CN106507541A - A kind of LED linear driver, drive circuit, chip and driving method - Google Patents
A kind of LED linear driver, drive circuit, chip and driving method Download PDFInfo
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- CN106507541A CN106507541A CN201611107527.XA CN201611107527A CN106507541A CN 106507541 A CN106507541 A CN 106507541A CN 201611107527 A CN201611107527 A CN 201611107527A CN 106507541 A CN106507541 A CN 106507541A
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- current sense
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/30—Driver circuits
- H05B45/395—Linear regulators
Abstract
The present invention provides a kind of LED linear driver, drive circuit, chip and driving method, including line voltage compensation module and clamp circuit；The voltage of the output voltage or NMOS tube drain terminal of line voltage compensation module samples input voltage source generates the compensation electric current of relation proportional to the input voltage；The first input end of clamp circuit is used for accessing the second reference voltage, and the second input is used for the voltage at the current sense resistor two ends that sampling is electrically connected with LED linear driver, and outfan is connected with the first compensation resistance；When the voltage at current sense resistor two ends is more than the second reference voltage, NMOS tube is ended, and compensation electric current all flows through the first compensation resistance；When the voltage at current sense resistor two ends is equal to the second reference voltage, compensation current segment flows through the first compensation resistance, makes the voltage the lowest point on current sense resistor be clamped at second reference voltage.The LED linear driver of the present invention, drive circuit, chip and driving method improve the line regulation of LED linear driver.
Description
Technical field
The present invention relates to the technical field of electronic circuit, more particularly to a kind of LED linear driver, drive circuit, core
Piece and driving method.
Background technology
Relative to switching mode driver, due to having low cost, without EMI interference, light modulation noiseless, easy optoelectronic integration
The clear superiority such as integrated, Linear actuator drive LED by leaps and bounds fast-developing with its unique advantage.However, line
Property driver also have and following cannot avoid：
1) input voltage range is narrow；
2) power supply conversion efficiency is low；
3) line regulation is poor.
In prior art, increasing technology is devoted to the above deficiency for improving Linear actuator.Especially, linear tune
Whole rate is a very important index, and the line regulation for therefore improving the output of LED linear constant-flow driver is highly desirable to.
Content of the invention
The shortcoming of prior art in view of the above, it is an object of the invention to provide a kind of LED linear driver, driving
Circuit, chip and driving method, based on line voltage compensation technology and clamp circuit, are effectively improved LED linear driver
Line regulation.
For achieving the above object and other related purposes, the present invention provides a kind of LED linear driver, including：Line voltage
Compensating module, the voltage of the output voltage or NMOS tube drain terminal of the line voltage compensation module samples input voltage source generate with
The compensation electric current of the proportional relation of the input voltage；Clamp circuit, the first input end of the clamp circuit are used for accessing the
Two reference voltages, the second input are used for the voltage at the current sense resistor two ends that sampling is electrically connected with LED linear driver, defeated
Go out end to be connected with first resistor；When the voltage at current sense resistor two ends is more than the second reference voltage, NMOS tube is ended, described
Compensation electric current all flows through the first resistor；When the voltage at current sense resistor two ends is equal to the second reference voltage, described
Compensation current segment flows through the first resistor, makes the voltage the lowest point on current sense resistor be clamped at described second with reference to electricity
Pressure.
Meanwhile, the present invention also provides a kind of LED linear driver, including：
Line voltage compensation module, the output voltage of the line voltage compensation module samples input voltage source or NMOS tube leakage
The voltage at end generates the compensation electric current of relation proportional to the input voltage；
Clamp circuit, the first input end of the clamp circuit are used for accessing the second reference voltage, and the second input is used for
The first reference voltage is accessed, outfan is connected with the first end of second resistance；When the first reference voltage is more than the second reference voltage
When, NMOS tube is ended, and the compensation electric current all flows through second resistance；When the first reference voltage is equal to the second reference voltage,
The compensation current segment flows through the second resistance, makes voltage the lowest point clamper on the current sense resistor described second
Reference voltage.
In one embodiment of the invention, also include：
Error amplifier, the positive input terminal of the error amplifier are used for receiving the first reference voltage, and negative input end is used for
Receive first resistor and the voltage on current sense resistor；
The drain electrode of the NMOS tube is connected with LED load, and source electrode electrically connects the current sense resistor, grid and the mistake
The outfan of difference amplifier is connected, and cuts for the NMOS when the error amplifier negative input end voltage is higher than positive input terminal voltage
Only, when negative input end voltage is less than or equal to positive input terminal voltage, NMOS is turned on.
In one embodiment of the invention, also include：
Error amplifier, the positive input terminal of the error amplifier are used for receiving the first reference voltage, and negative input end is used for
Receive the voltage at current sense resistor two ends；
The drain electrode of the NMOS tube is connected with LED load, and source electrode electrically connects the current sense resistor, grid and the mistake
The outfan of difference amplifier is connected, and cuts for the NMOS when the error amplifier negative input end voltage is higher than positive input terminal voltage
Only, when negative input end voltage is less than or equal to positive input terminal voltage, NMOS is turned on.
In one embodiment of the invention, also include：Reference voltage circuit, the reference voltage circuit are used for output first and join
Examine voltage.
In one embodiment of the invention, the reference voltage circuit includes reference voltage module, second resistance and the 3rd electricity
Resistance；The second resistance and 3rd resistor ground connection of the reference voltage module via series connection；The reference voltage module
It is described first with reference to electricity for providing the voltage at the junction point of original reference voltage, the second resistance and 3rd resistor
Pressure.
