CN208353669U - A kind of LED drive circuit and LED multi-path luminescent system - Google Patents

A kind of LED drive circuit and LED multi-path luminescent system Download PDF

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Publication number
CN208353669U
CN208353669U CN201821097952.XU CN201821097952U CN208353669U CN 208353669 U CN208353669 U CN 208353669U CN 201821097952 U CN201821097952 U CN 201821097952U CN 208353669 U CN208353669 U CN 208353669U
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transistor
mirror image
led
grid
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李俊杰
吴斯敏
殷晓文
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Shanghai Awinic Technology Co Ltd
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Shanghai Awinic Technology Co Ltd
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Abstract

The utility model discloses a kind of LED drive circuit and LED multi-path luminescent systems, pass through the electric current of mirror image drive module mirror image N-type mirrored transistor to presupposition multiple, and the cathode for being transmitted to LED after driving current by the load end of mirror image drive module is obtained, it is shone with carrying out driving to LED.Since clamper module is by the voltage clamping of the load end of mirror image drive module to predeterminated voltage, so that the voltage of the voltage of the load end of mirror image drive module and anode supply end and LED itself conduction voltage drop is irrelevant, no matter how anode supply end and LED conduction voltage drop itself change, the feedback loop that can be made up of the first operational amplifier guarantees that voltage is identical as the voltage of the load end of mirror image drive module at the drain electrode of N-type mirrored transistor, so that N-type mirrored transistor is identical with the operating voltage condition of mirror image drive module, so that the driving current precision that the cathode that the load end of mirror image drive module is LED provides is high.

Description

A kind of LED drive circuit and LED multi-path luminescent system
Technical field
The utility model relates to LED (Light Emitting Diode, light emitting diode) actuation techniques fields, more have Body says, is related to a kind of LED drive circuit and LED multi-path luminescent system.
Background technique
LED has the characteristics that power consumption is few, the service life is long, pollution-free, rich in color, controllability is strong, is the primary of light industry Revolution.With the development of LED, more and more LED products flood the market, such as the illuminating product and display device of LED application. Wherein, the electronic drive circuit of LED is an indispensable component part in LED product.
LED is mainly set in the backing structure of display device when being applied in display device, in red LED, yellow led In the colour mixture application of blue led, needs LED drive circuit that can provide the sufficiently high driving current of precision and be transmitted to LED, into And red LED, yellow led and blue led can blend accurate color by accurately light emission luminance, it is still, existing LED drive circuit by LED access power supply due to being influenced with the influence of LED conduction voltage drop itself, the driving current essence generated It spends lower.
Utility model content
In view of this, the present invention provides a kind of LED drive circuit and LED multi-path luminescent system, LED drive circuits The driving current precision that the cathode that load end by mirror image drive module is LED provides is high, and do not connected by the anode of LED The influence at anode supply end and LED conduction voltage drop itself.
To achieve the above object, the technical scheme that the utility model is provided is as follows:
A kind of LED drive circuit, comprising:
First current source, N-type transmission transistor, N-type mirrored transistor, the first operational amplifier, mirror image drive module and Clamper module;
The drain electrode of first current source output and the N-type transmission transistor and the grid of the N-type mirrored transistor Extremely it is connected, the grid of the N-type transmission transistor is connected with the output end of first operational amplifier, the N-type transmission The source electrode of transistor is connected with the negative phase end of the drain electrode of the N-type mirrored transistor and first operational amplifier, the N The source electrode of type mirrored transistor connects ground terminal;
After electric current to presupposition multiple of the mirror image drive module for N-type mirrored transistor described in mirror image, by described The load end of mirror image drive module is transmitted to the cathode of LED, the anode jointed anode power end of the LED, the mirror image driving The load end of module is connected with the in-phase end of first operational amplifier;
And the clamper module is used for the voltage clamping of the load end of the mirror image drive module to predeterminated voltage, And the predeterminated voltage is no more than the upper limit voltage at the drain electrode of the N-type mirrored transistor.
Optionally, the clamper module includes:
Second current source, second operational amplifier, N-type clamp transistor and current limiting element;
The output end of second current source and the in-phase end of the second operational amplifier and the current limiting element it is defeated Enter end to be connected, the output end of the second operational amplifier and the grid of its negative phase end and the N-type clamp transistor are homogeneous Even, the output end of the current limiting element connects ground terminal;
And the drain electrode of the N-type clamp transistor connects the cathode of the LED, the source electrode of the N-type clamp transistor Connect the load end of the mirror image drive module.
