CN101009958A - LED driving circuit with the temperature compensation - Google Patents
LED driving circuit with the temperature compensation Download PDFInfo
- Publication number
- CN101009958A CN101009958A CN200610006962.3A CN200610006962A CN101009958A CN 101009958 A CN101009958 A CN 101009958A CN 200610006962 A CN200610006962 A CN 200610006962A CN 101009958 A CN101009958 A CN 101009958A
- Authority
- CN
- China
- Prior art keywords
- signal
- circuit
- control
- current
- led
- 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.)
- Granted
Links
Images
Abstract
The provided drive circuit for controlling LED luminance comprises a control circuit to generate current and detect LED voltage for adjusting its current, wherein the LED current is relative with LED temperature.
Description
Technical field
The present invention relates to a kind of LED (light-emitting diode) driver, more particularly, the present invention relates to a kind of control circuit that is used to control this LED drive.
Background technology
LED drive can be controlled its brightness according to the temperature profile of this light-emitting diode.This LED drive is used for the current value of control flows through light-emitting diode.Though higher electric current can strengthen the brightness of light-emitting diode, can reduce the useful life of light-emitting diode.Fig. 1 shows an existing led driver circuit.Can adjust voltage source 10 and provide electric current I by a resistor 15
LEDGive a plurality of light-emitting diodes 20～25.Electric current I
LEDAs follows:
V wherein
F20～V
F25It is respectively the forward voltage of a plurality of light-emitting diodes 20～25.
The shortcoming of the existing LED drive shown in Fig. 1 is an electric current I
LEDMutability.Forward voltage V
F20～V
F25During variation, electric current I
LEDChange thereupon.Go up the variation that reaches working temperature, forward voltage V owing to produce
F20～V
F25Be not invariable.
Fig. 2 shows the other method of existing LED drive.One current source 35 is connected with light-emitting diode 20～25, in order to provide a constant current to light-emitting diode 20～25.Yet the shortcoming of foregoing circuit is that the colourity of this light-emitting diode and brightness change along with the variation of luminous diode temperature.For the colourity and/or the brightness constancy of maintenance light-emitting diode are constant, must adjust the electric current of light-emitting diode with variation of temperature.
Summary of the invention
The object of the present invention is to provide a kind of LED drive with temperature-compensating.
For achieving the above object, LED driving circuit provided by the invention, it comprises:
One control circuit, it is used to produce a led current of control one light-emitting diode;
One first resistor is connected to this control circuit, is used to determine the current value of this led current;
One control end of this control circuit is used to receive a control signal, to determine the work period of this led current;
One test side of this control circuit is coupled to this light-emitting diode, is used to detect a light-emitting diodes tube voltage, and wherein this light-emitting diodes tube voltage can be used to adjust this led current; And
One second resistor is connected to this control circuit, is used to determine one to adjust slope, and wherein this adjustment slope is represented the variation of the variation of this led current corresponding to this light-emitting diodes tube voltage.
Described LED driving circuit, wherein this led current comprises one first led current and one second led current; This second led current is relevant with this first led current; This light-emitting diodes tube voltage comprises one first forward voltage and one second forward voltage, wherein according to this first led current and this second led current and produce this first forward voltage and this second forward voltage respectively.
Described LED driving circuit, this control circuit comprises:
One pulse-width modulation circuit is coupled to this control end, is used to produce one first control signal to control the work period of this led current;
One sample circuit is coupled to this test side and this second resistor, is used for adjusting signal according to the resistance value of this light-emitting diodes tube voltage and this second resistor to produce one;
One modulation circuit is coupled to this first resistor, this pulse-width modulation circuit and this sample circuit, is used for according to the resistance value of this first resistor and this adjustment signal to produce a modulation signal; And
One first current mirroring circuit is coupled to this pulse-width modulation circuit and this modulation circuit, is used for producing this led current according to this first control signal and this modulation signal.
