CN104394635B - A kind of LED driver - Google Patents
A kind of LED driver Download PDFInfo
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- CN104394635B CN104394635B CN201410729323.4A CN201410729323A CN104394635B CN 104394635 B CN104394635 B CN 104394635B CN 201410729323 A CN201410729323 A CN 201410729323A CN 104394635 B CN104394635 B CN 104394635B
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Abstract
The application provides a kind of LED driver, and LED load is driven after being connected with DC DC translation circuits by AC DC translation circuits；The electric current of LED load is flowed through by current regulator detection, and controls the main switch of DC DC translation circuits, make LED driver constant current output；The signal of the output voltage of AC DC translation circuits and/or DC DC translation circuits is characterized by voltage control loop detection, and compare with a reference value, the main switch of AC DC translation circuits is controlled according to comparative result, the output voltage of AC DC translation circuits is less than LED load voltage；By above-mentioned connected mode and control mode, allow that the response speed of voltage control loop designs slower, to ensure PF values higher, realize PFC functions, therefore the response speed of current regulator can be designed comparatively fast, ensure the output current low ripple of LED driver, it is to avoid stroboscopic phenomenon occurs in LED load.
Description
Technical field
The present invention relates to field of LED drive technology, more particularly to a kind of LED driver.
Background technology
LED, as a kind of novel illumination device, because its luminous efficiency is high, is widely used in lighting field, and it is logical
Often constant current is needed to drive, in the prior art as the LED driver of its constant current driving frequently with single-stage solution.
And using the LED driver of single-stage solution, due to needing to take into account PFC (Power Factor Correction, work(
Rate factor correcting) function, i.e. its control loop need the very slow response speed just to have PF (Power Factor, work(higher
Rate factor) value, therefore, its control loop response speed is slower, and this can cause the output current to have larger ripple, the ripple
Cycle for the input ac voltage cycle half.When LED driver is connected and loaded, this current ripples will cause LED
There is stroboscopic phenomenon, this stroboscopic phenomenon will influence the service life of LED, also there is certain damage to human eye.
The content of the invention
In view of this, the invention provides a kind of LED driver, there is larger line to solve prior art output current
Ripple and cause LED the problem of stroboscopic phenomenon occur.
To achieve these goals, technical scheme provided in an embodiment of the present invention is as follows：
A kind of LED driver, including：
The AC-DC translation circuits and DC-DC conversion circuit of output end series connection, the AC-DC translation circuits and DC-DC are converted
Circuit is provided commonly for driving LED load；
The current regulator that output end is connected with the control end of main switch in the DC-DC conversion circuit, for detecting
The electric current of the LED load is flowed through, and controls the main switch of the DC-DC conversion circuit, make the LED driver constant current defeated
Go out；
The voltage control loop that output end is connected with the control end of main switch in the AC-DC translation circuits, for detecting
The signal of the output voltage of the AC-DC translation circuits and/or the DC-DC conversion circuit is characterized, and is compared with a reference value,
The main switch of the AC-DC translation circuits is controlled according to comparative result, the output voltage of the AC-DC translation circuits is less than
The LED load voltage.
Preferably, response speed of the response speed of the current regulator more than the voltage control loop.
Preferably, the input of the current regulator, the defeated of the DC-DC conversion circuit is connected on by sampling resistor
Go out loop.
Preferably, the voltage control loop is used to detect the signal of the output voltage for characterizing the AC-DC translation circuits, and
Compare with a reference value, the main switch of the AC-DC translation circuits is controlled according to comparative result, convert the AC-DC
The output voltage of circuit is less than the LED load voltage.
Preferably, the voltage control loop is used to detect the signal of the output voltage for characterizing the DC-DC conversion circuit, and
Compare with a reference value, the main switch of the AC-DC translation circuits is controlled according to comparative result, convert the AC-DC
The output voltage of circuit is less than the LED load voltage.
Preferably, the voltage control loop be used to detecting the signal of the output voltage for characterizing the AC-DC translation circuits with
The difference of the output voltage of the DC-DC conversion circuit, and compare with a reference value, the AC- is controlled according to comparative result
The main switch of DC translation circuits, makes the output voltage of the AC-DC translation circuits be less than the LED load voltage.
