CN106879109B - Controller, chip and method for eliminating LED drive system current ripples - Google Patents
Controller, chip and method for eliminating LED drive system current ripples Download PDFInfo
- Publication number
- CN106879109B CN106879109B CN201710071628.4A CN201710071628A CN106879109B CN 106879109 B CN106879109 B CN 106879109B CN 201710071628 A CN201710071628 A CN 201710071628A CN 106879109 B CN106879109 B CN 106879109B
- Authority
- CN
- China
- Prior art keywords
- voltage
- controller
- output end
- led
- led load
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
- F21V23/00—Arrangement of electric circuit elements in or on lighting devices
- F21V23/003—Arrangement of electric circuit elements in or on lighting devices the elements being electronics drivers or controllers for operating the light source, e.g. for a LED array
-
- 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]
Landscapes
- Engineering & Computer Science (AREA)
- Microelectronics & Electronic Packaging (AREA)
- General Engineering & Computer Science (AREA)
- Dc-Dc Converters (AREA)
Abstract
The present invention provides a kind of controller, chip and method for eliminating LED drive system current ripples, controller is electrically connected the output end and the first sampling resistor of LED load, the controller is configured as the voltage of the voltage and the first sampling resistor both ends of the output end of sampling LED load, and generates first voltage signal according to the voltage of the output end of the LED load and the voltage at first sampling resistor both ends；The controller generates the conducting state that control signal is used to control the power tube being electrically connected with the LED load according to the first voltage signal and the voltage at first sampling resistor both ends, so that the voltage swing of the first voltage signal is equal with reference voltage, the current ripples of the LED load are eliminated.Whole process of the present invention in dimming process eliminates LED current ripple, avoids the LED flickers of low-frequency jitter initiation.
Description
Technical field
The present invention relates to a kind of constant current drive control fields, more particularly to one kind for eliminating LED drive system electric current
Controller, chip and the method for ripple.
Background technology
As LED is in the overall application of lighting area, efficient APFC (Active Power Factor
Correction, active power factor correction) driver, controllable silicon light modulation or high PF (Power Factor, power factor)
Linear actuator obtained a large amount of use.Prime uses the Linear Driving of APFC drivers, controllable silicon light modulation or high PF
Device can include the working frequency ripple wave ingredient of 100hz/120hz in output current.Due to the presence of these ripple compositions so that LED
The brightness of light source also will appear corresponding fluctuation.With the development of Lighting Industry, people propose higher to the quality of LED light source
Requirement, do not dodge frequency, non-jitter become current high performance lED illumination driving new demand therefore how to eliminate LED current line
Wave becomes LED drive controls field emphasis of interest.
Elimination LED current is increased in the output stage of the Linear actuator of APFC drivers, controllable silicon light modulation or high PF
The power current ripple that prime generates can substantially be decayed, obtain the LED drive current of approximate DC, significantly by ripple chip
The quality for improving light source.
Currently, eliminating LED current ripple chip, there are mainly two types of schemes：
The first scheme：As shown in Figure 1, operational amplifier A 2 as one buffering (buffer) circuit, by front stage every
From, and make the input and output voltage of buffer circuit equal, i.e. VCOMPBUF=VCOMP.The output voltage V of buffer circuitCOMPBUFThrough
After crossing divider resistance R3 and R4 partial pressure, the positive input terminal of input operational amplifier A1.Operational amplifier A 1 and metal-oxide-semiconductor M0 and resistance
R0 constitutes a voltage current adapter, generates the driving current I of LEDLED,Buffering electricity
The voltage V of the input node DRAIN on roadDRAINWith reference voltage VREFCompare in comparator CMP：Work as VDRAIN<VREFWhen, switch
S1 is closed, the capacitance C1 electric discharges by current source I2 to node COMP, the voltage V of node COMPCOMPIt gradually reduces, to gradually
Reduce the electric current I for flowing through LEDLED, VDRAINIt will be stepped up；Work as VDRAIN>VREFWhen, switch S1 is disconnected, by current source I1 to section
The capacitance C1 chargings of point COMP, the voltage V of node COMPCOMPIt is stepped up, to incrementally increase the electric current I for flowing through LEDLED, make
Obtain VDRAINIt gradually reduces.Thus, it is possible to by the voltage V of input node DRAINDRAINIt controls in a relatively reasonable range,
The decaying to prime input current ripple is realized simultaneously.But due in each power frequency period, capacitance C1 be constantly present charging and
The process of electric discharge, thus forms certain voltage ripple in COMP pins, the amplitude of the voltage ripple by C1 capacitances size
It is determined with the size of current source I1, I2.The factors such as realization and cost based on circuit, the voltage ripple amplitude of COMP pins is about
Tens millivolts, the fluctuating range of the voltage determines that the framework can not be realized in the case where input current is smaller and eliminates LED
The function of current ripples cannot achieve the whole elimination ripple function in LED dimming process.