Described LED driving circuit, this pulse-width modulation circuit comprises:
One oscillator, it is used to produce a ramp signal, one second control signal, one first pulse signal and one second pulse signal;
One first comparator is in case it is used for producing when this control signal is lower than this ramp signal one first reset signal;
One second comparator is in case it is used for producing when this control signal is lower than a threshold signal one second reset signal; And
One latch cicuit is coupled to this second control signal, is used for producing this first control signal according to this second control signal,
Wherein according to this second control signal to enable this first control signal, according to this first reset signal and this second reset signal, so that this first control signal is invalid, and, produce this first pulse signal and this second pulse signal respectively according to the trailing edge and the rising edge of this second control signal.
Described LED driving circuit is wherein according to this first reset signal or this second reset signal, so that this first control signal is invalid.
Described LED driving circuit, this sample circuit comprises:
One first differential circuit is coupled to this test side, is used to detect this light-emitting diodes tube voltage;
One first sample circuit is used for according to this first pulse signal this first forward voltage of this light-emitting diodes tube voltage being taken a sample;
One second sample circuit is used for according to this second pulse signal this second forward voltage of this light-emitting diodes tube voltage being taken a sample;
One second differential circuit is used for producing a differential wave according to the difference of this first forward voltage and this second forward voltage; And
One voltage is coupled to this second resistor to current converter, is used for producing this adjustment signal according to the resistance value of this differential wave and this second resistor.
Described LED driving circuit, this modulation circuit comprises:
One current feedback circuit is used for producing a reference current according to the resistance value of a reference voltage and this first resistor; And
One second current mirroring circuit is used for producing this modulation signal according to this reference current and this adjustment signal;
Wherein according to this modulation signal that enables of this first control signal, being used to produce this first led current, and control this modulation signal, to be used to produce this second led current according to this second control signal.
A kind of LED controller provided by the invention, it comprises:
One control circuit, it is used to produce a led current of control one light-emitting diode;
One control end of this control circuit is used to receive a control signal that determines this led current; And
One test side of this control circuit is coupled to this light-emitting diode, is used to detect a light-emitting diodes tube voltage, and wherein this light-emitting diodes tube voltage is used to adjust this led current.
Described LED controller further comprises:
One first resistor is coupled to this control circuit, is used to determine the current value of this led current; And
One second resistor is coupled to this control circuit, is used to determine one to adjust slope, and wherein this adjustment slope is represented the variation of the variation of this led current corresponding to this light-emitting diodes tube voltage.
Described LED controller, wherein this led current comprises one first led current and one second led current, this second led current is relevant with this first led current, and this light-emitting diodes tube voltage comprises one first forward voltage and one second forward voltage, wherein produces this first forward voltage and this second forward voltage according to this first led current respectively with this second led current.
Described LED controller, this control circuit comprises:
One pulse-width modulation circuit is coupled to this control end, is used to produce one first control signal to control the work period of this led current;
One sample circuit is coupled to this test side, is used for adjusting signal according to this light-emitting diodes tube voltage to produce one;
One modulation circuit is coupled to this pulse-width modulation circuit and this sample circuit, is used for according to this adjustment signal to produce a modulation signal; And
One first current mirroring circuit is coupled to this pulse-width modulation circuit and this modulation circuit, is used for producing this led current according to this first control signal and this modulation signal.
Described LED controller, this pulse-width modulation circuit comprises:
One oscillator, it is used to produce a ramp signal, one second control signal, one first pulse signal and one second pulse signal;
One first comparator is in case it is used for producing when this control signal is lower than this ramp signal one first reset signal;
One second comparator is in case it is used for producing when this control signal is lower than a threshold signal one second reset signal; And
One latch cicuit is coupled to this second control signal, is used for producing this first control signal according to this second control signal;
Wherein according to this second control signal to enable this first control signal, so that this first control signal is invalid, and produce this first pulse signal and this second pulse signal respectively according to this first reset signal and this second reset signal according to the trailing edge and the rising edge of this second control signal.
Described LED controller, wherein according to this first reset signal or this second reset signal so that this first control signal is invalid.
Described LED controller, this sample circuit comprises:
One first differential circuit is coupled to this test side, is used to detect this light-emitting diodes tube voltage;
One first sample circuit is used for according to this first pulse signal this first forward voltage of this light-emitting diodes tube voltage being taken a sample;
One second sample circuit is used for according to this second pulse signal this second forward voltage of this light-emitting diodes tube voltage being taken a sample;
One second differential circuit is used for producing a differential wave according to the difference of this first forward voltage and this second forward voltage; And
One voltage is used for producing this adjustment signal according to this differential wave to current converter.
