of LED, including cold light LED lamp string 5 and warm light LED string 6, and LED is also Including above-mentioned LED constant current drive device.

Below in conjunction with operation principle, LED constant current drive device provided in an embodiment of the present invention is described further：

In embodiments of the present invention, LED constant current driving chip 1 is by controlling first switch pipe 31 and/or second switch pipe 41 on or off to carry out current constant control to cold light LED lamp string and/or warm light LED string.With LED constant current driving chip 1 Exemplified by carrying out current constant control to cold light LED lamp string, when electric on power switch 2, first switch pipe 31 turns on, now, the first electricity Feel L1 and carry out energy storage, when the first crest voltage detection unit 142 detects the electricity of the first end of the first crest voltage detection resistance When pressure rises to pre-set peak value voltage (corresponding first inductance L1 electric current rises to its peak point current), the detection of the first crest voltage The output of unit 142 shut-off control signal to the first control unit 140, the first control unit 140 controls according to shut-off control signal 3rd switching tube 143 turns off, and then controls first switch pipe 31 to turn off；When first switch pipe 31 turns off, on the first inductance L1 The electric energy of storage is that cold light LED lamp string is powered by the first sustained diode 1, when the first demagnetization detection unit 141 detects the When the voltage of the cold end of one switching tube 31 drops to and produces mutation, control is opened in the first demagnetization output of detection unit 141 Signal to the first control unit 140, the first control unit 140 controls the 3rd switching tube 143 to turn on, entered according to opening control signal And first switch pipe 31 is controlled to turn on.LED constant current driving chip 1 is by controlling the turn-on and turn-off of first switch pipe 31 come to be cold Light LED string 5 provides stable electric current.

In cold light LED 3 normal work of control circuit, the ON time of first switch pipe 31 is：

The turn-off time of first switch pipe 31 is：

Wherein, L be the first inductance L1 sensibility reciprocal, V_INFor the first bus capacitor C1 voltage, V_LEDFor cold light LED lamp string two The voltage difference at end, I_PKFor the first inductance L1 peak point current.

When electric under power switch 2, the first bus capacitor C1 voltage V_INDecline, due to the electricity at cold light LED lamp string both ends Pressure difference V_LED, the first inductance L1 sensibility reciprocal L and the first inductance L1 peak point current I_PKIt will not change immediately, therefore first opens Close the ON time T of pipe 31_ONIt can increase, as the ON time T of first switch pipe 31_ONWhen reaching default maximum ON time, the One control unit 140 can control first switch pipe 31 to turn off, now the first inductance L1 peak point current I_PKIt can not reach and set in advance The value put, i.e., with the first bus capacitor C1 voltage V_INDecline, the first inductance L1 peak point current I_PKIt is gradually reduced, this Sample can cause the turn-off time T of first switch pipe 31_OFFIt is gradually reduced, as the turn-off time T of first switch pipe 31_OFFLess than default During the overvoltage protection shut-in time, the overvoltage protection of system can be triggered.And when cold light LED 3 normal work of control circuit, due to One bus capacitor C1 voltage V_INIt is sufficiently high, the first inductance L1 peak point current I_PKIt will not decline, if now first switch The turn-off time T of pipe 31_OFFDiminish, be the voltage difference V because the both ends of cold light LED lamp string 5_LEDIncrease, when 5 liang of cold light LED lamp string The voltage difference V at end_LEDWhen protecting voltage more than preset overpressure, the overvoltage protection of system can be triggered.Therefore, electricity is controlled in cold light LED It is the voltage difference V because the both ends of cold light LED lamp string 5 if triggering the overvoltage protection of system in the case of the normal work of road 3_LEDCross Greatly, the overvoltage protection of system is triggered in the case where the ON time of first switch pipe 31 reaches default maximum ON time, Then it is considered 2 times electricity of power switch, the accurate detection to electric number under power switch 2 can be realized through the above way, and be not required to To increase extra reverse-filling diode between the bus capacitor C1 of rectifier bridge 70 and first, simplify LED constant current drive device Circuit structure.

It should be noted that in the embodiment of the present invention, the work of cold light LED control circuit 3 and warm light LED control circuit 4 Principle is identical, and accordingly, with respect to the operation principle of warm light LED control circuit 4, here is omitted.