Preferably, the voltage control loop is used to detect the output voltage of the AC-DC translation circuits and characterizes the DC-
The difference of the signal of the output voltage of DC translation circuits, and compare with a reference value, the AC-DC is controlled according to comparative result
The main switch of translation circuit, makes the output voltage of the AC-DC translation circuits be less than the LED load voltage.
Preferably, the voltage control loop be used to detecting the signal of the output voltage for characterizing the AC-DC translation circuits with
The difference of the signal of the output voltage of the DC-DC conversion circuit is characterized, and is compared with a reference value, according to comparative result control
The main switch of the AC-DC translation circuits is made, makes the output voltage of the AC-DC translation circuits less than LED load electricity
Pressure.
Preferably, a reference value in the voltage control loop is according to the default value of LED load voltage.
Preferably, a reference value in the voltage control loop is the LED load voltage.
Preferably, also include：The constant pressure source being connected with the input of the DC-DC conversion circuit.
Preferably, the AC-DC translation circuits are isolated form topology, the first secondary in the AC-DC translation circuits around
Group is connected with the first rectification module, the output end of first rectification module as the AC-DC translation circuits output end；Institute
The second vice-side winding stated in AC-DC translation circuits is connected with the second rectification module, the output end of second rectification module with
The input of the DC-DC conversion circuit is connected.
Preferably, the DC-DC conversion circuit is non-isolation type topology.
Preferably, the main switch in the DC-DC conversion circuit is arranged on same integrated electricity with the current regulator
In road.
The application provides a kind of LED driver, after being connected with DC-DC conversion circuit by AC-DC translation circuits
Drive LED load；The electric current of the LED load is flowed through by current regulator detection, and controls the master of the DC-DC conversion circuit
Switching tube, makes the LED driver constant current output；The AC-DC translation circuits and/or institute are characterized by voltage control loop detection
The signal of the output voltage of DC-DC conversion circuit is stated, and is compared with a reference value, the AC-DC conversion is controlled according to comparative result
The main switch of circuit, makes the output voltage of the AC-DC translation circuits be less than the LED load voltage.It is provided herein
The LED driver, by above-mentioned connected mode and control mode so that the response speed of the voltage control loop can set
Haggle over slow, to ensure PF values higher, realize PFC functions, therefore the response speed of the current regulator can be designed comparatively fast,
Ensure the output current low ripple of the LED driver, it is to avoid stroboscopic phenomenon occurs in LED load.
Brief description of the drawings
In order to illustrate more clearly about the embodiment of the present invention or technical scheme of the prior art, below will be to embodiment or existing
The accompanying drawing to be used needed for having technology description is briefly described, it should be apparent that, drawings in the following description are only this
Inventive embodiment, for those of ordinary skill in the art, on the premise of not paying creative work, can also basis
The accompanying drawing of offer obtains other accompanying drawings.
A kind of LED driver circuit figure that Fig. 1 is provided for the embodiment of the present application；
A kind of LED driver circuit figure that Fig. 2 is provided for another embodiment of the application；
A kind of LED driver circuit figure that Fig. 3 is provided for another embodiment of the application.
Specific embodiment
Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clear, complete
Site preparation is described, it is clear that described embodiment is only a part of embodiment of the invention, rather than whole embodiments.It is based on
Embodiment in the present invention, it is every other that those of ordinary skill in the art are obtained under the premise of creative work is not made
Embodiment, belongs to the scope of protection of the invention.
A kind of LED driver is the embodiment of the invention provides, there is larger ripple to solve prior art output current
And cause LED the problem of stroboscopic phenomenon occur.
Specifically, as shown in figure 1, the LED driver includes：
The AC-DC translation circuits 101 and DC-DC conversion circuit 102 of output end series connection；
The current regulator 103 that output end is connected with the control end of main switch in DC-DC conversion circuit 102；
The voltage control loop 104 that output end is connected with the control end of main switch in AC-DC translation circuits 101.
What deserves to be explained is, the high-voltage output end of AC-DC translation circuits 101 is connected with the positive pole of LED load in Fig. 1, DC-
The low-voltage output of DC translation circuits 102 is connected with the negative pole of the LED load；In actual applications, it would however also be possible to employ DC-DC
The high-voltage output end of translation circuit 102 is connected with the positive pole of LED load, the low-voltage output of AC-DC translation circuits 101 with it is described
The negative pole of LED load is connected；Fig. 1 is only a kind of example, AC-DC translation circuits 101 and DC-DC conversion circuit 102 and the LED
The connected mode of load is simultaneously not specifically limited, can be according to its actual applied environment depending on.