Described LED controller, this modulation circuit comprises:
One current feedback circuit is used for producing a reference current according to a reference voltage; And
One second current mirroring circuit is used for producing this modulation signal according to this reference current and this adjustment signal;
Wherein according to this modulation signal that enables of this first control signal, being used to produce this first led current, and control this modulation signal, to be used to produce this second led current according to this second control signal.
Therefore,, can adjust this led current, with the colourity that compensates this light-emitting diodes and the change of brightness according to this luminous diode temperature by enforcement of the present invention.
Description of drawings
Appended graphic providing to further understanding of the present invention, and be merged in this specification, constitute the part of this specification.These annexed drawings set forth embodiments of the invention, and can with the given description principle of the present invention of coming together to explain; Wherein:
Fig. 1 has provided a traditional LED drive.
Fig. 2 has provided another traditional LED drive.
Fig. 3 has provided the embodiment according to this LED driving circuit of the present invention.
Fig. 4 has provided another embodiment according to this LED driving circuit of the present invention.
Fig. 5 has provided the control circuit according to this LED driving circuit of the present invention.
Fig. 6 has provided the pulse-width modulation circuit according to this control circuit of the present invention, and wherein this pulse-width modulation circuit is used to control the work period and the brightness of this light-emitting diode.
Fig. 7 has provided the oscillator according to this pulse-width modulation circuit of the present invention.
Fig. 8 has provided the sample circuit according to this control circuit of the present invention.
Fig. 9 has provided the modulation circuit according to this control circuit of the present invention.
Figure 10 has provided a plurality of waveforms according to this control circuit of the present invention.
Embodiment
Fig. 3 and Fig. 4 are a plurality of embodiment according to a LED driving circuit of the present invention, and wherein light-emitting diode 20～25th, series connection.One voltage source V
INBe to supply with light-emitting diode 20～25.One control circuit 100 couples mutually with light-emitting diode 20～25.The power supply that Fig. 3 shows this control circuit 100 is provided by a voltage source V CC.The power supply that Fig. 4 shows control circuit 100 is directly provided by voltage source V IN.One output OUT of control circuit 100 produces a led current, to be used to control light-emitting diode 20～25.One first resistor 57 is connected to control circuit 100, is used to determine the current value of led current.One control end IN of control circuit 100 is used to receive a control signal V
CNT, with unlatching/cut-out led current, and the work period of decision led current.One test side VS of control circuit 100 links to each other with light-emitting diode 20～25, is used to detect a light-emitting diodes tube voltage.The light-emitting diodes tube voltage is by further in order to adjust led current.One second resistor 59 is coupled to control circuit 100, is used to determine one to adjust slope.This adjustment slope is represented the variation of the variation of led current corresponding to the light-emitting diodes tube voltage.The temperature correlation of light-emitting diode magnitude of voltage and light-emitting diode.Therefore, can adjust led current, with the variation of compensation colourity and brightness according to the variation of luminous diode temperature.
In order to detect the temperature of light-emitting diode, led current comprises one first led current I
1And one second led current I
2The second led current I
2With the first led current I
1Relevant.The light-emitting diodes tube voltage comprises one first light-emitting diode forward voltage V
1And one second light-emitting diode forward voltage V
2According to the first led current I
1And the second led current I
2And produce the first light-emitting diode forward voltage V respectively
1And the second light-emitting diode forward voltage V
2
Fig. 5 is the circuit diagram of control circuit 100 of the present invention.One pulse-width modulation circuit 200 is coupled to the control end IN of control circuit 100, to produce one first control signal S
1, this first control signal S
1Be used to control the work period of led current.One sample circuit 300 is coupled to test side VS and the input RT by control circuit 100 couples second resistor 59, and produces one according to the resistance value of the light-emitting diodes tube voltage and second resistor 59 and adjust signal I
AOne modulation circuit 400 is coupled to pulse-width modulation circuit 200, sample circuit 300 and the RI end by control circuit 100 is coupled to first resistor 57, and according to the resistance value of first resistor 57 and adjust signal I
A, be used to produce a modulation signal I
MA plurality of transistors 71,72,74,75 and 80 form one first current mirroring circuit 500, according to the first control signal S1 and modulation signal IM, produce led current at the output OUT of control circuit 100.According to the first control signal S
1Stop using, thereby cut off led current.