When power switch 2 is upper for the first time electric, cycle counter 11 resets, and exports " 0 " to coding and decoding module 12, coding " 0 " is converted to first state control signal S1 by decoding module 12, and by first state control signal S1 from its first output end Output first constant-current driven module 14 driving cold light LED control circuit 3, makes it control cold light to the first constant-current driven module 14 LED string lights；When power switch 2 is electric under for the first time, the lower output high level signal of electro-detection module 10 to cycle counter 11, Cycle counter 11 carries out first time displacement, and exports " 1 " to coding and decoding module 12, coding and decoding module 12 and change " 1 " For the second state control signal S2, and the second state control signal S2 is stored, when electric on second of power switch 2, Coding and decoding module 12 exports the second state control signal S2 to the second constant-current driven module 15 from its second output end, and second Constant-current driven module 15 drives warm light LED control circuit, makes it control warm light LED string to light；Similarly, when power switch 2 During second, cycle counter 11 carries out second and shifted, and exports " 2 " to coding and decoding module 12, coding and decoding module " 2 " are converted to third state control signal S3 by 12, and when electric in the third time of power switch 2, are exported from its 3rd output end Third state control signal S3 is to the first constant-current driven module 14 and the second constant-current driven module 15, the first constant-current driven module 14 Cold light LED control circuit 3 and warm light LED control circuit 4 are driven simultaneously with the second constant-current driven module 15, it is controlled cold light LED string and warm light LED string light simultaneously, to realize the purpose of colour temperature regulation.When electric under power switch third time, circulation Counter 11 carries out third time displacement, and exports " 3 " to coding and decoding module 12, and " 3 " are converted to the by coding and decoding module 12 Four state control signal S4, and when electric on power switch 2 the 4th time, the 4th state control signal is exported from its 4th output end To pulse width modulation module 13, pulse width modulation module 13 exports a frequency and accounted for S4 when receiving the 4th state control signal S4 Sky compares fixed pulsewidth modulation square-wave signal to the first constant-current driven module 14 and the second constant-current driven module 15, the first constant current The constant-current driven module 15 of drive module 14 and second drives cold light LED control circuit 3 and warm light LED to control respectively with predetermined current Circuit 4, so that it controls cold light LED lamp string and warm light LED string to be lighted with predetermined luminance respectively, and then realize brightness regulation Purpose.

Wherein, the frequency of pulsewidth modulation square-wave signal and dutycycle can be configured according to the actual requirements, not limited herein System, for example, can set pulsewidth modulation square-wave signal dutycycle be 50%.

The foregoing is merely illustrative of the preferred embodiments of the present invention, is not intended to limit the invention, all essences in the present invention All any modification, equivalent and improvement made within refreshing and principle etc., should be included in the scope of the protection.

Claims

1. in a kind of LED constant current driving chip, with the first switch pipe and warm light LED control circuit in cold light LED control circuit Second switch pipe connection, the LED constant current driving chip is by controlling the first switch pipe and/or the second switch pipe Break-make to carry out current constant control to cold light LED lamp string and/or warm light LED string, the cold light LED control circuit and described warm Light LED control circuit performs color to the cold light LED lamp string and the warm light LED string respectively under the control of power switch Temperature regulation and brightness regulation, it is characterised in that the LED constant current driving chip includes：First time electro-detection module, second time electricity Detection module, cycle counter, coding and decoding module, pulse width modulation module, the first constant-current driven module and the second constant current driving Module；

The test side of first time electro-detection module and the test side of second time electro-detection module are respectively with described first The drive control end of constant-current driven module connects with the drive control end of second constant-current driven module, the cycle counter The first control terminal, the second control terminal and output end respectively the output end with first time electro-detection module, under described second The input of the output end of electro-detection module and the coding and decoding module connects, the first output of the coding and decoding module End, the second output end and the first control terminal with first constant-current driven module, second constant current respectively of the 4th output end First control terminal of drive module and the control terminal connection of the pulse width modulation module, the 3rd output of the coding and decoding module End is connected with the second control terminal of first constant-current driven module and the second control terminal of second constant-current driven module, institute State the output end of pulse width modulation module and the 3rd control terminal of first constant-current driven module and second constant current driving mould The test side of the 3rd control terminal connection of block, the test side of first constant-current driven module and second constant-current driven module It is connected respectively with the cold end of the first switch pipe and the cold end of the second switch pipe；

