LED driving circuit

Abstract

This invention discloses a light-emitting diode (LED) driving circuit. The LED 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 also electrically connected to the first LED module. The LED driver circuit provides a first control signal to the first output buck-boost circuit and provides a fixed current to the first LED module. The first output voltage management circuit provides a first voltage feedback signal to the LED driver circuit. The LED driver circuit provides a first output voltage based on the first voltage feedback signal. The first output voltage is variable.

Description

Technical Field

[0001] This invention relates to a light-emitting diode (LED) driving circuit, and more particularly to an LED driving circuit that can provide different output voltages. Background Technology

[0002] The headlight drive circuits used on motorcycles generally use a fixed output voltage. However, due to the development of LED technology, different specifications of LED headlights have been launched one after another. The fixed output voltage drive circuit cannot be used for LED headlights with different drive voltages, which is quite inconvenient for the manufacturing or maintenance process. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a light-emitting diode (LED) driving circuit that addresses the shortcomings of existing technologies. The circuit comprises: an input voltage management circuit receiving 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 it into a first output voltage; an LED driver circuit electrically connected to the input voltage management circuit, the first output buck-boost circuit, and a second output buck-boost circuit; and a first output voltage management circuit electrically connected to the first output buck-boost circuit and the LED driver circuit. Specifically, when the first output buck-boost circuit is electrically connected to a first LED module through the first output voltage management circuit, a first current feedback circuit is electrically connected to the first LED module. The LED driver circuit provides a first control signal to the first output buck-boost circuit and a fixed current to the first LED module. The first output voltage 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. The first output voltage is variable.

[0004] Preferably, the first output buck-boost circuit includes a first switching 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 switching circuit 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 switching circuit, and the PWM signal providing device 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 terminal of the second capacitor is electrically connected to one terminal of the first inductor unit, and the other terminal of the first inductor unit is connected to the first capacitor. The first switch circuit is electrically connected to a first terminal of the first capacitor, a second terminal of the first capacitor is electrically connected to a first terminal of the second inductor, and the other terminal of the second inductor is electrically connected to a ground potential. The first switch circuit is electrically connected to the PWM signal providing device and a first terminal of the sensing impedance, and the other terminal of the sensing impedance is electrically connected to the LED driver circuit. 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 opening and closing of the first switch circuit.

[0005] Preferably, the LED driver circuit is a digital controller.

[0006] Preferably, the first switching circuit is a metal-oxide-semiconductor field-effect transistor, a bipolar transistor, or an insulated-gate bipolar transistor, the first inductor unit is a transformer, and the second inductor unit is an inductor assembly.

[0007] This invention also discloses a light-emitting diode (LED) driving circuit, characterized in that it includes: an input voltage management circuit for receiving a DC input voltage; a first output buck-boost circuit electrically connected to the input voltage management circuit for 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 for 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, 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; and 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 LED module through the first output voltage management circuit, the first current feedback circuit is electrically connected to... Connecting to the first LED module, the LED driver circuit provides a first control signal to the first output buck-boost circuit and a fixed current to the first LED module. The first output voltage 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. When the second output buck-boost circuit is electrically connected to a second LED module through the second output voltage management circuit, the second current feedback circuit is electrically connected to the second LED module. The LED driver circuit provides a second control signal to the first output buck-boost circuit and the fixed current to the second LED 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. The first output voltage and the second output voltage are variable.

[0008] Preferably, the first output voltage and the second output voltage are voltages of different magnitudes.

[0009] Preferably, the LED driver circuit is a digital controller.

[0010] Preferably, the first output buck-boost circuit includes a first switching 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 switching circuit 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 switching circuit, and the PWM signal providing device 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 terminal of the second capacitor is electrically connected to one terminal of the first inductor unit, and the other terminal of the first inductor unit is connected to the first inductor unit. The first switching circuit is electrically connected to a first terminal of the first capacitor, a second terminal of the first capacitor is electrically connected to a terminal of the second inductor, and the other terminal of the second inductor is electrically connected to a ground potential; wherein, the first switching circuit is electrically connected to the PWM signal providing device and a terminal of the sensing impedance, and the other terminal 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 switching circuit according to the control signal, so as to control the opening and closing of the first switching circuit.

[0011] Preferably, the PWM signal providing device is a pulse width modulation signal providing chip.

[0012] Preferably, the first switching circuit is a metal-oxide-semiconductor field-effect transistor, a bipolar transistor, or an insulated-gate bipolar transistor, the first inductor unit is a transformer, and the second inductor unit is an inductor assembly.

[0013] One of the advantages of this invention is that the LED driving circuit provided by this invention can connect one or more identical or different LED modules and provide the voltage required by each LED module, which can quickly select LED modules, speed up the design process, and reduce maintenance costs.

