CN101527988B - Light source driver module and circuit - Google Patents
Light source driver module and circuit Download PDFInfo
- Publication number
- CN101527988B CN101527988B CN200810082121XA CN200810082121A CN101527988B CN 101527988 B CN101527988 B CN 101527988B CN 200810082121X A CN200810082121X A CN 200810082121XA CN 200810082121 A CN200810082121 A CN 200810082121A CN 101527988 B CN101527988 B CN 101527988B
- Authority
- CN
- China
- Prior art keywords
- electrically connected
- voltage
- operational amplifier
- input end
- light source
- 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.)
- Expired - Fee Related
Links
Images
Landscapes
- Led Devices (AREA)
Abstract
The invention relates to a light source driver circuit, which comprises a voltage signal source and a current source for improving temperature effect, and is used for adjusting the brightness of a light-emitting diode serial. The first end of the light-emitting diode serial is electrically connected to a ground terminal. The current source for improving the temperature effect comprises an adjustable bias voltage source used for outputting an adjustable voltage, a current source controlled by the voltage and used for outputting current according to the voltage signal source, and a feedback circuit which is electrically connected between the second end of the light-emitting diode serial and the adjustable bias voltage source, and is used for controlling the voltage output by the adjustable bias voltage source according to the voltage of the second end of the light-emitting diode serial.
Description
Technical field
The present invention relates to a kind of light source driving circuit and module, the particularly a kind of light source driving circuit and module of deciding electric current and improving temperature effect that provide.
Background technology
With light emitting diode (Light Emitting Diode, LED) more and more general as the application of light emitting source.For example, the backlight module of traditional display panels is that (coldcathode fluorescent lamp CCFL) is used as light source with cathode fluorescent tube mostly.Nowadays, along with continuous lifting of the luminescence efficiency of light emitting diode and cost reduce day by day, light emitting diode replaces cathode fluorescent tube gradually as the backlight module light source.
In the prior art, regular meeting is connected into a string row with many light emitting diodes, to reduce total drive current size of required driving circuit quantity and reduction light emitting diode.Yet, because technologic deviation is difficult to guarantee that all light emitting diodes in the different tandems all have on all four component parameters.In addition, environmental factor such as temperature also may have influence on the component parameters of light emitting diode.For example, (forward voltage VF) often has a little difference to the forward voltage of different light emitting diodes.And when temperature rose, the page or leaf of light emitting diode also can and then descend to bias voltage, and the electric current of the feasible light emitting diode of flowing through will be with temperature change.Therefore even come the driven for emitting lights diode with the mode of series connection, still can be because of the rising of temperature, and change the brightness of light emitting diode originally.So, many light emitting diodes are connected into the framework of a string row can be equivalently the forward voltage error of all light emitting diodes in the same tandem be added up, always forward voltage error usually also can be different and different LED serial added up.
In the case, give different LED serials, always the electric current of indivedual LED serials of flowing through also can be different different because of the forward voltage error that each LED serial added up even identical driving voltage applied.And when the temperature of each LED serial rising is inequality, total page or leaf will be bigger to the variation of voltage error.Thus, LED serial will have different brightness because of the conducting electric current is inconsistent to each other.Therefore, when utilizing LED serial as the light source of the backlight module of display panels, regular meeting causes the bad phenomenon of display panels because of the inhomogeneous and coloured inequality of back light source brightness (Mura).
Summary of the invention
Therefore one of the object of the invention is to provide the light source driving circuit and the module of deciding electric current and improving temperature effect, to address the above problem.
The present invention provides a kind of light source driving circuit, and light source driving circuit is used to drive a LED serial.First end of LED serial is electrically connected at an earth terminal.Driving circuit comprises a voltage signal source; One voltage-controlled current source comprises one first operational amplifier, comprises a positive input terminal, is electrically connected at voltage signal source, a negative input end, and an output terminal; One first two-carrier junction transistor comprises an emitter-base bandgap grading, is electrically connected at the negative input end of first operational amplifier, and a base stage is electrically connected at the output terminal of first operational amplifier and a collector; One first resistance is electrically connected between the negative input end and earth terminal of first operational amplifier; One second operational amplifier comprises a positive input terminal, electrically connects the collector of the first two-carrier junction transistor, a negative input end, and an output terminal; One second resistance is electrically connected between the collector and a bias generator of the first two-carrier junction transistor; One the 3rd resistance is electrically connected between the negative input end and bias generator of second operational amplifier; And one second two-carrier junction transistor, comprise an emitter-base bandgap grading, be electrically connected at the negative input end of second operational amplifier, a base stage is electrically connected at the output terminal of second operational amplifier, and a collector, is electrically connected at second end of LED serial.