In one embodiment of the invention, the NMOS tube replaces with NPN triode；The colelctor electrode of the NPN triode with
Second end of the LED load is connected, and base stage is connected with the first end of the current sense resistor, and emitter stage is put with the error
The outfan of big device is connected.
In one embodiment of the invention, the clamp circuit includes the second error amplifier and the second NMOS tube；Described
The positive input terminal of two error amplifiers connects second reference voltage, and negative input end is connected with the current sense resistor, defeated
Go out end to be connected with the grid of second NMOS tube；The output of the drain electrode of second NMOS tube and the line voltage compensation module
End is connected, source ground.
In one embodiment of the invention, in the clamp circuit, second NMOS tube replaces with NPN triode；Described
The emitter stage of NPN triodes is connected with the outfan of second error amplifier, colelctor electrode and the first of the first resistor
End is connected, base earth.
In one embodiment of the invention, the clamp circuit includes the second error amplifier and the second NMOS tube；Described
The positive input terminal of two error amplifiers accesses second reference voltage, negative input end and the first error amplifier positive input
End is connected, and outfan is connected with the grid of second NMOS tube；The drain electrode cut-in operation voltage VDD of second NMOS tube,
Source electrode is connected with the outfan of the line voltage compensation module.
In one embodiment of the invention, in the clamp circuit, second NMOS tube replaces with NPN triode；Described
The emitter stage of NPN triodes is connected with the outfan of second error amplifier, colelctor electrode cut-in operation voltage VDD, base stage
It is connected with the junction point of the first resistor and the second resistance.
Meanwhile, the present invention also provides a kind of LED linear drive circuit, including input voltage source, LED load, reference voltage
Circuit, line voltage compensation module, error amplifier, NMOS tube, first resistor, current sense resistor and clamp circuit；
The reference voltage circuit is used for exporting the first reference voltage；
The input voltage source is connected with the first end of the LED load, for providing input voltage；
The outfan of the line voltage compensation module is connected with the first end of the first resistor, defeated with described for exporting
Enter the compensation electric current of the proportional relation of voltage；
The drain electrode of the NMOS tube is connected with the second end of the LED load, source electrode and the of the current sense resistor
One end is connected, and grid is connected with the outfan of the error amplifier, and the positive input terminal of the error amplifier is used for reception the
One reference voltage, negative input end are used for the voltage for receiving current sense resistor two ends；
The positive input terminal of the error amplifier is connected with the outfan of the reference voltage circuit, negative input end with described
The first end of first resistor is connected；Second end of the first resistor is connected with the first end of the current sense resistor, described
The second end ground connection of current sense resistor；
The first input end of the clamp circuit accesses the second reference voltage, the second input and the current sense resistor
First end be connected, outfan is connected with the first end of the first resistor, for by the voltage on the current sense resistor
The lowest point clamper is in second reference voltage.
In addition, the present invention also provides a kind of LED linear drive circuit, including input voltage source, LED load, reference voltage
Module, line voltage compensation module, error amplifier, NMOS tube, first resistor, second resistance, current sense resistor and clamper electricity
Road；
The first resistor and second resistance ground connection of the reference voltage module via series connection, original for providing
Reference voltage；
The input voltage source is connected with the first end of the LED load, for providing input voltage；
The outfan of the line voltage compensation module is connected with the junction point of the first resistor and the second resistance, is used
In the compensation electric current for being input into relation proportional to the input voltage；
The drain electrode of the NMOS tube is connected with the second end of the LED load, source electrode and the of the current sense resistor
One end is connected, and grid is connected with the outfan of the error amplifier, and the positive input terminal of the error amplifier is used for reception the
One reference voltage, negative input end are used for the voltage for receiving current sense resistor two ends；
The positive input terminal of the error amplifier is connected with the junction point of the first resistor and the second resistance, is accessed
First reference voltage, negative input end are connected with the first end of the current sense resistor, the second end of the current sense resistor
Ground connection；
The first input end of the clamp circuit accesses the second reference voltage, and the second input is with the error amplifier just
Input or negative input end are connected, and outfan is connected with the junction point of the first resistor and the second resistance, for by institute
The voltage the lowest point clamper on current sense resistor is stated in second reference voltage.
In addition, the present invention also provides a kind of chip driven for LED linear, including any of the above-described described LED linear
Driver.
Correspondingly, the present invention also provides a kind of chip driven for LED linear, including any of the above-described described LED line
Property driver and NMOS tube.
Correspondingly, the present invention also provides a kind of LED linear driving method, comprises the following steps：
1) voltage of the output voltage of line voltage compensation module samples input voltage source or NMOS tube drain terminal is generated and institute
State the compensation electric current of the proportional relation of input voltage；
2) when the voltage at current sense resistor two ends is more than the second reference voltage, NMOS tube is ended, the compensation electric current
The first resistor is all flow through；When the voltage at current sense resistor two ends is equal to the second reference voltage, the compensation electric current
The first resistor is flow through in part, makes the voltage the lowest point on current sense resistor be clamped at second reference voltage.
In one embodiment of the invention, step 2) replace with：
When the first reference voltage is more than the second reference voltage, the compensation electric current all flows through second resistance；When first
When reference voltage is equal to the second reference voltage, the compensation current segment flows through second resistance, makes on the current sense resistor
Voltage the lowest point clamper in second reference voltage.
As described above, the LED linear driver of the present invention, drive circuit, chip and driving method, with following beneficial effect
Really：
(1) based on line voltage compensation technology and clamp circuit, the Serial regulation of LED linear driver is effectively improved
Rate；
(2) output current of LED linear driver changes less in whole input voltage range.