Specifically operation principle is：
In the prior art, the stroboscopic phenomenon for causing LED to occur in order to avoid output current has larger ripple, adopts
With the LED driver of two-step scheme also by more selection, the input of following stage DC-DC converter directly with prime AC-DC
The output end of converter is connected, and the prime AC-DC converter is used to realize PFC functions that the rear class DC-DC converter to be used for
Constant current or pressure-keeping functions are realized, the control loop response speed of prime AC-DC converter can be very slow, without causing LED to drive
Dynamic device output current ripple problem, the control loop response speed of rear class DC-DC converter can be very fast, meets quick adjustment simultaneously
Reduce output current ripple demand, it is easy to solve the problems, such as single-stage solution.
But two-step scheme has carried out two times transfer due to input power, the efficiency of LED driver is set to be two-stage circuit
Efficiency product.Such as front stage circuits efficiency is η 1, and late-class circuit efficiency is η 2, then prior art is driven using the LED of two-step scheme
Efficiency eta=η 1* the η 2 of dynamic device, greatly reduce the efficiency of LED driver, increase loss, it is impossible to highlight LED illumination System section
The advantage of energy.
And using the LED driver of the present embodiment offer, AC-DC translation circuits 101 are connected with DC-DC conversion circuit 102
Drive the LED load jointly afterwards；Current regulator 103 detects the electric current for flowing through the LED load, and controls DC-DC to convert
The main switch of circuit 102, makes the LED driver constant current output；The detection of voltage control loop 104 characterizes AC-DC translation circuits
101 and/or DC-DC conversion circuit 102 output voltage signal, and compare with a reference value, AC- is controlled according to comparative result
The main switch of DC translation circuits 101, makes the output voltage of AC-DC translation circuits 101 be less than the LED load voltage, it is ensured that
DC-DC conversion circuit 102 can work；By above-mentioned connected mode and control mode, the response speed of voltage control loop 104 can
It is relatively slow to design, to ensure PF values higher, PFC functions are realized, so that the response speed of current regulator 103 can set
Haggle over fast, it is ensured that the output current low ripple of the LED driver, it is to avoid stroboscopic phenomenon occurs in the LED load.Meanwhile, it is false
Efficiency such as AC-DC translation circuits 101 is η 1, and the efficiency of DC-DC conversion circuit 102 is η 2, then the efficiency of the LED driver
η is only slightly less than η 1, and the degree of the efficiency eta less than η 1 of the LED driver depends on the processing power of DC-DC conversion circuit 102
Size, compared to existing technology the LED driver efficiency high of middle use two-step scheme and be lost low.
The LED driver that the present embodiment is provided, because the output end of AC-DC translation circuits 101 and DC-DC conversion circuit 102
Output end is connected and connects the LED load, therefore, current regulator 103 is detected and flows through the electric current of the LED load, can be with
By detecting the electric current of the output loop of DC-DC conversion circuit 102, or the electric current of the output loop of AC-DC translation circuits 101 comes real
It is existing, the electric current of any point of series loop of sampling, all equivalent with load current or identical, Fig. 1 is only a kind of example, is not done herein
It is specific to limit.