Optionally, the current limiting element is diode, N-type transistor or resistance in diode connection type.
Optionally, first current source includes:
Current reference source and the first image source, benchmark of first image source for the output of current reference source described in mirror image It is exported after electric current to certain multiple;
The output end of first image source is connected with the drain electrode of the N-type transmission transistor.
Optionally, second current source is the second image source, and second image source is for current reference described in mirror image It is exported after the reference current to certain multiple of source output.
Optionally, the current reference source includes: the first P-type transistor and the second P-type transistor, first image source It include: the 3rd P transistor and the 4th P-type transistor;
The source electrode of the source electrode of first P-type transistor and the third P-type transistor is all connected with power supply end;
The grid of first P-type transistor is connected with the grid of the third P-type transistor, and first p-type is brilliant The grid of body pipe is connected with the drain electrode of second P-type transistor;
The drain electrode of first P-type transistor is connected with the source electrode of second P-type transistor, second P-type crystal The drain electrode of pipe connects ground terminal, and the grid of second P-type transistor is connected with the grid of the 4th P-type transistor;
And the drain electrode of the third P-type transistor is connected with the source electrode of the 4th P-type transistor, the 4th p-type The drain electrode of transistor connects the drain electrode of the N-type transmission transistor.
Optionally, second image source includes: the 5th P-type transistor and the 6th P-type transistor;
The source electrode of 5th P-type transistor connects the power supply end, the grid connection of the 5th P-type transistor The grid of first P-type transistor, the drain electrode of the 5th P-type transistor connect the source electrode of the 6th P-type transistor, institute The drain electrode for stating the 6th P-type transistor is homogeneous with the in-phase end of the second operational amplifier and the input terminal of the current limiting element Even, the grid of the 6th P-type transistor is connected with the grid of second P-type transistor.
Optionally, the anode supply end and the power supply end are mutually independent power end;
Alternatively, the anode supply end and the power supply end are same power end.
Optionally, the mirror image drive module includes:
Multiple mirror image submodules, each mirror image submodule include:
N-type drives transistor and connection control unit, and the drain electrode of the N-type driving transistor of all mirror image submodules is equal It is connected to the load end of the mirror image drive module, the source electrode of the N-type driving transistor connects ground terminal, the N-type driving The grid of transistor connects the connection control unit;
Wherein, it is brilliant that the grid that the connection control unit is used to control the N-type driving transistor connects the N-type mirror image The grid or connection ground terminal of body pipe, and the grid of the N-type mirrored transistor is connected in the grid of N-type driving transistor When, N-type driving transistor for N-type mirrored transistor described in mirror image electric current to certain multiple.
Correspondingly, the utility model provides a kind of LED multi-path luminescent system, comprising:
LED multi-path and with the one-to-one driving circuit of every paths of LEDs, wherein the driving circuit is that above-mentioned LED drives Circuit.
Compared to the prior art, technical solution provided by the utility model has at least the following advantages:
The utility model provides a kind of LED drive circuit and LED multi-path luminescent system, comprising: the first current source, N-type Transmission transistor, N-type mirrored transistor, the first operational amplifier, mirror image drive module and clamper module;First current source Output end is connected with the grid of the drain electrode of the N-type transmission transistor and the N-type mirrored transistor, and the N-type transmission is brilliant The grid of body pipe is connected with the output end of first operational amplifier, the source electrode of the N-type transmission transistor and the N-type mirror As the drain electrode of transistor is connected with the negative phase end of first operational amplifier, the source electrode connection of the N-type mirrored transistor Ground terminal;After electric current to presupposition multiple of the mirror image drive module for N-type mirrored transistor described in mirror image, pass through the mirror As the load end of drive module is transmitted to the cathode of LED, the anode jointed anode power end of the LED, the mirror image driving mould The load end of block is connected with the in-phase end of first operational amplifier;And the clamper module is for driving the mirror image The voltage clamping of the load end of dynamic model block is to predeterminated voltage, and the predeterminated voltage is not more than the leakage of the N-type mirrored transistor Upper limit voltage at pole.
