CN108566702B - LED linear driving circuit - Google Patents
LED linear driving circuit Download PDFInfo
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- CN108566702B CN108566702B CN201810692845.XA CN201810692845A CN108566702B CN 108566702 B CN108566702 B CN 108566702B CN 201810692845 A CN201810692845 A CN 201810692845A CN 108566702 B CN108566702 B CN 108566702B
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- 238000005070 sampling Methods 0.000 claims abstract description 39
- 238000001514 detection method Methods 0.000 claims description 22
- 230000017525 heat dissipation Effects 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 11
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- 230000003321 amplification Effects 0.000 description 1
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/40—Details of LED load circuits
- H05B45/44—Details of LED load circuits with an active control inside an LED matrix
- H05B45/48—Details of LED load circuits with an active control inside an LED matrix having LEDs organised in strings and incorporating parallel shunting devices
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/30—Driver circuits
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/30—Driver circuits
- H05B45/395—Linear regulators
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Abstract
The invention relates to an LED linear driving circuit which is used for driving n sections of LED loads which are sequentially connected in series, wherein the positive electrode of a first section of LED load is connected with the positive electrode of direct-current voltage, and the negative electrode of an n-1 section of LED load is connected with the positive electrode of an n section of LED load; n is more than or equal to 2; the LED linear driving circuit is characterized by comprising: an input voltage sampling circuit, an error amplifying circuit, an adder circuit, a current detecting circuit and a load switching circuit. The LED linear driving circuit can enable an input current waveform to basically follow an input voltage to present a sine wave; the MOS tube in the LED linear driving circuit uses discrete devices, is flexibly placed on a PCB in parallel, and has good heat dissipation performance and reliability; in addition, 1-multistage LED load can be used at will according to the system efficiency requirement, and the more the number of stages of LED load is used, the higher the efficiency is.
Description
Technical Field
The invention relates to the field of driving circuits, in particular to an LED linear driving circuit.
Background
In the scheme of the traditional LED linear driving circuit, most of input current of the LED linear driving circuit is formed by overlapping 3-5 sections of square wave current, and as a result, the power factor of the circuit is low, and harmonic waves hardly pass the existing standard; the traditional LED linear driving circuit scheme adopts chip packaging, integrates a power MOS tube, and has the problems that the power MOS tube is difficult to radiate due to the fixed number of LED load sections, or multiple chips are required to be used in parallel, and the design is not flexible enough and the efficiency is not high due to the fixed number of LED load sections.
Disclosure of Invention
The invention aims to provide an LED linear driving circuit aiming at the prior art.
The technical scheme adopted for solving the technical problems is as follows: an LED linear driving circuit is used for driving n sections of LED loads which are sequentially connected in series, wherein the positive electrode of a first section of LED load is connected with the positive electrode of direct-current voltage, and the negative electrode of an n-1 section of LED load is connected with the positive electrode of an n section of LED load; n is more than or equal to 2; the LED linear driving circuit is characterized by comprising: an input voltage sampling circuit, an error amplifying circuit, an adder circuit, a current detecting circuit and a load switching circuit; wherein:
the first input end of the input voltage sampling circuit is connected with the anode or the cathode of the first section of LED load, the first output end of the input voltage sampling circuit is connected with the first input end of the error amplifying circuit, and the second output end of the input voltage sampling circuit is grounded;
the second input end of the error amplifying circuit is connected with the first output end of the adder circuit, and the first output end of the error amplifying circuit is connected with the first input end of the load switching circuit;
a first input end of the adder circuit is connected with a first output end of the current detection circuit, and a second input end of the adder circuit is connected with an n-th LED load cathode;
the first input end of the current detection circuit is connected with the first output end of the load switching circuit, and the second output end of the current detection circuit is grounded;
and the n-th input end of the load switching circuit is connected with the negative electrode of the n-1 th LED load.
In the LED linear driving circuit, the input voltage sampling circuit includes: a fourth resistor and a fifth resistor; the first end of the fourth resistor is connected with the first input end of the input voltage sampling circuit, and the second end of the fourth resistor is connected with the first output end of the input voltage sampling circuit; and a first end of the fifth resistor is connected with a first output end of the input voltage sampling circuit, and a second end of the fifth resistor is grounded.