The present invention more provides a kind of light source driver module, and light source driver module is used to drive a light emitting diode matrix.Light emitting diode matrix comprises K LED serial.Wherein, K is a positive integer.First end of each LED serial is electrically connected at an earth terminal.Driver module comprises a voltage signal source; K voltage-controlled current source, each voltage-controlled current source comprises one first operational amplifier, comprises a positive input terminal, is electrically connected at voltage signal source, a negative input end, and an output terminal; One first two-carrier junction transistor comprises an emitter-base bandgap grading, is electrically connected at the negative input end of first operational amplifier, and a base stage is electrically connected at the output terminal of first operational amplifier and a collector; One first resistance is electrically connected between the negative input end and earth terminal of first operational amplifier; One second operational amplifier comprises a positive input terminal, electrically connects the collector of the first two-carrier junction transistor, a negative input end, and an output terminal; One second resistance is electrically connected between the collector and a bias generator of the first two-carrier junction transistor; One the 3rd resistance is electrically connected between the negative input end and bias generator of second operational amplifier; And one second two-carrier junction transistor, comprise an emitter-base bandgap grading, be electrically connected at the negative input end of second operational amplifier; One base stage; Be electrically connected at the output terminal of second operational amplifier, reach a collector, be electrically connected at second end of a corresponding LED serial.
The present invention also provides a kind of light source driving circuit, and light source driving circuit is used to drive a LED serial.First end of LED serial is electrically connected at an earth terminal.Driving circuit comprises a voltage signal source; One current source comprises a variable bias source, in order to export a sizable voltage; One voltage-controlled current source comprises one first operational amplifier, comprises a positive input terminal, is electrically connected at voltage signal source, a negative input end, and an output terminal; One first two-carrier junction transistor comprises an emitter-base bandgap grading, is electrically connected at the negative input end of first operational amplifier, and a base stage is electrically connected at the output terminal of first operational amplifier and a collector; One first resistance is electrically connected between the negative input end and earth terminal of first operational amplifier; One second operational amplifier comprises a positive input terminal, electrically connects the collector of the first two-carrier junction transistor, a negative input end, and an output terminal; One second resistance is electrically connected between the collector and variable bias source of the first two-carrier junction transistor; One the 3rd resistance is electrically connected between the negative input end and variable bias source of second operational amplifier; One second two-carrier junction transistor comprises an emitter-base bandgap grading, is electrically connected at the negative input end of second operational amplifier, and a base stage is electrically connected at the output terminal of second operational amplifier, and a collector, is electrically connected at second end of LED serial; And a feedback circuit, be electrically connected between second end and variable bias source of LED serial, in order to according to the voltage on second end of LED serial, control the voltage swing that the variable bias source is exported.
The present invention more provides a kind of light source driver module, and light source driver module is used to drive a light emitting diode matrix.Light emitting diode matrix comprises K LED serial.Wherein, K is a positive integer.First end of each LED serial is electrically connected at an earth terminal.Driver module comprises a voltage signal source; K current source, each current source comprise a variable bias source, in order to export a sizable voltage; One VCCS comprises one first operational amplifier, comprises a positive input terminal, is electrically connected at voltage signal source, a negative input end, and an output terminal; One first two-carrier junction transistor comprises an emitter-base bandgap grading, is electrically connected at the negative input end of first operational amplifier, and a base stage is electrically connected at the output terminal of first operational amplifier and a collector; One first resistance is electrically connected between the negative input end and earth terminal of first operational amplifier; One second operational amplifier comprises a positive input terminal, electrically connects the collector of the first two-carrier junction transistor, a negative input end, and an output terminal; One second resistance is electrically connected between the collector and variable bias source of the first two-carrier junction transistor; One the 3rd resistance is electrically connected between the negative input end and variable bias source of second operational amplifier; One second two-carrier junction transistor comprises an emitter-base bandgap grading, is electrically connected at the negative input end of second operational amplifier; One base stage; Be electrically connected at the output terminal of second operational amplifier, reach a collector, be electrically connected at second end of a corresponding LED serial; And a feedback circuit, be electrically connected between second end and variable bias source of corresponding LED serial, in order to according to the voltage on second end of the LED serial of correspondence, control the voltage swing that the variable bias source is exported.