Second scheme：As shown in Fig. 2, operational amplifier A 2 as one buffering (buffer) circuit, by front stage every
From, and make the input and output voltage of buffer circuit equal, i.e. VCOMPBUF=VCOMP.The output voltage V of buffer circuitCOMPBUFThrough
After crossing divider resistance R3 and R4 partial pressure, the positive input terminal of input operational amplifier A1.Operational amplifier A 1 and metal-oxide-semiconductor M0 and resistance
R0 constitutes a voltage current adapter, generates the driving current I of LEDLED,Operation is put
The output voltage V of big device A1GATEWith reference voltage VREFCompare in comparator CMP：Work as VGATE>VREFWhen, switch S1 is closed, and is led to
Capacitance C1 electric discharges of the overcurrent source I2 to node COMP, the voltage V of node COMPCOMPIt gradually reduces, gradually reduces and flow through LED's
Electric current ILED, make the output voltage V of A1GATEIt gradually reduces；Work as VGATE<VREFWhen, switch S1 is disconnected, by current source I1 to node
The capacitance C1 chargings of COMP, the voltage V of node COMPCOMPIt is stepped up, that is, incrementally increases the electric current I for flowing through LEDLED, make VGATE
It is stepped up.Hereby it is achieved that the decaying to prime input current ripple.Similarly, due in each power frequency period, capacitance C1
It is constantly present the process of charging and discharging, thus forms certain ripple voltage, the amplitude of the ripple voltage in COMP pins
It is determined by the size of C1 capacitances and the size of current source I1, I2.The factors such as realization and cost based on circuit, COMP pins
The fluctuating range of about tens millivolts of ripple voltage amplitude, the voltage determines the situation that the framework can not be smaller in input current
The lower function of realizing the LED current ripple that disappears cannot achieve the whole elimination ripple function in dimming process.
Invention content
In view of the foregoing deficiencies of prior art, the purpose of the present invention is to provide one kind for eliminating LED drivings system
Controller, chip and the method for current ripples of uniting cannot achieve entirely for solving in the prior art in the dimming process of LED
Journey eliminates the problem of ripple.
In order to achieve the above objects and other related objects, the present invention provides a kind of for eliminating LED drive system electric current line
The controller of wave, the output end and the first sampling resistor of the controller electrical connection LED load, the controller are configured as adopting
The voltage of the voltage of the output end of sample LED load and the first sampling resistor both ends, and the electricity of the output end according to the LED load
Pressure and the voltage at first sampling resistor both ends generate first voltage signal；The controller is according to the first voltage signal
Control signal is generated for controlling the power tube being electrically connected with the LED load with the voltage at first sampling resistor both ends
Conducting state so that the voltage swing of the first voltage signal is equal with reference voltage, eliminates the electric current line of the LED load
Wave.
In one embodiment of the invention, the controller includes：Sampling module and control module；The sampling module is used
In the voltage for the output end voltage and first sampling resistor both ends for sampling the LED load, and it is defeated according to the LED load
The voltage of outlet and the voltage at first sampling resistor both ends generate first voltage signal and export to the control module；Institute
The output end that control module is electrically connected to the sampling module is stated, for receiving the first voltage signal, and according to described
One voltage signal generates the control signal.
In one embodiment of the invention, the sampling module includes first resistor and second resistance；Wherein, described first
Resistance is connected with the second resistance, and the other end of the first resistor is electrically connected the output end of the LED load, and described second
The other end of resistance is electrically connected one end of first sampling resistor.
In one embodiment of the invention, the control module include trsanscondutance amplifier, the first capacitance, partial pressure submodule and
Control submodule；The positive input terminal of the trsanscondutance amplifier is electrically connected the first resistor and described second of the sampling module
The tie point of resistance, for receiving the first voltage signal, negative input end is electrically connected reference voltage, and according to first electricity
Signal and the reference voltage is pressed to generate the first current signal；One end of first capacitance is electrically connected the trsanscondutance amplifier
Output end, other end ground connection；The partial pressure submodule is electrically connected to the output end of the trsanscondutance amplifier, for according to described the
The voltage at one capacitance both ends generates second voltage signal；The control submodule is electrically connected to the output end of the partial pressure submodule
With first sampling resistor, and described in being generated according to the second voltage signal and the voltage at first sampling resistor both ends
Control signal is exported to the control pole of the power tube.
In one embodiment of the invention, the control module further includes buffering submodule, described to buffer the defeated of submodule
Enter the output end that end is electrically connected to the trsanscondutance amplifier, output end is electrically connected to the input terminal of the partial pressure submodule, is used for
Realize the buffering between the trsanscondutance amplifier and the partial pressure submodule.
In one embodiment of the invention, the buffering submodule is the first operational amplifier；First operation amplifier
The positive input terminal of device is electrically connected to the output end of the trsanscondutance amplifier, and negative input end is electrically connected with output end.
In one embodiment of the invention, the partial pressure submodule includes 3rd resistor and the 4th resistance；The third electricity
Resistance is connected with the 4th resistance, and the other end of the 3rd resistor is electrically connected the output end of the trsanscondutance amplifier, and described the
The other end of four resistance is grounded；The control submodule is electrically connected to the tie point of the 3rd resistor and the 4th resistance,
For receiving the second voltage signal.
In one embodiment of the invention, the control submodule includes second operational amplifier；Second operation is put
The positive input terminal of big device is electrically connected to the tie point of the 3rd resistor and the 4th resistance, for receiving the second voltage
Signal；Negative input end is electrically connected to first sampling resistor, according to the second voltage signal and first sampling resistor
The voltage at both ends generates the control signal, and exports to the control pole of the power tube.