As shown in the above, technical solution provided by the utility model, it is brilliant by mirror image drive module mirror image N-type mirror image The electric current of body pipe is transmitted to the cathode of LED to presupposition multiple by the load end of mirror image drive module after obtaining driving current, It is shone with carrying out driving to LED.Wherein, since clamper module is by the voltage clamping of the load end of mirror image drive module to default electricity Pressure, and predeterminated voltage is not more than the upper limit voltage at the drain electrode of N-type mirrored transistor, so that the load end of mirror image drive module The voltage of voltage and anode supply end and LED itself conduction voltage drop is irrelevant, therefore, no matter anode supply end and LED itself How conduction voltage drop changes, and the feedback loop that can be made up of the first operational amplifier guarantees the leakage of N-type mirrored transistor Voltage is identical as the voltage of the load end of mirror image drive module at pole, so that N-type mirrored transistor and mirror image drive module Operating voltage condition is identical, and then guarantees the electric current of the more accurate mirror image N-type mirrored transistor of mirror image drive module, so that mirror As the driving current precision that the cathode that the load end of drive module is LED provides is high.
Detailed description of the invention
In order to illustrate the embodiment of the utility model or the technical proposal in the existing technology more clearly, below will be to embodiment Or attached drawing needed to be used in the description of the prior art is briefly described, it should be apparent that, the accompanying drawings in the following description is only It is the embodiments of the present invention, for those of ordinary skill in the art, without creative efforts, also Other attached drawings can be obtained according to the attached drawing of offer.
Fig. 1 is a kind of structural schematic diagram of LED drive circuit provided by the embodiments of the present application;
Fig. 2 is the structural schematic diagram of another LED drive circuit provided by the embodiments of the present application;
Fig. 3 is a kind of structural schematic diagram of LED multi-path luminescent system provided by the embodiments of the present application.
Specific embodiment
The following will be combined with the drawings in the embodiments of the present invention, carries out the technical scheme in the embodiment of the utility model Clearly and completely describe, it is clear that the described embodiments are only a part of the embodiments of the utility model, rather than whole Embodiment.Based on the embodiments of the present invention, those of ordinary skill in the art are without making creative work Every other embodiment obtained, fall within the protection scope of the utility model.
As described in background, it is mainly set in the backing structure of display device when LED is applied in display device, In the colour mixture application of red LED, yellow led and blue led, need LED drive circuit that can provide the sufficiently high drive of precision Streaming current is transmitted to LED, and then red LED, yellow led and blue led can be blended accurately by accurately light emission luminance Color, still, existing LED drive circuit due to by LED access power supply is influenced with the influence of LED conduction voltage drop itself, The driving current precision that it is generated is lower.
Based on this, the embodiment of the present application provides a kind of LED drive circuit and LED multi-path luminescent system, LED drive circuit The driving current precision that the cathode that load end by mirror image drive module is LED provides is high, and do not connected by the anode of LED The influence at anode supply end and LED conduction voltage drop itself.To achieve the above object, technical solution provided by the embodiments of the present application is such as Under, specifically combine Fig. 1 to Fig. 3 that technical solution provided by the embodiments of the present application is described in detail.
Refering to what is shown in Fig. 1, being a kind of structural schematic diagram of LED drive circuit provided by the embodiments of the present application, wherein LED Driving circuit includes:
First current source 100, N-type transmission transistor NL, N-type mirrored transistor N0, the first operational amplifier AMP1, mirror image Drive module 200 and clamper module 300;
The drain electrode and the N-type mirrored transistor of first current source, 100 output end and the N-type transmission transistor NL The grid of N0 is connected, and the grid of the N-type transmission transistor NL is connected with the output end of the first operational amplifier AMP1, The drain electrode of the source electrode of the N-type transmission transistor NL and the N-type mirrored transistor N0 and the first operational amplifier AMP1 Negative phase end be connected, the source electrode of the N-type mirrored transistor N0 connects ground terminal Gnd;
After electric current to presupposition multiple of the mirror image drive module 200 for N-type mirrored transistor N0 described in mirror image, pass through The load end B of the mirror image drive module 200 is transmitted to the cathode of LED, the anode jointed anode power end VDD_ of the LED LED, the load end of the mirror image drive module 200 are connected with the in-phase end of the first operational amplifier AMP1;
And the clamper module 300 is used for the voltage clamping of the load end B of the mirror image drive module 200 to pre- If voltage, and the upper limit voltage at drain electrode of the predeterminated voltage no more than the N-type mirrored transistor N0.