What deserves to be explained is, the LED driver with Voltage loop in the prior art, Voltage loop detection LED driver is defeated
Go out voltage, and according to the comparing of testing result and reference voltage, the switching tube of the translation circuit in control LED driver makes LED
The output voltage of driver is the voltage under reference voltage setting.And the LED driver that the present embodiment is provided, voltage
The detection of control ring 104 be not the LED driver output voltage, will not also control the LED driver output voltage to be
The voltage of a certain reference voltage setting, but output voltage V1 and/or DC-DC the conversion electricity of detection AC-DC translation circuits 101
The output voltage V2 on road 102, specifically includes：The output voltage V1 of AC-DC translation circuits 101, DC-DC conversion circuit 102 it is defeated
Go out the output voltage V1 of voltage V2, AC-DC translation circuit 101 and output voltage V2 of DC-DC conversion circuit 102 difference V1-V2,
Characterize the difference of the output voltage V2 of the signal K*V1 and DC-DC conversion circuit 102 of the output voltage V1 of AC-DC translation circuits 101
The signal of the output voltage V1 of K*V1-V2, AC-DC translation circuit 101 and output voltage V2 for characterizing DC-DC conversion circuit 102
The difference V1-K*V2 of K*V2, or characterize signal K1*V1 and the sign DC-DC changes of the output voltage V1 of AC-DC translation circuits 101
Change the difference K1*V1-K2*V2 of the signal K2*V2 of the output voltage V2 of circuit 102；Compare with a reference value again, according to comparative result control
AC-DC translation circuits 101 processed, make the output voltage V1 of AC-DC translation circuits 101 less than the voltage of the LED load, make DC-
The output voltage of DC translation circuits 102 will not be forced zero, to ensure that DC-DC conversion circuit 102 being capable of normal closed loop work；Together
When, when the voltage change of the LED load, the output voltage V1 and/or DC-DC conversion circuit of AC-DC translation circuits 101
102 output voltage V2 changes therewith so that the LED driver output voltage can dynamically track the LED load voltage；
It is not to control the output voltage of LED driver constant as in the prior art, therefore, the LED that the present embodiment passes through drives
Dynamic device applies to the load of wide scope, i.e., when the LED that the LED load of different loads voltage is connected to the present embodiment drives
During dynamic device, the LED driver can automatically export suitable voltage, drive the LED load to work.
Preferably, response speed of the response speed of current regulator 103 more than voltage control loop 104.
The LED driver that the present embodiment is provided, relatively slow, the Ke Yibao of the response speed design of voltage control loop 104
Card PF values higher, realize PFC functions；What now the response speed of current regulator 103 can be designed is very fast, it is ensured that described
The output current low ripple of LED driver, it is to avoid stroboscopic phenomenon occurs in the LED load.
Preferably, the input of current regulator 103 is connected on the output of DC-DC conversion circuit 102 by sampling resistor
Loop.
It should be noted that because the output end of AC-DC translation circuits 101 and DC-DC conversion circuit 102 is connected on one
Rise, therefore, current regulator 103, can be with the electric current of any point in measure loop, the electric current of any point when load current is detected
Load current all with series loop is identical；The present embodiment is only a kind of as shown in figure 1, have selected the negative pole of the LED load
Example, but this is not limited to, in concrete application, can be depending on applied environment.
Preferably, voltage control loop 104 is used to detect the signal of the output voltage V2 for characterizing DC-DC conversion circuit 102, such as
K*V2, and compare with a reference value, the main switch of AC-DC translation circuits 101 is controlled according to comparative result, become AC-DC
The output voltage for changing circuit 101 is less than the LED load voltage.
In the present embodiment, because the feedback signal of the input of voltage control loop 104 is K*V2, namely voltage control loop 104 controls
The output voltage V2 of DC-DC conversion circuit processed 102 is the business of a reference value and K.Because a reference value is not zero, DC-DC conversion electricity
The output voltage V2 on road 102 is not zero, and the output voltage V1 of AC-DC translation circuits is less than the LED load voltage.When the base
When quasi- value is constant, the output voltage V2 of DC-DC conversion circuit 102 is constant, when the LED load voltage is raised, AC-DC conversion
The output voltage V1 of circuit 101 is increased, and vice versa.Therefore, the control AC-DC of voltage control loop 104 translation circuits 101,
The output voltage V1 of AC-DC translation circuits 101 is changed with the LED load voltage change, the LED can finally driven
The output voltage of dynamic device dynamically tracks the LED load voltage.
Preferably, voltage control loop 104 is used to detecting the signal of the output voltage V1 for characterizing AC-DC translation circuits 101 (such as
K*V1, K are the proportionality coefficient obtained according to the parameter of component in circuit system), and compare with a reference value, according to
The main switch of comparative result control AC-DC translation circuits 101, makes the output voltage of AC-DC translation circuits 101 less than described
LED load voltage.
In the present embodiment, because the feedback signal of the input of voltage control loop 104 is K*V1, namely voltage control loop 104 controls
The output voltage V1 of AC-DC translation circuits processed 101 is the business of a reference value and K.Preferably, when the amplitude of a reference value be with
The LED load voltage monotonic increase, when the LED load voltage is raised, the output voltage V1 of AC-DC translation circuits 101
Increase, vice versa.Therefore, the control AC-DC of voltage control loop 104 translation circuits 101, make AC-DC translation circuits 101
Output voltage V1 changes with the LED load voltage change, the output voltage of LED driver is dynamically tracked institute
State LED load voltage.