In one embodiment of the invention, the output end voltage of the LED load and first sampling resistor both ends
Voltage is inversely proportional.
In one embodiment of the invention, the charge and discharge of first capacitance are the institutes exported by the trsanscondutance amplifier
State the realization of the first current signal.
In one embodiment of the invention, the second operational amplifier, the power tube and first sampling resistor
A voltage is constituted to the converter of electric current, the driving current for generating the LED load.
In one embodiment of the invention, pass through the mutual conductance for changing the trsanscondutance amplifier and/or first capacitance
Capacitance changes the time constant eliminated needed for the LED load current ripples, caused by eliminating the input current of different frequency
Current ripples.
In one embodiment of the invention, the mutual conductance by adjusting the trsanscondutance amplifier and/or first capacitance
Capacitance increases the time constant eliminated needed for low-frequency jitter, to remove low-frequency jitter.
The invention also discloses a kind of current ripples chips for eliminating LED drive system, including control as described above
Device processed.
The invention also discloses a kind of current ripples chips for eliminating LED drive system, including control as described above
Device, the power tube and first sampling resistor processed.
The invention also discloses a kind of LED drive system, including LED driver, LED load, controller as described above,
Wherein, the LED driver is used to generate the electric current for driving the LED load according to alternating voltage, and exports negative to the LED
It carries；The controller is electrically connected to the output end of the LED load, current ripples or low frequency for eliminating driving LED load
Shake.
The invention also discloses a kind of methods for eliminating LED drive system current ripples, using control as described above
Device processed, includes the following steps：The controller samples the voltage and first sampling resistor two of the output end of the LED load
The voltage at end, and generate first according to the voltage of the output end of the LED load and the voltage at first sampling resistor both ends
Voltage signal；The controller generates control letter according to the first voltage signal and the voltage at first sampling resistor both ends
Number, the conducting state for controlling the power tube being electrically connected with the LED load so that the voltage of the first voltage signal is big
It is small equal with the reference voltage, eliminate the LED load current ripples.
The invention also discloses a kind of methods for eliminating LED drive system current ripples, using control as described above
Device processed, includes the following steps：The sampling module samples the output end voltage and first sampling resistor two of the LED load
The voltage at end, and generate first according to the voltage of the output end of the LED load and the voltage at first sampling resistor both ends
Voltage signal is simultaneously exported to the trsanscondutance amplifier；The trsanscondutance amplifier is according to the first voltage signal and the reference electricity
Pressure generates the first current signal；First capacitance carries out charge and discharge according to first current signal；The partial pressure submodule
Second voltage signal is generated according to the voltage at first capacitance both ends；The control submodule is according to the second voltage signal
The control signal is generated with the voltage at first sampling resistor both ends, and is exported to the control pole of the power tube.
In one embodiment of the invention, pass through the mutual conductance for changing the trsanscondutance amplifier and/or first capacitance
Capacitance, changes the time constant needed for the current ripples for eliminating the LED load, and the input current to eliminate different frequency causes
Current ripples.
In one embodiment of the invention, the mutual conductance by adjusting the trsanscondutance amplifier and/or first capacitance
Capacitance increases the time constant eliminated needed for low-frequency jitter, to remove low-frequency jitter.
As described above, a kind of controller, chip and method for eliminating LED drive system current ripples of the present invention,
Based on the existing dimming driver for eliminating LED current ripple, eliminate for carrying out charge and discharge for the capacitance in buffer circuit
Current source, increase controller between LED load and the first sampling resistor, controller generates first voltage signal, and leads to
The voltage for crossing the first sampling resistor both ends of first voltage signal generates the control signal of the conducting state for controlling power tube,
So that the voltage of first voltage signal is equal with reference voltage, to eliminate the current ripples of LED load.In addition, of the invention
Traditional comparator is also replaced with trsanscondutance amplifier, to make output voltage VCSWith the voltage V of LED unit cathodeDRAINWith reference
Pressure difference between voltage is converted to electric current, to carry out charge and discharge to the first capacitance, realizes the whole elimination in dimming process
The current ripples of LED load；Also, the present invention also by adjusting the capacitance of the first capacitance and/or the mutual conductance of trsanscondutance amplifier, increases
Large time constant further avoids the sudden strain of a muscle for the LED that low-frequency jitter is caused to eliminate the shake of the low frequency less than 100hz
Bright problem.The structure of the present invention is simple, of low cost, effectively increases the working efficiency of LED.
Description of the drawings
Fig. 1 is shown as eliminating the electrical block diagram of the dimming driver of LED current ripple in the prior art.
Fig. 2 is shown as the electrical block diagram of another dimming driver for eliminating LED current ripple in the prior art.
Fig. 3 is shown as a kind of controller for eliminating LED drive system current ripples disclosed in the embodiment of the present invention
Theory structure schematic diagram.
Fig. 4 is shown as a kind of controller for eliminating LED drive system current ripples disclosed in the embodiment of the present invention
Electrical block diagram.