Description of the drawings
Fig. 1 is shown as the structural representation of the first preferred embodiment of the LED linear driver of the present invention；
Fig. 2 is shown as the LED linear driver of the present invention not comprising structural representation during clamp circuit；
Fig. 3 is shown as the LED linear driver of the present invention not comprising current-voltage waveform figure during clamp circuit；
Fig. 4 be shown as the present invention LED linear driver in current-voltage waveform figure；
Fig. 5 be shown as the present invention first preferred embodiment in clamp circuit structural representation；
Fig. 6 is shown as the structural representation of the second preferred embodiment of the LED linear driver of the present invention；
Fig. 7 be shown as the present invention the second preferred embodiment in clamp circuit structural representation.
Component label instructions
11 input voltage sources
12 LED loads
13 reference voltage circuits
14 line voltage compensation modules
15 error amplifiers
16 NMOS tubes
17 first resistors
18 current sense resistors
19 clamp circuits
21 input voltage sources
22 LED loads
23 reference voltage modules
24 line voltage compensation modules
25 error amplifiers
26 NMOS tubes
27 first resistors
28 second resistances
29 current sense resistors
20 clamp circuits
Specific embodiment
Embodiments of the present invention are described below by way of specific instantiation, those skilled in the art can be by this specification
Disclosed content understands other advantages and effect of the present invention easily.The present invention can also pass through in addition different concrete realities
The mode of applying is carried out or applies, and the every details in this specification can also be based on different viewpoints and application, without departing from
Various modifications and changes are carried out under the spirit of the present invention.It should be noted that, in the case where not conflicting, following examples and reality
Apply the feature in example to be mutually combined.
It should be noted that the diagram provided in following examples only illustrates the basic structure of the present invention in a schematic way
Think, only show then the component relevant with the present invention in schema rather than according to component count during actual enforcement, shape and size
Draw, which is actual when the implementing kenel of each component, quantity and ratio can be a kind of random change, and its assembly layout kenel
It is likely more complexity.
The present invention provides a kind of LED linear driver, including line voltage compensation module and clamp circuit.Line voltage compensation mould
The voltage of the output voltage or NMOS tube drain terminal in block sampled input voltage source generates relation proportional to the input voltage
Compensation electric current.The first input end of clamp circuit is used for accessing the second reference voltage, and the second input is used for sampling and LED linear
The voltage at the current sense resistor two ends of driver electrical connection, outfan are connected with first resistor；When current sense resistor two ends
Voltage be more than the second reference voltage when, NMOS tube end, described compensation electric current all flow through the first resistor；When electric current is examined
When the voltage at measuring resistance two ends is equal to the second reference voltage, the compensation current segment flows through the first resistor, examines electric current
Voltage the lowest point on measuring resistance is clamped at second reference voltage.
Therefore, by line voltage compensation module and clamp circuit, the line regulation of LED linear driver is improve, is made
Output current change in whole input voltage range less.Elaborate below by physical circuit of the invention
LED linear driver.
As shown in figure 1, in the first preferred embodiment of the present invention, LED linear drive circuit include input voltage source 11,
LED load 12, reference voltage circuit 13, line voltage compensation module 14, error amplifier EA 15, NMOS tube 16, first resistor
(R1) 17, current sense resistor Rcs 18 and clamp circuit 19.
Reference voltage circuit 13 is used for exporting the first reference voltage Vref 1.Specifically, reference voltage circuit 13 includes referring to
Voltage module, second resistance R2 and 3rd resistor R3, reference voltage module are used for providing reference voltage Vbg, reference voltage module
Second resistance R2 and 3rd resistor R3 ground connection via series connection.Voltage at the junction point of second resistance R2 and 3rd resistor R3 is
First reference voltage Vref 1.Therefore, the first reference voltage Vref 1=Vbg*R3/ (R2+R3).
Input voltage source 11 is connected with the first end of LED load 12, for providing input voltage Vac.
The outfan of line voltage compensation module 14 is connected with the first end of first resistor (R1) 17, for output and input electricity
The compensation electric current Ic1 of the proportional relations of pressure Vac.Wherein, Ic1=K*Vac, K are a constant.
The drain electrode of NMOS tube 16 is connected with the second end of LED load 12, the first end of source electrode and current sense resistor Rcs18
It is connected, grid is connected with the outfan of error amplifier EA 15, for being output as timing conducting in error amplifier EA 15,
End when error amplifier EA15 is output as negative.The drain electrode electricity of the input voltage Vac or metal-oxide-semiconductor in sampled input voltage source
Pressure (Vdrain), then be obtained electric current Ic1.
The positive input terminal of error amplifier EA15 is connected with the outfan of reference voltage circuit 13, negative input end and first electricity
The first end of resistance R117 is connected.Second end of first resistor (R1) 17 is connected with the first end of current sense resistor Rcs 18, electricity
The second end ground connection of stream detection resistance Rcs.
The first input end of clamp circuit 19 accesses the second reference voltage Vref 2, the second input and current sense resistor
The first end of Rcs 18 is connected, and outfan is connected with the first end of first resistor (R1) 17, for by current sense resistor Rcs18
On voltage Vcs2 the lowest point clamper in the second reference voltage Vref 2, wherein the second reference voltage Vref 2 is less than the first reference point
Vref1.