Preferably, voltage control loop 104 is used to detecting the signal of the output voltage V1 for characterizing AC-DC translation circuits 101 (such as
K*V1) with the difference of the output voltage V2 of DC-DC conversion circuit 102, i.e. K*V1-V2, and compare with a reference value, according to than
Compared with the main switch of output control AC-DC translation circuits 101, the output voltage of AC-DC translation circuits 101 is set to be less than the LED
Load voltage.
In the present embodiment, because the feedback signal of the input of voltage control loop 104 is K*V1-V2, namely voltage control loop 104
Control characterizes the signal K*V1's and the output voltage V2 of DC-DC conversion circuit 102 of the output voltage V1 of AC-DC translation circuits 101
Difference on the basis of value Vref because below equation can be released：
K*V1-V2=Vref (1)
V1+V2=Vo (2)
Wherein, Vo is the LED load voltage, i.e., the output voltage of described LED driver.
Can be drawn by equation (1) and (2)：
V1=(Vo+Vref)/(K+1)
V2=(K*Vo-Vref)/(K+1)
Above formula show the output voltage V1 and the output voltage V2 of DC-DC conversion circuit 102 of AC-DC translation circuits 101 with
The relation of the output voltage Vo (i.e. described LED load voltage) of the LED driver.
What deserves to be explained is, a reference value Vref can be fixed value, when the LED load voltage is raised, AC-DC conversion
The output voltage V1 of circuit 101 is increased, and the output voltage V2 of DC-DC conversion circuit 102 is increased, and vice versa.Cause
This, the control of voltage control loop 104 AC-DC translation circuits 101 make the defeated of AC-DC translation circuits 101 and DC-DC conversion circuit 102
Go out voltage all to change with the LED load voltage change, the output voltage of the LED driver can finally dynamically tracked
The LED load voltage.
Preferably, a reference value Vref can also be with the LED load voltage monotonic increase；So, when the LED load
When voltage is raised, a reference value Vref is also raised, and the output voltage V1 of AC-DC translation circuits 101 is increased, but DC-DC becomes
The output voltage V2 for changing circuit 102 is slow when being fixed value compared with a reference value Vref with the elevated speed of load voltage, or, DC-DC
The output voltage V2 of translation circuit 102 is constant, and vice versa.
Preferably, voltage control loop 104 is used to detect the output voltage V1 of AC-DC translation circuits 101, with sign DC-DC
The difference of the signal (such as K*V2) of the output voltage V2 of translation circuit 102, i.e. V1-K*V2, and compare with a reference value, according to
The main switch of comparative result control AC-DC translation circuits 101, makes the output voltage of AC-DC translation circuits 101 less than described
LED load voltage.
Preferably, voltage control loop 104 is used to detect the signal K1* of the output voltage V1 for characterizing AC-DC translation circuits 101
V1 with characterize DC-DC conversion circuit 102 output voltage V2 signal K2*V2 difference K1*V1-K2*V2, and with the benchmark
Value compares, and the main switch of AC-DC translation circuits 101 is controlled according to comparative result, makes the output electricity of AC-DC translation circuits 101
Force down in the LED load voltage.
Concrete principle is same as the previously described embodiments, and here is omitted.
What deserves to be explained is, shown in Fig. 1, the input of voltage control loop 104 and the output end of DC-DC conversion circuit 102
It is connected, is a kind of example, now the input quantity of voltage control loop 104 is the output voltage V2 of DC-DC conversion circuit 102.
The value that above-described embodiment lists voltage control loop 104 and can detect has：Characterize the defeated of AC-DC translation circuits 101
Go out signal K*V1, the signal K*V2 of the output voltage V2 of sign DC-DC conversion circuit 102, the sign AC-DC conversion electricity of voltage V1
Difference K*V1-V2, AC-DC of the signal K*V1 of the output voltage V1 on the road 101 and output voltage V2 of DC-DC conversion circuit 102
The difference V1- of the output voltage V1 of the translation circuit 101 and signal K*V2 of the output voltage V2 for characterizing DC-DC conversion circuit 102
K*V2, or characterize the signal K1*V1 and sign DC-DC conversion circuit 102 of the output voltage V1 of AC-DC translation circuits 101
The difference K1*V1-K2*V2 of the signal K2*V2 of output voltage V2；When K is 1, the output electricity of AC-DC translation circuits 101 is that is to say
Pressure V1, the output voltage V2 of DC-DC conversion circuit 102, or the output voltage V1 and DC-DC of AC-DC translation circuits 101 are converted
The difference V1-V2 of the output voltage V2 of circuit 102；Then detected value is compared with the corresponding a reference value, according to than
Compared with the main switch of output control AC-DC translation circuits 101, the output voltage of AC-DC translation circuits 101 is set to be less than the LED
Load voltage.