Fig. 6 is the circuit diagram of pulse-width modulation circuit 200.Pulse-width modulation circuit comprises an oscillator 250, is used to produce a ramp signal RAMP, one second control signal S
2, one first pulse signal SMP1 and one second pulse signal SMP2.In case control signal V
CNTBe lower than ramp signal RAMP, one first comparator 210 will produce one first (reset) signal RST1 that resets.In case control signal V
CNTBe lower than a threshold signal (threshold signal) V
TH, one second comparator 215 will produce one second reset signal RST2.One flip-flop (flip-flop) 235, a NOR gate 236, an inverter 230 and a plurality of and door 231,232 formation one latch cicuits (latch circuit), latch cicuit is coupled to the second control signal S
2, the first reset signal RST1 and the second reset signal RST2.The second control signal S
2Provide the clock pulse of enabling (clock) by inverter 230 for flip-flop 235.The second control signal S
2Further be connected to input with door 231.Be connected to the output of second comparator 215 with another input of door 231.With the output of door 231 be connected to NOR gate 236 input and with the input of door 232.Be connected to the output of first comparator 210 with another input of door 232.Be applied in the signal of the output of door 232 output and be used to reset flip-flop 235.The output of flip-flop 235 is connected to another input of NOR gate 236, is used for producing the first control signal S at the output of NOR gate 236
1According to the second control signal S
2, therefore latch cicuit produces the first control signal S
1According to the second control signal S
2To enable the first control signal S
1, and according to the first reset signal RST1 and/or the second reset signal RST2 so that the first control signal S
1According to the second control signal S
2Trailing edge (falling edge) and rising edge (rising edge) produce the first pulse signal SMP1 and the second pulse signal SMP2 respectively.
Fig. 7 is the circuit diagram according to the oscillator 250 of pulse-width modulation circuit 200 of the present invention.One current source 251 links to each other with a capacitor 255 by a switch 253, to be used for capacitor 255 chargings.One current source 252 links to each other with capacitor 255 by a switch 254, to be used for capacitor 255 discharges.One has one first trigger point (trip-point) voltage V
1Comparator 261 be connected to capacitor 255, be lower than the first trigger point voltage V in case be used for the voltage of capacitor 255
1The time produce a charging signals.One has one second trigger point voltage V
2Comparator 260 be connected to capacitor 255, be higher than the second trigger point voltage V in case be used for the voltage of capacitor 255
2The time produce a discharge signal.A plurality of NAND gate 262 and 263 form a RS latch cicuit (RS-latch), link to each other with charging signals and discharge signal respectively.Thereby the output of NAND gate 262 produces the second control signal S
2By inverter 264, the second control signal S
2Be connected to a pulse generator 270, be used to produce the first pulse signal SMP1.The second control signal S2 is connected to a pulse generator 280, to be used to produce the second pulse signal SMP2.The second control signal S
2Be connected with the output of inverter 264, to be used for control switch 254 and 253 respectively.Produce ramp signal RAMP at capacitor 255.