First time electro-detection module detects ON time and the turn-off time of the first switch pipe, when detecting described the The ON time of one switching tube reaches default maximum ON time, and the turn-off time of the first switch pipe is less than preset overpressure When protecting the shut-in time, first time electro-detection module judges electricity under the power switch and exports shift control signal；Institute ON time and turn-off time that second time electro-detection module detects the second switch pipe are stated, when detecting the second switch The ON time of pipe reaches default maximum ON time, and the turn-off time of the second switch pipe is less than preset overpressure protection and closed When closing the time, second time electro-detection module judges electricity under the power switch and exports shift control signal；The circulation Counter carries out cyclic shift according to the shift control signal and exports shift result；The coding and decoding module is by the shifting Position result is converted to corresponding state control signal, and the power switch again on it is electric when, controlled and believed according to the state Number control first constant-current driven module and/or second constant-current driven module drive the cold light LED control circuit and/ Or the warm light LED control circuit performs the colour temperature regulation；The pulse width modulation module is receiving the coding and decoding mould During the state control signal of block output, first constant-current driven module and described second are controlled according to the state control signal Constant-current driven module is made described in the cold light LED control circuit and warm light LED control circuit control respectively with predetermined current Cold light LED lamp string and the warm light LED string light according to predetermined luminance；

Wherein, the default maximum ON time is the maximum of the first switch pipe and second switch pipe pre-set ON time；When the ON time of the first switch pipe reaches the default maximum ON time, first constant current is driven Dynamic model block controls the first switch pipe shut-off, when the ON time of the second switch pipe reaches the default maximum conducting Between when, second constant-current driven module controls the second switch pipe shut-off.

2. LED constant current driving chip as claimed in claim 1, it is characterised in that first time electro-detection module includes：The One ON time detection unit, the first turn-off time detection unit and the first displacement control unit；

The input of the first ON time detection unit, the input of the first turn-off time detection unit and described Second input of one displacement control unit connects the test side as first time electro-detection module altogether, during first conducting Between detection unit output end and first turn-off time detection end unit output end respectively with first shift control The first input end of unit and the connection of the 3rd input, the output end of first displacement control unit is first time electric-examination Survey the output end of module；

When the ON time for detecting the first switch pipe reaches the default maximum ON time, it is described first conducting when Between detection unit export high level signal to first displacement control unit first input end；When detecting that described first opens When closing the turn-off time of pipe less than the preset overpressure protection shut-in time, the high electricity of the first turn-off time detection unit output Put down to the 3rd input of first displacement control unit；When the first input end of first displacement control unit is high electricity When flat and the second input is changed into low level from high level, first displacement control unit exports shift control signal.

3. LED constant current driving chip as claimed in claim 2, it is characterised in that the first ON time detection unit bag Include the first NMOS tube, the second NMOS tube, the first PMOS, the second PMOS, the first electric capacity and first comparator；

The grid of first NMOS tube and the grid of first PMOS connect altogether detects list as first ON time The input of member, the grid of the draining of first NMOS tube, the drain electrode of first PMOS and second NMOS tube are total to It is connected to the grid of second PMOS, the draining of second NMOS tube, the drain electrode of second PMOS and described first The positive pole of electric capacity is connected to the in-phase input end of the first comparator altogether, and the anti-phase input of the first comparator terminates the first base The source electrode of reference voltage source, the source electrode of first PMOS and second PMOS is connected to power supply, first NMOS tube altogether Source electrode, the source electrode of second NMOS tube and the negative pole of first electric capacity be connected to altogether ground, the output of the first comparator Hold as the output end of the first ON time detection unit.

4. LED constant current driving chip as claimed in claim 2, it is characterised in that first displacement control unit includes the One rest-set flip-flop, the first phase inverter and the first controlling switch；

The set end and reset terminal of first rest-set flip-flop be respectively first displacement control unit first input end and Second input, the input and output end of first phase inverter respectively with the in-phase output end of first rest-set flip-flop and The control terminal connection of first controlling switch, the first end of first controlling switch and the second end are respectively first shifting The 3rd input and output end of position control unit.

5. LED constant current driving chip as claimed in claim 2, it is characterised in that the first turn-off time detection unit bag Include the 5th NMOS tube, the first bias current sources, the second electric capacity and the second comparator；

The grid of 5th NMOS tube be the first turn-off time detection unit input, the leakage of the 5th NMOS tube The in-phase input end of pole, the positive pole of second electric capacity and second comparator is connected to the of first bias current sources altogether One end, the second termination power of first bias current sources, the anti-phase input of second comparator terminate the second benchmark electricity Potential source, the source electrode of the 5th NMOS tube are connected to ground, the output end of second comparator altogether with the negative pole of second electric capacity For the output end of the first turn-off time detection unit.