For example, as the output voltage V1 of the detection AC-DC of voltage control loop 104 translation circuits 101, if AC-DC conversion electricity
The output voltage V1 on road 101 is equal to the voltage of the LED load, then the output voltage V2 of DC-DC conversion circuit 102 is equal to zero,
Sampled value in voltage control loop 104 is more than a reference value, and voltage control loop 104 will control the main switch of AC-DC translation circuits 101
Pipe, makes its output voltage V1 reductions, because the voltage of the LED load is constant under same state, AC-DC translation circuits 101
Output voltage V1 reductions the output voltage V2 of DC-DC conversion circuit 102 will be made to raise, circulation regulation is until DC-DC conversion is electric
The output voltage V2 on road 102 is increased to a reference value, this ensure that the output voltage V1 of AC-DC translation circuits 101 is less than load
Voltage.
When voltage control loop 104 detects the output voltage V2 of DC-DC conversion circuit 102, if DC-DC conversion circuit 102
Output voltage V2 close to zero, the sampled value in voltage control loop 104 is less than a reference value, and voltage control loop 104 will control AC-DC
The main switch of translation circuit 101, make its output voltage V1 reduction, due to the LED load voltage under same state not
Become, the output voltage V1 reductions of AC-DC translation circuits 101 will raise the output voltage V2 of DC-DC conversion circuit 102, circulate
Regulation is increased to a reference value up to the output voltage V2 of DC-DC conversion circuit 102, this ensure that AC-DC translation circuits 101
Output voltage V1 is less than load voltage.
When the output voltage V1 of the detection AC-DC of voltage control loop 104 translation circuits 101 is defeated with DC-DC conversion circuit 102
When going out the difference V1-V2 of voltage V2, if the output voltage V1 of AC-DC translation circuits 101 is equal to the voltage of the LED load, DC-
The a reference value that the output voltage V2 of DC translation circuits 102 is equal to design in zero, V1-V2=V1, voltage control loop 104 must be small
In current sample values V1-V2, voltage control loop 104 will control the main switch of AC-DC translation circuits 101, make its output electricity
Pressure V1 reductions, because load voltage is constant under same state, the output voltage V1 reductions of AC-DC translation circuits 101 will make DC-
The output voltage V2 of DC translation circuits 102 is raised, and circulation regulation is until the output voltage V2 of DC-DC conversion circuit 102 is increased to
A reference value, this ensure that the output voltage V1 of AC-DC translation circuits 101 is less than load voltage.
Above-mentioned three kinds of voltage detecting modes, ensure that the output voltage V1 of AC-DC translation circuits 101 less than described
The voltage of LED load, while can also ensure that the LED driver is applied to the load of wide scope.
Depending on the signal that voltage control loop 104 is specifically detected can be according to specific applicable cases, specific limit is not done herein
It is fixed.For example, the detection of voltage control loop 104 V1-V2 can also be replaced with detection K*V1-V2, its operation principle (adjusts controlling party
Formula) and detect that V1-V2 is identical, no longer repeat one by one herein.
Preferably, a reference value in voltage control loop 104 is according to the default value of LED load voltage.
Preferably, a reference value in voltage control loop 104 is the LED load voltage.
The a reference value can be carried out default or use the LED load voltage according to the LED load voltage, now
Voltage control loop 104 can control AC-DC translation circuits 101 to export by controlling the main switch of AC-DC translation circuits 101
Voltage V1 is raised with the rising of the LED load voltage, reduced with the reduction of load voltage.Because AC-DC conversion electricity
The processing power ratio on road 101 is higher, and the efficiency of whole LED driver is also higher, when the output electricity of AC-DC translation circuits 101
When pressure V1 is raised with the rising of the LED load voltage, the power of its output is raised also with the rising of bearing power,
Ensure that the power of the LED driver in wide range of load voltage all maintains a level higher.