[0014] 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 for reference and illustration only and are not intended to limit the present invention. Attached Figure Description

[0015] Figure 1 This is a functional block diagram of the light-emitting diode driving circuit according to the first embodiment of the present invention.

[0016] Figure 2 This is another functional block diagram of the light-emitting diode driving circuit of the first embodiment of the present invention.

[0017] Figure 3 This is an enlarged schematic diagram of different light-emitting diode modules.

[0018] Figure 4 This is a functional block diagram of the light-emitting diode driving circuit according to the second embodiment of the present invention. Detailed Implementation

[0019] The following specific embodiments illustrate the implementation of the "light-emitting diode driving circuit" disclosed in this invention. Those skilled in the art can understand the advantages and effects of this invention from the content disclosed in this specification. This 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 this invention. Furthermore, the accompanying drawings of this invention are for simple illustrative purposes only and are not depictions of actual dimensions, as stated in advance. The following embodiments will further describe the relevant technical content of this invention in detail, but the disclosed content is not intended to limit the scope of protection of this invention. In addition, the term "or" used herein may, depending on the actual situation, include any combination of any one or more of the associated listed items.

[0020] [First Embodiment]

[0021] Please see Figure 1 as well as Figure 2 , Figure 1 This is a functional block diagram of the light-emitting diode driving circuit according to the first embodiment of the present invention. Figure 2 This is another functional block diagram of the light-emitting diode driving circuit of the first embodiment of the present invention.

[0022] In this embodiment, a light-emitting diode (LED) driving circuit SYS1 is provided. The LED 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.

[0023] In this embodiment, the LED driver circuit SYS1 is a multi-output voltage LED driver circuit. That is, the LED driver circuit SYS1 can simultaneously provide multiple different voltage outputs, and each voltage output is variable.

[0024] The input voltage management circuit 1 is used to receive a DC input voltage VDC. The DC input voltage VDC can be between 5V and 24V. In this embodiment, the DC input voltage VDC is 12V.

[0025] The first output step-up / step-down 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.

[0026] LED driver circuit 3 is electrically connected to input voltage management circuit 1 and first output buck-boost circuit 2.

[0027] 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 a first output voltage OV1 to the first light-emitting diode module LM1, 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 a first output voltage feedback signal VFS1 to the LED driver circuit 3. Then, the LED driver circuit 3 provides a 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 magnitude of the fixed current can be from 0.1A to 1A, and is not limited in this invention.

[0028] The first output voltage OV1 is determined by the first LED module LM1. The first output voltage OV1 is variable. That is, the first output voltage OV1 is determined by the first LED module LM1. When the first LED module LM1 is replaced with another type of LED module, the first output voltage OV1 will be adjusted according to the replaced LED module to provide a voltage suitable for the replaced LED module.

[0029] In this embodiment, the LED 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 can determine whether the first LED module LM1 is operating normally.

[0030] 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.

[0031] The LED driver circuit 3 determines the first output voltage OV1 based on 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 to drive the first light-emitting diode module LM1, based on the first output voltage feedback signal VFS1. The LED driver circuit 3 controls the first output voltage management circuit 4 to output a fixed current, for example, 0.5 amps. Since the first light-emitting diode module LM1 has an impedance, for example, 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 that fixed current (0.5 amps). A 30-ohm (15V) voltage is applied across the first LED module LM1. This 15V voltage signal is the output voltage that the first output voltage management circuit 4 needs to detect. The first output voltage management circuit 4 then uses a voltage detection circuit (not shown) to obtain a first output voltage feedback signal VFS1 from this 15V voltage signal through voltage division or sensing. Next, the first output voltage management circuit 4 transmits 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 enables the first LED module LM1 to emit light based on the first output voltage feedback signal VFS1.

[0032] Please see Figure 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 connected in parallel and are respectively connected to the ground potential.

[0033] The LED driver circuit 3 is a digital controller. That is, the LED driver circuit 3 is a programmable controller that can provide predetermined control signals to the first output buck-boost circuit 2. Furthermore, the LED driver circuit SYS1 also includes a low-dropout voltage converter (LDO) disposed between the DC input voltage VDC and the LED driver circuit 3. The LDO is used to convert the DC input voltage VDC to 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.

[0034] The first output buck-boost circuit 2 includes a first switching 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.

[0035] 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 terminal of the first inductor unit 21 is electrically connected to the first switching circuit 22 and the first terminal 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 inductor unit 23 is electrically connected to ground potential.

[0036] The first switching circuit 22 is connected to the PWM signal providing device 25 and the sensing impedance 25. The sensing impedance 25 is connected to the LED driver circuit 3.

[0037] 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 then provides a pulse width modulation signal to the first switching circuit 22 according to the first control signal, so as to control the opening and closing of the first switching circuit 22.