In the LED linear driving circuit, the error amplifying circuit includes: a first triode and a second triode; the first triode is a PNP triode, the base electrode of the first triode is connected with the collector electrode of the second triode, the emitting electrode of the first triode is connected with the first output end of the error amplifying circuit, and the collector electrode of the first triode is grounded;
the second triode is an NPN triode, the base electrode of the second triode is connected with the second input end of the error amplifying circuit, and the emitting electrode of the second triode is connected with the first input end of the error amplifying circuit.
In the LED linear driving circuit, the adder circuit includes: a sixth resistor and a seventh resistor; the first end of the sixth resistor is connected with the first input end of the adder circuit, and the second end of the sixth resistor is connected with the first output end of the adder circuit;
the first end of the seventh resistor is connected with the second input end of the adder circuit, and the second end of the seventh resistor is connected with the first output end of the adder circuit.
In the LED linear driving circuit, the current detecting circuit includes: a fourth diode, an eighth resistor, and a ninth resistor; the fourth diode is connected in parallel with the ninth resistor, the positive electrode of the fourth diode is connected with the first input end of the current detection circuit, the negative electrode of the fourth diode is connected with the first end of the eighth resistor, and the second end of the eighth resistor is grounded.
In the LED linear driving circuit, the load switching circuit may further include: a first switching circuit and a second switching circuit; wherein:
the first input end of the first switching circuit is connected with the third input end of the load switching circuit, the second input end of the first switching circuit is connected with the first input end of the load switching circuit, the third input end of the first switching circuit is connected with the second input end of the load switching circuit, and the first output end of the first switching circuit is connected with the first output end of the load switching circuit;
the first input end of the second switching circuit is connected with the fourth input end of the load switching circuit, the second input end of the second switching circuit is connected with the first input end of the load switching circuit, the third input end of the second switching circuit is connected with the third input end of the load switching circuit, and the first output end of the second switching circuit is connected with the first output end of the load switching circuit.
Further, in the LED linear driving circuit, the x-th switching circuit includes: an x-th resistor Rx, an x-th diode Dx, an xMOS tube Mx and an x-th controllable switch Sx; x is more than or equal to 1; wherein;
the first end of the x-th resistor Rx is connected with the grid electrode of the x-th MOS tube Mx, and the second end of the x-th resistor Rx is connected with the drain electrode of the x-th MOS tube Mx;
the positive electrode Dx of the x-th diode is connected with the grid electrode of the x-th MOS tube Mx, and the negative electrode of the x-th diode Dx is connected with the second input end of the x-th switching circuit;
the grid electrode of the x-th MOS tube Mx is connected with one end of the x-th controllable switch Sx, the drain electrode of the x-th MOS tube Mx is connected with the third input end of the x-th switching circuit, and the source electrode of the x-th MOS tube Mx is connected with the first output end of the x-th switching circuit;
the other end of the x-th controllable switch Sx is connected with the first output end of the x-th switching circuit, the positive electrode of the switch control end of the x-th controllable switch Sx is connected with the first input end of the x-th switching circuit, and the negative electrode of the switch control end of the x-th controllable switch Sx is connected with the first output end of the x-th switching circuit.
Compared with the prior art, the invention has the advantages that:
firstly, the LED linear driving circuit provided by the invention can enable the input current waveform to basically follow the input voltage to present a sine wave, so that the input current waveform in the circuit can more easily pass the existing standard;
secondly, in the LED linear driving circuit provided by the invention, the MOS tubes use discrete devices, and the MOS tubes are placed on the PCB in a parallel manner, so that the positions of the MOS tubes are placed more flexibly, and the heat dissipation performance and the reliability of the MOS tubes are effectively improved;
the current detection circuit in the LED linear driving circuit comprises an eighth resistor and a ninth resistor, and the fourth diode is arranged to offset the be junction voltage of the triode Q2 in the error amplifying circuit, so that the current waveform is more approximate to the output voltage of the input voltage sampling circuit; the ninth resistor is arranged to further adjust the current waveform to be more approximate to the output voltage of the input voltage sampling circuit, so that the circuit realizes high PF and low harmonic;
finally, the LED linear driving circuit provided by the invention can randomly use LED loads of 1 to multiple sections according to the system efficiency requirement, and the more the number of sections of the LED loads is used, the higher the efficiency is.