Component label instructions
100 controllers
110 sampling modules
120 control modules
121 partial pressure submodules
122 control submodules
123 buffering submodules
200 LED loads
Specific implementation mode
Illustrate that embodiments of the present invention, those skilled in the art can be by this specification below by way of specific specific example
Disclosed content understands other advantages and effect of the present invention easily.The present invention can also pass through in addition different specific realities
The mode of applying is embodied or practiced, the various details in this specification can also be based on different viewpoints with application, without departing from
Various modifications or alterations are carried out under the spirit of the present invention.It should be noted that in the absence of conflict, following embodiment and implementation
Feature in example can be combined with each other.
Please refer to attached drawing.It should be noted that the diagram provided in following embodiment only illustrates this hair in a schematic way
Bright basic conception, then in schema only display and related component in the present invention rather than component count when according to actual implementation,
Shape and size are drawn, when actual implementation kenel, quantity and the ratio of each component can be a kind of random change, and its component
Being laid out kenel may also be increasingly complex.
A kind of controller, chip and method for eliminating LED drive system current ripples of the present invention, in LED load
Output end and the first sampling resistor between be electrically connected a controller, for generate first voltage signal and generate control power
The control signal of the conducting state of pipe so that the voltage swing of first voltage signal is equal with reference voltage, eliminates LED load
Current ripples.
Embodiment 1
Present embodiment discloses a kind of controllers for eliminating LED drive system current ripples, use MOS below with power tube
It is illustrated for pipe, in other realization methods, power tube can also be triode or other kinds of power tube.Such as figure
Shown in 3, controller 100 is electrically connected with the output end of LED load 200 and the first sampling resistor R0.Controller 100 is for sampling
The voltage V of the output end of LED load 200DRAINWith the voltage V at the first both ends sampling resistor R0CS, also, according to LED load 200
Output end voltage VDRAINWith the voltage V at the first both ends sampling resistor R0CSGenerate first voltage signal VDV1；Further,
Controller 100 is also according to first voltage signal VDV1With first voltage signal VDV1Generate corresponding control signal VGATE, pass through control
Signal V processedGATEControl the conducting state of power tube M0 so that first voltage signal VDV1Voltage swing and reference voltage VREFPhase
Deng to eliminate the current ripples of LED load.Wherein, LED drive system includes but not limited to LED load 200, first adopts
Sample resistance R0, power tube M0, current source I0 and C0.In addition, the drain electrode of power tube M0 is connected with the output end of LED load 200；Source
Pole is connected with one end of the first sampling resistor R0.
Preferably, as shown in figure 3, controller 100 is realized by sampling module 110 and control module 120, wherein adopt
Egf block 110 is used to sample the voltage V of the output end of LED load 200DRAINWith the voltage V at the first both ends sampling resistor R0CS, and
And according to the voltage V of the output end of LED load 200DRAINWith the voltage V at the first both ends sampling resistor R0CSGenerate first voltage
Signal VDV1, and export to control module 120.
Preferably, as shown in figure 4, sampling module 110 includes first resistor R1 and second resistance R2；The one of first resistor R1
End is connected with the drain electrode of the output end of LED load 200 and power tube M0 respectively, and the other end is connected with one end of second resistance R2；
The other end of second resistance R2 is connected with the first sampling resistor R0 of sampling；The tie point S1 of first resistor R1 and second resistance R2 makees
For the output end of sampling module 110, it is connected with the input terminal of control module 120.First resistor R1 and second resistance R2 group ingredients
Press collector：The voltage V of the output end of first resistor R1 acquisition LED loads 200DRAIN, second resistance R2 acquisition the first sampling electricity
Hinder the voltage V at the both ends R0CS。
Control module 120 is for receiving first voltage signal VDV1, and according to first voltage signal VDV1Generate control signal
VGATE；And it exports to the grid of power tube M0, the i.e. control pole of power tube.
As shown in figure 4, control module 120 includes：Trsanscondutance amplifier OTA1, the first capacitance C1, partial pressure submodule 121 and control
System module 122.Wherein,
The output end of the positive input terminal and sampling module 110 of trsanscondutance amplifier OTA1, i.e. first resistor R1 and second resistance
The tie point S of R2 is connected；Negative input end connects reference voltage VREF, it is used for the first voltage signal V of positive input terminalDV1It is defeated with bearing
Enter the reference voltage V at endREFBetween pressure difference be converted into electric current, generate the first current signal.
One end of first capacitance C1 is connected with the output end of trsanscondutance amplifier OTA1, other end ground connection；
One end of partial pressure submodule 121 is connect with the output end of trsanscondutance amplifier OTA1, for according to the first capacitance C1 two
The voltage at end generates second voltage signal VCSREF.Preferably, as shown in figure 4, partial pressure submodule 121 includes but not limited to third electricity
Hinder R3 and the 4th resistance R4.One end of 3rd resistor R3 is connect with the output end of trsanscondutance amplifier OTA1, the other end and the 4th electricity
The one end for hindering R4 is connected；The other end of 4th resistance R4 is grounded；The tie point S2 of 3rd resistor R3 and the 4th resistance R4, which is used as, to be divided
The output end for pressing submodule 121, is connected with the input terminal of control submodule 122.Wherein, 3rd resistor R3 and the 4th resistance R4 make
For divider resistance, by second voltage signal VCSREFIt is input to control submodule 122.