Fig. 8 is the circuit diagram of sample circuit 300, and wherein a plurality of operational amplifiers 310,320 and a plurality of resistor 305,306,307,308,311,312 form one first differential circuit (differentialcircuit) 301.Resistor 305 and 306 forms a voltage divider, is connected to the input of operational amplifier 310 from the test side VS of control circuit 100, to be used to detect the light-emitting diodes tube voltage.Resistor 307 and 308 forms another voltage divider, is connected to the input of operational amplifier 320 from the output OUT of control circuit 100.Operational amplifier 320 is used for operating as a buffer.Operational amplifier 310 links to each other with 312 with resistor 311, is used for operating as a differential amplifier.Therefore, the signal difference of operational amplifier 310 output test side VS and output OUT.Above-mentioned difference is represented light-emitting diode voltage.One switch 325 and a capacitor 326 form one first sample circuit.One switch 327 and a capacitor 328 form one second sample circuit.Switch 325 and 327 is respectively by the first pulse signal SMP1 and second pulse signal SMP2 control.The output of operational amplifier 310 is connected to first sample circuit and second sample circuit.Therefore, according to the first pulse signal SMP1, first sample circuit is to the first light-emitting diode forward voltage V of light-emitting diodes tube voltage
1Take a sample.According to the second pulse signal SMP2, second sample circuit is to the second light-emitting diode forward voltage V of light-emitting diodes tube voltage
2Take a sample.A plurality of operational amplifiers 330,340, transistor 341,342,343 and resistor 335,345 form one second differential circuit 302, are connected to first sample circuit and second sample circuit, are used for according to the first light-emitting diode forward voltage V
1With the second light-emitting diode forward voltage V
2Difference produce a differential wave.Capacitor 328 and switch 327 are connected to the input of operational amplifier 340.Operational amplifier 340 is as a buffer.Capacitor 326 and switch 325 are connected to the input of operational amplifier 330.Operational amplifier 330,340, resistor 335 and transistor 341 produce an electric current I 341.Transistor 342 and 343 forms one first current mirror, is connected to electric current I 341, is used to produce an electric current I 343.Electric current I 343 and resistor 345 produce differential wave.One operational amplifier 350 and a plurality of transistor 351,352,353,354,367,368 form a voltage to current converter.The input of operational amplifier 350 receives this differential wave.Another input of operational amplifier 350, the RI end by control circuit 100 is connected to second resistor 59.Therefore, voltage produces according to the resistance value of the differential wave and second resistor 59 current converter and adjusts signal I
AOne resistor 370 is connected to second resistor 59 from transistor 351 by the RI end, is used to protect voltage to current converter, not with second resistor, 59 short circuits of holding by RI.
Fig. 9 is the modulation circuit 400 according to control circuit 100 of the present invention.One operational amplifier 410 and a transistor 411 have formed a current feedback circuit.One reference voltage V
RBe connected to the input of operational amplifier 410.Another input of operational amplifier 410 is connected to first resistor 57 by the input RI of control circuit 100, to be used for according to reference voltage V
RProduce a reference current I411 with the resistance value of first resistor 57.One resistor 470 is connected to first resistor 57 from transistor 411, be used for the protective current generator not with 57 short circuits of first resistor.A plurality of transistors 412～418 form one second current mirroring circuit 480, to be used for according to reference current I411 and to adjust signal I
AProduce modulation signal I
MTransistor 412,413 and 414 forms one second current mirror, according to reference current I411 and adjustment signal I
A, be used to produce electric current I 413 and I414.Transistor 415 and 416 forms one the 3rd current mirror, is used for producing an electric current I 416 according to electric current I 413.Transistor 417 and 418 forms one the 4th current mirror, is used for producing an electric current I 418 according to electric current I 414.Produce modulation signal I according to electric current I 416 and I418
MThe first control signal S
1Be sent to a transistor 430 by inverter 420.Transistor 430 further is coupled to second current mirror, is used for according to the first control signal S
1Cut off electric current I 413 and I414.One transistor 431 is coupled to the 3rd current mirror, is used for according to the second control signal S
2Cut off electric current I 416.Therefore, according to the first control signal S
1Enable modulation signal I
M, to produce the first led current I
1According to the second control signal S
2, further control modulation signal I
M, to produce the second led current I
2
Figure 10 is the first control signal S
1Waveform, in ramp signal RAMP rising periodic process, by comparison control signal V
CNTProduce the first control signal S with ramp signal RAMP
1The second control signal S
2In ramp signal RAMP process decline cycle, produce.According to the first control signal S
1Inefficacy (high levle) make modulation signal I
MLost efficacy (low level).According to the first control signal S
1Enable (low level) control modulation signal I
M, to produce the first led current I
1, and according to the second control signal S
2Enable (high levle), to produce the second led current I
2At the first led current I
1In the periodic process, oscillator 250 produces the first pulse signal SMP1, with to the first light-emitting diode forward voltage V
1Take a sample.At the second led current I
2In the periodic process, oscillator 250 produces the second pulse signal SMP2 with to the second light-emitting diode forward voltage V
2Take a sample.Therefore according to the first led current I
1With the second led current I
2, the definable first light-emitting diode forward voltage V
1, and confirm the second light-emitting diode forward voltage V
2, electric current I wherein
1And I
2Can provide by following:
I
1＝I
0×e
V1/VT-------------------------------------------------------?(5)
I
2＝I
0×e
V2/VT-------------------------------------------------------?(6)
Wherein k is Boltzmann constant (Boltzmann ' s constant), and q is an electronic charge, and T
EmpBe absolute temperature.