Preferably, as shown in Fig. 2 the LED driver also includes：It is connected with the input of DC-DC conversion circuit 102
Constant pressure source Vs.
It is connected with DC-DC conversion circuit 102 using constant pressure source Vs, then the voltage constant that DC-DC conversion circuit 102 is received is not
Become.
Preferably, as shown in figure 3, AC-DC translation circuits 101 are isolated form topology, in AC-DC translation circuits 101 the
One vice-side winding 111 is connected with the first rectification module 112, and the output end of the first rectification module 112 is used as AC-DC translation circuits
101 output end；The second vice-side winding 113 in AC-DC translation circuits 101 is connected with the second rectification module 114, the second rectification
The output end of module 114 is connected with the input of DC-DC conversion circuit 102.
Preferably, as shown in figure 3, the input of voltage control loop 104 respectively with the input of DC-DC conversion circuit 102
And output end is connected.
When AC-DC translation circuits 101 are isolated form topology, the input voltage Vs of DC-DC conversion circuit 102 uses AC-DC
The output voltage of the rectification module 114 of translation circuit 101 second, now the first rectification module 112 is defeated with the second rectification module 114
Go out that voltage is proportional, then the output voltage V1 of the input voltage Vs of DC-DC conversion circuit 102 and AC-DC translation circuits 101
Also into this ratio, such as Vs/V1=K；If now voltage control loop 104 is wanted to be designed to detect the defeated of AC-DC translation circuits 101
During the difference V1-V2 of the output voltage V2 for going out voltage V1 and DC-DC conversion circuit 102, it is also possible to by detecting DC-DC conversion circuit
102 input voltage Vs and output voltage V2, obtains K*V1-V2；So the input of voltage control loop 104 may be designed in
It is connected with the input and output end of DC-DC conversion circuit 102 respectively.
Preferably, the DC-DC conversion circuit is non-isolation type topology.
When the DC-DC conversion circuit is non-isolation type topology, the input of the voltage control loop can also be without
It is connected with the low pressure, input end and low-voltage output of DC-DC conversion circuit 102.
Preferably, the main switch in the DC-DC conversion circuit is arranged on same integrated electricity with the current regulator
In road.
The integration section of the DC-DC conversion circuit and the current regulator, can be according to specific applicable cases
It is fixed, it is not specifically limited herein.
Each embodiment is described by the way of progressive in the present invention, and what each embodiment was stressed is and other realities
Apply the difference of example, between each embodiment identical similar portion mutually referring to.For device disclosed in embodiment
Speech, because it is corresponded to the method disclosed in Example, so description is fairly simple, related part is referring to method part illustration
.
The above is only the preferred embodiment of the present invention, make skilled artisans appreciate that or realizing of the invention.It is right
Various modifications of these embodiments will be apparent to one skilled in the art, general original as defined herein
Reason can be realized in other embodiments without departing from the spirit or scope of the present invention.Therefore, the present invention will not
Be intended to be limited to the embodiments shown herein, and be to fit to it is consistent with principles disclosed herein and features of novelty most
Scope wide.
Claims (11)
1. a kind of LED driver, it is characterised in that including：
The AC-DC translation circuits and DC-DC conversion circuit, the AC-DC translation circuits and DC-DC conversion circuit of output end series connection
It is provided commonly for driving LED load；
The current regulator that output end is connected with the control end of main switch in the DC-DC conversion circuit, flows through for detecting
The electric current of the LED load, and the main switch of the DC-DC conversion circuit is controlled, make the LED driver constant current output；
The voltage control loop that output end is connected with the control end of main switch in the AC-DC translation circuits, characterizes for detecting
The signal of the output voltage of the AC-DC translation circuits and/or the DC-DC conversion circuit, and compare with a reference value, according to
Comparative result controls the main switch of the AC-DC translation circuits, makes the output voltage of the AC-DC translation circuits less than described
LED load voltage；
Response speed of the response speed of the current regulator more than the voltage control loop.
2. LED driver according to claim 1, it is characterised in that the input of the current regulator, by sampling
Output loop of the resistant series in the DC-DC conversion circuit.
3. LED driver according to claim 1, it is characterised in that the voltage control loop be used to detect characterize it is described
The difference of the signal of the output voltage of AC-DC translation circuits and the output voltage of the DC-DC conversion circuit, and with the benchmark
Value compares, and the main switch of the AC-DC translation circuits is controlled according to comparative result, makes the output of the AC-DC translation circuits
Voltage is less than the LED load voltage.