As shown in Fig. 2 in above-mentioned LED linear constant-current drive circuit, if removing clamp circuit, only with line voltage compensation
When module carries out line voltage compensation, Vref1=Vcs2+Ic1*R1.The electric current Ic1 of wherein line voltage compensation module output flows through the
One resistance R1 can realize line voltage compensation so that the voltage Vcs2 on current sense resistor Rcs reduces, also so that output current
Iled reduces.Now, the electric current for obtaining in LED load is：
Iled=(Vref1-Ic1*R1)/Rcs=(Vref1-K*Vac*R1)/Rcs
By above-mentioned formula as can be seen that input voltage Vac is bigger, the electric current Iled in LED load is less, current/voltage
Oscillogram is as shown in Figure 3.Design parameter value is as shown in table 1.
The parameter of table 1, input voltage Vac and LED load electric current Iled
| Vac(Vac) | Iled_avg(mA) |
| Vac=200 | 23.1 |
| Vac=210 | 24.3 |
| Vac=220 | 25.0 |
| Vac=230 | 25.2 |
| Vac=240 | 24.8 |
| Vac=250 | 24.1 |
| Vac=260 | 23.2 |
| 200Vac 260Vac output current deviations | 8.7% |
As shown in Table 1, when input voltage Vac takes minima (200Vac) and maximum (260Vac), LED load electric current
The meansigma methodss of Iled are almost identical.But in whole input voltage range (200Vac-260Vac), electric current Iled is average for LED load
Value changes are still above 8%, therefore the space that the line regulation of output is also further lifted.
As shown in figure 4, after increased clamp circuit, voltage Vcs2 the lowest point or the electric current the lowest point quilt of LED load is flow through
Clamper to a fixed value, so as to avoid enter into depth compensation.Therefore, the application of clamp circuit improves LED load output
Line voltage regulation, allows output current to change in whole input voltage range less.Specifically, drop in voltage Vcs2
When Vref2, clamp circuit absorbs an electric current Ic2 so that minimum points of the voltage Vcs2 at the lowest point is equal to Vref2, so as to
So that the lowest point electric current of Iled remains fixed value Vref2/Rcs, it is to avoid Iled electric currents enter the depth compensation of the lowest point, so as to
Improve the line regulation performance of Iled electric currents.Wherein, Ic2=Ic1- (Vref1-Vref2)/R1.
After clamp circuit is increased, the parameter of input voltage Vac and LED load electric current Iled is as indicated with 2.
The parameter of table 2, input voltage Vac and LED load electric current Iled
| Vac Input(Vac) | Iled_avg(mA) |
| Vac=200 | 24.3 |
| Vac=210 | 25.0 |
| Vac=220 | 25.2 |
| Vac=230 | 24.9 |
| Vac=240 | 25.0 |
| Vac=250 | 25.2 |
| Vac=260 | 25.5 |
| 200Vac 260Vac output current deviations | 4.8% |
| 200Vac 240Vac output current deviations | 3.6% |
As shown in Table 2, after increasing clamp circuit, the LED linear constant-current drive circuit of the present invention may insure input voltage
When in the range of 200Vac-260Vac, line regulation is less than 5%, and line regulation is less than in the range of the 200Vac-240Vac
4%, so as to drastically increase the line regulation of LED linear constant-current drive circuit, meet the demand of side circuit.
Preferably, NMOS tube could alternatively be NPN triode.When using NPN triode, the colelctor electrode of NPN triode
It is connected with the second end of LED load, base stage is connected with the first end of current sense resistor Rcs, emitter stage and error amplifier EA
Outfan be connected.
With reference to Fig. 5, in the first preferred embodiment of the present invention, clamp circuit includes error amplifier EA2 and NMOS tube
MC1.The positive input terminal of error amplifier EA2 connects the second end of the second reference voltage Vref 2, negative input end and first resistor R1
It is connected, outfan is connected with the grid of NMOS tube MC1.The drain electrode of NMOS tube MC1 is connected with the first end of first resistor R1, source electrode
Ground connection.
When voltage Vcs2 is higher than the second reference voltage Vref 2, error amplifier EA2 exports low level, and NMOS tube MC1 is cut
Only, clamp circuit does not work.When voltage Vcs2 is less than the second reference voltage Vrefs 2 of V, by error amplifier EA2 and NMOS
Ic1 is injected into the current drain on R1 to ground by the loop that the clamp circuit that pipe MC1 is formed is formed with R1, clamp circuit so that
Vcs2=Vref2.Therefore, in the LED linear constant-current drive circuit of the present invention when voltage Vcs2 drops to equal to Vref2,
Clamp circuit absorbs an electric current Ic2 so that minimum points of the voltage Vcs2 at the lowest point is equal to Vref2, so that Iled
The lowest point electric current remains fixed value Vref2/Rcs, it is to avoid Iled electric currents enter the depth compensation of the lowest point, so as to improve Iled
The line regulation performance of electric current.
Preferably, NMOS tube can also replace with NPN triode.The emitter stage of NPN triodes is with error amplifier EA2's
Outfan is connected, and colelctor electrode is connected with the first end of first resistor R1, base earth.
Meanwhile, the present invention also provides a kind of LED linear driver, including line voltage compensation module and clamp circuit.Line electricity
The voltage of the output voltage or NMOS tube drain terminal in pressure compensating module sampled input voltage source generate with the input voltage into than
The compensation electric current of example relation.The first input end of clamp circuit is used for accessing the second reference voltage, and the second input is used for accessing
First reference voltage, outfan are connected with the first end of second resistance；When the first reference voltage is more than the second reference voltage,
NMOS tube is ended, and the compensation electric current all flows through second resistance；When the first reference voltage is equal to the second reference voltage, described
Compensation current segment flows through the second resistance, makes the voltage the lowest point clamper on the current sense resistor in the described second reference
Voltage.