Aforesaid equation shows the temperature that can accurately detect light-emitting diode from the light-emitting diodes tube voltage.Therefore the temperature of light-emitting diode can further be used to adjust led current, with the colourity and the brightness of compensation light-emitting diode.
Though be shown specifically and described the present invention, for one skilled in the art, can make various changes in form and details and do not break away from the spirit and scope of the present invention that limit by accessory claim with reference to embodiment.
Claims (15)
1, a kind of LED driving circuit, it comprises:
One control circuit, it is used to produce a led current of control one light-emitting diode;
One first resistor is connected to this control circuit, is used to determine the current value of this led current;
One control end of this control circuit is used to receive a control signal, to determine the work period of this led current;
One test side of this control circuit is coupled to this light-emitting diode, is used to detect a light-emitting diodes tube voltage, and wherein this light-emitting diodes tube voltage can be used to adjust this led current; And
One second resistor is connected to this control circuit, is used to determine one to adjust slope, and wherein this adjustment slope is represented the variation of the variation of this led current corresponding to this light-emitting diodes tube voltage.
2, LED driving circuit as claimed in claim 1 is characterized in that, wherein this led current comprises one first led current and one second led current; This second led current is relevant with this first led current; This light-emitting diodes tube voltage comprises one first forward voltage and one second forward voltage, wherein according to this first led current and this second led current and produce this first forward voltage and this second forward voltage respectively.
3, LED driving circuit as claimed in claim 1 is characterized in that, this control circuit comprises:
One pulse-width modulation circuit is coupled to this control end, is used to produce one first control signal to control the work period of this led current;
One sample circuit is coupled to this test side and this second resistor, is used for adjusting signal according to the resistance value of this light-emitting diodes tube voltage and this second resistor to produce one;
One modulation circuit is coupled to this first resistor, this pulse-width modulation circuit and this sample circuit, is used for according to the resistance value of this first resistor and this adjustment signal to produce a modulation signal; And
One first current mirroring circuit is coupled to this pulse-width modulation circuit and this modulation circuit, is used for producing this led current according to this first control signal and this modulation signal.
4, LED driving circuit as claimed in claim 3 is characterized in that, this pulse-width modulation circuit comprises:
One oscillator, it is used to produce a ramp signal, one second control signal, one first pulse signal and one second pulse signal;
One first comparator is in case it is used for producing when this control signal is lower than this ramp signal one first reset signal;
One second comparator is in case it is used for producing when this control signal is lower than a threshold signal one second reset signal; And
One latch cicuit is coupled to this second control signal, is used for producing this first control signal according to this second control signal,
Wherein according to this second control signal to enable this first control signal, according to this first reset signal and this second reset signal, so that this first control signal is invalid, and, produce this first pulse signal and this second pulse signal respectively according to the trailing edge and the rising edge of this second control signal.
5, LED driving circuit as claimed in claim 4 is characterized in that, wherein according to this first reset signal or this second reset signal, so that this first control signal is invalid.
6, LED driving circuit as claimed in claim 3 is characterized in that, this sample circuit comprises:
One first differential circuit is coupled to this test side, is used to detect this light-emitting diodes tube voltage;
One first sample circuit is used for according to this first pulse signal this first forward voltage of this light-emitting diodes tube voltage being taken a sample;
One second sample circuit is used for according to this second pulse signal this second forward voltage of this light-emitting diodes tube voltage being taken a sample;
One second differential circuit is used for producing a differential wave according to the difference of this first forward voltage and this second forward voltage; And
One voltage is coupled to this second resistor to current converter, is used for producing this adjustment signal according to the resistance value of this differential wave and this second resistor.