As shown in the above, technical solution provided by the embodiments of the present application passes through mirror image drive module mirror image N-type mirror image The electric current of transistor is transmitted to the yin of LED to presupposition multiple by the load end of mirror image drive module after obtaining driving current Pole is shone with carrying out driving to LED.Wherein, due to clamper module by the voltage clamping of the load end of mirror image drive module to pre- If voltage, and predeterminated voltage is not more than the upper limit voltage at the drain electrode of N-type mirrored transistor, so that the load of mirror image drive module The voltage of the voltage at end and anode supply end and LED itself conduction voltage drop is irrelevant, therefore, no matter anode supply end and LED How conduction voltage drop itself changes, and the feedback loop that can be made up of the first operational amplifier guarantees N-type mirrored transistor Drain electrode at voltage it is identical as the voltage of the load end of mirror image drive module so that N-type mirrored transistor and mirror image drive mould The operating voltage condition of block is identical, and then guarantees the driving current essence that the cathode that the load end of mirror image drive module is LED provides Degree is high.
Provided by the embodiments of the present application one specific LED drive circuit composed structure is described in detail below with reference to Fig. 2, Refering to what is shown in Fig. 2, for the structural schematic diagram of another LED drive circuit provided by the embodiments of the present application, wherein the application is implemented Example provide the clamper module 300 include:
Second current source 310, second operational amplifier AMP2, N-type clamp transistor NC and current limiting element 320;
The in-phase end and current limliting member of the output end of second current source 310 and the second operational amplifier AMP2 The input terminal of part 320 is connected, the output end and its negative phase end and the N-type clamper crystal of the second operational amplifier AMP2 The grid of pipe NC is connected, and the output end of the current limiting element 320 connects ground terminal Gnd;
And the drain electrode of the N-type clamp transistor NC connects the cathode of the LED, the N-type clamp transistor NC's Source electrode connects the load end B of the mirror image drive module 200.
Clamper module 300 provided by the embodiments of the present application, the electric current of the second current source 310 flow through current limiting element 320 and obtain One voltage VE then makes it export VF=VE by the buffer amplifier that second operational amplifier AMP2 is formed by connecting, into And make the output of second operational amplifier AMP2 that there is stronger driving capability, to control N-type clamp transistor NC. In one embodiment of the application, N-type clamp transistor NC provided by the present application has biggish size, lesser to make it have Conduction impedance, to its size, design parameter the application is not particularly limited, and needs specifically to be designed according to practical application.
N-type clamp transistor NC is used to carry out clamper to the voltage of the load end B of mirror image drive module 200, that is, works as driving When electric current flows through N-type clamp transistor NC, the gate source voltage difference VGS of N-type clamp transistor NC can be a determining value (such as 0.9V~1.5V, including endpoint value), that is, the voltage VB of the load end B of mirror image drive module 200 can be lower than mono- level pressure value of VF, And the pressure value and driving current have positive relationship, are divided by the voltage VA variation at the drain electrode to N-type mirrored transistor N0 Analysis, with the voltage value of optimization design VE=VF based on the analysis results, can design the load end B for obtaining mirror image drive module 200 Voltage VB=VF-VGS be predeterminated voltage, and the predeterminated voltage no more than N-type mirrored transistor N0 drain electrode at voltage VA Upper limit voltage.
Therefore, no matter how the voltage of anode supply end VDD_LED and LED conduction voltage drop itself changes, and mirror image drives mould The voltage VB of the load end B of block 200 can be by N-type clamp transistor NC clamper in predeterminated voltage, and predeterminated voltage is not more than N-type The upper limit voltage of voltage VA at the drain electrode of mirrored transistor N0, the equal energy of feedback loop of the first operational amplifier AMP1 connection Enough guarantee that voltage VA is identical as the voltage VB of load end B of mirror image drive module 200 at the drain electrode of N-type mirrored transistor N0, with So that N-type mirrored transistor N0 is identical with the operating voltage condition of mirror image drive module 200, and then guarantee mirror image drive module 200 load end B is that the driving current precision that the cathode of LED provides is high.
In one embodiment of the application, the current limiting element 320 provided by the present application can connect for diode, in diode Connect the N-type transistor or resistance of mode.Preferably, current limiting element 320 provided by the embodiments of the present application is in diode connection side The N-type transistor ND of formula, current limiting element 320 are belonged to the N-type of N-type mirrored transistor N0 and subsequent descriptions driving transistor NX N-type transistor, therefore it can be drawn on position close to each other when drawing, so these N-types are brilliant in semiconductor fabrication The parameters such as the conduction threshold of body pipe are all identical changes, and the mismatch very little with respect between can improve the work occurred when manufacture Skill deviation influences LED drive circuit bring.