Change of the line voltage compensation module by detection line voltage, extracts from the divider resistance tap of reference voltage module
One electric current is reducing the first reference voltage to realize the function of line voltage compensation.Therefore, by line voltage compensation module and pincers
Position circuit, improves the line regulation of LED linear driver so that output current changes more in whole input voltage range
Little.LED linear driver of the invention is elaborated below by physical circuit.
As shown in fig. 6, the present invention the second preferred embodiment in, LED linear drive circuit include input voltage source 21,
LED load 22, reference voltage module 23, line voltage compensation module 24, error amplifier EA25, NMOS tube 26, first resistor
(R2) 27, second resistance (R3) 28, current sense resistor Rcs 29 and clamp circuit 20.
Reference voltage module 23 is grounded via the first resistor (R2) 27 and second resistance (R3) 28 of series connection, for providing original
Beginning reference voltage Vbg.
Input voltage source 21 is connected with the first end of LED load 22, for providing input voltage Vac.
The outfan of line voltage compensation module 24 is connected with the junction point of first resistor (R2) 27 and second resistance (R3) 28,
For being input into the compensation electric current Ic1 of relation proportional to input voltage Vac.Wherein, Ic1=K*Vac, K are a constant.
The drain electrode of NMOS tube 26 is connected with the second end of LED load 22, the first end of source electrode and current sense resistor Rcs29
It is connected, grid is connected with the outfan of error amplifier EA25, for being output as timing conducting in error amplifier EA25,
End when error amplifier EA25 is output as negative.The input voltage Vac or the drain voltage of metal-oxide-semiconductor in sampled input voltage source
(Vdrain), then electric current Ic1 is obtained.
The positive input terminal of error amplifier EA25 is connected with the junction point of first resistor (R2) 27 and second resistance (R3) 28,
The first reference voltage Vref 1 is accessed, negative input end is connected with the first end of current sense resistor Rcs29, current sense resistor
The second end ground connection of Rcs29.
The first input end of clamp circuit 20 accesses the second reference voltage Vref 2, the second input and error amplifier
EA25 positive input terminals or negative input end are connected, outfan and first resistor (R2) 27 and the junction point phase of second resistance (R3) 28
Even, for by the voltage Vcs1 the lowest point clamper on current sense resistor Rcs29, in the second reference voltage Vref 2, wherein second joins
Voltage Vref2 is examined less than the first reference point Vref1.
If removing clamp circuit, when carrying out line voltage compensation only with line voltage compensation module, Vref1=(Vbg-Ic1*
R2) * R3/ (R3+R2)=Vcs1=Iled*Rcs.The electric current Ic1 of wherein input line voltage compensating module causes first with reference to electricity
Pressure Vref1 reduces, also so that output current Iled reduces.
After increased clamp circuit, 1 the lowest point of the first reference voltage Vref or flowing through the electric current the lowest point of LED load is clamped
Position to a fixed value, so as to avoid enter into depth compensation.Therefore, the application of clamp circuit improves the line of LED load output
Voltage regulation factor, allows output current to change in whole input voltage range less.Specifically, in the first reference voltage Vref 1
When dropping to equal to the second reference voltage Vref 2, clamp circuit flows out an electric current Ic2 so that the first reference voltage Vref 1 exists
Minimum point at the lowest point is equal to Vref2 so that the lowest point electric current of Iled remains fixed value Vref2/Rcs, it is to avoid Iled electricity
Stream enters the depth compensation of the lowest point, so as to improve the line regulation performance of Iled electric currents.
Wherein, Vref1=Vcs1=(Ic1-Ic2) * R3+Vref2, therefore Ic2=Ic1- (Vref1-Vref2)/R3.Work as pincers
When position circuit works, by injection current Ic2 in the divider resistance being made up of R2 and R3 so that Vref2=Vref1=
Vcs1.
Preferably, NMOS tube could alternatively be NPN triode.When using NPN triode, the colelctor electrode of NPN triode
It is connected with the second end of LED load, base stage is connected with the first end of current sense resistor Rcs, emitter stage and error amplifier EA
Outfan be connected.
With reference to Fig. 7, in second preferred embodiment of the present invention, clamp circuit includes error amplifier EA3 and NMOS tube
MC2.The positive input terminal of error amplifier EA3 accesses the second reference voltage Vref 2, and negative input end is just defeated with error amplifier EA3
Enter end or negative input end is connected, outfan is connected with the grid of NMOS tube MC2.The drain electrode cut-in operation voltage of NMOS tube MC2
VDD, source electrode are connected with the junction point of first resistor R2 and second resistance R3.
When the first reference voltage Vref 1 is higher than the second reference voltage Vref 2, error amplifier EA3 exports low level,
NMOS tube MC3 is ended, and clamp circuit does not work.When the first reference voltage Vref 1 drops to equal to the second reference voltage Vref 2
When, the grid voltage of output adjustment voltage NMOS tube MC2 of error amplifier EA3, NMOS tube MC2 are turned on and output current Ic2,
So that the first reference voltage Vref 1 drops to equal to would not be further continued for declining during the second reference voltage Vref 2.
Therefore, when the first reference voltage Vref 1 drops to equal to second in the LED linear constant-current drive circuit of the present invention
During reference voltage Vref 2, clamp circuit output current Ic2 so that the first reference voltage Vref 1 is equal in the minimum point at the lowest point
Vref2, so that the lowest point electric current of Iled remains fixed value Vref2/Rcs, it is to avoid Iled electric currents enter the depth of the lowest point
Degree compensation, so that improve the line regulation performance of Iled electric currents.