Drawings
Fig. 1 is a schematic diagram of an LED linear driving circuit in the present embodiment;
fig. 2 is a schematic diagram of an input voltage sampling circuit in the present embodiment;
fig. 3 is a schematic diagram of an error amplifying circuit in the present embodiment;
fig. 4 is a schematic diagram of an adder circuit in the present embodiment;
fig. 5 is a schematic diagram of a current detection circuit in the present embodiment;
fig. 6 is a schematic diagram of a load switching circuit in the present embodiment.
Description of the embodiments
The invention is described in further detail below with reference to the embodiments of the drawings.
As shown in fig. 1, the LED linear driving circuit in this embodiment is configured to drive n LED loads sequentially connected in series, where the n LED loads are LED1, …, and LEDn, respectively; n is more than or equal to 2; reference numeral 11 denotes a rectifier bridge circuit, reference numeral 12 denotes an LED load circuit, and the LED linear driving circuit 10 includes: an input voltage sampling circuit 101, an error amplifying circuit 102, an adder circuit 103, a current detecting circuit 104, and a load switching circuit 105; wherein:
a first input end of the input voltage sampling circuit 101 is connected with the positive electrode or the negative electrode of the LED1 load, a first output end of the input voltage sampling circuit 101 is connected with a first input end of the error amplifying circuit 102, and a second output end of the input voltage sampling circuit 101 is grounded; thereby, a shape and a size for obtaining an input voltage are realized as the inverting input terminal of the error amplifying circuit 102;
a second input terminal of the error amplifying circuit 102 is connected to a first output terminal of the adder circuit 103, and a first output terminal of the error amplifying circuit 102 is connected to a first input terminal of the load switching circuit 105; thereby, the method is used for controlling the size and the shape of the LED load current to obtain an input current with a certain value and a shape similar to a sine wave;
a first input terminal of the adder circuit 103 is connected with a first output terminal of the current detection circuit 104, and a second input terminal of the adder circuit 103 is connected with a negative electrode of the LEDn load; thereby, realizing a voltage for generating a sum of the magnitude of the LED load voltage and the magnitude of the input voltage to cancel the input power variation caused by the input voltage variation, and basically realizing a constant input power or input current;
a first input end of the current detection circuit 104 is connected with a first output end of the load switching circuit 105, and a second output end of the current detection circuit 104 is grounded; thereby, a voltage signal for converting the LED load current into a certain ratio is realized;
the second input of the load switching circuit 105 is connected to the negative pole of the LED1 load, the third input of the load switching circuit 105 is connected to the negative pole of the LED2 load, and so on, the n+1-th input of the load switching circuit 105 is connected to the negative pole of the LEDn load. Thus, the number of loads for switching the LEDs is realized, so that enough LEDs are lighted under the condition of a certain voltage, and higher power efficiency is obtained.
The mains voltage generates a sine wave absolute value waveform after passing through the rectifier bridge circuit 11, the waveform passes through the input voltage sampling circuit 101, a sine wave absolute value waveform with a certain value is generated at the first output end of the input voltage sampling circuit 101, and the error amplifying circuit 102 reversely references the voltage.
When the voltage gradually rises from 0V to be greater than the turn-on voltage of the LED1 load, the internal control circuit of the load switching circuit 105 turns on the MOS transistor between the second input end and the first output end, and the MOS transistor may also be turned on before the voltage reaches the turn-on voltage of the LED1 load, at this time, the LED1 load generates a current, the current flows through the current detection circuit 104 and returns to the ground, and a voltage with a certain value is generated at the first output end of the current detection circuit 104, and the voltage reaches the second input end of the error amplifying circuit 102 through the adder circuit 103; if the voltage is greater than the output voltage of the input voltage sampling circuit 101, the gate voltage of the MOS transistor in the load switching circuit 105 is pulled down by the first output end of the error amplifying circuit 102, otherwise, is pulled up, so that the circuit can make the current waveform flowing through the LED load consistent with the input voltage waveform;
when the voltage continues to rise to be greater than the voltage of the LED1 load plus the voltage of the LED1 load, the load switching circuit 105 enables the MOS tube between the third input end and the first output end of the load switching circuit 105 to be turned on, and meanwhile, the MOS tube between the second input end and the first output end of the load switching circuit 105 is turned off, the LED1 load and the LED2 load are tested to generate currents, and the current waveforms are in a controlled state as described above; and so on until the LED n load is turned on;
when the input voltage drops, aiming at the LED n load-LED 1 load, the LED n load is turned off in the opposite direction in sequence, and one working cycle is completed.
