LED boost constant current control circuit

Abstract

The utility model belongs to the technical field of LEDs, and relates to an LED boost constant current control circuit, which comprises a protection circuit, an electromagnetic compatibility circuit, an AC-DC rectification circuit, a starting circuit, an integrated control circuit, a constant current sampling circuit, an overvoltage protection circuit and an output filter circuit which are electrically connected in sequence, and is characterized in that the protection circuit is used for protecting the LED boost constant current control circuit; the electromagnetic compatibility circuit is used for reducing electromagnetic interference and enhancing electromagnetic sensitivity of the circuit, the AC-DC rectifying circuit is used for providing a direct current power supply, and the starting circuit is used for providing a starting signal to enable the integrated control circuit to enter a working state. The integrated control circuit is used for receiving an input signal and controlling the working state of the LED boost constant current control circuit. The adaptivity of the power supply can be effectively improved, the application range of the power supply is widened, and implementation of a full-voltage working scene of the power supply is realized.

Description

Technical Field

[0001] The utility model relates to the technical field of LEDs, and more specifically to an LED boost constant current control circuit. Background Art

[0002] LED boost constant current control circuits are used to drive LED lamps, ensuring they operate at high voltage while maintaining a constant current. Existing LED boost constant current control circuits utilize transformers with auxiliary windings, which complicates the manufacturing process and places higher demands on winding layout, insulation design, and control circuit design. This results in high cost and system instability when the input voltage is unstable. Furthermore, existing technologies employ a single resistor to step down the power supply, or draw power from other low-voltage sources. This approach is only suitable for built-in MOS systems and is not suitable for high-power, full-voltage applications. Utility Model Content

[0003] In view of the above-mentioned defects of the prior art, the present invention provides an LED boost constant current control circuit, comprising:

[0004] The protection circuit, electromagnetic compatibility circuit, AC-DC rectifier circuit, startup circuit, integrated control circuit, constant current sampling circuit, overvoltage protection circuit and output filter circuit are electrically connected in sequence. The protection circuit is used to protect the LED boost constant current control circuit, the electromagnetic compatibility circuit is used to reduce electromagnetic interference and enhance the electromagnetic sensitivity of the circuit, the AC-DC rectifier circuit is used to provide a DC power supply, the startup circuit is used to provide a startup signal to put the integrated control circuit into operation, the integrated control circuit is used to receive an input signal and control the operating state of the LED boost constant current control circuit, the constant current sampling circuit is used to monitor the current value in the LED lamp bead in real time and feed back the sampling result to the integrated control circuit, the overvoltage protection circuit is used to perform overvoltage protection on the LED boost constant current control circuit, and the output filter circuit is used to smooth the ripple and noise in the output voltage.

[0005] Preferably, the protection circuit includes: one end of a fuse F1 is connected to one end of a varistor RV1.

[0006] Preferably, the electromagnetic compatibility circuit includes: pin 3 of the common-mode inductor L1 is respectively connected to one end of the capacitor CY1, one end of the capacitor CX1, one end of the resistor R1, and pin 1 of the common-mode inductor L2, the other end of the capacitor CY1 is connected to one end of the capacitor CY2, the pin 4 of the common-mode inductor L1 is respectively connected to the other end of the capacitor CY2, the other end of the capacitor CX1, and one end of the resistor R3, the other end of the resistor R1 is connected to one end of the resistor R2, and the other end of the resistor R2 is connected to the other end of the resistor R3.

[0007] Preferably, the AC-DC rectifier circuit includes: a rectifier bridge BG1.

[0008] Preferably, the starting circuit includes: one end of the resistor R23 is connected to one end of the resistor R24, the other end of the resistor R24 ​​is connected to one end of the resistor R25, the other end of the resistor R25 is connected to one end of the diode ZD1, the other end of the diode ZD1 is connected to one end of the capacitor C9, the other end of the capacitor C9 is connected to the positive electrode of the diode D2, the negative electrode of the diode D2 is respectively connected to one end of the resistor R7 and one end of the capacitor C1, the other end of the resistor R7 is connected to one end of the resistor R6, and the other end of the resistor R6 is connected to the other end of the resistor R23.

