A high-power LED constant current drive circuit for space applications

Abstract

A constant current drive circuit for high-power LEDs in space is disclosed. This circuit employs a high-quality, radiation-hardened switching regulator as the main controller for the high-power LED constant current. A field-programmable gate array (FPGA) controls a high-speed switching transistor to control the radiation-hardened switching regulator, thereby controlling the lighting and shutdown of the high-power LED. The FPGA is also used to configure the digital-to-analog converter (DAC), outputting an adjustable voltage which is then buffered by an operational amplifier to adjust the current of the high-power LED, thus controlling its brightness. This invention aims to solve the problem of high-reliability, high-conversion-efficiency constant current drive for high-power LEDs in low-light imaging environments for space cameras. It significantly reduces the additional power consumption caused by the high-power LED driving method, avoids the increased weight and size due to heat dissipation measures required for the drive circuit, and saves limited space resources.

Description

Technical Field

[0001] This invention relates to a high-power LED constant current driving circuit for space applications, mainly used in situations where space cameras require high-power LED supplementary lighting to increase the imaging signal-to-noise ratio when imaging in low-light environments, and belongs to the field of space low-light imaging and detection. Background Technology

[0002] With the rapid development of deep space exploration, humanity's demand for exploring scientific questions regarding the morphology, composition, structure, water ice content, and distribution of deep space targets is becoming increasingly strong. For example, comprehensive exploration and research of the Moon is currently one of the hot topics in space science research, but substantial exploration of the lunar poles at higher latitudes has not yet been conducted. To study the lunar surface morphology and geological structure of the lunar poles, it is necessary to use space cameras to image and observe these regions. The lunar poles have a low solar altitude angle and significant topographic relief and permanent shadow craters. These topographic reliefs create vast shadowed areas, and the permanent shadow craters receive no sunlight. Since there is no atmospheric scattering on the lunar surface, the shadowed areas at the poles will be completely dark, greatly increasing the difficulty of imaging observations.

[0003] Currently, low-light imaging methods can be broadly categorized into two types: active imaging and passive imaging. Active imaging involves adding active illumination to the observation camera to increase the target's reflective brightness and achieve a higher signal-to-noise ratio. This type of active imaging requires additional active illumination equipment and consumes a significant amount of energy. Passive imaging utilizes special cameras with weak signal amplification capabilities to obtain high-quality images, such as electron-multiplying CCDs or cameras with image intensifiers. However, this low-light imaging mechanism cannot create images from nothing; it requires the target to have at least weak illumination. Otherwise, even with magnification, a good signal-to-noise ratio cannot be obtained. Since the Moon lacks atmospheric scattering, the lunar polar shadow regions, especially the permanently shadowed craters, are completely dark, making it virtually impossible to obtain good image quality using passive imaging. Therefore, to obtain good image quality in the lunar polar shadow regions, it is necessary to add active illumination to the observation camera to achieve a higher signal-to-noise ratio.

[0004] Compared to commonly used incandescent and halogen lamps, LED lamps offer advantages such as low operating voltage, low power consumption, high luminous efficiency, long lifespan, small size, strong directivity, high resistance to vibration and shock, and the absence of toxic elements, making them more suitable for active lighting applications in space. The current-voltage characteristics of LEDs are similar to those of ordinary diodes. If constant voltage control is used, even a slight voltage change will cause a large current change, resulting in drastic fluctuations in the LED's luminous intensity. This can affect the image quality of the observation camera and significantly reduce the LED's lifespan. Therefore, LEDs generally employ constant current control methods to ensure stable luminous intensity. The high-power LED constant current driving method for active illumination in space low-light imaging has the following requirements: First, to achieve a longer detection distance, high-power LEDs are needed for illumination, requiring the LED constant current driver to have high power output capability. Second, given the strict requirements for power consumption, size, and weight in space applications, a highly integrated and efficient LED constant current driving circuit should be used to save PCB area and reduce additional power loss, avoiding additional volume and weight increases caused by heat dissipation measures. Third, to adapt to different low-light illumination conditions and different detection distances to adjust the LED luminous intensity and save power resources, it is required to have intelligent management of the luminous intensity, on / off mechanisms of the high-power LEDs. This places high demands on the high-power LED constant current driving method.