Preferably, NMOS tube can also replace with NPN triode.The emitter stage of NPN triodes is with error amplifier EA3's
Outfan is connected, and colelctor electrode cut-in operation voltage VDD, base stage are connected with the junction point of first resistor R2 and second resistance R3.
Meanwhile, the present invention also provides a kind of chip driven for LED linear, and which includes that any of the above-described LED linear is driven
Dynamic device.
Correspondingly, the present invention also provides a kind of chip driven for LED linear, and which includes any of the above-described LED linear
Driver and NMOS tube.
Corresponding with the first embodiment of above-mentioned LED linear driver, the present invention also provides a kind of LED linear driving side
Method, comprises the following steps：
1) voltage of the output voltage of line voltage compensation module samples input voltage source or NMOS tube drain terminal is generated and institute
State the compensation electric current of the proportional relation of input voltage.
2) when the voltage at current sense resistor two ends is more than the second reference voltage, NMOS tube is ended, the compensation electric current
The first resistor is all flow through；When the voltage at current sense resistor two ends is equal to the second reference voltage, the compensation electric current
The first resistor is flow through in part, makes the voltage the lowest point on current sense resistor be clamped at second reference voltage.
The concrete principle of the LED linear driving method is identical with the principle of the first embodiment of above-mentioned LED linear driver,
Therefore will not be described here.
Corresponding with the second embodiment of above-mentioned LED linear driver, the present invention also provides a kind of LED linear driving side
Method, comprises the following steps：
1) voltage of the output voltage of line voltage compensation module samples input voltage source or NMOS tube drain terminal is generated and institute
State the compensation electric current of the proportional relation of input voltage；
2) when the first reference voltage is more than the second reference voltage, the compensation electric current all flows through second resistance；When
When one reference voltage is equal to the second reference voltage, the compensation current segment flows through second resistance, makes the current sense resistor
On voltage the lowest point clamper in second reference voltage.
The concrete principle of the LED linear driving method is identical with the principle of the second embodiment of above-mentioned LED linear driver,
Therefore will not be described here.
In sum, LED linear driver of the invention, drive circuit, chip and driving method are based on line voltage compensation
Technology and clamp circuit, are effectively improved the line regulation of LED linear driver so that the output of LED linear driver
Electric current changes less in whole input voltage range.So, the present invention effectively overcome various shortcoming of the prior art and
Tool high industrial utilization.
The principle and its effect of above-described embodiment only illustrative present invention, of the invention not for limiting.Any ripe
The personage for knowing this technology all can carry out modifications and changes to above-described embodiment under the spirit and the scope without prejudice to the present invention.Cause
This, those of ordinary skill in the art is complete with institute under technological thought without departing from disclosed spirit such as
Into all equivalent modifications or change, should by the present invention claim be covered.
Claims (17)
1. a kind of LED linear driver, it is characterised in that：Including：
Line voltage compensation module, the output voltage or NMOS tube drain terminal of the line voltage compensation module samples input voltage source
Voltage generates the compensation electric current of relation proportional to the input voltage；
Clamp circuit, the first input end of the clamp circuit are used for accessing the second reference voltage, and the second input is used for sampling
The voltage at the current sense resistor two ends electrically connected with LED linear driver, outfan are connected with first resistor；
When the voltage at current sense resistor two ends is more than the second reference voltage, NMOS tube is ended, and the compensation electric current all flows
Cross the first resistor；When the voltage at current sense resistor two ends is equal to the second reference voltage, the compensation current segment stream
The first resistor is crossed, makes the voltage the lowest point on current sense resistor be clamped at second reference voltage.
2. a kind of LED linear driver, it is characterised in that：Including：
Line voltage compensation module, the output voltage or NMOS tube drain terminal of the line voltage compensation module samples input voltage source
Voltage generates the compensation electric current of relation proportional to the input voltage；
Clamp circuit, the first input end of the clamp circuit are used for accessing the second reference voltage, and the second input is used for accessing
First reference voltage, outfan are connected with the first end of second resistance；When the first reference voltage is more than the second reference voltage,
NMOS tube is ended, and the compensation electric current all flows through second resistance；When the first reference voltage is equal to the second reference voltage, described
Compensation current segment flows through the second resistance, makes the voltage the lowest point clamper on the current sense resistor in the described second reference
Voltage.
3. LED linear driver according to claim 1, it is characterised in that：Also include：
Error amplifier, the positive input terminal of the error amplifier are used for receiving the first reference voltage, and negative input end is used for receiving
Voltage in first resistor and current sense resistor；
The drain electrode of the NMOS tube is connected with LED load, and source electrode electrically connects the current sense resistor, and grid is put with the error
The outfan of big device is connected, for the NMOS cut-offs when the error amplifier negative input end voltage is higher than positive input terminal voltage,
When negative input end voltage is less than or equal to positive input terminal voltage, NMOS is turned on.
4. LED linear driver according to claim 2, it is characterised in that：Also include：
Error amplifier, the positive input terminal of the error amplifier are used for receiving the first reference voltage, and negative input end is used for receiving
The voltage at current sense resistor two ends；
The drain electrode of the NMOS tube is connected with LED load, and source electrode electrically connects the current sense resistor, and grid is put with the error
The outfan of big device is connected, for the NMOS cut-offs when the error amplifier negative input end voltage is higher than positive input terminal voltage,
When negative input end voltage is less than or equal to positive input terminal voltage, NMOS is turned on.