Description of drawings
Fig. 1 is the synoptic diagram according to the light source driving circuit of first embodiment of the invention.
Fig. 2 is the synoptic diagram of the voltage signal source of first embodiment of the invention.
Fig. 3 is the synoptic diagram of the voltage signal source of second embodiment of the invention.
Fig. 4 is the synoptic diagram according to the light source driver module of first embodiment of the invention.
Fig. 5 is the synoptic diagram according to the light source driving circuit of second embodiment of the invention.
Fig. 6 is the synoptic diagram according to the light source driver module of second embodiment of the invention.
The reference numeral explanation
Amp
1, Amp
2Operational amplifier
I
R1, I
R2, I
X, I
LElectric current
The M light emitting diode matrix
The X LED serial
Q
1, Q
2Transistor
R
1, R
2, R
XResistance
The T cycle
Ta, Tb, Tc ON time
V
CC, V
R2, V
R1, V
Q1, V
Q2, voltage
V
RX、V
1(+)、V
1(-)、V
2(+)、
V
2(-)、V
LED、V
X、V
REF、V
1、
V
2、V
IN
100,500 driving circuits
110 VCCSs
120 voltage signal sources
400,600 driver modules
510 feedback circuits
520 compensating circuits
530 DC-DC converters
540 improve the current source of temperature effect.
Embodiment
In the middle of instructions and follow-up claim, used some vocabulary to censure specific element.Having common knowledge the knowledgeable in the affiliated field should understand, and same element may be called with different nouns by manufacturer.This instructions and follow-up claim are not used as the mode of distinct elements with the difference of title, but the benchmark that is used as distinguishing with the difference of element on function.Be an open term mentioned " comprising " in the middle of instructions and the follow-up claim in the whole text, so should be construed to " comprise but be not limited to ".In addition, " electric connection " speech is to comprise any indirect means that are electrically connected that directly reach at this.Therefore, be electrically connected at one second device, then represent this first device can be directly connected in this second device, or be connected to this second device through other device or the intersegmental ground connection of connection hand if describe one first device in the literary composition.
Please refer to Fig. 1.Fig. 1 is the synoptic diagram according to the light source driving circuit 100 of one first embodiment of light source driving circuit of the present invention.As shown in the figure, driving circuit 100 comprises a VCCS 110 and voltage signal source 120.Voltage signal source 120 is in order to provide a voltage V
INWith control VCCS 110, and produce electric current I
LTo drive the diode tandem X (a plurality of diode series connection) of load.And electric current I
LWith diode tandem X load the size and irrelevant, and only with voltage V
INRelevant.Therefore, the light source driving circuit 100 of the present invention voltage V that just can be produced according to voltage signal source 120
IN, come Control current I
LSize, and then the brightness of control diode tandem X.
Please continue with reference to figure 1.VCCS 110 comprises two operational amplifier A mp
1With Amp
2, two two-carrier junction transistors (Bipolar Junction Transistor, BJT) Q
1With Q
2, three resistance R
1, R
2With R
XOperational amplifier A mp
1Comprise a positive input terminal, be electrically connected at voltage signal source 120, a negative input end, be electrically connected at transistor Q
1Emitter-base bandgap grading, an and output terminal is electrically connected at transistor Q
1Base stage; Resistance R
1One end is electrically connected at transistor Q
1Emitter-base bandgap grading, the other end is electrically connected at an earth terminal; Resistance R
2One end is electrically connected at transistor Q
1Collector, the other end is electrically connected at bias generator V
CCOperational amplifier A mp
2Comprise a positive input terminal, be electrically connected at transistor Q
1Collector, a negative input end, be electrically connected at transistor Q
2Emitter-base bandgap grading, an and output terminal is electrically connected at transistorized base stage; Resistance R
XOne end is electrically connected at transistor Q
2Emitter-base bandgap grading, the other end is electrically connected at bias generator V
CCAnd the collector of transistor Q2 is electrically connected at diode tandem X, in order to electric current I to be provided
LGive diode tandem X.
