CN103929849A - Isolation led drive circuit - Google Patents
Isolation led drive circuit Download PDFInfo
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- CN103929849A CN103929849A CN201410116145.8A CN201410116145A CN103929849A CN 103929849 A CN103929849 A CN 103929849A CN 201410116145 A CN201410116145 A CN 201410116145A CN 103929849 A CN103929849 A CN 103929849A
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Abstract
The invention discloses an isolation LED drive circuit, and belongs to the technical field of LED drive. The isolation LED drive circuit comprises a fly-wheel diode, a transformer, an auxiliary winding, a power tube, a sense resistor and a constant current controller. An LED is connected with a primary side winding of the transformer in series, the fly-wheel diode is connected with the two ends of a series branch formed by the LED and the primary side winding of the transformer in parallel in the reverse direction, the input end of the power tube is connected with the primary side winding of the transformer, the output end of the power tube is grounded through the sensor resistor, and the auxiliary winding is connected in a secondary side loop of the transformer in series. The constant current controller comprises a zero crossing detector, a bottom detector, a peak detector, a scaling factor amplifier, an on-off control unit, an integral unit, a transconductance amplifier, a comparator and an RS trigger. A duty ratio mapping technology is adopted for the isolation LED drive circuit, and constant current precision of the circuit under different loads is guaranteed.
Description
Technical field
The invention discloses isolation LED drive circuit, belong to the technical field that LED drives.
Background technology
At lighting field, light-emitting diode (LED:Light Emitting Diode) illumination has become current main flow, the driving chip that LED is relevant also becomes the focus in integrated circuit (IC) design field, and the design level of drive circuit is uneven, the constant current accuracy of domestic most driving chip can only accomplish ± 5%, efficiency is generally lower, efficiency is generally between 70% to 90%, the Driving technique of real high-accuracy high-efficiency rate, mostly rest in external several large company's hands, so in domestic LED driving field, be difficult to find power output in 15-20W, efficiency is higher than 90%, constant current accuracy is at ± 2% drive circuit, and the present invention is exactly for above-mentioned deficiency, a LED constant-current control module of design.
LED type of drive is generally divided into isolation and non-isolation type, isolated form type of drive, and efficiency is difficult to break through 90%, and the present invention adopts non-isolation type to drive.The mode that realizes at present constant current adopts the popular erasing time to become the structure of fixed proportion with the cycle mostly, and this kind of structure is difficult to accomplish full voltage, high efficiency, and maximum duty cycle is less than 50%, and power is difficult to break through 10W.
Summary of the invention
Technical problem to be solved by this invention is the deficiency for above-mentioned background technology, and isolation LED drive circuit is provided.
The present invention adopts following technical scheme for achieving the above object:
Isolation LED drive circuit, comprise fly-wheel diode, transformer, auxiliary winding, power tube, detection resistance, LED is connected with transformer primary side windings in series, fly-wheel diode is connected in reverse parallel in the two ends of the series arm being comprised of LED, transformer primary side winding, power tube input is connected with transformer primary side winding, power tube output is through detecting grounding through resistance, and described auxiliary winding is serially connected in transformer secondary loop;
Described isolation LED drive circuit also comprises constant-current controller, and described constant-current controller comprises: zero-crossing detector, the lowest point detector, peak detector, scale factor amplifier, switch control unit, integral unit, trsanscondutance amplifier, comparator, rest-set flip-flop;
When described power tube turn-offs, transformer secondary output winding starts demagnetization conducting, scale factor amplifier amplifies processes the voltage peak that peak detector detects, scale factor amplifier output signal is input to integral unit through switch control unit, integral unit extracts the DC component of switching pulse, be cross over the relatively DC component of switching pulse of amplifier, reference voltage obtains the integration current of proofreading and correct, the integrating capacitor that comparator positive input terminal is connected to produces control switch open-interval reference voltage under the integration current effect of proofreading and correct, comparator is control switch open-interval reference voltage relatively, the cut-off signals of sawtooth waveforms upset power output pipe,
When the demagnetization of transformer secondary output winding finishes, the transformer secondary output winding demagnetization end signal that described zero-crossing detector detects is input to integral unit by switch control unit, and the lowest point detector is detecting the start signal of power tube drain terminal voltage power output pipe at the bottom of lowest trough time;
Described rest-set flip-flop obtains the duty cycle signals of power tube according to the cut-off signals of power tube, start signal.