Refering to what is shown in Fig. 2, first current source 100 provided by the embodiments of the present application includes:
Current reference source 110 and the first image source 120, first image source 120 is for current reference source described in mirror image It is exported after the reference current Ib to certain multiple of 110 outputs;
The output end of first image source 120 is connected with the drain electrode of the N-type transmission transistor NL.
And second current source 310 provided by the embodiments of the present application can be the second image source, second mirror image It is exported after the reference current Ib to certain multiple that source 310 is exported for current reference source 110 described in mirror image.
In the embodiment of the present application, current source provided by the present application can be casecode current source, i.e. the application is real The current reference source 110 for applying example offer includes: the first P-type transistor P1 and the second P-type transistor P2, first mirror image Source includes: the 3rd P transistor and the 4th P-type transistor P4;
The source electrode of the source electrode of the first P-type transistor P1 and the third P-type transistor P3 are all connected with power supply end VDD;
The grid of the first P-type transistor P1 is connected with the grid of the third P-type transistor P3, and the first P The grid of transistor npn npn P1 is connected with the drain electrode of the second P-type transistor P2;
The drain electrode of the first P-type transistor P1 is connected with the source electrode of the second P-type transistor P2, second p-type The drain electrode of transistor P2 connects ground terminal Gnd, and the grid of the second P-type transistor P2 is with the 4th P-type transistor P4's Grid is connected, and the grid Circumscribing port Vdp of the second P-type transistor P2;
And the drain electrode of the third P-type transistor P3 is connected with the source electrode of the 4th P-type transistor P4, described The drain electrode of four P-type transistor P4 connects the drain electrode of the N-type transmission transistor NL.
And second image source 310 provided by the embodiments of the present application includes: the 5th P-type transistor P5 and the 6th p-type Transistor P6;
The source electrode of the 5th P-type transistor P5 connects the power supply end VDD, the 5th P-type transistor P5's Grid connects the grid of the first P-type transistor P1, and it is brilliant that the drain electrode of the 5th P-type transistor P5 connects the 6th p-type The source electrode of body pipe P6, the drain electrode of the 6th P-type transistor P6 and the in-phase end of the second operational amplifier AMP1 and described The input terminal of current limiting element 320 is connected, the grid of the grid of the 6th P-type transistor P6 and the second P-type transistor P2 Extremely it is connected.
In one embodiment of the application, the anode supply end VDD_LED provided by the present application and the power supply end VDD can be mutually independent power end;
Alternatively, the anode supply end VDD_LED provided by the present application and power supply end VDD can also be same Power end.
Refering to what is shown in Fig. 2, the mirror image drive module 200 provided by the embodiments of the present application includes:
Multiple mirror image submodules 210, each mirror image submodule 210 include:
N-type drives transistor NX and connection control unit 211, and the N-type of all mirror image submodules 210 drives transistor The drain electrode of NX is connected to the load end B of the mirror image drive module 200, and the source electrode of the N-type driving transistor NX connects Ground terminal Gnd, the grid of the N-type driving transistor NX connect the connection control unit 211;
Wherein, the grid that the connection control unit 211 is used to control the N-type driving transistor NX connects the N-type The grid or connection ground terminal Gnd of mirrored transistor N0, and the N-type mirror is connected in the grid of N-type driving transistor NX As transistor N0 grid when, N-type driving transistor NX for N-type mirrored transistor NX described in mirror image electric current to certain Multiple.
It should be understood that in the grid of the grid connection N-type mirrored transistor N0 of N-type driving transistor NX, N-type driving Transistor NX for mirror image N-type mirrored transistor N0 electric current to certain multiple, wherein the mirror of all N-types driving transistor NX Picture multiple can be identical, can not also be identical, is not particularly limited to this.Since all N-types driving transistor NX is connected in parallel on The load end B of mirror image drive module 200, so, when mirror image drive module 200 works, the load end of mirror image drive module 200 The driving current of B output is the electric current for all N-types driving transistor NX that grid is connected to the grid of N-type mirrored transistor N0 The sum of, therefore, drive the grid of transistor NX to connect the grid of N-type mirrored transistor N0 by control preset quantity N-type, with To mirror image N-type mirrored transistor N0 electric current to required multiple driving current.