[0038] In this embodiment, the PWM signal providing device 25 is a pulse width modulation signal providing chip. The first switching 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 assembly.

[0039] 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 terminal of the first capacitor C1 and the second inductor unit 23. The other 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 terminal 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.

[0040] The first output step-up / step-down circuit 2 is a step-up / step-down voltage converter circuit that can provide a constant output voltage or a constant output current. In addition, in this embodiment, the first output step-up / step-down circuit 2 can provide an output voltage within a voltage range, for example, 5V to 30V.

[0041] The first current feedback circuit 5 may include a current sensing impedance to detect the output current and provide a first output current feedback signal CFS1. The LED driver circuit 3 can adjust the brightness of the first light-emitting diode module LM1 or perform overcurrent protection based on the first output current feedback signal CFS1.

[0042] Please see Figure 3The symbols 3A to 3L represent schematic diagrams of different LED modules. Symbols L2 to L5 represent different LED units. Symbols 3A to 3L represent LED units used individually, in series, or in parallel, resulting in different voltage requirements. Therefore, the volt rating next to each LED module in symbols 3A to 3L indicates the required voltage for that module.

[0043] The LED driver circuit SYS1 in this embodiment can be connected to LED modules with different voltage requirements without requiring additional circuit modifications to change the voltage output, which can effectively reduce design and maintenance costs.

[0044] [Second Embodiment]

[0045] Please see Figure 4 , Figure 4 This is a functional block diagram of a light-emitting diode (LED) driving circuit according to a second embodiment of the present invention. This embodiment provides a multi-output LED driving circuit SYS2.

[0046] The LED driver 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 second output buck-boost circuit 6, a second output voltage management circuit 7, and a second current feedback circuit 8.

[0047] In this embodiment, the first output voltage management circuit 4 and the second output voltage management circuit 7 are circuits with the same structure, the first output buck-boost circuit 2 and the second output buck-boost circuit 6 are circuits with the same structure, and the first current feedback circuit 5 and the second current feedback circuit 8 are circuits with the same structure. The circuit structure is described in more detail in the first embodiment and will not be repeated in this embodiment.

[0048] 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 is also electrically connected to the first light-emitting diode module LM1. The first current feedback circuit 5 will then transmit the first current feedback signal CFS1 corresponding to the current flowing through the first light-emitting diode module LM1 to the LED driver circuit 3.

[0049] 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.

[0050] 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. The second current feedback circuit 8 will send the second current feedback signal CFS2 corresponding to the second light-emitting diode module LM2 to the LED driver circuit 3.

[0051] 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 light-emitting diode module LM1.

[0052] 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.

[0053] The first output voltage OV1 is determined by the first LED module LM1, and the second output voltage OV2 is determined by the second LED module LM2. Both the first output voltage OV1 and the second output voltage OV2 are adjustable. That is, the first output voltage OV1 is determined by the first LED module LM1; when the first LED module LM1 is replaced with another type of LED module, the first output voltage OV1 will be adjusted according to the replaced LED module to provide a suitable voltage. 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 LED module LM2.

[0054] The first output voltage management circuit 4 will provide a first output voltage feedback signal VFS1 to the LED driver circuit 3.

[0055] The second output voltage management circuit 7 will provide a second output voltage feedback signal VFS2 to the LED driver circuit 3.

[0056] 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 a first output voltage feedback signal VFS1 to the LED driver circuit 3. Then, the LED driver circuit 3 provides a first output voltage OV1 suitable for the first light-emitting diode module LM1 according to the first output voltage feedback signal VFS1.

[0057] 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 a second output voltage feedback signal VFS2 to the LED driver circuit 3. Then, the LED driver circuit 3 provides a second output voltage OV2 suitable for the second light-emitting diode module LM2 based on the second output voltage feedback signal VFS2. In this embodiment, the magnitude of the fixed current can be from 0.1A to 1A, and is not limited in this invention.

[0058] In this embodiment, the first output voltage OV1 and the second output voltage OV2 can be the same or different voltages.

[0059] 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 buck-boost 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 circuits can be designed as modular circuits and paired with the LED driver circuit 3 to provide multiple sets of adjustable output voltage LED driving circuits.

[0060] [Beneficial Effects of the Examples]

[0061] One of the advantages of this invention is that the LED driving circuit provided by this invention can connect one or more identical or different LED modules and provide the voltage required by each LED module, which can quickly select LED modules, speed up the design process, and reduce maintenance costs.

[0062] The content disclosed above is only a preferred and feasible embodiment of the present invention, and is not intended to limit the scope of the patent application of the present invention. Therefore, all equivalent technical changes made using the contents of the present invention specification and drawings are included in the scope of the patent application of the present invention.