The operation principles of driving circuit 100 is following: because operational amplifier A mp
1, Amp
2Positive-negative input end be imaginary short, so operational amplifier A mp
1Positive and negative input terminal voltage equate [V
1(+)=V
1(-)], operational amplifier A mp
2Positive and negative input terminal voltage equate [V
2(+)=V
2(-)], operational amplifier A mp again
1Positive input terminal be electrically connected at voltage signal source 120, and the current potential on it is voltage V
INSo resistance R
1Cross-pressure equal voltage V
IN(V
R1=V
IN); Resistance R
XWith R
2Cross-pressure also equate (V
RX=V
R2).In addition because operational amplifier A mp
1, Amp
2Input impedance be regarded as infinity, so operational amplifier A mp
1, Amp
2Input current be regarded as zero.So transistor Q
1Emitter current can be considered the resistance R of flowing through
1Electric current I
R1, know resistance R again
1Cross-pressure V
R1Equal V
IN, so transistor Q
1Emitter current just be V
IN/ R
1And because transistor Q
1Base current very little, therefore suppose transistor Q
1Emitter current equal transistor Q
1Collector current, so the resistance R of flowing through
2Electric current be V
IN/ R
1And because resistance R
2With R
XOne end is electrically connected to bias generator V jointly
CC, the other end then is electrically connected to operational amplifier A mp respectively
2Positive and negative input end [V
2(+)=V
2(-)], so resistance R
2With R
XCross-pressure identical.Effluent through resistance R at last via above-mentioned
XElectric current I
XBe R
2* (V
IN/ R
1)/R
X, set resistance R again
1With R
2Resistance identical, I then
XBe V
IN/ R
XAnd transistor Q
2Emitter current promptly equal electric current I
X(operational amplifier A mp
2Input impedance infinitely great), and transistorized base current is very little, so transistor Q
2Emitter current I
XPromptly equal transistor Q
2Collector current I
L(load current of diode tandem X).Therefore, according to above-mentioned, the load current I of diode tandem X
L=V
IN/ R
XThat is to say that the load current of diode tandem X and the load of itself size are irrelevant, only with input voltage V
INWith resistance R
XRelevant.And work as resistance R
XDuring for definite value, load current I
LSize only with input voltage V
INRelevant, control is convenient.Therefore, according to driving circuit 100 of the present invention, voltage V capable of using
IN, come Control current I
LSize, and then the brightness of control diode tandem X.
Please refer to Fig. 2.Fig. 2 is the voltage V of the voltage signal source 120 of first embodiment of the invention
INSynoptic diagram.As shown in the figure, contained voltage V on the voltage signal source 120
IN, can be one and can adjust responsibility (its cycle is T for Pulse Width Modulation, voltage signal PWM), and voltage is V when conducting than the pulse-length modulation of (dutyratio)
X, voltage is zero when closing.The time of its conducting can be Ta, Tb or Tc, and end sees that the user designs, and when desiring to make the brightness of diode tandem X high more, then can heighten (like Ta) to the time of conducting; Otherwise,, then can turn down (like Tc) to the time of conducting when desiring to make the brightness of diode tandem X low more.As long as the cycle T of voltage signal is lower than 1/16 second, human eye does not see that just LED serial X has the situation of flicker.So just can effectively control the brightness of diode tandem X.
Please refer to Fig. 3.Fig. 3 is the voltage V of the voltage signal source 120 of second embodiment of the invention
INSynoptic diagram.As shown in the figure, contained voltage V on the voltage signal source 120
IN, also can directly adjust its size, control the brightness of diode tandem X.When desiring to make the brightness of diode tandem X high more, then can be with voltage V
INHeighten; Otherwise, when desiring to make the brightness of diode tandem X low more, then can be with voltage V
INTurn down.So just can effectively control the brightness of diode tandem X.
In addition, the voltage V of voltage signal source 120
INThe mode that also can combine Fig. 2 and Fig. 3, meaning promptly in Fig. 2, except that the adjustment responsibility than, also adjustable-voltage V
XSize (in order to fine setting), can effectively control the brightness of diode tandem equally.
Please refer to Fig. 4.Fig. 4 is the synoptic diagram according to the light source driver module 400 of first embodiment of the invention.As shown in the figure, driver module 400 comprises a voltage signal source 120 and a plurality of VCCSs 110, in order to drive diode array M (comprising a plurality of diode tandems).Voltage signal source 120 is electrically connected at the operational amplifier A mp of each VCCS 110
1Positive input terminal (said) and the transistor Q of each VCCS 110 as Fig. 1
2Collector be electrically connected at corresponding diode tandem X (said) as Fig. 1.Voltage signal source 120 is in order to output voltage V
INTo control the electric current that each VCCS 110 is exported, thus, each VCCS 110 all can be mutually the same, and make whole diode array M can have equal brightness, can not produce the problem of brightness disproportionation.