In one embodiment of the application, connection control unit 211 provided by the present application may include a phase inverter INV and two The identical transistor M1 and transistor M2 of a conductivity type (such as transistor M1 and transistor M2 are N-type transistor), wherein brilliant The grid of body pipe M1 is connected with the input terminal of phase inverter INV, and transistor M1 is connected to the grid and N of N-type driving transistor NX Between the grid of type mirrored transistor N0, and, the grid of transistor M2 is connected with the output end of phase inverter INV, and transistor M 2 are connected between the grid and ground terminal Gnd of N-type driving transistor NX;Need to control N-type driving transistor NX grid with When the grid of N-type mirrored transistor N0 is connected, the control signal of the input terminal access of the grid and phase inverter INV of transistor M1, Transistor M1 conducting is controlled, and the grid for controlling N-type driving transistor NX is connected with the grid of N-type mirrored transistor N0, and, Since phase inverter INV is to the reverse phase of control signal, the control signal of reverse phase then controls transistor M2 cut-off, avoids N-type driving brilliant The grid of body pipe NX is connected with ground terminal Gnd;In addition, brilliant in the grid and N-type mirror image for needing to disconnect N-type driving transistor NX When connection between the grid of body pipe N0, the control signal of the input terminal access of the grid and phase inverter INV of transistor M1, control Transistor M1 shutdown, and the connection controlled between the grid of N-type driving transistor NX and the grid of N-type mirrored transistor N0 is disconnected It opens, and, since phase inverter INV is to the reverse phase of control signal, the control signal of reverse phase then controls transistor M2 conducting, controls N The grid of type driving transistor NX is connected with ground terminal Gnd, and then turns off N-type driving transistor NX rapidly.
Correspondingly, the embodiment of the present application provides a kind of LED multi-path luminescent system, comprising:
LED multi-path and with the one-to-one driving circuit of every paths of LEDs, wherein the driving circuit be above-mentioned any one reality The LED drive circuit of example offer is provided.
Refering to what is shown in Fig. 3, being a kind of structural schematic diagram of LED multi-path luminescent system provided by the embodiments of the present application, wherein LED multi-path luminescent system includes:
Red light-emitting diode LR, green light LED LG and blue light-emitting diode LB, and, including for driving The driving circuit 410 of red light-emitting diode LR, the driving circuit 420 for driving green light LED LG and for driving The driving circuit 430 of green light LED LB, wherein on driving circuit 410, driving circuit 420 and driving circuit 430 be State the LED drive circuit that any one embodiment provides.
It should be understood that LED multi-path luminescent system provided by the embodiments of the present application, due to red light-emitting diode LR, green The respective conduction voltage drop of light-emitting diode LG and blue light-emitting diode LB is different, wherein green light LED LG It is essentially identical with the conduction voltage drop of blue light-emitting diode LB, and the conduction voltage drop of red light-emitting diode LR is less than green luminescence The conduction voltage drop of diode LG and blue light-emitting diode LB, therefore, in red light-emitting diode LR, green light LED LG When being all connected with same anode power end VDD_LED with the anode of blue light-emitting diode LB, if not set pincers in driving circuit Position module, then red light-emitting diode LR, green light LED LG and blue light-emitting diode LB are to respective corresponding driving electricity The voltage of the load end of mirror image drive module impacts in road;And due to driving circuit 410 provided by the embodiments of the present application, drive Dynamic circuit 420 and driving circuit 430 are all set in clamper module, because regardless of red light-emitting diode LR, two pole of green luminescence How the conduction voltage drop of pipe LG and blue light-emitting diode LB change, and will not make to the voltage of the load end of mirror image drive module At influence, the voltage clamping of the load end of mirror image drive module passes through the first operational amplifier composition in predeterminated voltage Feedback loop guarantees that voltage is identical as the voltage of the load end of mirror image drive module at the drain electrode of N-type mirrored transistor, so that It is identical with the operating voltage condition of mirror image drive module to obtain N-type mirrored transistor, and then guarantees that mirror image drive module is more accurate Mirror image N-type mirrored transistor electric current so that the load end of mirror image drive module be LED cathode provide driving current essence Degree is high, and the final light mixing effect for guaranteeing LED multi-path luminescent system is high.