When the effective value of the input voltage increases, the voltage output from the input voltage sampling circuit 101 increases, and if no control is applied, the input power increases, so that a compensation circuit needs to be added. Specifically, voltage control for the output of the input voltage sampling circuit 101 is realized by the adder circuit 103. In this embodiment, the second input of the adder circuit 103 is connected to the negative pole of the LEDn load, and the second input of the adder circuit 103 may also be connected to any node that is responsive to a change in the effective value of the input voltage. When the effective value of the input voltage increases, the effective value of the negative voltage of the LEDn load also increases, so that the voltage of the second input terminal of the adder circuit 103 also increases, and therefore the voltage of the first output terminal of the adder circuit 103 also increases, so that the voltage of the second input terminal (forward direction) of the error amplifying circuit 102 increases; for the error amplification circuit 102, if its forward and reverse voltages increase by the same magnitude, its output is unchanged, i.e., the LED load current is unchanged; if the forward increasing amplitude is larger than the reverse, the LED load current output becomes smaller, and the circuit can be in a constant current or constant power state by reasonably adjusting the amplitudes of the forward increasing amplitude and the reverse increasing amplitude.
Fig. 2 is a schematic diagram of the input voltage sampling circuit 101 in the present embodiment. In fig. 2, a first end of a resistor R4 is connected to a first input end of the input voltage sampling circuit 101, and a second end of the resistor R4 is connected to a first output end of the input voltage sampling circuit 101; a first end of the resistor R5 is connected to the first output end of the input voltage sampling circuit 101, and a second end of the resistor R5 is grounded. The input voltage with a certain value is obtained through the voltage division of the resistors R4 and R5, and a reference current waveform is provided on one hand, and a current amplitude reference is provided on the other hand.
Fig. 3 is a schematic diagram of the error amplifying circuit 102 in the present embodiment. In fig. 3, the error amplifying circuit 102 includes a triode Q1 and a triode Q2, the triode Q1 is a PNP type triode, a base electrode of the triode Q1 is connected with a collector electrode of the triode Q2, an emitter electrode of the triode Q1 is connected with a first output end of the error amplifying circuit 102, and a collector electrode of the triode Q1 is grounded; the triode Q2 is an NPN triode, the base electrode of the triode Q2 is connected with the second input end of the error amplifying circuit 102, and the emitter electrode of the triode Q2 is connected with the first input end of the error amplifying circuit 102.
When the LED output current is greater than the set value, the driving current of the be pole of the triode Q2 will increase, and the current is amplified by the triode Q2 and used for driving the be pole of the triode Q1, so that the collector current of the triode Q1 also increases, and the driving voltage of the MOS transistor inside the load switching circuit 105 decreases, so as to achieve the effect of decreasing the LED output current, otherwise, the LED output current is finally consistent with the sampling voltage of the voltage sampling circuit 101.
Fig. 4 is a schematic diagram of the adder circuit 103 in the present embodiment. In fig. 4, the adder circuit 103 includes a resistor R6 and a resistor R7, a first end of the resistor R6 is connected to the first input terminal of the adder circuit 103, and a second end of the resistor R6 is connected to the first output terminal of the adder circuit 103; a first terminal of the resistor R7 is connected to the second input of the adder circuit 103 and a second terminal of the resistor R7 is connected to the first output of the adder circuit 103.
Since the resistance values of the resistor R6 and the resistor R7 are far greater than the internal resistance of the current detection circuit 104, the output of the current detection circuit 104 can be approximately used as a voltage source, and the output of the adder can be approximately equal to the output voltage of the current detection circuit 104 plus the negative voltage of the LEDn load with a certain ratio, wherein the ratio is R6/(r6+r7).
Fig. 5 is a schematic diagram of the current detection circuit 104 in the present embodiment. In fig. 5, the current detection circuit 104 includes a fourth diode D4, an eighth resistor R8, and a ninth resistor R9; the fourth diode D4 is connected in parallel with the ninth resistor R9;
the anode of the fourth diode D4 is connected with the first input end of the current detection circuit 104, and the cathode of the fourth diode D4 is connected with the first end of the resistor R8; the second terminal of resistor R8 is grounded.
The resistor R8 is a current sampling resistor, and the fourth diode D4 is used for counteracting the be junction voltage of the triode Q2 in the error amplifying circuit 102, so that the current waveform is more approximate to the output voltage of the input voltage sampling circuit 101; the resistor R9 serves as an aid to further adjust the current waveform to be closer to the output voltage of the input voltage sampling circuit 101, so that the circuit achieves high PF and low harmonics.