Please refer to Fig. 5.Fig. 5 is the synoptic diagram according to the light source driving circuit 500 of second embodiment of the invention.As shown in the figure, driving circuit 500 has comprised the current source 540 that a voltage signal source 120 and improves temperature effect.The current source 540 that improves temperature effect comprises a VCCS 110, a feedback circuit 510, a compensating circuit 520 and DC-DC converter (DC/DC converter) 530.Voltage signal source 120 is said with operation principles such as Fig. 1 of VCCS 110, repeats no more at this.Fig. 5 is compared to Fig. 1 different portions: Fig. 5 has increased feedback circuit 510, compensating circuit 520 and DC-DC converter 530 newly.In Fig. 1, bias generator V
CCBe fixing, and in Fig. 5, bias generator V
CCSize, the voltage V that will be exported by DC-DC converter 530
2Determine.The driving circuit of Fig. 5 so purpose of design is: when luminous diode temperature rises, its forward voltage will descend, that is to say, as shown in the figure, voltage V
LEDWill descend, and can know V by Fig. 1
CC=V
IN+ V
Q2+ V
LED, working as voltage V
LEDDuring decline, unnecessary cross-pressure will drop on transistor Q
2Upward cause V
Q2Increase.Thus, transistor Q
2The power that consumes increases, and produces more thermal energy, so transistor Q
2Temperature just can raise, and then the temperature that influences light emitting diode raises again, and the forward voltage of light emitting diode and then descend once again.So the round-robin effect will cause the temperature of light emitting diode to continue to rise.Therefore, just be designed to can be with bias generator V for driving circuit 500
CCAdjust, as voltage V
LEDDuring decline, driving circuit 500 is simultaneously with bias generator V
CCThe voltage of decline same degree, electric crystal Q thus
2On cross-pressure will can not increase, can not improve temperature yet.So just, can effectively improve the temperature effect of light emitting diode.
Please continue with reference to figure 5.Feedback circuit 510 can be an error amplifier, comprises two input ends and an output terminal.One input end of error amplifier is electrically connected at an end of diode tandem in order to receive voltage V
LED, another input end is in order to receive a reference voltage level V
REF, its output terminal can directly be received the control end of DC-DC converter 530 in order to control output voltage V
2Size (so in present embodiment, error amplifier is electrically connected at DC-DC converter 530 via a compensating circuit 520).As voltage V
LEDBe higher than reference voltage level V
REFThe time, error amplifier just transmits one first predetermined value to DC-DC converter 530, so that output voltage V
2Rise; Otherwise, as voltage V
LEDBe lower than reference voltage level V
REFThe time, error amplifier just transmits one second predetermined value to DC-DC converter 530, so that output voltage V
2Descend.And compensating circuit 520 is to meet 530 scopes that can receive of DC-DC converter in order to adjust this first predetermined value and this second predetermined value.
DC-DC converter 530 can be a switch type DC-DC converter (switchingregulator), in order to receive a direct current voltage V
1, change its voltage swing, and export a voltage V
2And voltage V
2Size, be that the conducting responsibility ratio according to DC-DC converter 530 switches decides, when the responsibility of conducting when high more, voltage V
2Just high more; Otherwise, when the responsibility of conducting when low more, voltage V
2Just low more.That is to say that first predetermined value that error amplifier transmitted and second predetermined value can be controlled the conducting responsibility ratio of DC-DC converter 530 switches, adjust voltage V with this
2Size (bias voltage V just
CCSize).
Please refer to Fig. 6.Fig. 6 is the synoptic diagram according to the light source driver module 600 of second embodiment of the invention.As shown in the figure, driver module 600 comprises a voltage signal source 120 and a plurality of current sources 540 that improve temperature effect, in order to drive diode array M (comprising a plurality of diode tandems).Voltage signal source 120 is electrically connected at the operational amplifier A mp of each current source 540
1The collector of transistor Q2 of positive input terminal (said) and each current source 540 as Fig. 1 be electrically connected at corresponding diode tandem X (said) as Fig. 1.Voltage signal source 120 is in order to output voltage V
INTo control the electric current that each current source 540 is exported, thus, each current source 540 all can be mutually the same, and make whole diode array M can have equal brightness, can not produce the problem of brightness disproportionation, also can solve the problem that temperature rises simultaneously.
To sum up state, light source driving circuit provided by the present invention and driver module except can effectively improving the uneven problem of control led lighting, and rise and the effect that causes forward bias voltage drop to descend for diode temperature, also can effectively improve.
The above is merely preferred embodiment of the present invention, and all equalizations of doing according to claim of the present invention change and modify, and all should belong to covering scope of the present invention.