In one embodiment of the application, LED multi-path luminescent system provided by the present application be can be applied in display device, also It can be applied in illuminating device, or be applied in other light emitting structures, this application is not particularly limited.
The embodiment of the present application provides a kind of LED drive circuit and LED multi-path luminescent system, comprising: the first current source, N Type transmission transistor, N-type mirrored transistor, the first operational amplifier, mirror image drive module and clamper module;First electric current Source output terminal is connected with the grid of the drain electrode of the N-type transmission transistor and the N-type mirrored transistor, the N-type transmission The grid of transistor is connected with the output end of first operational amplifier, the source electrode of the N-type transmission transistor and the N-type The drain electrode of mirrored transistor is connected with the negative phase end of first operational amplifier, and the source electrode of the N-type mirrored transistor connects Connect ground terminal;After electric current to presupposition multiple of the mirror image drive module for N-type mirrored transistor described in mirror image, by described The load end of mirror image drive module is transmitted to the cathode of LED, the anode jointed anode power end of the LED, the mirror image driving The load end of module is connected with the in-phase end of first operational amplifier;And the clamper module is used for the mirror image The voltage clamping of the load end of drive module is to predeterminated voltage, and the predeterminated voltage is no more than the N-type mirrored transistor Upper limit voltage at drain electrode.
As shown in the above, technical solution provided by the embodiments of the present application passes through mirror image drive module mirror image N-type mirror image The electric current of transistor is transmitted to the yin of LED to presupposition multiple by the load end of mirror image drive module after obtaining driving current Pole is shone with carrying out driving to LED.Wherein, due to clamper module by the voltage clamping of the load end of mirror image drive module to pre- If voltage, and predeterminated voltage is not more than the upper limit voltage at the drain electrode of N-type mirrored transistor, so that the load of mirror image drive module The voltage of the voltage at end and anode supply end and LED itself conduction voltage drop is irrelevant, therefore, no matter anode supply end and LED How conduction voltage drop itself changes, and the feedback loop that can be made up of the first operational amplifier guarantees N-type mirrored transistor Drain electrode at voltage it is identical as the voltage of the load end of mirror image drive module so that N-type mirrored transistor and mirror image drive mould The operating voltage condition of block is identical, and then guarantees the driving current essence that the cathode that the load end of mirror image drive module is LED provides Degree is high.
The foregoing description of the disclosed embodiments can be realized professional and technical personnel in the field or using originally practical new Type.Various modifications to these embodiments will be readily apparent to those skilled in the art, and determine herein The General Principle of justice can be realized in other embodiments without departing from the spirit or scope of the present utility model.Cause This, the present invention will not be limited to the embodiments shown herein, and is to fit to and principles disclosed herein The widest scope consistent with features of novelty.

Claims (10)

1. a kind of LED drive circuit characterized by comprising
First current source, N-type transmission transistor, N-type mirrored transistor, the first operational amplifier, mirror image drive module and clamper Module;
First current source output and the drain electrode of the N-type transmission transistor and the grid of the N-type mirrored transistor are equal It is connected, the grid of the N-type transmission transistor is connected with the output end of first operational amplifier, and the N-type transmits crystal The source electrode of pipe is connected with the negative phase end of the drain electrode of the N-type mirrored transistor and first operational amplifier, the N-type mirror As the source electrode of transistor connects ground terminal;
After electric current to presupposition multiple of the mirror image drive module for N-type mirrored transistor described in mirror image, pass through the mirror image The load end of drive module is transmitted to the cathode of LED, the anode jointed anode power end of the LED, the mirror image drive module Load end be connected with the in-phase end of first operational amplifier;
And the clamper module is used for the voltage clamping of the load end of the mirror image drive module to predeterminated voltage, and institute Predeterminated voltage is stated no more than the upper limit voltage at the drain electrode of the N-type mirrored transistor.
2. LED drive circuit according to claim 1, which is characterized in that the clamper module includes:
Second current source, second operational amplifier, N-type clamp transistor and current limiting element;
The input terminal of the output end of second current source and the in-phase end of the second operational amplifier and the current limiting element It is connected, the output end of the second operational amplifier is connected with the grid of its negative phase end and the N-type clamp transistor, institute State the output end connection ground terminal of current limiting element;
And the drain electrode of the N-type clamp transistor connects the cathode of the LED, the source electrode connection of the N-type clamp transistor The load end of the mirror image drive module.
3. LED drive circuit according to claim 2, which is characterized in that the current limiting element is diode, is in diode The N-type transistor or resistance of connection type.