As further prioritization scheme of the present invention:
Switch control unit comprises the first switching tube, second switch pipe, first mapping block reverse with power tube control signal, with zero passage detection signal the second mapping block in the same way, the first mapping block is exported the control signal that makes the first switching tube closure when transformer secondary output winding starts demagnetization conducting, the second mapping block is exported the control signal that makes the conducting of second switch pipe when secondary winding demagnetization finishes, wherein:
Rest-set flip-flop output described in described the first mapping block input termination, the first switch controlled utmost point described in the first mapping block output termination,
Described the second mapping block input is taken over null detector output, the second switch management and control utmost point processed described in the second mapping block output termination,
The described first switching tube input utmost point connects ratio unit output, and the described second switch pipe input utmost point connects the first switching tube output stage, second switch pipe output stage ground connection.
The present invention adopts technique scheme, there is following beneficial effect: power tube start-up time is in the moment of minimum voltage in metal-oxide-semiconductor drain electrode, by auxiliary winding, the voltage detecting of metal-oxide-semiconductor drain electrode is arrived to the valley floor detection module of constant flow module, and then unlatching metal-oxide-semiconductor, rather than the puppet " quasi-resonant mode " that adopts the constant time lag after output zero passage to open.
Accompanying drawing explanation
Fig. 1 is the embodiment that the present invention isolates LED drive circuit.
Fig. 2 is the block diagram that the present invention isolates LED drive circuit.
Number in the figure explanation: F1 is fuse, and RV is piezo-resistance, and L1, L2 are inductance, CX1, C0, C2, C3, C4, C5, C6, C7, C8, C9, C10 are electric capacity, and BR1 is rectifier bridge, and R1A, R2A are divider resistance, T1 is transformer, R0, R1, R2, R4, R5, R6, R9, R10, R11, R12, R14 are resistance, and D1, D2, D3 are diode, and U1 is CSC8810 chip, NA is auxiliary winding, C is integrating capacitor, and SW0, SW1 are first, second switching tube, and Q1 is power tube.
Embodiment
Below in conjunction with accompanying drawing, the technical scheme of invention is elaborated:
As shown in Figure 2, the isolation LED drive circuit the present invention relates to, comprise fly-wheel diode, transformer, auxiliary winding, power tube MOSFET N, detect resistance, LED is connected with transformer primary side windings in series, fly-wheel diode is connected in reverse parallel in the two ends of the series arm being comprised of LED, transformer primary side winding, power tube input is connected with transformer primary side winding, power tube output is through detecting grounding through resistance, auxiliary winding is serially connected in transformer secondary loop, according to the constant-current controller of LED peak value, the lowest point, the conducting of zero crossing power ratio control pipe.Constant-current controller comprises: zero-crossing detector, the lowest point detector, peak detector, scale factor, switch control unit, integral unit (being comprised of resistance R 0, capacitor C 0, resistance R 1, capacitor C 10), trsanscondutance amplifier, comparator, rest-set flip-flop.Switch control unit comprises the first switching tube, second switch pipe, first mapping block reverse with power tube control signal, with zero passage detection signal the second mapping block in the same way, the first mapping block is exported the control signal that makes the first switching tube closure when transformer secondary output winding starts demagnetization conducting, the second mapping block is exported the control signal that makes the conducting of second switch pipe when secondary winding demagnetization finishes, and two mapping blocks have delay function.When MOSFET N turn-offs, transformer secondary output winding starts demagnetization conducting, through the first mapping block output, make the control signal of the first switching tube SW0 closure, and now second switch pipe SW1 turn-offs, scale factor amplifier output signal is input to integral unit through the first switching tube SW0; When secondary winding demagnetization finishes, pass through zero-crossing detector, secondary winding demagnetization end signal detected, by the second mapping block output, make the control signal of second switch pipe SW1 conducting, and now the first switching tube SW0 turn-offs, integral unit input end grounding now, by the lowest point detector, the drain terminal voltage that MOSFET N detected is opened MOSFET N in time at the bottom of lowest trough.Rest-set flip-flop obtains the duty cycle signals Q of power tube according to the cut-off signals of power tube, start signal.