The first input end of control submodule 122 with partial pressure submodule 121 output end be connected, second output terminal respectively with
First sampling resistor R0 is connected with the source electrode of power tube M0, and output end is connected with the grid of power tube M0.Control submodule 122 is logical
Cross second voltage signal VCSREFWith the voltage V at the first both ends sampling resistor R0CSGenerate corresponding control signal VGATE.Preferably,
As shown in figure 4, control submodule 122 is using second operational amplifier A2.The positive input terminal and partial pressure of second operational amplifier A2
The output end of submodule 121 is connected；That is the positive input terminal of second operational amplifier A2 is connected to 3rd resistor R3 and the 4th resistance
The tie point S2 of R4；Negative input end is connected with the first sampling resistor R0, and output end is connected with the grid of power tube M0.
Preferably, as shown in figure 4, control module 120 further includes a buffering submodule 123, it is connected to trsanscondutance amplifier
Between OTA1 and partial pressure submodule 121, for realizing the buffering between trsanscondutance amplifier OTA1 and partial pressure submodule 121.Wherein,
In the present embodiment, buffering submodule 123 preferably uses the first operational amplifier A 1, the positive input terminal of the first operational amplifier A 1
It is connected with one end of the output end of trsanscondutance amplifier OTA1 and the first capacitance C1；Negative input end is defeated with the first operational amplifier A 1
Outlet is connected.
In the present embodiment, the divider of first resistor R1 and second resistance R2 compositions is for sampling the first sampling resistor R0 two
The voltage V at endCSWith the voltage V of the output end of LED load 200DARIN, generate first voltage signal VDV1, and be input to mutual conductance and put
The positive input terminal of big device OTA1, the negative input termination reference voltage V of trsanscondutance amplifier OTA1REF.First reference voltage VDV1With ginseng
Examine voltage VREFPressure difference electric current is converted by trsanscondutance amplifier OTA1, and the first capacitance C1 at node COMP is filled
Electricity or electric discharge.First operational amplifier A 1 realizes a buffer circuit, makes VCOMPBUF=VCOMP, VCOMPBUFBy 3rd resistor R3
Second voltage signal V is obtained with after the partial pressure of the 4th resistance R4CSREF, it is input to the positive input terminal of second operational amplifier A2.The
Two operational amplifier As 2 realize conversion of the voltage to electric current with metal-oxide-semiconductor M0, the first sampling resistor R0, generate LED load 200
Driving current ILED, that is,The voltage V of the output end of LED load 200DRAINWith the first sampling
The V at the both ends resistance R0CSBetween relationship be：Wherein, reference voltage VREFIt is solid
Fixed constant, therefore, the voltage V at the both ends of the first sampling resistor R0CSWith the voltage V of the output end of LED load 200DRAINIt is anti-
Than relationship, i.e. VCSBecome larger, VDRAINBecome smaller.Also, the voltage at the both ends of the first sampling resistor R0 meets VCS=ILED*R0.Therefore,
When the electric current of LED load 200 increases, system can reduce VDRAINSo that the power consumption W=I of the chip in LED loadLED*VDARIN
It reduces, reduces the fever of chip, improve the efficiency of LED unit.
Further, when dimming angle very little (prime input current very little), the elimination LED current ripple of the present embodiment
Function it is still effective.At this point, the voltage V at the both ends due to the first sampling resistor R0CSIt is relatively low, by adjusting LED load 200
The voltage V of output endDRAINSo that the voltage of the positive input terminal of trsanscondutance amplifier OTA1, i.e. first voltage signal VDV1Maintain with
The reference voltage V of negative input endREFEqual situation, in this way, entirely eliminating the loop of ripple still can work normally.Pass through
In this way, the whole process that the present embodiment realizes LED current goes ripple function.
In addition, the present embodiment will be by that will sample VDRAINWith VCSResult be input to trsanscondutance amplifier OTA1 positive input terminals, join
Examine voltage VREFIt is input to the negative input end of trsanscondutance amplifier OTA1, trsanscondutance amplifier OTA1 converts the voltage difference of input to electricity
Stream carries out charge and discharge to the first capacitance C1, obtains LED and remove ripple and go the time constant needed for low-frequency jitter.In this reality
It applies in example, by the design of the mutual conductance (△ io/ △ vin) to trsanscondutance amplifier OTA1 and/or the selection of the first capacitance C1 capacitances,
LED can be flexibly changed to remove ripple and go the effect of low-frequency jitter.When the mutual conductance value of trsanscondutance amplifier OTA1 is smaller, knot
The first capacitance C1 is closed, larger time constant may be implemented, reaches low-frequency caused by eliminating the reasons such as dimmer jitter and trembles
Dynamic function, avoids the generation of the flashing state of the LED caused due to low-frequency jitter.
Preferably, the controller of the present embodiment can both make an individual chip, be mounted on LED load 200, first
Between sampling resistor R0 and power tube M0；It can also be matched with LED load 200, the first sampling resistor R0 and power tube M0,
Common set makes a chip, to eliminate the current ripples of LED drive system.
In addition, in order to protrude the innovative part of the present invention, it will not be proposed by the invention with solution in the present embodiment
The less close module of technical problem relationship introduces, but this does not indicate that there is no other modules in the present embodiment.