Claims (26)
1. light source driving circuit, this light source driving circuit is used to drive a LED serial, and first end of this LED serial is electrically connected at an earth terminal, and this light source driving circuit comprises:
Voltage signal source;
Voltage-controlled current source comprises:
First operational amplifier comprises:
Positive input terminal is electrically connected at this voltage signal source;
Negative input end; And
Output terminal;
The first two-carrier junction transistor comprises:
Emitter-base bandgap grading is electrically connected at the negative input end of this first operational amplifier;
Base stage is electrically connected at the output terminal of this first operational amplifier; And
Collector;
First resistance is electrically connected between the negative input end and this earth terminal of this first operational amplifier;
Second operational amplifier comprises:
Positive input terminal electrically connects the collector of this first two-carrier junction transistor;
Negative input end; And
Output terminal;
Second resistance is electrically connected between the collector and a bias generator of this first two-carrier junction transistor;
The 3rd resistance is electrically connected between the negative input end and this bias generator of this second operational amplifier; And
The second two-carrier junction transistor comprises:
Emitter-base bandgap grading is electrically connected at the negative input end of this second operational amplifier;
Base stage is electrically connected at the output terminal of this second operational amplifier; And
Collector is electrically connected at second end of this LED serial.
2. light source driving circuit as claimed in claim 1, wherein, this first and second resistance has similar resistance.
3. light source driving circuit as claimed in claim 1, wherein, this LED serial comprises the light emitting diode of a plurality of series connection.
4. light source driving circuit as claimed in claim 1, wherein, this voltage signal source is the voltage signal source of a pulse-length modulation or the voltage signal source of adjustable-voltage size.
5. light source driver module, this light source driver module is used to drive a light emitting diode matrix, and this light emitting diode matrix comprises K LED serial; Wherein, K is a positive integer, and first end of each LED serial is electrically connected at an earth terminal, and this light source driver module comprises:
Voltage signal source;
K voltage-controlled current source, each voltage-controlled current source comprises:
First operational amplifier comprises:
Positive input terminal is electrically connected at this voltage signal source;
Negative input end; And
Output terminal;
The first two-carrier junction transistor comprises:
Emitter-base bandgap grading is electrically connected at the negative input end of this first operational amplifier;
Base stage is electrically connected at the output terminal of this first operational amplifier; And
Collector;
First resistance is electrically connected between the negative input end and this earth terminal of this first operational amplifier;
Second operational amplifier comprises:
Positive input terminal electrically connects the collector of this first two-carrier junction transistor;
Negative input end; And
Output terminal;
Second resistance is electrically connected between the collector and a bias generator of this first two-carrier junction transistor;
The 3rd resistance is electrically connected between the negative input end and this bias generator of this second operational amplifier; And
The second two-carrier junction transistor comprises:
Emitter-base bandgap grading is electrically connected at the negative input end of this second operational amplifier;
Base stage is electrically connected at the output terminal of this second operational amplifier; And
Collector is electrically connected at second end of a corresponding LED serial.
6. light source driver module as claimed in claim 5, wherein, this first and second resistance has similar resistance.
7. light source driver module as claimed in claim 5, wherein, each LED serial comprises the light emitting diode of a plurality of series connection.
8. light source driver module as claimed in claim 5, wherein, this voltage signal source is the voltage signal source of a pulse-length modulation or the voltage signal source of adjustable-voltage size.
9. light source driving circuit, this light source driving circuit is used to drive a LED serial, and first end of this LED serial is electrically connected at an earth terminal, and this driving circuit comprises:
Voltage signal source;
Current source comprises:
The variable bias source;
Voltage-controlled current source comprises:
First operational amplifier comprises:
Positive input terminal is electrically connected at this voltage signal source;
Negative input end; And
Output terminal;
The first two-carrier junction transistor comprises:
Emitter-base bandgap grading is electrically connected at the negative input end of this first operational amplifier;
Base stage is electrically connected at the output terminal of this first operational amplifier; And
Collector;
First resistance is electrically connected between the negative input end and this earth terminal of this first operational amplifier;
Second operational amplifier comprises:
Positive input terminal electrically connects the collector of this first two-carrier junction transistor;
Negative input end; And
Output terminal;
Second resistance is electrically connected between the collector and this variable bias source of this first two-carrier junction transistor;
The 3rd resistance is electrically connected between the negative input end and this variable bias source of this second operational amplifier;
The second two-carrier junction transistor comprises:
Emitter-base bandgap grading is electrically connected at the negative input end of this second operational amplifier;
Base stage is electrically connected at the output terminal of this second operational amplifier; And
Collector is electrically connected at second end of this LED serial; And
Feedback circuit is electrically connected between second end and this variable bias source of this LED serial, in order to according to the voltage on second end of this LED serial, controls the voltage swing that this variable bias source is exported.