Fig. 6 is a schematic diagram of the load switching circuit 105 in the present embodiment. The load switching circuit 105 includes: the first switching circuit 1051, the second switching circuit 1052, the third switching circuit 1053, and so on, until the nth switching circuit 105n, n is the number of switching circuits required, and the system efficiency is higher as the number is greater. Wherein:
a first input terminal of the first switching circuit 1051 is connected to a third input terminal of the load switching circuit 105, a second input terminal of the first switching circuit 1051 is connected to a first input terminal of the load switching circuit 105, a third input terminal of the first switching circuit 1051 is connected to a second input terminal of the load switching circuit 105, and a first output terminal of the first switching circuit 1051 is connected to a first output terminal of the load switching circuit 105;
a first input terminal of the second switching circuit 1052 is connected to a fourth input terminal of the load switching circuit 105, a second input terminal of the second switching circuit 1052 is connected to a first input terminal of the load switching circuit 105, a third input terminal of the second switching circuit 1052 is connected to a third input terminal of the load switching circuit 105, and a first output terminal of the second switching circuit 1052 is connected to a first output terminal of the load switching circuit 105; the connection method of the third switching circuit 1053 is analogized in turn; the first input terminal of the nth switching circuit 105n is connected to the n+1 input terminal of the load switching circuit 105, the second input terminal of the nth switching circuit 105n is connected to the first input terminal of the load switching circuit 105, the third input terminal of the nth switching circuit 105n is connected to the n+1 input terminal of the load switching circuit 105, and the first output terminal of the nth switching circuit 105n is connected to the first output terminal of the load switching circuit 105.
The x-th switching circuit 105x of any one of the first to n-th switching circuits 1051 to 105n includes: an x-th resistor Rx, an x-th diode Dx, an x-th MOS tube Mx and an x-th controllable switch. For convenience of description, the number x here represents the x-th switching circuit 105x, 1. Ltoreq.x. Ltoreq.n;
one end of the x-th resistor Rx is connected with the grid electrode of the x-th MOS tube Mx, and the other end of the x-th resistor Rx is connected with the drain electrode of the x-th MOS tube Mx; the positive electrode of the x-th diode Dx is connected with the grid electrode of the x-th MOS tube Mx, and the negative electrode of the x-th diode Dx is connected with the second input end of the x-th switching circuit 105 x;
the grid electrode of the x-th MOS tube Mx is connected with one end of a switch of the controllable switch Sx, the drain electrode of the x-th MOS tube Mx is connected with the third input end of the x-th switching circuit 105x, and the source electrode of the x-th MOS tube Mx is connected with the first output end of the x-th switching circuit 105 x; the other end of the switch of the controllable switch Sx is connected with the first output end of the x-th switching circuit 105x, the positive electrode of the switch control end of the controllable switch Sx is connected with the first input end of the x-th switching circuit 105x, and the negative electrode of the switch control end of the controllable switch Sx is connected with the first output end of the x-th switching circuit 105 x.
The function of the xth resistor Rx is to provide a voltage for turning on the xth MOS transistor Mx, where the voltage needs to be provided when or before the voltage appears at the drain of the MOS transistor, that is, when or before the input voltage is equal to the sum of the forward voltages of the LED1+ LED2+ … + LED x, the xth MOS transistor is to be in an on state, and the power supply connection position is not limited to the drain of the xth MOS transistor, but also can be the drain of the xth MOS transistor or any other node where the voltage is higher than the drain of the xth MOS transistor. Simultaneously, when the voltage appears at the drain electrode of the x-th MOS tube, the grid electrode of the x-1-th MOS tube is pulled down through the controllable switch Sx-1, namely the x-1-th MOS tube is closed; because the grid electrodes of the MOS tubes are connected to the same point through the diode Dx, the turn-on of other MOS tubes cannot be influenced by the fact that the grid voltage of one MOS tube is lowered. Therefore, the LED load can be switched when the voltage rises, so that as many LED loads as possible are in a conducting state, and the system efficiency is improved; and when the voltage drops, the operation is reversed.
The control signal of each controllable switch Sx takes a signal from the drain electrode of the MOS tube mx+1, but the last controllable switch Sn takes a signal from the MOS tube Mn, and the signal is not used for switching the LED load, but is used for realizing overvoltage protection of the input voltage, when the input voltage is too high, the circuit can be in a protection state, that is, the MOS tube Mn is closed, and the whole circuit is not output.