[0005] High-power LED drivers with mature and highly integrated features are already available for ground applications, characterized by high conversion efficiency, low additional losses, and small footprint. However, their low quality makes them unsuitable for space environments. Currently, there are no high-quality, application-specific integrated circuits (ASICs) specifically designed for high-power LED constant current driving, both domestically and internationally, necessitating custom design. To achieve high integration, high-power LED drivers often employ linear regulators (such as...). Figure 2 (As shown) or an integrated regulator driving method using a switching regulator as the current feedback adjustment element, such as Figure 3 As shown. This type of driver circuit has the advantages of high integration, small footprint, availability of high-quality regulators, and ease of implementation. However, its disadvantages are also quite prominent: the entire driver circuit consumes a significant amount of additional power. Taking a linear regulator as an example, the calculation is as follows:

[0006] P LOSS = (VCC_IN - VCC_LED +) × I LED +I LED 2 ×R SENSE

[0007] Not only in the LED current adjustment resistor R senseThe existing voltage regulators require significant additional power consumption, and the voltage difference across the linear regulators also consumes additional power. This not only results in a huge waste of power resources for space equipment but also necessitates additional cooling devices to dissipate heat from the regulators and feedback resistors, and makes it impossible to adjust the brightness of the LEDs. Therefore, the current solution of using voltage regulators to drive high-power LEDs cannot meet the high conversion efficiency requirements of high-power LEDs in space. Summary of the Invention

[0008] (a) Technical problems to be solved

[0009] To address the problem that existing high-power LEDs have low driving efficiency and are unsuitable for space applications when using high-power LEDs for low-light imaging in space cameras, this invention provides a high-power LED constant current driving circuit for space applications.

[0010] (II) Technical Solution

[0011] The technical solution provided by this invention is as follows:

[0012] A high-power LED constant current drive circuit for space applications, the circuit comprising a field-programmable gate array (FPGA) U1, a digital-to-analog converter (DAC) U2, an amplifier U3, a radiation-resistant switching regulator U4, a high-speed switching transistor Q1, an inductor L1, resistors R1, R2, R3, R4, R5, R6, R7, R8, and R9, capacitors C1, C2, C3, C4, C5, and C6, and a high-power light-emitting diode (LED) D1;

[0013] Among them, the radiation-resistant switching regulator U4 uses a radiation-resistant step-down synchronous voltage converter with a large-area heat dissipation pad at the bottom as the current constant regulation controller for the high-power light-emitting diode LED D1. This current constant regulation controller has the characteristics of high conversion efficiency and low feedback node voltage.

[0014] The amplifier U3 outputs a reference voltage, which, together with resistors R6, R7, R8, and R9, provides the feedback input voltage for the radiation-hardened switching regulator U4. The radiation-hardened switching regulator U4 uses an internal voltage feedback loop to maintain a constant voltage at its feedback input terminal FB, thereby maintaining a constant voltage across resistor R7, which reduces the voltage across resistors R8 and R9 and lowers the power consumption of resistors R8 and R9.

[0015] Furthermore, the field-programmable gate array (FPGA) U1 configures the digital-to-analog converter (DAC) U2, outputs an adjustable voltage, and after passing through the amplifier U3 and buffer, adjusts the power supply current of the high-power LED D1, thereby controlling the brightness of the high-power LED D1.

[0016] Furthermore, both resistors R8 and R9 are power resistors, and they are connected in parallel to reduce the heat power of each resistor.

[0017] Furthermore, when the voltage output by the amplifier U3 is greater than the voltage at the feedback input terminal FB of the radiation-resistant switching regulator U4, it drives the high-power light-emitting diode LED D1 to light up.

[0018] Furthermore, a high-speed switching transistor Q1 is used as an enable switch to control the turning on and off of the high-power light-emitting diode LED D1.

[0019] Furthermore, the output of amplifier U3 uses an RC filter circuit formed by resistor R5 and capacitor C3 to filter out noise and form a stable reference voltage, thereby ensuring the constant current control accuracy of the high-power light-emitting diode LED D1.