7, LED driving circuit as claimed in claim 3 is characterized in that, this modulation circuit comprises:
One current feedback circuit is used for producing a reference current according to the resistance value of a reference voltage and this first resistor; And
One second current mirroring circuit is used for producing this modulation signal according to this reference current and this adjustment signal;
Wherein according to this modulation signal that enables of this first control signal, being used to produce this first led current, and control this modulation signal, to be used to produce this second led current according to this second control signal.
8, a kind of LED controller, it comprises:
One control circuit, it is used to produce a led current of control one light-emitting diode;
One control end of this control circuit is used to receive a control signal that determines this led current; And
One test side of this control circuit is coupled to this light-emitting diode, is used to detect a light-emitting diodes tube voltage, and wherein this light-emitting diodes tube voltage is used to adjust this led current.
9, LED controller as claimed in claim 8 is characterized in that, further comprises:
One first resistor is coupled to this control circuit, is used to determine the current value of this led current; And
One second resistor is coupled to this control circuit, is used to determine one to adjust slope, and wherein this adjustment slope is represented the variation of the variation of this led current corresponding to this light-emitting diodes tube voltage.
10, LED controller as claimed in claim 8, it is characterized in that, wherein this led current comprises one first led current and one second led current, this second led current is relevant with this first led current, and this light-emitting diodes tube voltage comprises one first forward voltage and one second forward voltage, wherein produces this first forward voltage and this second forward voltage according to this first led current respectively with this second led current.
11, LED controller as claimed in claim 8 is characterized in that, this control circuit comprises:
One pulse-width modulation circuit is coupled to this control end, is used to produce one first control signal to control the work period of this led current;
One sample circuit is coupled to this test side, is used for adjusting signal according to this light-emitting diodes tube voltage to produce one;
One modulation circuit is coupled to this pulse-width modulation circuit and this sample circuit, is used for according to this adjustment signal to produce a modulation signal; And
One first current mirroring circuit is coupled to this pulse-width modulation circuit and this modulation circuit, is used for producing this led current according to this first control signal and this modulation signal.
12, LED controller as claimed in claim 11 is characterized in that, this pulse-width modulation circuit comprises:
One oscillator, it is used to produce a ramp signal, one second control signal, one first pulse signal and one second pulse signal;
One first comparator is in case it is used for producing when this control signal is lower than this ramp signal one first reset signal;
One second comparator is in case it is used for producing when this control signal is lower than a threshold signal one second reset signal; And
One latch cicuit is coupled to this second control signal, is used for producing this first control signal according to this second control signal;
Wherein according to this second control signal to enable this first control signal, so that this first control signal is invalid, and produce this first pulse signal and this second pulse signal respectively according to this first reset signal and this second reset signal according to the trailing edge and the rising edge of this second control signal.
13, LED controller as claimed in claim 12 is characterized in that, wherein according to this first reset signal or this second reset signal so that this first control signal is invalid.
14, LED controller as claimed in claim 11 is characterized in that, this sample circuit comprises:
One first differential circuit is coupled to this test side, is used to detect this light-emitting diodes tube voltage;
One first sample circuit is used for according to this first pulse signal this first forward voltage of this light-emitting diodes tube voltage being taken a sample;
One second sample circuit is used for according to this second pulse signal this second forward voltage of this light-emitting diodes tube voltage being taken a sample;
One second differential circuit is used for producing a differential wave according to the difference of this first forward voltage and this second forward voltage; And
One voltage is used for producing this adjustment signal according to this differential wave to current converter.