While the preferred embodiments of the present invention have been described in detail, it is to be clearly understood that the same may be varied in many ways by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (5)
1. An LED linear driving circuit is used for driving n sections of LED loads which are sequentially connected in series, the positive electrode of a first section of LED load is connected with the positive electrode of a rectifier bridge circuit, and the negative electrode of an n-1 section of LED load is connected with the positive electrode of an n section of LED load; n is more than or equal to 2; the LED linear driving circuit is characterized by comprising: an input voltage sampling circuit, an error amplifying circuit, an adder circuit, a current detecting circuit and a load switching circuit; wherein:
the first input end of the input voltage sampling circuit is connected with the anode or the cathode of the first section of LED load, the first output end of the input voltage sampling circuit is connected with the first input end of the error amplifying circuit, the second output end of the input voltage sampling circuit is grounded, and the second output end of the input voltage sampling circuit is connected with the cathode of the rectifier bridge circuit;
the second input end of the error amplifying circuit is connected with the first output end of the adder circuit, and the first output end of the error amplifying circuit is connected with the first input end of the load switching circuit;
a first input end of the adder circuit is connected with a first output end of the current detection circuit, and a second input end of the adder circuit is connected with an n-th LED load cathode; the adder circuit generates voltage, the value of the voltage is the sum of the LED load voltage value and the input voltage value, so as to offset the input power change caused by the input voltage change, and constant input power or input current is realized;
the first input end of the current detection circuit is connected with the first output end of the load switching circuit, and the second output end of the current detection circuit is grounded;
the n-th input end of the load switching circuit is connected with the negative electrode of the n-1 th LED load; the LED linear driving circuit comprises n switching circuits; n is more than or equal to 2;
the x-th switching circuit comprises an x-th resistor Rx, an x-th diode Dx, an x-th MOS tube Mx and an x-th controllable switch Sx; x is more than or equal to 1 and less than or equal to n; wherein;
the first end of the x-th resistor Rx is connected with the grid electrode of the x-th MOS tube Mx, and the second end of the x-th resistor Rx is connected with the drain electrode of the x-th MOS tube Mx;
the anode Dx of the x-th diode is connected with the grid electrode of the xMOS tube Mx, and the cathode of the x-th diode Dx is connected with the second input end of the x-th switching circuit;
the grid electrode of the x-th MOS tube Mx is connected with one end of the x-th controllable switch Sx, the drain electrode of the x-th MOS tube Mx is connected with the third input end of the x-th switching circuit, and the source electrode of the x-th MOS tube Mx is connected with the first output end of the x-th switching circuit;
the other end of the x-th controllable switch Sx is connected with the first output end of the x-th switching circuit, the positive electrode of the switch control end of the x-th controllable switch Sx is connected with the first input end of the x-th switching circuit, and the negative electrode of the switch control end of the x-th controllable switch Sx is connected with the first output end of the x-th switching circuit;
the third input end of the x-th switching circuit is connected with the x+1-th input end of the load switching circuit;
the first input end of the x-th switching circuit is connected with the third input end of the x+1th switching circuit except the n-th switching circuit; the first input end of the nth switching circuit is connected with the n+1 input end of the load switching circuit;
the second input end of the x-th switching circuit is connected with the first input end of the load switching circuit;
the first output of each of the n switching circuits is connected to the first output of the load switching circuit.
2. The LED linear driving circuit of claim 1, wherein the input voltage sampling circuit comprises: a fourth resistor (R4) and a fifth resistor (R5); the first end of the fourth resistor is connected with the first input end of the input voltage sampling circuit, and the second end of the fourth resistor is connected with the first output end of the input voltage sampling circuit; and a first end of the fifth resistor is connected with a first output end of the input voltage sampling circuit, and a second end of the fifth resistor is grounded.
3. The LED linear driving circuit according to claim 1, wherein the error amplifying circuit includes: a first transistor (Q1) and a second transistor (Q2); the first triode is a PNP triode, the base electrode of the first triode is connected with the collector electrode of the second triode, the emitting electrode of the first triode is connected with the first output end of the error amplifying circuit, and the collector electrode of the first triode is grounded;
the second triode is an NPN triode, the base electrode of the second triode is connected with the second input end of the error amplifying circuit, and the emitting electrode of the second triode is connected with the first input end of the error amplifying circuit.