Claims

1. A light-emitting diode driving circuit, characterized in that, include: An input voltage management circuit receives a DC input voltage; A first output step-up / step-down circuit is electrically connected to 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, the first output buck-boost circuit, and a second output buck-boost circuit. A first output voltage management circuit is electrically connected to the first output buck-boost circuit and the LED driver circuit; Specifically, when the first output buck-boost circuit is electrically connected to a first light-emitting diode module through the first output voltage management circuit, a 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. The first output voltage management circuit provides a first voltage feedback signal to the LED driver circuit based on the fixed current received by the first light-emitting diode module. The LED driver circuit provides the first output voltage based on the first voltage feedback signal generated by the fixed current received by the first light-emitting diode module. The first output voltage is variable.

2. The LED driving circuit as described in claim 1, characterized in that, The first output buck-boost circuit includes a first switching circuit, a first inductor unit, a second inductor unit, a sensing impedance, a PWM signal providing device, a first capacitor, and a second capacitor; The first switching circuit is connected to the first inductor unit, and the first inductor unit is connected to the second inductor unit. The PWM signal providing device is electrically connected to the first switching circuit, and the PWM signal providing device 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 a first end of the first inductor unit, the other end of the first inductor unit is electrically connected to the first switching circuit and a first end of the first capacitor, a second end of the first capacitor is electrically connected to a first end of the second inductor unit, and the other end of the second inductor unit is electrically connected to a ground potential; The first switching 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. 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 switching circuit according to the control signal, so as to control the opening and closing of the first switching circuit.

3. The LED driving circuit as described in claim 2, characterized in that, The LED driver circuit is a digital controller.

4. The LED driving circuit as described in claim 3, characterized in that, The first switching circuit is a metal-oxide-semiconductor field-effect transistor, a bipolar transistor, or an insulated-gate bipolar transistor. The first inductor unit is a transformer, and the second inductor unit is an inductor assembly.

5. A light-emitting diode driving circuit, characterized in that, include: An input voltage management circuit receives a DC input voltage; A first output step-up / step-down circuit is electrically connected to the input voltage management circuit, receives the DC input voltage, and converts the DC input voltage into a first output voltage; A second output step-up / step-down circuit is electrically connected to the input voltage management circuit, receives the DC input voltage, and converts the DC input voltage 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 buck-boost circuit. A first output voltage management circuit is electrically connected to the first output buck-boost circuit and the LED driver circuit; A second output voltage management circuit is electrically connected to the second output buck-boost circuit and the LED driver circuit; Specifically, when the first output buck-boost circuit is electrically connected to a first light-emitting diode module through the first output voltage management circuit, a 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. The first output voltage management circuit provides a first voltage feedback signal to the LED driver circuit based on the fixed current received by the first light-emitting diode module. The LED driver circuit provides the first output voltage based on the first voltage feedback signal generated by the fixed current received by the first light-emitting diode module. Specifically, when the second output buck-boost circuit is electrically connected to a second LED module through the second output voltage management circuit, a second current feedback circuit is electrically connected to the second LED 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 LED module. The second output voltage management circuit provides a second voltage feedback signal to the LED driver circuit based on the fixed current received by the second LED module. The LED driver circuit provides the second output voltage based on the second voltage feedback signal generated by the fixed current received by the second LED module. The first output voltage and the second output voltage are variable.

6. The LED driving circuit as described in claim 5, characterized in that, The first output voltage and the second output voltage are voltages of different magnitudes.

7. The LED driving circuit as described in claim 5, characterized in that, The LED driver circuit is a digital controller.

8. The LED driving circuit as described in claim 5, characterized in that, The first output buck-boost circuit includes a first switching circuit, a first inductor unit, a second inductor unit, a sensing impedance, a PWM signal providing device, a first capacitor, and a second capacitor; The first switching circuit is connected to the first inductor unit, and the first inductor unit is connected to the second inductor unit. The PWM signal providing device is electrically connected to the first switching circuit, and the PWM signal providing device 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 a first end of the first inductor unit, the other end of the first inductor unit is electrically connected to the first switching circuit and a first end of the first capacitor, a second end of the first capacitor is electrically connected to a first end of the second inductor unit, and the other end of the second inductor unit is electrically connected to a ground potential; The first switching 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. 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 switching circuit according to the control signal, so as to control the opening and closing of the first switching circuit.

9. The LED driving circuit as described in claim 8, characterized in that, The PWM signal providing device is a pulse width modulation signal providing chip.

10. The light-emitting diode driving circuit as described in claim 9, characterized in that, The first switching circuit is a metal-oxide-semiconductor field-effect transistor, a bipolar transistor, or an insulated-gate bipolar transistor. The first inductor unit is a transformer, and the second inductor unit is an inductor assembly.

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