Peak detector be responsible for detection power pipe sampling resistor voltage, and the reaction of the magnitude of voltage detecting size is the electric current of LED, and when turn-offing, preserves by switch this voltage flow valuve, the magnitude of voltage that scale factor is responsible for peak detector to detect amplifies processing, the first mapping block is responsible for when the demagnetization of secondary winding starts the first switching tube SW0 is closed, and now second switch pipe SW1 disconnects, the second mapping block detects the zero crossing of secondary winding current by auxiliary winding, second switch pipe SW1 is closed, now the first switching tube SW0 disconnects, so the voltage of scale factor output just changes V into
b* SW (nT), SW (nT) is duty cycle information, by direct voltage V
bchanging peak value into is V
b, low level is zero, and duty ratio and the identical switching pulse signal of output duty cycle, then, through second order passive low ventilating filter below, obtains correction voltage V
d, trsanscondutance amplifier is by voltage V
dwith reference voltage V
rEFcarry out, produce the integration current of proofreading and correct, to being cross over amplifier GM external capacitor, discharge and recharge, and then MOSFET N open-interval reference voltage is controlled in generation, the negative terminal of comparator C MP connects saw-toothed wave generator, and when MOSFET N closes, sawtooth waveforms is output as zero, when opening moment, MOSFET N starts charging, when integrating capacitor C voltage surpasses V
ctime, comparator C MP upset, closes MOSFET N.MOSFET N opens when drain electrode is in minimum voltage, by auxiliary winding, the voltage detecting of MOSFET N drain electrode is arrived to the valley floor detection module of constant flow module, and then unlatching metal-oxide-semiconductor, rather than the puppet " quasi-resonant mode " that adopts the constant time lag after output zero passage to open.
A kind of isolation LED drive circuit as shown in Figure 1.Between live wire, zero line, be connected to the protective circuit that fuse F1, piezo-resistance RV form; inductance L 1, inductance L 2, capacitor C X1 form prime filter circuit; rectifier bridge BR1 input is connected on capacitor C X1 two-stage; capacitor C 1 is connected on rectifier bridge BR1 output; resistance R 1A, resistance R 2A are composed in series bleeder circuit; the former limit of transformer T1 circuit is connected to the clamp circuit of resistance R 4, capacitor C 2, diode D1 composition, and transformer T1 secondary circuit is connected to the filter circuit of capacitor C 8, capacitor C 9, diode D3, resistance R 14 compositions.U1(CSC8810 chip) be the corresponding drive circuit of this patent, PIN1 (CS) is current sample pin, in conjunction with the peak current of resistance R 7 resistance R 8 sampled power pipe Q1; PIN3 (COMP) is compensation pin, and capacitor C 5 is integrating capacitor, realizes the function of comparator in conjunction with capacitor C 6, capacitor C 7, resistance R 9; PIN4 (ZCS) the lowest point is detected and zero cross signal detection pin, in conjunction with resistance R 10, resistance R 11, resistance R 12, realize the function of zero-crossing detector, the lowest point detector; PIN5(VDD) supply pin is driving chip power supply in conjunction with capacitor C 3, capacitor C 4, resistance R 2, diode D2, auxiliary winding NA; PIN6 (driver output) is through the grid of resistance R 5, resistance R 6 driven MOS pipes.
The electric current of inductance equals the output of LED, owing to adopting metal-oxide-semiconductor zero drain electrode level detection, it is zero Dead Time that circuit exists certain electric current certainly, and the size of Dead Time changes with the line change in voltage of load and input, general circuit is set as constant time lag this time, and fixing time delay will cause line regulation and the load regulation variation of output current, so this circuit adopts output duty cycle mapping techniques, Dead Time accurate recording, and be adapted in constant flow module.
LED output current can be used suc as formula (1) and calculate, wherein I
ofor output current, I
pKfor the peak current of LED, T
oNfor the ON time of power tube, T
dfor the erasing time of energy storage inductor.
By formula (1), can be found out, want to realize constant current, must guarantee that both products are constant, general design is constant peak electric current, duty ratio is set as to fixed proportion, and the present invention adopts duty ratio mapping techniques.The variation of monitoring output loading and input voltage, follows the tracks of duty cycle information in time in real time, and specific algorithm is as follows,
V
B=V
CS×K (2),
V
C=V
B×SW(nT) (3),
V
D=∫V
Cdt (4),
I
E=(V
D-V
REF)×gm (5),
V
E=∫I
Edt/C (6),
Wherein, R
cSfor sampling resistor, V
bfor LED current peak detected value V
cSrevise the output after K times, V
cfor the signal obtaining after switch element is processed, now by direct voltage V
bchanging peak value into is V
b, low level is zero and duty ratio and the identical switching pulse signal of output duty cycle, by fourier expansion formula, can calculate, now the DC component of switching pulse signal is V
b* D, D is duty ratio SW (nT), and the mode of extracting DC component from signal adopts low pass filter exactly, low pass filter this as integrator, the DC component V that is switching pulse by the signal after integration
d.