5. LED linear driver according to claim 1, it is characterised in that：Also include：Reference voltage circuit, the ginseng
Examine potential circuit for export the first reference voltage.
6. LED linear driver according to claim 5, it is characterised in that：The reference voltage circuit is included with reference to electricity
Die block, second resistance and 3rd resistor；The second resistance and threeth electricity of the reference voltage module via series connection
Resistance ground connection；The reference voltage module is used for providing at the junction point of original reference voltage, the second resistance and 3rd resistor
Voltage be first reference voltage.
7. LED linear driver according to claim 1 and 2, it is characterised in that：The NMOS tube replaces with tri- poles of NPN
Pipe；The colelctor electrode of the NPN triode is connected with the second end of the LED load, base stage and the of the current sense resistor
One end is connected, and emitter stage is connected with the outfan of the error amplifier.
8. LED linear driver according to claim 1, it is characterised in that：The clamp circuit includes that the second error is put
Big device and the second NMOS tube；The positive input terminal of second error amplifier connects second reference voltage, negative input end with
The current sense resistor is connected, and outfan is connected with the grid of second NMOS tube；The drain electrode of second NMOS tube with
The outfan of the line voltage compensation module is connected, source ground.
9. LED linear driver according to claim 8, it is characterised in that：In the clamp circuit, the 2nd NMOS
Pipe replaces with NPN triode；The emitter stage of the NPN triodes is connected with the outfan of second error amplifier, current collection
Pole is connected with the first end of the first resistor, base earth.
10. LED linear driver according to claim 2, it is characterised in that：The clamp circuit includes that the second error is put
Big device and the second NMOS tube；The positive input terminal of second error amplifier accesses second reference voltage, negative input end with
The first error amplifier positive input terminal is connected, and outfan is connected with the grid of second NMOS tube；2nd NMOS
The drain electrode cut-in operation voltage VDD of pipe, source electrode are connected with the outfan of the line voltage compensation module.
11. LED linear drivers according to claim 10, it is characterised in that：In the clamp circuit, described second
NMOS tube replaces with NPN triode；The emitter stage of the NPN triodes is connected with the outfan of second error amplifier,
Colelctor electrode cut-in operation voltage VDD, base stage are connected with the junction point of the first resistor and the second resistance.
A kind of 12. LED linear drive circuits, it is characterised in that：Including input voltage source, LED load, reference voltage circuit, line
Voltage compensation module, error amplifier, NMOS tube, first resistor, current sense resistor and clamp circuit；
The reference voltage circuit is used for exporting the first reference voltage；
The input voltage source is connected with the first end of the LED load, for providing input voltage；
The outfan of the line voltage compensation module is connected with the first end of the first resistor, for output and the input electricity
It is pressed into the compensation electric current of proportionate relationship；
The drain electrode of the NMOS tube is connected with the second end of the LED load, the first end of source electrode and the current sense resistor
It is connected, grid is connected with the outfan of the error amplifier, the positive input terminal of the error amplifier is used for receiving the first ginseng
Voltage is examined, negative input end is used for the voltage for receiving current sense resistor two ends；
The positive input terminal of the error amplifier is connected with the outfan of the reference voltage circuit, negative input end and described first
The first end of resistance is connected；Second end of the first resistor is connected with the first end of the current sense resistor, the electric current
The second end ground connection of detection resistance；
The first input end of the clamp circuit accesses the second reference voltage, and the of the second input and the current sense resistor
One end is connected, and outfan is connected with the first end of the first resistor, for by the voltage the lowest point on the current sense resistor
Clamper is in second reference voltage.
A kind of 13. LED linear drive circuits, it is characterised in that：Including input voltage source, LED load, reference voltage module, line
Voltage compensation module, error amplifier, NMOS tube, first resistor, second resistance, current sense resistor and clamp circuit；
The first resistor and second resistance ground connection of the reference voltage module via series connection, for providing original reference
Voltage；
The input voltage source is connected with the first end of the LED load, for providing input voltage；
The outfan of the line voltage compensation module is connected with the junction point of the first resistor and the second resistance, for defeated
Enter the compensation electric current of relation proportional to the input voltage；
The drain electrode of the NMOS tube is connected with the second end of the LED load, the first end of source electrode and the current sense resistor
It is connected, grid is connected with the outfan of the error amplifier, the positive input terminal of the error amplifier is used for receiving the first ginseng
Voltage is examined, negative input end is used for the voltage for receiving current sense resistor two ends；
The positive input terminal of the error amplifier is connected with the junction point of the first resistor and the second resistance, accesses first
Reference voltage, negative input end are connected with the first end of the current sense resistor, the second end ground connection of the current sense resistor；
The first input end of the clamp circuit accesses the second reference voltage, the second input and the error amplifier positive input
End or negative input end are connected, and outfan is connected with the junction point of the first resistor and the second resistance, for by the electricity
Voltage the lowest point clamper in stream detection resistance is in second reference voltage.
A kind of 14. chips driven for LED linear, it is characterised in that：Drive including the LED linear described in claim 1 or 2
Device.
A kind of 15. chips driven for LED linear, it is characterised in that：Drive including the LED linear described in claim 1 or 2
Device and NMOS tube.
A kind of 16. LED linear driving methods, it is characterised in that：Comprise the following steps：
1) voltage of the output voltage of line voltage compensation module samples input voltage source or NMOS tube drain terminal generates defeated with described
Enter the compensation electric current of the proportional relation of voltage；
2) when the voltage at current sense resistor two ends is more than the second reference voltage, NMOS tube is ended, and the compensation electric current is whole
Flow through the first resistor；When the voltage at current sense resistor two ends is equal to the second reference voltage, the compensation current segment
The first resistor is flow through, makes the voltage the lowest point on current sense resistor be clamped at second reference voltage.