10. light source driving circuit as claimed in claim 9, wherein, when the voltage on second end of this LED serial reduced, this feedback circuit downgraded the voltage that this variable bias source is exported.
11. light source driving circuit as claimed in claim 10, wherein, this variable bias source is a DC-DC converter, is one second voltage with this first voltage transitions also in order to receive one first voltage, and the size of this second voltage is controlled by this feedback circuit.
12. light source driving circuit as claimed in claim 11, wherein, this DC-DC converter is a switch type DC-DC converter.
13. light source driving circuit as claimed in claim 9, wherein, this feedback circuit comprises an error operational amplifier, and this error operational amplifier comprises:
First input end is electrically connected at second end of this LED serial;
Second input end is in order to receive a reference voltage level; And
Output terminal is electrically connected at this variable bias source, in order to according to the voltage level of this first input end of this error operational amplifier and the voltage level of this second input end, exports the voltage level of one first predetermined value or the voltage level of one second predetermined value.
14. light source driving circuit as claimed in claim 13; Also comprise a compensating circuit; Be electrically connected between this error operational amplifier and this variable bias source, in order to the voltage level of the voltage level of adjusting this first predetermined value or this second predetermined value to suitable size to meet this receptible scope in variable bias source.
15. light source driving circuit as claimed in claim 9, wherein, this first and second resistance has similar resistance.
16. light source driving circuit as claimed in claim 9, wherein, this LED serial comprises the light emitting diode of a plurality of series connection.
17. light source driving circuit as claimed in claim 9, wherein, this voltage signal source is the voltage signal source of a pulse-length modulation or the voltage signal source of adjustable-voltage size.
18. a light source driver module, this light source driver module is used to drive a light emitting diode matrix, and this light emitting diode matrix comprises K LED serial; Wherein, K is a positive integer, and first end of each LED serial is electrically connected at an earth terminal, and this driver module comprises:
Voltage signal source;
K current source, each current source comprises:
The variable bias source;
One VCCS comprises:
First operational amplifier comprises:
Positive input terminal is electrically connected at this voltage signal source;
Negative input end; And
Output terminal;
The first two-carrier junction transistor comprises:
Emitter-base bandgap grading is electrically connected at the negative input end of this first operational amplifier;
Base stage is electrically connected at the output terminal of this first operational amplifier; And
Collector;
First resistance is electrically connected between the negative input end and this earth terminal of this first operational amplifier;
Second operational amplifier comprises:
Positive input terminal electrically connects the collector of this first two-carrier junction transistor;
Negative input end; And
Output terminal;
Second resistance is electrically connected between the collector and this variable bias source of this first two-carrier junction transistor;
The 3rd resistance is electrically connected between the negative input end and this variable bias source of this second operational amplifier;
The second two-carrier junction transistor comprises:
Emitter-base bandgap grading is electrically connected at the negative input end of this second operational amplifier;
Base stage is electrically connected at the output terminal of this second operational amplifier; And
Collector is electrically connected at second end of a corresponding LED serial; And
Feedback circuit is electrically connected between second end and this variable bias source of this corresponding LED serial, in order to according to the voltage on second end of this LED serial of correspondence, controls the voltage swing that this variable bias source is exported.
19. light source driver module as claimed in claim 18, wherein, when the voltage on second end of this LED serial of correspondence reduced, this feedback circuit downgraded the voltage that this variable bias source is exported.
20. light source driver module as claimed in claim 18, wherein, this variable bias source is a DC-DC converter, is one second voltage with this first voltage transitions also in order to receive one first voltage, and the size of this second voltage is controlled by this feedback circuit.
21. light source driver module as claimed in claim 20, wherein, this DC-DC converter is a switch type DC-DC converter.
22. light source driver module as claimed in claim 21, wherein, this feedback circuit comprises an error operational amplifier, and this error operational amplifier comprises:
First input end is electrically connected at second end of this corresponding LED serial;
Second input end is in order to receive a reference voltage level; And
Output terminal is electrically connected at this variable bias source, in order to according to the voltage level of this first input end of this error operational amplifier and the voltage level of this second input end, exports the voltage level of one first predetermined value or the voltage level of one second predetermined value.