V
D=V
B×(T
ON+T
D)/T
S (7),
V
dcompare generation correcting current with reference voltage, integration current I
eform the Superlow-pass filter that bandwidth is 10Hz, output control switch open-interval reference voltage V with the integrating capacitor C of trsanscondutance amplifier
e, V
efor the direct voltage of stable output, it is 0 and the fixing triangular wave of slope that sawtooth waveforms module produces low level, when triangular wave rises to V
etime, CMP output switching activity, closes output mos pipe.
From above-mentioned analysis can show that circuit is stable, V
rEFlevel must equal V
dif both are not identical will produce correcting current, continue the opening time of metal-oxide-semiconductor to adjust, until both current potentials are identical.So can draw:
V
D=V
REF (8),
V
REF=V
D=V
B×(T
ON+T
D)/T
S=I
PK×R
CS×K×(T
ON+T
D)/T
S (9),
By (9) formula, can be drawn:
I
PK×(T
ON+T
D)/T
S=V
REF/R
CS (10),
If K=1, so:
I
PK×(T
ON+T
D)/T
S=V
REF/R
CS (11),
And then draw output current:
I
o=1/2×(V
REF/R
CS) (12),
Identical with general constant current expression formula, but the mode realizing is completely different.
V wherein
rEFdefinite value, R
cSexternal sampling resistance.
Wherein scale factor K is correction factor, by revising the size of K, can make the voltage of sampling resistor meeting under the prerequisite of the normal work of all modules, as much as possible little, and then reduces the consumption of external sampling resistance.
The power tube start-up time of the present invention's design is in the moment of minimum voltage in metal-oxide-semiconductor drain electrode, by auxiliary winding, the voltage detecting of metal-oxide-semiconductor drain electrode is arrived to the valley floor detection module of constant flow module, and then unlatching metal-oxide-semiconductor, rather than the puppet " quasi-resonant mode " that adopts the constant time lag after output zero passage to open, the present invention adopts " duty ratio mapping techniques ", has guaranteed the constant current accuracy of circuit under different loads.
Claims (2)
1. isolate LED drive circuit, comprise fly-wheel diode, transformer, auxiliary winding, power tube, detection resistance, LED is connected with transformer primary side windings in series, fly-wheel diode is connected in reverse parallel in the two ends of the series arm being comprised of LED, transformer primary side winding, power tube input is connected with transformer primary side winding, power tube output is through detecting grounding through resistance, and described auxiliary winding is serially connected in transformer secondary loop;
It is characterized in that: described isolation LED drive circuit also comprises constant-current controller, and described constant-current controller comprises: zero-crossing detector, the lowest point detector, peak detector, scale factor amplifier, switch control unit, integral unit, trsanscondutance amplifier, comparator, rest-set flip-flop;
When described power tube turn-offs, transformer secondary output winding starts demagnetization conducting, scale factor amplifier amplifies processes the voltage peak that peak detector detects, scale factor amplifier output signal is input to integral unit through switch control unit, integral unit extracts the DC component of switching pulse, be cross over the relatively DC component of switching pulse of amplifier, reference voltage obtains the integration current of proofreading and correct, the integrating capacitor that comparator positive input terminal is connected to produces control switch open-interval reference voltage under the integration current effect of proofreading and correct, comparator is control switch open-interval reference voltage relatively, the cut-off signals of sawtooth waveforms upset power output pipe,
When the demagnetization of transformer secondary output winding finishes, the transformer secondary output winding demagnetization end signal that described zero-crossing detector detects is input to integral unit by switch control unit, and the lowest point detector is detecting the start signal of power tube drain terminal voltage power output pipe at the bottom of lowest trough time;
Described rest-set flip-flop obtains the duty cycle signals of power tube according to the cut-off signals of power tube, start signal.
2. isolation LED drive circuit according to claim 1, it is characterized in that: described switch control unit comprises the first switching tube, second switch pipe, first mapping block reverse with power tube control signal, with zero passage detection signal the second mapping block in the same way, the first mapping block is exported the control signal that makes the first switching tube closure when transformer secondary output winding starts demagnetization conducting, the second mapping block is exported the control signal that makes the conducting of second switch pipe when secondary winding demagnetization finishes, wherein:
Rest-set flip-flop output described in described the first mapping block input termination, the first switch controlled utmost point described in the first mapping block output termination,
Described the second mapping block input is taken over null detector output, the second switch management and control utmost point processed described in the second mapping block output termination,
The described first switching tube input utmost point connects ratio unit output, and the described second switch pipe input utmost point connects the first switching tube output stage, second switch pipe output stage ground connection.