It should be noted that the diagram provided in the present embodiment only illustrates the basic conception of the present invention in a schematic way,
Then component count, shape and size when only display is with related component in the present invention rather than according to actual implementation in schema are painted
System, when actual implementation kenel, quantity and the ratio of each component can be a kind of random change, and its assembly layout kenel also may be used
It can be increasingly complex.
Embodiment 2
Present embodiment discloses a kind of methods for eliminating LED drive system current ripples, use 1 institute of embodiment public
The controller opened：
First, using controller using the voltage V of the output end of LED load 200DRAINWith the first both ends sampling resistor R0
Voltage VCS, and according to the voltage V of the output end of LED load 200DRAINWith the voltage V at the first both ends sampling resistor R0CSGenerate the
One voltage signal VDV1；Controller is again according to first voltage signal VDV1With the voltage V at the first sampling resistor both endsCSGenerate control letter
Number VGATE, to the conducting state for the power tube M0 that control is connected with LED load 200 so that first voltage signal VDV1Voltage
Size and reference voltage VREFIt is equal, realize the elimination of the current ripples of LED load 200.
Specifically, sampling module 110 samples the output end voltage V of LED load 200DRAINWith the first both ends sampling resistor R0
Voltage VCS, and according to the voltage V of the output end of LED load 200DRAINWith the first sampling resistor R0 both ends VCSVoltage generate
First voltage signal VDV1And it exports to trsanscondutance amplifier OTA1；
Trsanscondutance amplifier OTA1 is according to first voltage signal VDV1With reference voltage VREFGenerate the first current signal；
First capacitance C1 carries out charge and discharge according to the first current signal；
It divides submodule 121 and second voltage signal V is generated according to the voltage at the first both ends capacitance C1CSREF；
Control submodule 122 is according to second voltage signal VCSREFControl letter is generated with the voltage at the first both ends sampling resistor C1
Number VGATE, and export to the grid of power tube M0.
In the present embodiment, the voltage V at the both ends of the first sampling resistor R0CSWith the voltage of the output end of LED load 200
VDRAINInverse relation, i.e. VCSBecome larger, VDRAINBecome smaller.Due to the voltage V at the both ends of the first sampling resistor R0CSIt is relatively low, pass through tune
The voltage V of the output end of whole LED load 200DRAINSo that the voltage of the positive input terminal of trsanscondutance amplifier OTA1, i.e. first voltage
Signal VDV1Maintain the reference voltage V with negative input endREFEqual situation, in this way, the loop for entirely eliminating ripple still may be used
With normal work, in this way, the whole process that the present embodiment realizes LED current goes ripple function.Also, by trsanscondutance amplifier
The design of the mutual conductance (△ io/ △ vin) of OTA1 and/or the selection of the first capacitance C1 capacitances, can flexibly change LED go ripple with
And go the effect of low-frequency jitter.When the mutual conductance value of trsanscondutance amplifier OTA1 is smaller, in conjunction with the first capacitance C1, may be implemented compared with
Big time constant reaches low-frequency dither functions caused by eliminating the reasons such as dimmer jitter, avoids since low frequency is trembled
Dynamic and the flashing state of the LED of initiation generation.
In conclusion a kind of controller, chip and method for eliminating LED drive system current ripples of the present invention,
Based on the existing dimming driver for eliminating LED current ripple, eliminate for carrying out charge and discharge for the capacitance in buffer circuit
Current source, increase controller between LED load and the first sampling resistor, controller generates first voltage signal, and leads to
The voltage for crossing the first sampling resistor both ends of first voltage signal generates the control signal of the conducting state for controlling power tube,
So that the voltage of first voltage signal is equal with reference voltage, to eliminate the current ripples of LED load.In addition, of the invention
Traditional comparator is also replaced with trsanscondutance amplifier, to make output voltage VCSWith the voltage V of LED unit cathodeDRAINWith reference
Pressure difference between voltage is converted to electric current, to carry out charge and discharge to the first capacitance, realizes the whole elimination in dimming process
The current ripples of LED load；Also, the present invention also by adjusting the capacitance of the first capacitance and/or the mutual conductance of trsanscondutance amplifier, increases
Large time constant further avoids the sudden strain of a muscle for the LED that low-frequency jitter is caused to eliminate the shake of the low frequency less than 100hz
Bright problem.The structure of the present invention is simple, of low cost, effectively increases the working efficiency of LED.So the present invention effectively overcomes
Various shortcoming in the prior art and have high industrial utilization.
The above-described embodiments merely illustrate the principles and effects of the present invention, and is not intended to limit the present invention.It is any ripe
The personage for knowing this technology can all carry out modifications and changes to above-described embodiment without violating the spirit and scope of the present invention.Cause
This, institute is complete without departing from the spirit and technical ideas disclosed in the present invention by those of ordinary skill in the art such as
At all equivalent modifications or change, should by the present invention claim be covered.
Claims (20)
1. a kind of controller for eliminating LED drive system current ripples, which is characterized in that
The output end and the first sampling resistor of the controller electrical connection LED load, it is negative that the controller is configured as sampling LED
The voltage of the voltage of the output end of load and the first sampling resistor both ends, and according to the voltage of the output end of the LED load and institute
The voltage for stating the first sampling resistor both ends generates first voltage signal；
The controller generates control signal according to the first voltage signal and the voltage at first sampling resistor both ends and uses
In the conducting state of power tube that control is electrically connected with the LED load so that the voltage swing of the first voltage signal and
Reference voltage is equal, eliminates the current ripples of the LED load.