23. light source driver module as claimed in claim 22; Also comprise a compensating circuit; Be electrically connected between this error operational amplifier and this variable bias source, in order to the voltage level of the voltage level of adjusting this first predetermined value or this second predetermined value to suitable size to meet the receptible scope of this switch type DC-DC converter.
24. light source driver module as claimed in claim 18, wherein, this first and second resistance has similar resistance.
25. light source driver module as claimed in claim 18, wherein, each LED serial comprises the light emitting diode of a plurality of series connection.
26. light source driver module as claimed in claim 18, wherein, this voltage signal source is the voltage signal source of a pulse-length modulation or the voltage signal source of adjustable-voltage size.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200810082121XA CN101527988B (en) | 2008-03-03 | 2008-03-03 | Light source driver module and circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200810082121XA CN101527988B (en) | 2008-03-03 | 2008-03-03 | Light source driver module and circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101527988A CN101527988A (en) | 2009-09-09 |
| CN101527988B true CN101527988B (en) | 2012-08-08 |
Family
ID=41095620
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN200810082121XA Expired - Fee Related CN101527988B (en) | 2008-03-03 | 2008-03-03 | Light source driver module and circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101527988B (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102102828B (en) * | 2009-12-18 | 2014-02-05 | 华映视讯（吴江）有限公司 | LED (Light-Emitting Diode) module |
| CN102956202A (en) * | 2011-08-29 | 2013-03-06 | 通嘉科技股份有限公司 | Current control level, constant-current control system, and current control method |
| CN110189709B (en) | 2018-02-23 | 2020-12-29 | 京东方科技集团股份有限公司 | Control circuit, backlight driving device and display device |
| TWI692273B (en) * | 2019-06-05 | 2020-04-21 | 茂達電子股份有限公司 | System and method of driving led string |
| CN113282130A (en) * | 2021-06-08 | 2021-08-20 | 西安中颖电子有限公司 | High-precision LED constant current driving circuit |
| CN113484367A (en) * | 2021-07-07 | 2021-10-08 | 上海电气数智生态科技有限公司 | Circuit and method for improving measurement precision of multi-channel water quality sensor |
| CN115294928B (en) * | 2022-10-08 | 2022-12-27 | 成都利普芯微电子有限公司 | Shadow elimination circuit, line driving circuit and display screen |
-
2008
- 2008-03-03 CN CN200810082121XA patent/CN101527988B/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN101527988A (en) | 2009-09-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101527988B (en) | Light source driver module and circuit | |
| KR100771780B1 (en) | Led driving apparatus having fuction of over-voltage protection and duty control | |
| US7777704B2 (en) | System and method for controlling a multi-string light emitting diode backlighting system for an electronic display | |
| US8253342B2 (en) | Light emitting diode illumination system | |
| TWI383709B (en) | Light source driving module and circuit | |
| TWI400986B (en) | Light emitting diode driving circuit | |
| US7999486B2 (en) | Driving circuit and method for light emitting diode | |
| US9185763B2 (en) | Light emitting diode string driving method | |
| TW200915911A (en) | Driver device for LEDs | |
| CN101836505A (en) | LED dimming apparatus | |
| US10397997B2 (en) | Dimming controllers and dimming methods capable of receiving PWM dimming signal and DC dimming signal | |
| CN102256418B (en) | PWM (pulse width modulation) dimming circuit | |
| CN111048045B (en) | Light emitting diode driving device and light emitting diode backlight module | |
| CN106507560A (en) | light-emitting diode backlight module and driving device thereof | |
| US8598803B2 (en) | LED driver having a pre-chargeable feedback for maintaining current and the method using the same | |
| KR101243144B1 (en) | driving circuit of LED driver for LCD panel | |
| CN101206836B (en) | Drive circuit for backlight module group | |
| CN101998725A (en) | Drive circuit of light-emitting diode | |
| TWI467548B (en) | Backlight module and driving method thereof | |
| CN102056367B (en) | Light-emitting diode driving circuit with wide operating voltage range | |
| CN106572562B (en) | A kind of method of the multiple LED pixel points of single channel constant current drive control | |
| CN104640259B (en) | The drive circuit and driving method of light emitting diode | |
| CN213462406U (en) | Analog dimming circuit for LED driving chip | |
| CN201821557U (en) | LED lamp controlled through multi-channel constant voltage and constant current | |
| CN114554650B (en) | LED drive circuit, bias voltage generator thereof and LED lighting device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20120808 Termination date: 20200303 |