4. LED drive circuit according to claim 2, which is characterized in that first current source includes:
Current reference source and the first image source, reference current of first image source for the output of current reference source described in mirror image It is exported after to certain multiple;
The output end of first image source is connected with the drain electrode of the N-type transmission transistor.
5. LED drive circuit according to claim 4, which is characterized in that second current source is the second image source, institute It is exported after stating reference current to certain multiple of second image source for the output of current reference source described in mirror image.
6. LED drive circuit according to claim 5, which is characterized in that the current reference source includes: the first p-type crystalline substance Body pipe and the second P-type transistor, first image source include: the 3rd P transistor and the 4th P-type transistor;
The source electrode of the source electrode of first P-type transistor and the third P-type transistor is all connected with power supply end;
The grid of first P-type transistor is connected with the grid of the third P-type transistor, and first P-type transistor Grid be connected with the drain electrode of second P-type transistor;
The drain electrode of first P-type transistor is connected with the source electrode of second P-type transistor, second P-type transistor Drain electrode connection ground terminal, the grid of second P-type transistor are connected with the grid of the 4th P-type transistor;
And the drain electrode of the third P-type transistor is connected with the source electrode of the 4th P-type transistor, the 4th P-type crystal The drain electrode of pipe connects the drain electrode of the N-type transmission transistor.
7. LED drive circuit according to claim 6, which is characterized in that second image source includes: the 5th p-type crystalline substance Body pipe and the 6th P-type transistor;
The source electrode of 5th P-type transistor connects the power supply end, described in the grid connection of the 5th P-type transistor The grid of first P-type transistor, the drain electrode of the 5th P-type transistor connect the source electrode of the 6th P-type transistor, and described the The drain electrode of six P-type transistors is connected with the input terminal of the in-phase end of the second operational amplifier and the current limiting element, institute The grid for stating the 6th P-type transistor is connected with the grid of second P-type transistor.
8. LED drive circuit according to claim 6, which is characterized in that the anode supply end and the power supply End is mutually independent power end;
Alternatively, the anode supply end and the power supply end are same power end.
9. LED drive circuit according to claim 1, which is characterized in that the mirror image drive module includes:
Multiple mirror image submodules, each mirror image submodule include:
N-type drives transistor and connection control unit, and the drain electrode of the N-type driving transistor of all mirror image submodules is connected Source electrode for the load end of the mirror image drive module, the N-type driving transistor connects ground terminal, and the N-type drives crystal The grid of pipe connects the connection control unit;
Wherein, the grid that the connection control unit is used to control the N-type driving transistor connects the N-type mirrored transistor Grid or connection ground terminal, and the N-type driving transistor grid connect the grid of the N-type mirrored transistor when, N-type driving transistor for N-type mirrored transistor described in mirror image electric current to certain multiple.
10. a kind of LED multi-path luminescent system characterized by comprising
LED multi-path and with the one-to-one driving circuit of every paths of LEDs, wherein the driving circuit is that claim 1~9 is any LED drive circuit described in one.
CN201821097952.XU 2018-07-11 2018-07-11 A kind of LED drive circuit and LED multi-path luminescent system Active CN208353669U (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108848594A (en) * 2018-07-11 2018-11-20 上海艾为电子技术股份有限公司 A kind of LED drive circuit and LED multi-path luminescent system
CN109819555A (en) * 2019-04-10 2019-05-28 上海艾为电子技术股份有限公司 A kind of LED drive circuit of the low EMI of once-through type high-resolution
CN109831854A (en) * 2019-04-10 2019-05-31 上海艾为电子技术股份有限公司 A kind of LED drive circuit of the low EMI of matrix type high-resolution

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108848594A (en) * 2018-07-11 2018-11-20 上海艾为电子技术股份有限公司 A kind of LED drive circuit and LED multi-path luminescent system
CN109819555A (en) * 2019-04-10 2019-05-28 上海艾为电子技术股份有限公司 A kind of LED drive circuit of the low EMI of once-through type high-resolution
CN109831854A (en) * 2019-04-10 2019-05-31 上海艾为电子技术股份有限公司 A kind of LED drive circuit of the low EMI of matrix type high-resolution
CN109831854B (en) * 2019-04-10 2021-03-16 上海艾为电子技术股份有限公司 Matrix type LED drive circuit with high resolution and low EMI

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