2. controller according to claim 1, it is characterised in that：The controller includes：Sampling module and control module；
The sampling module is used to sample the voltage of the output end voltage and first sampling resistor both ends of the LED load,
And first voltage signal and defeated is generated according to the voltage at the voltage of the LED load output end and first sampling resistor both ends
Go out to the control module；
The control module is electrically connected to the output end of the sampling module, for receiving the first voltage signal, and according to
The first voltage signal generates the control signal.
3. controller according to claim 2, it is characterised in that：The sampling module includes first resistor and the second electricity
Resistance；Wherein,
The first resistor is connected with the second resistance, and the other end of the first resistor is electrically connected the defeated of the LED load
Outlet, the other end of the second resistance are electrically connected one end of first sampling resistor.
4. controller according to claim 3, it is characterised in that：The control module includes trsanscondutance amplifier, the first electricity
Hold, divide submodule and control submodule；
The positive input terminal of the trsanscondutance amplifier is electrically connected the first resistor of the sampling module and the second resistance
Tie point, for receiving the first voltage signal, negative input end is electrically connected reference voltage, and according to the first voltage signal
The first current signal is generated with the reference voltage；
One end of first capacitance is electrically connected the output end of the trsanscondutance amplifier, other end ground connection；
The partial pressure submodule is electrically connected to the output end of the trsanscondutance amplifier, for the electricity according to first capacitance both ends
Pressure generates second voltage signal；
The control submodule is electrically connected to the output end of the partial pressure submodule and first sampling resistor, and according to described
Second voltage signal and the voltage at first sampling resistor both ends generate the control signal and export to the control of the power tube
Pole processed.
5. controller according to claim 4, it is characterised in that：The control module further includes buffering submodule, described
The input terminal of buffering submodule is electrically connected to the output end of the trsanscondutance amplifier, and output end is electrically connected to the partial pressure submodule
Input terminal, for realizing the trsanscondutance amplifier and it is described partial pressure submodule between buffering.
6. controller according to claim 5, it is characterised in that：The buffering submodule is the first operational amplifier；Institute
The positive input terminal for stating the first operational amplifier is electrically connected to the output end of the trsanscondutance amplifier, and negative input end is electrically connected with output end
It connects.
7. controller according to claim 4 or 5, it is characterised in that：The partial pressure submodule includes 3rd resistor and
Four resistance；
The 3rd resistor is connected with the 4th resistance, and the other end of the 3rd resistor is electrically connected the trsanscondutance amplifier
Output end, the other end ground connection of the 4th resistance；
The control submodule is electrically connected to the tie point of the 3rd resistor and the 4th resistance, for receiving described second
Voltage signal.
8. controller according to claim 7, it is characterised in that：The control submodule includes second operational amplifier；
The positive input terminal of the second operational amplifier is electrically connected to the tie point of the 3rd resistor and the 4th resistance, uses
In the reception second voltage signal；Negative input end is electrically connected to first sampling resistor, according to the second voltage signal
The control signal is generated with the voltage at first sampling resistor both ends, and is exported to the control pole of the power tube.
9. controller according to claim 1, it is characterised in that：The output end voltage of the LED load and described first
The voltage at sampling resistor both ends is inversely proportional.
10. controller according to claim 4, it is characterised in that：The charge and discharge of first capacitance be by it is described across
Lead first current signal realization of amplifier output.
11. controller according to claim 8, it is characterised in that：The second operational amplifier, the power tube and institute
It states the first sampling resistor and constitutes a voltage to the converter of electric current, the driving current for generating the LED load.
12. controller according to claim 4, it is characterised in that：By change the trsanscondutance amplifier mutual conductance and/or
The capacitance of first capacitance changes the time constant eliminated needed for the LED load current ripples, to eliminate different frequency
Current ripples caused by input current.
13. controller according to claim 4, it is characterised in that：By adjusting the trsanscondutance amplifier mutual conductance and/or
The capacitance of first capacitance increases the time constant eliminated needed for low-frequency jitter, to remove low-frequency jitter.
14. a kind of current ripples chip for eliminating LED drive system, it is characterised in that：Described in claim 1 or 4
Controller.
15. a kind of current ripples chip for eliminating LED drive system, it is characterised in that：Described in claim 1 or 4
Controller, the power tube and first sampling resistor.
16. a kind of LED drive system, it is characterised in that：Including any in LED driver, LED load, such as claim 1-13
Controller described in, wherein
The LED driver is used to generate the electric current for driving the LED load according to alternating voltage, and exports negative to the LED
It carries；
The controller is electrically connected to the output end of the LED load, for eliminate the current ripples for driving the LED load or
Low-frequency jitter.
17. a kind of method for eliminating LED drive system current ripples, it is characterised in that：Using as described in claim 1
Controller includes the following steps：
The controller samples the voltage of the voltage and first sampling resistor both ends of the output end of the LED load, and root
First voltage signal is generated according to the voltage of output end and the voltage at first sampling resistor both ends of the LED load；
The controller generates control signal according to the first voltage signal and the voltage at first sampling resistor both ends, uses
In the conducting state of power tube that control is electrically connected with the LED load so that the voltage swing of the first voltage signal and
The reference voltage is equal, eliminates the LED load current ripples.