[0009] Preferably, the integrated control circuit includes: pin 4 of the power management chip U1 is connected to one end of the resistor R8, the other end of the resistor R8 is respectively connected to the cathode of the diode D1 and one end of the resistor R9, and the anode of the diode D1 is respectively connected to the other end of the resistor R9 and the base of the power tube Q1.

[0010] Preferably, the constant current sampling circuit includes: one end of the resistor R11 is respectively connected to one end of the resistor R12, one end of the resistor R13, one end of the resistor R14, one end of the resistor R15, and one end of the resistor R22, and the other end of the resistor R11 is respectively connected to the other end of the resistor R12, the other end of the resistor R13, the other end of the resistor R14, and the other end of the resistor R15.

[0011] Preferably, the overvoltage protection circuit includes: one end of the resistor R17 is connected to one end of the resistor R18, the other end of the resistor R18 is connected to one end of the resistor R19, the other end of the resistor R19 is respectively connected to one end of the resistor R20, one end of the resistor R5, and one end of the capacitor C10, and the other end of the resistor R20 is respectively connected to the other end of the resistor R5 and the other end of the capacitor C10.

[0012] Preferably, the output filter circuit includes: pin 1 of the inductor L5 is connected to one end of the resistor R27, the positive electrode of the capacitor EC2, and the positive electrode of the capacitor EC1 respectively; the other end of the resistor R27 is connected to one end of the resistor R26; the other end of the resistor R26 is connected to one end of the resistor R29; the other end of the resistor R29 is connected to the negative electrode of the capacitor EC2, the negative electrode of the capacitor EC1, and the pin 2 of the inductor L5 and is grounded; the pin 3 of the inductor L5 is connected to the LED+, and the pin 4 of the inductor L5 is connected to the LED-

[0013] Preferably, the LED boost constant current control circuit further includes a surge protection circuit, and the surge protection circuit is connected to the startup circuit and the overvoltage protection circuit.

[0014] The implementation of the LED boost constant current control circuit of the present invention has the following beneficial effects: by adopting a protection circuit, an electromagnetic compatibility circuit, an AC-DC rectifier circuit, a starting circuit, an integrated control circuit, a constant current sampling circuit, an overvoltage protection circuit and an output filter circuit that are electrically connected in sequence, it can ensure that the power supply can work when the low voltage input is 85V, and can work stably when the high voltage input is 265V; it can effectively improve the adaptability of the power supply, widen the application range of the power supply, and realize the implementation of the full voltage working scenario of the power supply without being affected by circuit conversion; the output current is stable, and at the same time, it is not easy to have problems such as current fluctuation, which can effectively improve the stability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative work. The following will further illustrate the present invention in conjunction with the drawings and embodiments. In the drawings:

[0016] Figure 1 This is a block diagram of the LED boost constant current control circuit of the utility model;

[0017] Figure 2 This is a circuit diagram of a preferred embodiment of the LED boost constant current control circuit of the utility model;

[0018] Figure 3 This is a schematic diagram of the circuit module division of a preferred embodiment of the LED boost constant current control circuit of the present invention.

[0019] In the figure, 10-protection circuit, 20-electromagnetic compatibility circuit, 30-AC-DC rectifier circuit, 40-start-up circuit, 50-integrated control circuit, 60-constant current sampling circuit, 70-overvoltage protection circuit, 80-output filter circuit, 90-surge protection circuit, 100-π-type filter circuit. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0021] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0022] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features specified as "first" or "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that ordinary technicians in this field can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0023] See also Figure 1 , is a block diagram of the LED boost constant current control circuit of the utility model. Figure 1As shown, the LED boost constant current control circuit provided in the first embodiment of the present invention includes at least a protection circuit 10, an electromagnetic compatibility circuit 20, an AC-DC rectifier circuit 30, a starting circuit 40, an integrated control circuit 50, a constant current sampling circuit 60, an overvoltage protection circuit 70 and an output filter circuit 80 that are electrically connected in sequence. The protection circuit 10 is used to protect the LED boost constant current control circuit, the electromagnetic compatibility circuit 20 is used to reduce electromagnetic interference and enhance the electromagnetic sensitivity of the circuit, the AC-DC rectifier circuit 30 is used to provide a DC power supply, the starting circuit is used to provide a starting signal to put the integrated control circuit 50 into an operating state, the integrated control circuit 50 is used to receive an input signal and control the operating state of the LED boost constant current control circuit, the constant current sampling circuit 60 is used to monitor the current value in the LED lamp bead in real time and feed back the sampling result to the integrated control circuit 50, the overvoltage protection circuit 70 is used to perform overvoltage protection on the LED boost constant current control circuit, and the output filter circuit 80 is used to smooth ripple and noise in the output voltage.

[0024] Figure 2 This is a circuit diagram of a preferred embodiment of the LED boost constant current control circuit of the utility model; Figure 3 This is a schematic diagram of the circuit module division of a preferred embodiment of the LED boost constant current control circuit of the present invention. Figure 2 、 Figure 3 As shown, the protection circuit includes: one end of the fuse F1 is connected to one end of the varistor RV1.

[0025] The connection design of fuse F1 and varistor RV1 significantly improves circuit safety and stability, providing crucial protection. As a key nonlinear resistor, varistor RV1 is extremely sensitive to voltage fluctuations. Under normal operating voltage, RV1 exhibits a high-resistance state, with minimal impact on the circuit. However, when an abnormal overvoltage occurs in the circuit, RV1's resistance drops dramatically, rapidly absorbing and dissipating the overvoltage energy and clamping it to a safe level.

[0026] Fuse F1, acting as a short-circuit protection element, quickly melts when it detects excessive current, shutting off the circuit and preventing a sustained short circuit caused by damage to varistor RV1 or other components. This dual protection mechanism ensures that the circuit can quickly and effectively shut off power in the event of an abnormality such as overvoltage or a short circuit, preventing serious consequences such as equipment damage or even fire.

[0027] During specific implementation, a varistor RV2 may be further provided between the AC-DC rectifier circuit and the startup circuit. Here, the varistor RV2 also serves to protect the circuit.

[0028] The electromagnetic compatibility circuit includes: pin 3 of the common-mode inductor L1 is respectively connected to one end of the capacitor CY1, one end of the capacitor CX1, one end of the resistor R1, and pin 1 of the common-mode inductor L2; the other end of the capacitor CY1 is connected to one end of the capacitor CY2; pin 4 of the common-mode inductor L1 is respectively connected to the other end of the capacitor CY2, the other end of the capacitor CX1, and one end of the resistor R3; the other end of the resistor R1 is connected to one end of the resistor R2; and the other end of the resistor R2 is connected to the other end of the resistor R3.

[0029] The AC-DC rectifier circuit includes a rectifier bridge BG1.

[0030] The startup circuit includes: one end of a resistor R23 is connected to one end of a resistor R24, the other end of the resistor R24 ​​is connected to one end of a resistor R25, the other end of the resistor R25 is connected to one end of a diode ZD1, the other end of the diode ZD1 is connected to one end of a capacitor C9, the other end of the capacitor C9 is connected to the positive electrode of a diode D2, the negative electrode of the diode D2 is respectively connected to one end of a resistor R7 and one end of a capacitor C1, the other end of the resistor R7 is connected to one end of a resistor R6, and the other end of the resistor R6 is connected to the other end of the resistor R23.

[0031] The integrated control circuit includes: Pin 4 of the power management chip U1 is connected to one end of resistor R8; the other end of resistor R8 is connected to the cathode of diode D1 and one end of resistor R9, respectively; and the anode of diode D1 is connected to the other end of resistor R9 and the base of power transistor Q1, respectively. In a specific implementation, the power management chip U1 can be, but is not limited to, an LT6911 UXE, N32905U1DN, or AP2008TCER-ADJ. In this embodiment, the LT6911 UXE is selected.

[0032] During the conversion process, power management chip U1 monitors the output voltage in real time and adjusts the on-time of the field-effect transistors (FETs) through PWM (pulse width modulation), thereby achieving precise control of the output voltage. If the output voltage deviates from the set value, power management chip U1 quickly adjusts the duty cycle of the PWM signal to restore output voltage stability.

[0033] In addition, the power management chip U1 also has multiple protection functions, such as overcurrent protection, overheating protection, etc., to ensure that the power supply can be quickly cut off in abnormal situations to prevent equipment damage.

[0034] The integrated control circuit can adjust the output voltage and current to achieve constant current drive for LED lights. At the same time, it also has a communication interface that can communicate with the host computer through a wireless serial port to achieve remote control and monitoring.

[0035] The constant current sampling circuit includes: one end of resistor R11 is connected to one end of resistor R12, one end of resistor R13, one end of resistor R14, one end of resistor R15, and one end of resistor R22, respectively; the other end of resistor R11 is connected to the other end of resistor R12, the other end of resistor R13, the other end of resistor R14, and the other end of resistor R15, respectively. The constant current sampling circuit is used to monitor the current value in the LED lamp bead in real time and feed the sampling result back to the integrated control circuit. This feedback mechanism enables the integrated control circuit to adjust the output voltage in time according to current changes, thereby maintaining a constant current in the LED lamp bead.

[0036] The overvoltage protection circuit includes: one end of resistor R17 is connected to one end of resistor R18, the other end of resistor R18 is connected to one end of resistor R19, the other end of resistor R19 is connected to one end of resistor R20, one end of resistor R5, and one end of capacitor C10, respectively; and the other end of resistor R20 is connected to the other end of resistor R5 and the other end of capacitor C10, respectively. The overvoltage protection circuit quickly cuts off power when it detects an abnormal increase in output voltage, further protecting the LED lamp beads and the entire circuit from damage. This protection mechanism greatly improves the reliability and safety of the control circuit.

[0037] The output filter circuit includes: Pin 1 of inductor L5 is connected to one end of resistor R27, the positive electrode of capacitor EC2, and the positive electrode of capacitor EC1. The other end of resistor R27 is connected to one end of resistor R26, and the other end of resistor R26 is connected to one end of resistor R29. The other end of resistor R29 is connected to the negative electrode of capacitor EC2, the negative electrode of capacitor EC1, and pin 2 of inductor L5, and is also connected to ground. Pin 3 of inductor L5 is connected to LED+, and pin 4 of inductor L5 is connected to LED-. This filtering effect makes the output voltage more stable and smooth, ensuring stable LED light emission.

[0038] In a specific implementation, the LED boost constant current control circuit further includes a surge protection circuit 90, which is connected to the startup circuit 40 and the overvoltage protection circuit 70. In some optional implementations, the surge protection circuit includes: the cathode of the diode D4 is respectively connected to one end of the capacitor C4 and the cathode of the diode D3, and the anode of the diode D4 is respectively connected to the other end of the capacitor C4.

[0039] In a specific implementation, the LED boost constant current control circuit further includes a π-type filter circuit 100, which can be disposed between the AC-DC rectifier circuit 30 and the protection circuit 10. The π-type filter circuit 100 can specifically include: one end of a capacitor C3 connected to one end of an inductor L3 and one end of a resistor R4, the other end of the inductor L3 connected to the other end of the resistor R4 and one end of a capacitor C2, and the other end of the capacitor C2 connected to ground.

[0040] The working principle of the LED boost constant current control circuit of this utility model is:

[0041] The AC power input passes through the protection circuit (fuse F1 and varistor RV1, varistor RV2), AC-DC rectifier circuit (including rectifier bridge stack BG1), pre-bridge EMC anti-interference circuit (including common mode inductor L1, common mode inductor L2, capacitor CY1, capacitor CY2, capacitor CX1), post-bridge EMC anti-interference circuit (including I-shaped inductor L3 and capacitor C2, capacitor C3, capacitor C8) to obtain the bus DC voltage of the circuit, and the starting circuit (including resistor R23, resistor R24, resistor R6, resistor R7, diode ZD1, diode D2, chip capacitor C1, chip capacitor C9) is connected to the bus. The line voltage is obtained and supplied to the HV pin of the power management chip U1. When the input voltage is low, the circuit consisting of resistors R6, R7, diode ZD1, D2, chip capacitor C1, and C9 does not stabilize the voltage. Resistors R6 and R7 can only be used to provide operating current to the HV pin of the power management chip U1, stabilizing the normal operation of the power management chip U1. When the input voltage is high, the circuit consisting of resistors R23, R24, R25, diode ZD1, D2, chip capacitor C1, and C9 stabilizes the operating voltage and supplies power to the HV pin of the power management chip U1. This ensures that the power management chip U1 can operate normally within the full voltage range of 85V to 265V. Power management chip U1 outputs a PWM signal to turn power transistor Q1 on and off. When on, the bus voltage flows through common-mode inductor L4, storing energy in power transistor Q1. When Q1 is off, the voltage stored in common-mode inductor L4 is superimposed on the bus voltage and output to capacitors EC1 and EC2, thereby boosting the voltage. The built-in CS reference voltage uses external resistors R11, R12, R113, R15, and R22 to detect voltage feedback, achieving a constant current output. A voltage divider circuit consisting of resistors R17, R18, R19, R20, R5, and capacitor C10 provides feedback voltage for overvoltage protection. The output voltage is filtered through common-mode inductor L5 to remove common-mode signals, resulting in a circuit that more closely complies with EMC standards.

[0042] When the LED boost constant-current control circuit is powered on, the startup circuit first activates the integrated control circuit. The integrated control circuit receives the input signal and feedback from the constant-current sampling circuit to adjust the output voltage and current to achieve constant-current operation of the LED lamp. Simultaneously, the protection circuit and electromagnetic compatibility circuit protect the circuit from abnormal voltages and electromagnetic interference, respectively. The AC-DC rectifier circuit converts AC power to DC, providing a stable power supply for the entire circuit. Finally, the voltage, smoothed by the output filter circuit, drives the LED lamp beads to illuminate.

[0043] It can be seen that by adopting this embodiment, adaptive matching of power supply at high and low voltages can be achieved. When the input voltage is low, resistors R6 and R7 are used to provide operating current to the HV pin of the power management chip U1, stabilizing the normal operation of the power management chip U1. The larger the resistors R6 and R7, the smaller the JFET power loss and the lower the chip temperature. When the input voltage is high, the circuit composed of resistors R23, R24, R25, diode ZD1, diode D2, chip capacitor C1, and chip capacitor C9 stabilizes the operating voltage to supply power to the HV pin of the power management chip U1. At the same time, the power consumption of resistors R23, R24, and R25 meets the derating requirements for the maximum AC voltage input and no-load, ensuring that the power management chip can operate normally within the full voltage range of 85V to 265V.

[0044] By adopting this embodiment, the anti-interference capability of the power management chip U1 against lightning surges can be improved, thereby protecting the power management chip U1.

[0045] This embodiment has low cost and simple process, and can be implemented without changing the transformer or adding an auxiliary winding to the transformer.

[0046] Through the design of the above embodiments, the present invention has the following beneficial effects: by adopting a protection circuit, an electromagnetic compatibility circuit, an AC-DC rectifier circuit, a startup circuit, an integrated control circuit, a constant current sampling circuit, an overvoltage protection circuit and an output filter circuit that are electrically connected in sequence, it can ensure that the power supply can work when the low voltage input is 85V, and can work stably when the high voltage input is 265V; it can effectively improve the adaptability of the power supply, widen the application range of the power supply, and realize the implementation of the full voltage working scenario of the power supply without being affected by circuit conversion; the output current is stable, and at the same time, it is not easy to have problems such as current fluctuation, which can effectively improve the stability of the system.

[0047] While the present invention has been described with reference to specific embodiments, those skilled in the art will appreciate that various modifications and equivalents may be made without departing from the scope of the present invention. Furthermore, numerous modifications may be made to adapt the present invention to specific applications without departing from its scope. Therefore, the present invention is not limited to the specific embodiments disclosed herein but encompasses all embodiments falling within the scope of the claims.

Claims

1. An LED boost constant current control circuit, characterized in that: include: The protection circuit, electromagnetic compatibility circuit, AC-DC rectifier circuit, startup circuit, integrated control circuit, constant current sampling circuit, overvoltage protection circuit and output filter circuit are electrically connected in sequence. The protection circuit is used to protect the LED boost constant current control circuit, the electromagnetic compatibility circuit is used to reduce electromagnetic interference and enhance the electromagnetic sensitivity of the circuit, the AC-DC rectifier circuit is used to provide a DC power supply, the startup circuit is used to provide a startup signal to put the integrated control circuit into operation, the integrated control circuit is used to receive an input signal and control the operating state of the LED boost constant current control circuit, the constant current sampling circuit is used to monitor the current value in the LED lamp bead in real time and feed back the sampling result to the integrated control circuit, the overvoltage protection circuit is used to perform overvoltage protection on the LED boost constant current control circuit, and the output filter circuit is used to smooth the ripple and noise in the output voltage.

2. The LED boost constant current control circuit according to claim 1, characterized in that: The protection circuit includes: one end of a fuse F1 is connected to one end of a varistor RV1.

3. The LED boost constant current control circuit according to claim 1, characterized in that: The electromagnetic compatibility circuit includes: pin 3 of the common-mode inductor L1 is respectively connected to one end of the capacitor CY1, one end of the capacitor CX1, one end of the resistor R1, and pin 1 of the common-mode inductor L2; the other end of the capacitor CY1 is connected to one end of the capacitor CY2; pin 4 of the common-mode inductor L1 is respectively connected to the other end of the capacitor CY2, the other end of the capacitor CX1, and one end of the resistor R3; the other end of the resistor R1 is connected to one end of the resistor R2; and the other end of the resistor R2 is connected to the other end of the resistor R3.

4. The LED boost constant current control circuit according to claim 1, characterized in that: The AC-DC rectifier circuit includes a rectifier bridge BG1.

5. The LED boost constant current control circuit according to claim 1, characterized in that: The startup circuit includes: one end of a resistor R23 is connected to one end of a resistor R24, the other end of the resistor R24 ​​is connected to one end of a resistor R25, the other end of the resistor R25 is connected to one end of a diode ZD1, the other end of the diode ZD1 is connected to one end of a capacitor C9, the other end of the capacitor C9 is connected to the positive electrode of a diode D2, the negative electrode of the diode D2 is respectively connected to one end of a resistor R7 and one end of a capacitor C1, the other end of the resistor R7 is connected to one end of a resistor R6, and the other end of the resistor R6 is connected to the other end of the resistor R23.

6. The LED boost constant current control circuit according to claim 1, characterized in that: The integrated control circuit includes: pin 4 of the power management chip U1 is connected to one end of the resistor R8, the other end of the resistor R8 is respectively connected to the cathode of the diode D1 and one end of the resistor R9, and the anode of the diode D1 is respectively connected to the other end of the resistor R9 and the base of the power tube Q1.

7. The LED boost constant current control circuit according to claim 1, characterized in that: The constant current sampling circuit includes: one end of the resistor R11 is respectively connected to one end of the resistor R12, one end of the resistor R13, one end of the resistor R14, one end of the resistor R15, and one end of the resistor R22; the other end of the resistor R11 is respectively connected to the other end of the resistor R12, the other end of the resistor R13, the other end of the resistor R14, and the other end of the resistor R15.

8. The LED boost constant current control circuit according to claim 1, characterized in that: The overvoltage protection circuit includes: one end of a resistor R17 is connected to one end of a resistor R18, the other end of the resistor R18 is connected to one end of a resistor R19, the other end of the resistor R19 is respectively connected to one end of a resistor R20, one end of a resistor R5, and one end of a capacitor C10, and the other end of the resistor R20 is respectively connected to the other end of the resistor R5 and the other end of the capacitor C10.

9. The LED boost constant current control circuit according to claim 1, characterized in that: The output filter circuit includes: pin 1 of inductor L5 is respectively connected to one end of resistor R27, the positive electrode of capacitor EC2, and the positive electrode of capacitor EC1; the other end of resistor R27 is connected to one end of resistor R26; the other end of resistor R26 is connected to one end of resistor R29; the other end of resistor R29 is respectively connected to the negative electrode of capacitor EC2, the negative electrode of capacitor EC1, and pin 2 of inductor L5 and is grounded; pin 3 of inductor L5 is connected to LED+, and pin 4 of inductor L5 is connected to LED-.

10. The LED boost constant current control circuit according to any one of claims 1 to 9, characterized in that: The LED boost constant current control circuit further includes a surge protection circuit, which is connected to the startup circuit and the overvoltage protection circuit.

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