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Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
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CN104300945A (en) * | 2014-10-14 | 2015-01-21 | 上海贝岭股份有限公司 | Primary side feedback control power switch circuit |
CN106787750A (en) * | 2016-12-19 | 2017-05-31 | 深圳市群芯科创电子有限公司 | Valley-Switching control circuit under a kind of constant current state |
CN108809261A (en) * | 2018-06-30 | 2018-11-13 | 国网江苏省电力有限公司连云港供电分公司 | Novel high speed current control amplifier for PZT multiple-level stack actuators |
CN109152149A (en) * | 2018-10-13 | 2019-01-04 | 深圳市比尔达科技有限公司 | Self-adapting detecting firm power exports emergency power supply control circuit and its emergency power supply |
CN110277897A (en) * | 2019-07-15 | 2019-09-24 | 无锡硅动力微电子股份有限公司 | A kind of constant-current control circuit and switching power circuit |
CN113659839A (en) * | 2021-07-16 | 2021-11-16 | 杭州电子科技大学 | Primary side current analog circuit of flyback converter and using device thereof |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN101868094A (en) * | 2010-06-22 | 2010-10-20 | 海洋王照明科技股份有限公司 | LED driving circuit and LED lamp |
US20130181635A1 (en) * | 2012-01-13 | 2013-07-18 | Texas Instruments Incorporated | LED Driver with Primary Side Sensing |
CN103298215A (en) * | 2013-06-09 | 2013-09-11 | 浙江大学 | Control circuit of flyback LED (Light Emitting Diode) driver |
CN103424602A (en) * | 2013-09-02 | 2013-12-04 | 南京埃科孚电子科技有限公司 | Secondary winding current detection circuit based on source electrode drive |
CN203814007U (en) * | 2014-03-26 | 2014-09-03 | 无锡市晶源微电子有限公司 | Isolation led drive circuit |
-
2014
- 2014-03-26 CN CN201410116145.8A patent/CN103929849B/en active Active
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN101868094A (en) * | 2010-06-22 | 2010-10-20 | 海洋王照明科技股份有限公司 | LED driving circuit and LED lamp |
US20130181635A1 (en) * | 2012-01-13 | 2013-07-18 | Texas Instruments Incorporated | LED Driver with Primary Side Sensing |
CN103298215A (en) * | 2013-06-09 | 2013-09-11 | 浙江大学 | Control circuit of flyback LED (Light Emitting Diode) driver |
CN103424602A (en) * | 2013-09-02 | 2013-12-04 | 南京埃科孚电子科技有限公司 | Secondary winding current detection circuit based on source electrode drive |
CN203814007U (en) * | 2014-03-26 | 2014-09-03 | 无锡市晶源微电子有限公司 | Isolation led drive circuit |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN104300945A (en) * | 2014-10-14 | 2015-01-21 | 上海贝岭股份有限公司 | Primary side feedback control power switch circuit |
CN106787750A (en) * | 2016-12-19 | 2017-05-31 | 深圳市群芯科创电子有限公司 | Valley-Switching control circuit under a kind of constant current state |
CN108809261A (en) * | 2018-06-30 | 2018-11-13 | 国网江苏省电力有限公司连云港供电分公司 | Novel high speed current control amplifier for PZT multiple-level stack actuators |
CN109152149A (en) * | 2018-10-13 | 2019-01-04 | 深圳市比尔达科技有限公司 | Self-adapting detecting firm power exports emergency power supply control circuit and its emergency power supply |
CN109152149B (en) * | 2018-10-13 | 2024-04-19 | 深圳市比尔达科技有限公司 | Self-adaptive detection constant power output emergency power supply control circuit and emergency power supply thereof |
CN110277897A (en) * | 2019-07-15 | 2019-09-24 | 无锡硅动力微电子股份有限公司 | A kind of constant-current control circuit and switching power circuit |
CN110277897B (en) * | 2019-07-15 | 2023-12-29 | 无锡硅动力微电子股份有限公司 | Constant current control circuit and switching power supply circuit |
CN113659839A (en) * | 2021-07-16 | 2021-11-16 | 杭州电子科技大学 | Primary side current analog circuit of flyback converter and using device thereof |
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Address after: No. 5, Xijin Road, Xinwu District, Wuxi City, Jiangsu Province, 214000 Patentee after: Wuxi Jingyuan Microelectronics Co.,Ltd. Address before: Room 209, building a, block 106-c, national high tech Industrial Development Zone, Wuxi City, Jiangsu Province, 214028 Patentee before: Wuxi Jingyuan Microelectronics Co.,Ltd. |
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