6. LED constant current driving chip as claimed in claim 1, it is characterised in that second time electro-detection module includes：The Two ON time detection units, the second turn-off time detection unit and the second displacement control unit；

The input of the second ON time detection unit, the input of the second turn-off time detection unit and described Second input of two displacement control units connects the test side as second time electro-detection module altogether, during second conducting Between detection unit output end and second turn-off time detection end unit output end respectively with second shift control The first input end of unit and the connection of the 3rd input, the output end of second displacement control unit is second time electric-examination Survey the output end of module；

When the ON time for detecting the second switch pipe reaches the default maximum ON time, it is described second conducting when Between detection unit export high level signal to second displacement control unit first input end；When detecting that described second opens When closing the turn-off time of pipe less than the preset overpressure protection shut-in time, the high electricity of the second turn-off time detection unit output Put down to the 3rd input of second displacement control unit；When the first input end of second displacement control unit is high electricity When flat and the second input is changed into low level from high level, second displacement control unit exports shift control signal.

7. a kind of LED constant current drive device, connect with cold light LED lamp string and warm light LED series winding, the LED constant current drive device Including power switch, rectification module, the first bus capacitor, cold light LED control circuit and warm light LED control circuit, its feature exists In the LED constant current drive device also includes LED constant current driving chip as claimed in any one of claims 1 to 6；

The first end of the power switch and the second end connect the output end of AC power and the input of the rectification module respectively, First output of the rectification module terminates the supply pin of the LED constant current driving chip, the second output of the rectification module End, the input of the cold light LED lamp string, the first control terminal of the cold light LED control circuit, the warm light LED string Input, the first control terminal of the warm light LED control circuit are connected to the positive pole of first bus capacitor altogether, and described first is female Second control of the negative pole ground connection of line capacitance, the second control terminal of the cold light LED control circuit and the warm light LED control circuit End processed connects the output end of the cold light LED lamp string and the output end of the warm light LED string respectively；

The cold light LED control circuit includes first switch pipe, the first load capacitance, the first load resistance, the first inductance, first Fly-wheel diode and the first crest voltage detection resistance；The warm light LED control circuit includes second switch pipe, the second load electricity Appearance, the second load resistance, the second inductance, the second fly-wheel diode and the second crest voltage detection resistance；

The negative electrode of the positive pole of first load capacitance, the first end of first load resistance and first fly-wheel diode The first control terminal as the cold light LED control circuit, the negative pole of first load capacitance, the first load electricity are connect altogether Second end of resistance and the first end of first inductance connect the second control terminal as the cold light LED control circuit altogether, described The anode of second end of the first inductance and first fly-wheel diode is connected to the hot end of the first switch pipe altogether, described The control terminal and cold end of first switch pipe control pin and the first source with the first grid of the LED constant current driving chip respectively Pole control pin connection, the first end of the first crest voltage detection resistance and the first peak value of the LED constant current driving chip Voltage detecting pin connects, the second end ground connection of the first crest voltage detection resistance；The positive pole of second load capacitance, institute State the first end of the second load resistance and the negative electrode of second fly-wheel diode connects as the warm light LED control circuit altogether First control terminal, the negative pole of second load capacitance, the of the second end of second load resistance and second inductance One end connects the second control terminal as the warm light LED control circuit altogether, and the second end of second inductance is continuous with described second The anode of stream diode is connected to the hot end of the second switch pipe, the control terminal and cold end of the second switch pipe altogether Pin and the second source electrode control pin is controlled to be connected with the second grid of the LED drive chip respectively, the second crest voltage inspection The first end of measuring resistance is connected with the second crest voltage detection pin of the LED constant current driving chip, second crest voltage The second end ground connection of detection resistance.

8. LED constant current drive device as claimed in claim 7, it is characterised in that the rectification module includes rectifier bridge, started Resistance and start-up capacitance；

The input of the rectifier bridge is the input of the rectification module, the output end of the rectifier bridge and the startup resistance First end connect the second output end as the rectification module, second end for starting resistance and the start-up capacitance altogether Positive pole connects the first output end as the rectification module, the negative pole ground connection of the start-up capacitance altogether.

9. LED constant current drive device as claimed in claim 7, it is characterised in that the cold light LED control circuit also includes the One overvoltage protection resistance, the warm light LED control circuit also include the second overvoltage protection resistance；

The first end of the first overvoltage protection resistance and the first end of the second overvoltage protection resistance are permanent with the LED respectively Flow driving chip the first overvoltage protection pin and the second overvoltage protection pin connection, the second end of the first overvoltage protection resistance and Second end of the second overvoltage protection resistance is grounded.

10. a kind of LED, including cold light LED lamp string and warm light LED string, it is characterised in that the LED is also included as weighed Profit requires the LED constant current drive device described in 7-9 any one.