17. LED linear driving methods according to claim 16, it is characterised in that：Step 2) replace with：
When the first reference voltage is more than the second reference voltage, the compensation electric current all flows through second resistance；When the first reference
When voltage is equal to the second reference voltage, the compensation current segment flows through second resistance, makes the electricity on the current sense resistor
Pressure the lowest point clamper is in second reference voltage.
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107148121A (en) * | 2017-06-30 | 2017-09-08 | 苏州菲达旭微电子有限公司 | A kind of chop control linear switch constant current and constant power circuit |
| CN109246889A (en) * | 2018-09-26 | 2019-01-18 | 华域视觉科技(上海)有限公司 | The LED drive circuit and its driving method and storage medium of DC-DC and linear combination |
| CN109714869A (en) * | 2019-03-07 | 2019-05-03 | 无锡奥利杰科技有限公司 | A kind of LED illumination driving current Serial regulation and adjusting control circuit |
| CN110034734A (en) * | 2018-01-11 | 2019-07-19 | 晶豪科技股份有限公司 | For compensating the compensation circuit of the input bias of error amplifier |
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| CN110855277A (en) * | 2019-12-02 | 2020-02-28 | 思瑞浦微电子科技（苏州）股份有限公司 | Adjustable clamping circuit |
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103442489A (en) * | 2013-09-01 | 2013-12-11 | 郑儒富 | Average pattern constant-current controlling circuit and controlling method for LED driving circuit |
| CN103746574A (en) * | 2014-01-07 | 2014-04-23 | 无锡芯朋微电子股份有限公司 | Line voltage compensation circuit |
| CN104093257A (en) * | 2014-07-31 | 2014-10-08 | 上海贝岭股份有限公司 | Power regulation circuit for linear LED (light-emitting diode) drive power supply |
| WO2015101154A1 (en) * | 2013-12-30 | 2015-07-09 | 深圳市晟碟绿色集成科技有限公司 | Line voltage compensation ac led driving device |
| CN106020307A (en) * | 2016-06-23 | 2016-10-12 | 电子科技大学 | Linear constant-current power supply with constant power consumption |
| CN106163009A (en) * | 2016-08-18 | 2016-11-23 | 杰华特微电子（杭州）有限公司 | Illumination driving circuit and illuminator |
| CN206611607U (en) * | 2016-12-06 | 2017-11-03 | 上海晶丰明源半导体股份有限公司 | A kind of LED linear driver, drive circuit and chip |
-
2016
- 2016-12-06 CN CN201611107527.XA patent/CN106507541B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103442489A (en) * | 2013-09-01 | 2013-12-11 | 郑儒富 | Average pattern constant-current controlling circuit and controlling method for LED driving circuit |
| WO2015101154A1 (en) * | 2013-12-30 | 2015-07-09 | 深圳市晟碟绿色集成科技有限公司 | Line voltage compensation ac led driving device |
| CN103746574A (en) * | 2014-01-07 | 2014-04-23 | 无锡芯朋微电子股份有限公司 | Line voltage compensation circuit |
| CN104093257A (en) * | 2014-07-31 | 2014-10-08 | 上海贝岭股份有限公司 | Power regulation circuit for linear LED (light-emitting diode) drive power supply |
| CN106020307A (en) * | 2016-06-23 | 2016-10-12 | 电子科技大学 | Linear constant-current power supply with constant power consumption |
| CN106163009A (en) * | 2016-08-18 | 2016-11-23 | 杰华特微电子（杭州）有限公司 | Illumination driving circuit and illuminator |
| CN206611607U (en) * | 2016-12-06 | 2017-11-03 | 上海晶丰明源半导体股份有限公司 | A kind of LED linear driver, drive circuit and chip |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107148121A (en) * | 2017-06-30 | 2017-09-08 | 苏州菲达旭微电子有限公司 | A kind of chop control linear switch constant current and constant power circuit |
| CN110034734A (en) * | 2018-01-11 | 2019-07-19 | 晶豪科技股份有限公司 | For compensating the compensation circuit of the input bias of error amplifier |
| CN110034734B (en) * | 2018-01-11 | 2023-04-07 | 晶豪科技股份有限公司 | Compensation circuit for compensating input bias of error amplifier |
| CN109246889A (en) * | 2018-09-26 | 2019-01-18 | 华域视觉科技(上海)有限公司 | The LED drive circuit and its driving method and storage medium of DC-DC and linear combination |
| CN109246889B (en) * | 2018-09-26 | 2024-03-05 | 华域视觉科技(上海)有限公司 | DC-DC and linear combination LED driving circuit, driving method thereof and storage medium |
| CN109714869A (en) * | 2019-03-07 | 2019-05-03 | 无锡奥利杰科技有限公司 | A kind of LED illumination driving current Serial regulation and adjusting control circuit |
| CN110177410A (en) * | 2019-05-24 | 2019-08-27 | 深圳市晟碟半导体有限公司 | A kind of LED light adjusting circuit, dimming device and light-dimming method |
| CN110855277A (en) * | 2019-12-02 | 2020-02-28 | 思瑞浦微电子科技（苏州）股份有限公司 | Adjustable clamping circuit |
| CN114217116A (en) * | 2022-02-21 | 2022-03-22 | 苏州贝克微电子股份有限公司 | Current detection circuit with controllable detection current |
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