15, LED controller as claimed in claim 11 is characterized in that, this modulation circuit comprises:
One current feedback circuit is used for producing a reference current according to a reference voltage; And
One second current mirroring circuit is used for producing this modulation signal according to this reference current and this adjustment signal;
Wherein according to this modulation signal that enables of this first control signal, being used to produce this first led current, and control this modulation signal, to be used to produce this second led current according to this second control signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2006100069623A CN100477869C (en) | 2006-01-26 | 2006-01-26 | LED driving circuit with the temperature compensation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2006100069623A CN100477869C (en) | 2006-01-26 | 2006-01-26 | LED driving circuit with the temperature compensation |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101009958A true CN101009958A (en) | 2007-08-01 |
| CN100477869C CN100477869C (en) | 2009-04-08 |
Family
ID=38697990
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2006100069623A Expired - Fee Related CN100477869C (en) | 2006-01-26 | 2006-01-26 | LED driving circuit with the temperature compensation |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN100477869C (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101835310A (en) * | 2010-05-05 | 2010-09-15 | 海洋王照明科技股份有限公司 | LED constant current drive circuit and LED lamp |
| CN104812144A (en) * | 2011-12-07 | 2015-07-29 | 戴乐格半导体公司 | High performance adaptive switched led driver |
| CN104981862A (en) * | 2013-01-14 | 2015-10-14 | 伊格尼斯创新公司 | Driving scheme for emissive displays providing compensation for driving transistor variations |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8525437B2 (en) * | 2010-09-16 | 2013-09-03 | Samsung Electro-Mechanics Co., Ltd. | Device for controlling current of LED |
-
2006
- 2006-01-26 CN CNB2006100069623A patent/CN100477869C/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101835310A (en) * | 2010-05-05 | 2010-09-15 | 海洋王照明科技股份有限公司 | LED constant current drive circuit and LED lamp |
| CN104812144A (en) * | 2011-12-07 | 2015-07-29 | 戴乐格半导体公司 | High performance adaptive switched led driver |
| CN104812144B (en) * | 2011-12-07 | 2017-09-22 | 戴乐格半导体公司 | High performance self-adaption switching LED driver |
| CN104981862A (en) * | 2013-01-14 | 2015-10-14 | 伊格尼斯创新公司 | Driving scheme for emissive displays providing compensation for driving transistor variations |
| CN104981862B (en) * | 2013-01-14 | 2018-07-06 | 伊格尼斯创新公司 | For changing the drive scheme for the active display for providing compensation to driving transistor |
Also Published As
| Publication number | Publication date |
|---|---|
| CN100477869C (en) | 2009-04-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9674909B2 (en) | Driving circuit for light-emitting element with burst dimming control | |
| US7259525B2 (en) | High efficiency switching LED driver | |
| US7286123B2 (en) | LED driver circuit having temperature compensation | |
| CN101505561B (en) | Control circuit for led drive and its off-line control circuit | |
| CN101304625B (en) | Drive circuit and electronic apparatus equipped therewith | |
| US7550932B2 (en) | Control method and device for a power-converting module that drives a light-emitting component | |
| US20100033146A1 (en) | Current sensing for high voltage buck converter | |
| JP3878393B2 (en) | DC-AC switching circuit for driving an electroluminescent lamp exhibiting capacitive load characteristics | |
| US10122255B2 (en) | Devices, systems and processes for average current control | |
| KR19980071764A (en) | Charge pump circuit | |
| CN101505558B (en) | Light emission element driving circuit having compensation mechanism | |
| US8513895B2 (en) | High efficiency LED driver with current source regulations | |
| CN100477869C (en) | LED driving circuit with the temperature compensation | |
| KR20060133020A (en) | Power supply and display | |
| KR101087749B1 (en) | Apparatus for detecting current, and driver for light emitting diode comprising the same | |
| US20190229717A1 (en) | Semiconductor device, load drive system and method of detecting inductor current | |
| KR100859040B1 (en) | LED backlight driver | |
| CN109448621B (en) | Drive circuit and display device | |
| JP5719260B2 (en) | Lighting device | |
| US20210211124A1 (en) | Gate driver | |
| CN113841326B (en) | Switching converter with multiple drive stages and related modes | |
| US8570102B2 (en) | Switching amplifier | |
| US7359649B2 (en) | Infrared transmitter circuit and electronic device | |
| CN100531487C (en) | LED driving device | |
| JP2010015879A (en) | Method of setting brightness of light emitting element, and interface circuit |
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: 20090408 Termination date: 20220126 |