4. LED driver according to claim 1, it is characterised in that the voltage control loop is used to detect the AC-DC
The difference of the output voltage of translation circuit and the signal of the output voltage for characterizing the DC-DC conversion circuit, and with the benchmark
Value compares, and the main switch of the AC-DC translation circuits is controlled according to comparative result, makes the output of the AC-DC translation circuits
Voltage is less than the LED load voltage.
5. LED driver according to claim 1, it is characterised in that the voltage control loop be used to detect characterize it is described
The difference of the signal of the signal of the output voltage of AC-DC translation circuits and the output voltage of the sign DC-DC conversion circuit, and
Compare with a reference value, the main switch of the AC-DC translation circuits is controlled according to comparative result, convert the AC-DC
The output voltage of circuit is less than the LED load voltage.
6. LED driver according to claim 1, it is characterised in that a reference value in the voltage control loop is
According to the default value of LED load voltage.
7. LED driver according to claim 1, it is characterised in that a reference value in the voltage control loop is
The LED load voltage.
8. LED driver according to claim 1, it is characterised in that also include：It is defeated with the DC-DC conversion circuit
Enter the connected constant pressure source in end.
9. LED driver according to claim 1, it is characterised in that the AC-DC translation circuits are isolated form topology,
The first vice-side winding in the AC-DC translation circuits is connected with the first rectification module, the output end of first rectification module
As the output end of the AC-DC translation circuits；The second vice-side winding and the second rectification module in the AC-DC translation circuits
It is connected, the output end of second rectification module is connected with the input of the DC-DC conversion circuit.
10. LED driver according to claim 1, it is characterised in that the DC-DC conversion circuit is opened up for non-isolation type
Flutter.
11. LED drivers according to claim 1, it is characterised in that the main switch in the DC-DC conversion circuit
It is arranged in same integrated circuit with the current regulator.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410729323.4A CN104394635B (en) | 2014-12-04 | 2014-12-04 | A kind of LED driver |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410729323.4A CN104394635B (en) | 2014-12-04 | 2014-12-04 | A kind of LED driver |
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| Publication Number | Publication Date |
|---|---|
| CN104394635A CN104394635A (en) | 2015-03-04 |
| CN104394635B true CN104394635B (en) | 2017-06-13 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201410729323.4A Active CN104394635B (en) | 2014-12-04 | 2014-12-04 | A kind of LED driver |
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Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105187749B (en) * | 2015-09-25 | 2018-08-31 | 深圳创维－Rgb电子有限公司 | A kind of television backlight Drive And Its Driving Method |
| CN108811257A (en) * | 2018-08-07 | 2018-11-13 | 四维生态科技（杭州）有限公司 | A kind of control method of LED illumination System and LED load circuit |
| CN114867155B (en) * | 2021-01-20 | 2023-04-18 | 英飞特电子（杭州）股份有限公司 | LED driving power supply and efficiency adjusting method thereof |
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|---|---|---|---|---|
| CN101447734A (en) * | 2007-11-29 | 2009-06-03 | 三星电机株式会社 | DC/DC converter |
| CN202424506U (en) * | 2012-01-11 | 2012-09-05 | 西南交通大学 | Single-stage high power factor correction converter with low output power frequency ripple wave |
| CN204272450U (en) * | 2014-12-04 | 2015-04-15 | 英飞特电子（杭州）股份有限公司 | A kind of LED driver |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000308345A (en) * | 1999-04-14 | 2000-11-02 | Shindengen Electric Mfg Co Ltd | Ac input power unit |
| US8564989B2 (en) * | 2010-12-22 | 2013-10-22 | Intel Corporation | Cold swap load adaptive power supply |
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2014
- 2014-12-04 CN CN201410729323.4A patent/CN104394635B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101447734A (en) * | 2007-11-29 | 2009-06-03 | 三星电机株式会社 | DC/DC converter |
| CN202424506U (en) * | 2012-01-11 | 2012-09-05 | 西南交通大学 | Single-stage high power factor correction converter with low output power frequency ripple wave |
| CN204272450U (en) * | 2014-12-04 | 2015-04-15 | 英飞特电子（杭州）股份有限公司 | A kind of LED driver |
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| CN104394635A (en) | 2015-03-04 |
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