18. a kind of method for eliminating LED drive system current ripples, it is characterised in that：Using as claimed in claim 4
Controller includes the following steps：
The sampling module samples the voltage of the output end voltage and first sampling resistor both ends of the LED load, and root
First voltage signal is generated with the voltage at first sampling resistor both ends and export according to the voltage of output end of the LED load
To the trsanscondutance amplifier；
The trsanscondutance amplifier generates the first current signal according to the first voltage signal and the reference voltage；
First capacitance carries out charge and discharge according to first current signal；
The partial pressure submodule generates second voltage signal according to the voltage at first capacitance both ends；
The control submodule generates the control according to the second voltage signal and the voltage at first sampling resistor both ends
Signal processed, and export to the control pole of the power tube.
19. according to the method for claim 18, it is characterised in that：By change the trsanscondutance amplifier mutual conductance and/or
The capacitance of first capacitance changes the time constant needed for the current ripples for eliminating the LED load, to eliminate different frequency
Input current caused by current ripples.
20. according to the method for claim 18, it is characterised in that：By adjusting the trsanscondutance amplifier mutual conductance and/or
The capacitance of first capacitance increases the time constant eliminated needed for low-frequency jitter, to remove low-frequency jitter.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710071628.4A CN106879109B (en) | 2017-02-09 | 2017-02-09 | Controller, chip and method for eliminating LED drive system current ripples |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710071628.4A CN106879109B (en) | 2017-02-09 | 2017-02-09 | Controller, chip and method for eliminating LED drive system current ripples |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106879109A CN106879109A (en) | 2017-06-20 |
| CN106879109B true CN106879109B (en) | 2018-11-09 |
Family
ID=59166506
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710071628.4A Active CN106879109B (en) | 2017-02-09 | 2017-02-09 | Controller, chip and method for eliminating LED drive system current ripples |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106879109B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107426880B (en) * | 2017-09-07 | 2023-04-18 | 上海晶丰明源半导体股份有限公司 | LED current ripple eliminating circuit, method and chip thereof, and LED equipment |
| CN107426881B (en) * | 2017-09-07 | 2023-09-22 | 上海晶丰明源半导体股份有限公司 | Integrator, LED current ripple cancellation circuit and method |
| CN111194112B (en) * | 2018-11-13 | 2021-06-25 | 通嘉科技股份有限公司 | Ripple suppressor |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7642733B2 (en) * | 2008-05-19 | 2010-01-05 | Leadtrend Technology Corp. | Driving circuit for light emitting device with compensation mechanism and driving method thereof |
| CN103813596B (en) * | 2014-03-10 | 2016-02-24 | 杭州士兰微电子股份有限公司 | The method of LED drive circuit and reduction LED current ripple |
| CN206481476U (en) * | 2017-02-09 | 2017-09-08 | 上海晶丰明源半导体股份有限公司 | Controller, chip and LED drive system |
-
2017
- 2017-02-09 CN CN201710071628.4A patent/CN106879109B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN106879109A (en) | 2017-06-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107529241B (en) | A kind of linear Constant-power LED drive circuit of single hop and method | |
| CN105188232B (en) | Constant current driver circuit for LED, light adjusting circuit and its control method | |
| CN105282929B (en) | A kind of full voltage piece-wise linear constant current LED drive circuit of automatic switchover mode | |
| CN103648219B (en) | Light-emitting diode (LED) switch constant-current driving circuit | |
| CN104661392B (en) | A kind of LED switch constant-current drive circuit | |
| CN104427688B (en) | LED alternating-current drive circuit | |
| CN206585793U (en) | Controller, chip and LED drive system | |
| CN106879109B (en) | Controller, chip and method for eliminating LED drive system current ripples | |
| CN106710531B (en) | Backlight control circuit and electronic device | |
| CN106919211B (en) | Electronic device | |
| CN204145814U (en) | The linear constant current drive circuit that a kind of multistage controls | |
| CN104780646B (en) | A kind of LED drive circuit for supporting controllable silicon light modulation | |
| CN105916241B (en) | Auxiliary power circuit, LED drive circuit, LED driver | |
| CN107071967B (en) | A kind of LED adjusting control circuit and dimming controlling method | |
| CN205546103U (en) | Flyback drive circuit | |
| CN206481476U (en) | Controller, chip and LED drive system | |
| CN107529244B (en) | Linear Constant-power LED drive circuit and method | |
| CN105101539A (en) | Light-emitting diode (LED) constant current driving circuit | |
| CN206977744U (en) | A kind of controller and chip of double LED drive systems | |
| CN110504826A (en) | LED drive system goes ripple circuit and method | |
| CN205657888U (en) | Auxiliary power circuit , LED drive circuit , LED driver | |
| CN208834723U (en) | Multi-channel LED backlight drive circuit and LCD TV | |
| CN106658866B (en) | For eliminating the controller, chip and method of LED drive system current ripples | |
| CN207896874U (en) | Expansible parallel operation DC-DC power source device | |
| CN107770893A (en) | The PWM method of supplying power to of soft and smooth control LED brightness |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |