TW202341813A - Light-emitting diode driving circuit - Google Patents

Abstract

A light-emitting diode driving circuit is provided. The a light-emitting diode driving circuit includes an input voltage management circuit, a first output buck-boost circuit, an LED driver circuit, a first output voltage management circuit and a first current feedback circuit. When the first output buck-boost circuit is electrically connected to a first LED module, the first current feedback circuit is electrically connected to the first LED module, and the LED driver circuit provides the first control signal to the first LED driver circuit. The output buck-boost circuit provides a fixed current to the first light-emitting diode module. The first output voltage management circuit provides a first voltage feedback signal to the LED driver circuit. The LED driver circuit provides the first output voltage according to the first voltage feedback signal. The first output voltage is variable.

Description

Light emitting diode drive circuit

The present invention relates to a light-emitting diode driving circuit, and in particular to a light-emitting diode driving circuit that can provide different output voltages.

Generally, the car light driving circuits used on motorcycles use a fixed output voltage. However, due to the development of LED technology, LED car lights of different specifications have been launched one after another. The driving circuit with a fixed output voltage cannot be applied to LED car lights with different driving voltages. , which is quite inconvenient for the manufacturing process or maintenance process.

The technical problem to be solved by the present invention is to provide a light-emitting diode driving circuit in view of the shortcomings of the existing technology, including: an input voltage management circuit that receives a DC input voltage; a first output voltage-boosting and bucking circuit that is electrically connected to all The input voltage management circuit receives the DC input voltage and converts the DC input voltage into a first output voltage; an LED driver circuit is electrically connected to the input voltage management circuit and the first output buck-boost circuit. circuit and the second output buck-boost circuit; a first output voltage management circuit electrically connected to the first output buck-boost circuit and the LED driver circuit; a first current feedback circuit electrically connected to all The LED driver circuit; wherein, when the first output buck-boost circuit is electrically connected to a first light-emitting diode module, the first current feedback circuit is electrically connected to the first light-emitting diode module. The LED driver circuit provides a first control signal to the first output buck-boost circuit and a fixed current to the first light-emitting diode module, and the first output voltage management circuit provides a A first voltage feedback signal is provided to the LED driver circuit, and the LED driver circuit provides the first output voltage according to the first voltage feedback signal; wherein the first output voltage is variable.

In order to solve the above technical problems, one of the technical solutions adopted by the present invention is to provide a light-emitting diode driving circuit, which includes: an input voltage management circuit that receives a DC input voltage; a first output buck-boost circuit that electrically electrically connected to the input voltage management circuit, receiving the DC input voltage, and converting the DC input voltage into a first output voltage; a second output buck-boost circuit, electrically connected to the input voltage management circuit, receiving The DC input voltage is converted into a second output voltage; an LED driver circuit is electrically connected to the input voltage management circuit, the first output buck-boost circuit and the second output A buck-boost circuit; a first output voltage management circuit electrically connected to the first output buck-boost circuit and the LED driver circuit; a second output voltage management circuit electrically connected to the second output buck-boost circuit circuit and the LED driver circuit; a first current feedback circuit, electrically connected to the LED driver circuit; a second current feedback circuit, electrically connected to the LED driver circuit; wherein, when the first output rises and falls When the voltage circuit is electrically connected to a first light-emitting diode module, the first current feedback circuit is electrically connected to the first light-emitting diode module, and the LED driver circuit provides a first control signal to The first output buck-boost circuit provides a fixed current to the first light-emitting diode module, and the first output voltage management circuit provides a first voltage feedback signal to the LED driver circuit. The LED driver circuit provides the first output voltage according to the first voltage feedback signal; wherein, when the second output buck-boost circuit is electrically connected to a second light-emitting diode module, the second current The feedback circuit is electrically connected to the second light-emitting diode module, the LED driver circuit provides a second control signal to the first output buck-boost circuit, and provides the fixed current to the second light-emitting diode module. In the polar body module, the second output voltage management circuit provides a second voltage feedback signal to the LED driver circuit, and the LED driver circuit provides the second output voltage according to the second voltage feedback signal; wherein, The first output voltage and the second output voltage are variable.

One of the beneficial effects of the present invention is that the light-emitting diode driving circuit provided by the present invention can connect one or more identical or different light-emitting diode modules, and provide the required information for each light-emitting diode module. voltage, LED modules can be quickly selected, speeding up design and reducing maintenance costs.

In order to further understand the features and technical content of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are only for reference and illustration and are not used to limit the present invention.

The following is a specific embodiment to illustrate the implementation of the "light emitting diode driving circuit" disclosed in the present invention. Those skilled in the art can understand the advantages and effects of the present invention from the content disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of the present invention. In addition, the drawings of the present invention are only simple schematic illustrations and are not depictions based on actual dimensions, as is stated in advance. The following embodiments will further describe the relevant technical content of the present invention in detail, but the disclosed content is not intended to limit the scope of the present invention. In addition, the term "or" used in this article shall include any one or combination of more of the associated listed items depending on the actual situation.

[First Embodiment]

Please refer to FIG. 1 and FIG. 2 . FIG. 1 is a functional block diagram of a light-emitting diode driving circuit according to the first embodiment of the present invention. FIG. 2 is another functional block diagram of the light-emitting diode driving circuit according to the first embodiment of the present invention.

In this embodiment, a light-emitting diode driving circuit SYS1 is provided. The light-emitting diode driving circuit SYS1 includes an input voltage management circuit 1, a first output buck-boost circuit 2, an LED driver circuit 3, a first output voltage management circuit 4 and a first current feedback circuit 5.

In this embodiment, the light-emitting diode driving circuit SYS1 is a multi-output voltage light-emitting diode driving circuit. That is, the light-emitting diode driving circuit SYS1 can provide outputs of multiple different voltages at the same time, and each voltage output is variable.

The input voltage management circuit 1 is used to receive a direct current input voltage VDC. The DC input voltage VDC can range from 5V to 24V. In this embodiment, the DC input voltage VDC is 12V.

The first output buck-boost circuit 2 is electrically connected to the input voltage management circuit 1, receives the DC input voltage VDC, and converts the DC input voltage VDC into a first output voltage OV1.

The LED driver circuit 3 is electrically connected to the input voltage management circuit 1 and the first output buck-boost circuit 2 .

When the first output buck-boost circuit 2 is electrically connected to a first light-emitting diode module LM1 through the first output voltage management circuit 4, and the first output buck-boost circuit 2 provides the first output voltage OV1 to the first light-emitting diode module LM1 Diode module LM1. At this time, the LED driver circuit 3 controls the first output buck-boost circuit 2 to provide a fixed current to the first light-emitting diode module LM1, so that the first output voltage management circuit 4 provides the first output voltage feedback signal VFS1 to LED driver circuit 3. Then the LED driver circuit 3 provides the first output voltage OV1 that allows the first light-emitting diode module LM1 to emit light according to the first output voltage feedback signal VFS1. In this embodiment, the size of the fixed current may be 0.1A to 1A, which is not limited in the present invention.

The first output voltage OV1 is determined according to the first light-emitting diode module LM1. The first output voltage OV1 is variable. That is to say, the first output voltage OV1 is determined based on the first light-emitting diode module LM1. When the first light-emitting diode module LM1 is changed to another type of light-emitting diode module, the first output voltage OV1 OV1 will be adjusted according to the replaced LED module to provide a voltage suitable for the replaced LED module.

In this embodiment, the light-emitting diode driving circuit SYS1 further includes a first current feedback circuit 5 and a first output voltage management circuit 4 . The first current feedback circuit 5 is electrically connected to the LED driver circuit 3 and is used to provide a first output current feedback signal CFS1 to the LED driver circuit 3 so that the LED driver circuit 3 determines whether the first light-emitting diode module LM1 operates normally. .

The first output voltage management circuit 4 is electrically connected to the LED driver circuit 3 and is used to provide a first output voltage feedback signal VFS1 to the LED driver circuit 3 .

The LED driver circuit 3 determines the first output voltage OV1 according to the first output voltage feedback signal VFS1. The LED driver circuit 3 controls the first output voltage management circuit 4 to output a first output voltage OV1 for driving the first light-emitting diode module LM1 according to the first output voltage feedback signal VFS1. The LED driver circuit 3 controls the first output voltage management circuit 4 to a fixed current, such as 0.5 amps. Since the first light-emitting diode module LM1 has an impedance, such as 30 ohms, when a fixed current of 0.5 amps flows through the first light-emitting diode module LM1, there will be a voltage corresponding to the fixed current of 0.5 amps. (0.5 amps * 30 ohms = 15V) across the first light-emitting diode module LM1. This 15V voltage signal is the output voltage that the first output voltage management circuit 4 needs to detect. Then the first output voltage management circuit 4 will pass this 15V voltage signal through a voltage detection circuit (not shown). The first output voltage feedback signal VFS1 is obtained through voltage division or sensing. Then, the first output voltage management circuit 4 sends the first output voltage feedback signal VFS1 to the LED driver circuit 3 . Then, the LED driver circuit 3 determines the first output voltage OV1 that can cause the first light-emitting diode module LM1 to emit light according to the first output voltage feedback signal VFS1.

Referring to FIG. 2 , the input voltage management circuit 1 includes an input filter circuit 11 , an input voltage protection circuit 12 and an input voltage detection circuit 13 . In this embodiment, the input filter circuit 11 , the input voltage protection circuit 12 and the input voltage detection circuit 13 are arranged in parallel and connected to the ground potential respectively.

LED driver circuit 3 is a digital controller. That is, the LED driver circuit 3 is a programmable controller that can provide a predetermined control signal to the first output buck-boost circuit 2 . In addition, the light-emitting diode driving circuit SYS1 also includes a low dropout voltage conversion circuit LDO, which is arranged between the DC input voltage VDC and the LED driver circuit 3 . The low dropout voltage conversion circuit LDO is used to convert the DC input voltage VDC into a voltage suitable for the LED driver circuit 3. In other embodiments, the LED driver circuit 3 may also receive the DC voltage converted by the input voltage management circuit 1 as the driving voltage.

The first output buck-boost circuit 2 includes a first switch circuit 22, a first inductor unit 21, a second inductor unit 23, a sensing impedance 24, a PWM signal providing device 25, a first capacitor C1 and a second capacitor C2.

In this embodiment, the first terminal of the second capacitor C2 is electrically connected to one terminal of the first inductor unit 21 . The other end of the first inductor unit 21 is electrically connected to the first switch circuit 22 and the first end of the first capacitor C1. The second terminal of the first capacitor C1 is electrically connected to one terminal of the second inductor unit 23 . The second inductance unit 23 is electrically connected to the ground potential.

The first switch circuit 22 is connected to the PWM signal providing device 25 and the sensing impedance 25 . Sense impedance 25 is connected to LED driver circuit 3.

In this embodiment, the LED driver circuit 3 provides a first control signal to the PWM signal providing device 25 . The PWM signal providing device 25 will provide a pulse width modulation signal to the first switch circuit 22 according to the first control signal to control the opening and closing of the first switch circuit 22.

In this embodiment, the PWM signal providing device 25 is a pulse width modulation signal providing chip. The first switch circuit 22 is a metal oxide semiconductor field effect transistor (MOSFET), a bipolar transistor (BJT) or an insulated gate bipolar transistor (IGBT). The first inductor unit 22 is a transformer. The second inductor unit 23 is an inductor element.

The first output voltage management circuit 4 includes an output voltage detection circuit 42 and an output filter circuit 41 . One end of the output filter circuit 41 is connected to the second end of the first capacitor C1 and the second inductor unit 23 . One end of the output filter circuit 41 is connected to the first light-emitting diode module LM1. One end of the output voltage detection circuit 42 is connected to one end of the output filter circuit 41 and the second end of the first capacitor C1. The other end of the output voltage detection circuit 42 is connected to the LED driver circuit 3 to provide a voltage feedback signal VFS.

The first output buck-boost circuit 2 is a buck-boost voltage converter circuit that can provide a constant voltage output voltage or a constant current output current. In addition, the first output buck-boost circuit 2 in this embodiment can provide a Output voltage within the voltage range, for example: 5V to 30V.

The first current feedback circuit 5 may include a current sensing impedance to detect the output current to provide a first output current feedback signal CFS1. The LED driver circuit 3 can perform brightness adjustment or over-current protection of the first light-emitting diode module LM1 according to the first output current feedback signal CFS1.

Please refer to Figure 3. Reference numbers 3A to 3L are schematic diagrams of different light-emitting diode modules. Labels L2 to L5 represent different light-emitting diode units. Labels 3A to 3L are respectively composed of multiple light-emitting diode units used individually, in series, or in parallel, which will produce different voltage requirements. Therefore, the number of volts next to each LED module in labels 3A to 3L is the voltage required by each LED module.

The light-emitting diode driving circuit SYS1 of this embodiment can be connected to light-emitting diode modules with different voltage requirements without the need to modify the circuit to change the voltage output, which can effectively reduce design costs and maintenance costs.

[Second Embodiment]

Please refer to FIG. 4 , which is a functional block diagram of a light-emitting diode driving circuit according to a second embodiment of the present invention. In this embodiment, a multi-output light-emitting diode driving circuit SYS2 is provided.

The light-emitting diode driving circuit SYS2 includes an input voltage management circuit 1, a first output buck-boost circuit 2, an LED driver circuit 3, a first output voltage management circuit 4, a first current feedback circuit 5, a first Two output boost and buck circuits 6 , a second output voltage management circuit 7 and a second current feedback circuit 8 .

In this embodiment, the first output voltage management circuit 4 and the second output voltage management circuit 7 are circuits with the same structure, and the first output voltage boost circuit 2 and the second output voltage boost circuit 6 are circuits with the same structure. The first current feedback circuit 5 and the second current feedback circuit 8 have the same structure. The circuit structure is described in more detail in the first embodiment and will not be described again in this embodiment.

The first output buck-boost circuit 2 is connected to the first output voltage management circuit 4 . The first output buck-boost circuit 2 and the first output voltage management circuit 4 are electrically connected to the LED driver circuit 3 . When the first output voltage management circuit 4 is connected to the first light-emitting diode module LM1, the first current feedback circuit 5 will also be electrically connected to the first light-emitting diode module LM1, and the first current feedback circuit 5 will The first current feedback signal CFS1 corresponding to the current flowing through the first light-emitting diode module LM1 is sent to the LED driver circuit 3 .

Similarly, the second output buck-boost circuit 6 is connected to the second output voltage management circuit 7 . The second output buck-boost circuit 6 and the second output voltage management circuit 7 are connected to the LED driver circuit 3 . The second current feedback circuit 8 is also electrically connected to the LED driver circuit 3 .

When the second output voltage management circuit 7 is connected to the second light-emitting diode module LM2, the second current feedback circuit 8 will also be electrically connected to the second light-emitting diode module LM2, and the second current feedback circuit 8 will The second current feedback signal CFS2 corresponding to the second light-emitting diode module LM2 flows to the LED driver circuit 3 .

When the first output buck-boost circuit 4 is electrically connected to a first light-emitting diode module LM1, the first output buck-boost circuit 2 and the first output voltage management circuit 4 will output a first output voltage OV1 to the first output voltage OV1. One light-emitting diode module LM1.

When the second output buck-boost circuit 6 is electrically connected to a second light-emitting diode module LM2, the second output buck-boost circuit 6 and the second output voltage management circuit 7 will output a second output voltage OV2 to the second light-emitting diode module LM2. Two LED modules LM2.

The first output voltage OV1 is determined based on the first light-emitting diode module LM1, and the second output voltage OV2 is determined based on the second light-emitting diode module LM2. The first output voltage OV1 and the second output voltage OV2 are adjustable. That is to say, the first output voltage OV1 is determined based on the first light-emitting diode module LM1. When the first light-emitting diode module LM1 is changed to another type of light-emitting diode module, the first output voltage OV1 OV1 will be adjusted according to the replaced LED module to provide a voltage suitable for the replaced LED module. Similarly, the second output voltage OV2 provided by the output buck-boost circuit 2 can also be adjusted according to the type of the connected second light-emitting diode module LM2 .

The first output voltage management circuit 4 provides a first output voltage feedback signal VFS1 to the LED driver circuit 3 .

The second output voltage management circuit 7 provides a second output voltage feedback signal VFS2 to the LED driver circuit 3 .

First, the LED driver circuit 3 controls the first output buck-boost circuit 2 to provide a fixed current to the first light-emitting diode module LM1, so that the first output voltage management circuit 4 provides the first output voltage feedback signal VFS1 to the LED. Driver circuit 3. Then the LED driver circuit 3 provides the first output voltage OV1 suitable for the first light-emitting diode module LM1 according to the first output voltage feedback signal VFS1.

Similarly, the LED driver circuit 3 controls the second output buck-boost circuit 6 to provide a fixed current to the second light-emitting diode module LM2, so that the second output voltage management circuit 6 provides the second output voltage feedback signal VFS2 to LED driver circuit 3. Then the LED driver circuit 3 provides the second output voltage OV2 suitable for the second light-emitting diode module LM2 according to the second output voltage feedback signal VFS2. In this embodiment, the size of the fixed current may be 0.1A to 1A, which is not limited in the present invention.

In this embodiment, the first output voltage OV1 and the second output voltage OV2 may be voltages of the same magnitude or different magnitudes.

In this embodiment, the first output buck-boost circuit 2, the first output voltage management circuit 4 and the first current feedback circuit 5, together with the LED driver circuit 3, jointly output the first output voltage OV1. The second output step-up and step-down circuit 6, the second output voltage management circuit 7 and the second current feedback circuit 8, together with the LED driver circuit 3, jointly output the second output voltage OV2. These two sets of circuits can be designed as modular circuits respectively and matched with the LED driver circuit 3 to provide multiple sets of light-emitting diode driving circuits with adjustable output voltages.

[Beneficial effects of the embodiment]

One of the beneficial effects of the present invention is that the light-emitting diode driving circuit provided by the present invention can connect one or more identical or different light-emitting diode modules, and provide the required information for each light-emitting diode module. voltage, LED modules can be quickly selected, speeding up design and reducing maintenance costs.

The contents disclosed above are only preferred and feasible embodiments of the present invention, and do not limit the scope of the patent application of the present invention. Therefore, all equivalent technical changes made by using the description and drawings of the present invention are included in the application of the present invention. within the scope of the patent.

SYS1, SYS2: LED driver circuit 1: Input voltage management circuit 2: First output buck-boost circuit 3:LED driver circuit 4: First output voltage management circuit 5: First current feedback circuit VDC: DC input voltage LM1: The first light-emitting diode module OV1: first output voltage VFS1: first output voltage feedback signal CFS1: first output current feedback signal 6: Second output buck-boost circuit 7: Second output voltage management circuit 8: Second current feedback circuit LM2: Second LED module OV2: Second output voltage VFS2: Second output voltage feedback signal CFS2: Second output current feedback signal 11:Input filter circuit 12:Input voltage protection circuit 13:Input voltage detection circuit 21: First inductor unit C1: first capacitor C2: second capacitor LDO: low dropout voltage conversion circuit 22: First switch circuit 23: Second inductance unit 24: Sensing impedance 25:PWM signal providing device 41: Output filter circuit 42: Output voltage detection circuit

FIG. 1 is a functional block diagram of a light-emitting diode driving circuit according to the first embodiment of the present invention.

FIG. 2 is another functional block diagram of the light-emitting diode driving circuit according to the first embodiment of the present invention.

Figure 3 is an enlarged schematic diagram of different light-emitting diode modules.

FIG. 4 is a functional block diagram of a light-emitting diode driving circuit according to the second embodiment of the present invention.

SYS1: LED driver circuit

1: Input voltage management circuit

2: First output buck-boost circuit

3:LED driver circuit

4: First output voltage management circuit

5: First current feedback circuit

VDC: DC input voltage

LM1: The first light-emitting diode module

OV1: first output voltage

VFS1: first output voltage feedback signal

CFS1: first output current feedback signal

Claims (10)

A light-emitting diode driving circuit, including: An input voltage management circuit receives a DC input voltage; a first output buck-boost circuit, electrically connected to the input voltage management circuit, receiving the DC input voltage, and converting the DC input voltage into a first output voltage; An LED driver circuit electrically connected to the input voltage management circuit and the first output buck-boost circuit and the second output buck-boost circuit; a first output voltage management circuit electrically connected to the first output buck-boost circuit and the LED driver circuit; Wherein, when the first output buck-boost circuit is electrically connected to a first light-emitting diode module through the first output voltage management circuit, the first current feedback circuit is electrically connected to the first light-emitting diode module. Diode module, the LED driver circuit provides a first control signal to the first output buck-boost circuit, provides a fixed current to the first light-emitting diode module, the first output voltage The management circuit provides a first voltage feedback signal to the LED driver circuit, and the LED driver circuit provides the first output voltage according to the first voltage feedback signal; Wherein, the first output voltage is variable. The light-emitting diode driving circuit of claim 1, wherein the first output buck-boost circuit includes a first switch circuit, a first inductor unit, a second inductor unit, a sensing impedance, a PWM signal providing device, a first capacitor and a second capacitor; Wherein, the first switch circuit is connected to the first inductor unit, and the first inductor unit is connected to the second inductor unit; Wherein, the PWM providing circuit is electrically connected to the first switching unit, and the driving signal providing circuit provides a pulse width modulation signal to the first switching circuit to control the opening and closing of the first switching circuit. ; Wherein, a first end of the second capacitor is electrically connected to one end of the first inductance unit, and the other end of the first inductance unit is electrically connected to the first switch circuit and a side of the first capacitor. A first end, a second end of the first capacitor is electrically connected to one end of the second inductance unit, and the other end of the second inductance unit is electrically connected to a ground potential; The first switch circuit is electrically connected to the PWM signal providing device and one end of the sensing impedance, and the other end of the sensing impedance is electrically connected to the LED driver circuit; Wherein, the LED driver circuit provides a control signal to the PWM signal providing device, and the PWM signal providing device provides a pulse width modulation signal to the first switch circuit according to the control signal to control the first switch. Opening and closing of circuits. The light-emitting diode driver circuit of claim 2, wherein the LED driver circuit is a digital controller. The light-emitting diode driving circuit of claim 3, wherein the first switch circuit is a metal-oxide semiconductor field-effect transistor (MOSFET), a bipolar transistor (BJT) or an insulated gate dual-electrode transistor. Polar transistor (IGBT), the first inductance unit is a transformer, and the second inductance unit is an inductance element. A light-emitting diode driving circuit, including: An input voltage management circuit receives a DC input voltage; a first output buck-boost circuit, electrically connected to the input voltage management circuit, receiving the DC input voltage, and converting the DC input voltage into a first output voltage; a second output buck-boost circuit, electrically connected to the input voltage management circuit, receiving the DC input voltage, and converting the DC input voltage into a second output voltage; An LED driver circuit electrically connected to the input voltage management circuit and the first output buck-boost circuit and the second output buck-boost circuit; a first output voltage management circuit electrically connected to the first output buck-boost circuit and the LED driver circuit; a second output voltage management circuit electrically connected to the second output buck-boost circuit and the LED driver circuit; Wherein, when the first output buck-boost circuit is electrically connected to a first light-emitting diode module through the first output voltage management circuit, the first current feedback circuit is electrically connected to the first light-emitting diode module. Diode module, the LED driver circuit provides a first control signal to the first output buck-boost circuit, provides a fixed current to the first light-emitting diode module, the first output voltage The management circuit provides a first voltage feedback signal to the LED driver circuit, and the LED driver circuit provides the first output voltage according to the first voltage feedback signal; Wherein, when the second output buck-boost circuit is electrically connected to a second light-emitting diode module through the second output voltage management circuit, the second current feedback circuit is electrically connected to the second light-emitting diode module. diode module, the LED driver circuit provides a second control signal to the first output buck-boost circuit, provides the fixed current to the second light-emitting diode module, the second output The voltage management circuit provides a second voltage feedback signal to the LED driver circuit, and the LED driver circuit provides the second output voltage according to the second voltage feedback signal; Wherein, the first output voltage and the second output voltage are variable. The light-emitting diode driving circuit of claim 5, wherein the first output voltage and the second output voltage are voltages of different magnitudes. The light-emitting diode driver circuit of claim 5, wherein the LED driver circuit is a digital controller. The light-emitting diode driving circuit of claim 5, wherein the first output buck-boost circuit includes a first switch circuit, a first inductor unit, a second inductor unit, a sensing impedance, a PWM signal providing device, a first capacitor and a second capacitor; Wherein, the first switch unit is connected to the first inductor unit, and the first inductor unit is connected to the second inductor unit; Wherein, the PWM signal providing device is electrically connected to the first switch unit, and the PWM signal providing device provides a pulse width modulation signal to the first switch unit to control the opening and closing of the first switch unit. close; Wherein, a first end of the second capacitor is electrically connected to one end of the first inductance unit, and the other end of the first inductance unit is electrically connected to the first switch circuit and a side of the first capacitor. A first end, a second end of the first capacitor is electrically connected to one end of the second inductance unit, and the other end of the second inductance unit is electrically connected to a ground potential; The first switch circuit is electrically connected to the PWM signal providing device and one end of the sensing impedance, and the other end of the sensing impedance is electrically connected to the LED driver circuit; Wherein, the LED driver circuit provides the first control signal to the PWM signal providing device, and the PWM signal providing device provides a pulse width modulation signal to the first switch circuit according to the control signal to control The opening and closing of the first switch circuit. The light-emitting diode driving circuit of claim 8, wherein the PWM signal providing device is a pulse width modulation signal providing chip. The light-emitting diode driving circuit of claim 9, wherein the first switch circuit is a metal oxide semiconductor field effect transistor (MOSFET), a bipolar transistor (BJT) or an insulated gate dual Polar transistor (IGBT), the first inductance unit is a transformer, and the second inductance unit is an inductance element.

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