4. The LED linear driving circuit according to claim 1, wherein the adder circuit includes: a sixth resistor (R6) and a seventh resistor (R7); the first end of the sixth resistor is connected with the first input end of the adder circuit, and the second end of the sixth resistor is connected with the first output end of the adder circuit;
the first end of the seventh resistor is connected with the second input end of the adder circuit, and the second end of the seventh resistor is connected with the first output end of the adder circuit.
5. The LED linear driving circuit according to claim 1, wherein the current detection circuit includes: a fourth diode (D4), an eighth resistor (R8) and a ninth resistor (R9); the fourth diode is connected in parallel with the ninth resistor, the positive electrode of the fourth diode is connected with the first input end of the current detection circuit, the negative electrode of the fourth diode is connected with the first end of the eighth resistor, and the second end of the eighth resistor is grounded.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810692845.XA CN108566702B (en) | 2018-06-29 | 2018-06-29 | LED linear driving circuit |
| EP19183185.8A EP3589080B1 (en) | 2018-06-29 | 2019-06-28 | Led linear driving circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810692845.XA CN108566702B (en) | 2018-06-29 | 2018-06-29 | LED linear driving circuit |
Publications (2)
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| CN108566702B true CN108566702B (en) | 2024-02-27 |
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| CN201810692845.XA Active CN108566702B (en) | 2018-06-29 | 2018-06-29 | LED linear driving circuit |
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| CN (1) | CN108566702B (en) |
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| CN111312128B (en) * | 2020-02-26 | 2023-08-29 | 歌尔光学科技有限公司 | Driving circuit and digital light processing projector |
| CN112512171A (en) * | 2020-12-25 | 2021-03-16 | 惠州市安规电子有限公司 | LED amplifying unit and dimming drive circuit comprising same |
Citations (7)
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| JP2013016959A (en) * | 2011-07-01 | 2013-01-24 | Sanken Electric Co Ltd | Load drive circuit |
| CN103079314A (en) * | 2012-12-28 | 2013-05-01 | 电子科技大学 | Multipath current-source switching device |
| WO2013107894A1 (en) * | 2012-01-20 | 2013-07-25 | Osram Gmbh | Optoelectronic component device |
| CN103561509A (en) * | 2013-10-17 | 2014-02-05 | 易美芯光（北京）科技有限公司 | LED drive circuit structure with separated switching tube |
| CN206077773U (en) * | 2016-09-29 | 2017-04-05 | 华南理工大学 | A kind of driving lighting circuit of stagewise AC LED |
| WO2017198126A1 (en) * | 2016-05-16 | 2017-11-23 | 上海路傲电子科技有限公司 | Linear constant-current drive circuit |
| CN209234083U (en) * | 2018-06-29 | 2019-08-09 | 宁波伟依特照明电器有限公司 | A kind of LED linear driving circuit |
-
2018
- 2018-06-29 CN CN201810692845.XA patent/CN108566702B/en active Active
-
2019
- 2019-06-28 EP EP19183185.8A patent/EP3589080B1/en active Active
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013016959A (en) * | 2011-07-01 | 2013-01-24 | Sanken Electric Co Ltd | Load drive circuit |
| WO2013107894A1 (en) * | 2012-01-20 | 2013-07-25 | Osram Gmbh | Optoelectronic component device |
| CN103079314A (en) * | 2012-12-28 | 2013-05-01 | 电子科技大学 | Multipath current-source switching device |
| CN103561509A (en) * | 2013-10-17 | 2014-02-05 | 易美芯光（北京）科技有限公司 | LED drive circuit structure with separated switching tube |
| WO2017198126A1 (en) * | 2016-05-16 | 2017-11-23 | 上海路傲电子科技有限公司 | Linear constant-current drive circuit |
| CN206077773U (en) * | 2016-09-29 | 2017-04-05 | 华南理工大学 | A kind of driving lighting circuit of stagewise AC LED |
| CN209234083U (en) * | 2018-06-29 | 2019-08-09 | 宁波伟依特照明电器有限公司 | A kind of LED linear driving circuit |
Also Published As
| Publication number | Publication date |
|---|---|
| EP3589080B1 (en) | 2021-06-16 |
| CN108566702A (en) | 2018-09-21 |
| EP3589080A1 (en) | 2020-01-01 |
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