[0020] Furthermore, the field-programmable gate array (FPGA) U1 outputs a control signal LED_EN to the first terminal of resistor R3. The second terminal of resistor R3 is connected to the base of high-speed switching transistor Q1. The first terminal of resistor R1 is connected to the external input power supply VCC_IN, and the second terminal of resistor R1 is connected to the second terminal of resistor R3. The first terminal of resistor R2 is connected to the external input power supply VCC_IN, and the second terminal of resistor R2 is connected to the collector of high-speed switching transistor Q1. The first terminal of resistor R4 is connected to the second terminal of resistor R3, and the second terminal of resistor R4 is connected to ground. The emitter of high-speed switching transistor Q1 is connected to ground. The first terminal of capacitor C1 is connected to the external input power supply VCC_IN, and the second terminal of capacitor C1 is connected to the first terminal of capacitor C2. The second terminal of capacitor C2 is connected to ground.

[0021] Furthermore, the SPI control bus of the field programmable gate array FPGA U1 is connected to the input of the digital-to-analog converter U2, the output of the digital-to-analog converter U2 is connected to the positive input of the amplifier U3, and the inverting input of the amplifier U3 is connected to the output of the amplifier U3; the first end of the resistor R5 is connected to the output of the amplifier U3, the first end of the capacitor C3 is connected to the second end of the resistor R5, and the second end of the resistor R6 is connected to the first end of the capacitor C3.

[0022] Furthermore, the first terminal of resistor R6 is connected to the feedback input terminal FB of the radiation-hardened switching regulator U4; the voltage input terminal VIN of the radiation-hardened switching regulator U4 is connected to the external input power supply VCC_IN; the enable input terminal EN of the radiation-hardened switching regulator U4 is connected to the collector of the high-speed switching transistor Q1; the ground input terminal GND of the radiation-hardened switching regulator U4 is connected to ground; the voltage output terminal VOUT of the radiation-hardened switching regulator U4 is connected to the first terminal of inductor L1; the second terminal of inductor L1 is connected to the first terminal of capacitor C4; the second terminal of capacitor C4 is connected to the second terminal of resistor R7; the first terminal of resistor R7 is connected to the feedback input terminal FB of the radiation-hardened switching regulator U4; the first terminals of resistors R8 and R9 are connected to the second terminal of resistor R7; and the second terminals of resistors R8 and R9 are connected to ground.

[0023] Furthermore, the anode of the high-power LED D1 is connected to the first terminal of capacitor C4, and the cathode of the high-power LED D1 is connected to the second terminal of capacitor C4; the first terminal of capacitor C5 is connected to the second terminal of inductor L1, the second terminal of capacitor C5 is connected to the first terminal of capacitor C6, and the second terminal of capacitor C6 is connected to ground; the first terminal VCC_LED+ of capacitor C4 is the positive output of the current of the high-power LED D1, and the second terminal VCC_LED- of capacitor C4 is the negative input of the current of the high-power LED D1.

[0024] In the above technical solution, the radiation-hardened switching regulator U4 uses a high-quality, high-efficiency, low-feedback node voltage, radiation-hardened buck synchronous voltage converter (such as the RSS1206HRH, with an average conversion efficiency of 90% and a feedback node voltage of 0.789V) with a large-area heat dissipation pad on the bottom. Its internal voltage feedback compensation network regulates the output voltage, ensuring a constant voltage at the feedback input node FB, thereby maintaining a constant current flow through the high-power LED and achieving constant current drive. The FPGA enables the radiation-hardened switching regulator U4 by controlling the high-speed switching transistor Q1 to turn it on or off, thus controlling the high-power LED's on / off state. The FPGA configures the DAC U2 to output different voltage amplitude values ​​V. SET The current flowing through the high-power LED is controlled, thereby controlling the LED's brightness. Resistor R5 and capacitor C3 form an RC low-pass filter circuit. An external reference voltage V can be set. SET The voltage divider network composed of resistors R6, R7, R8, and R9 effectively reduces the current of the high-power LED, adjusting the voltage across power resistors R8 and R9, thereby reducing the power consumed by the power resistors. The current flowing through the high-power LED is determined by the following formula:

[0025]

[0026] Among them, V FB For the input voltage of the feedback node of the radiation-hardened switching regulator U4, V SET This is the reference voltage for setting the LED current output after the DAC U2 output is buffered by amplifier U3. This can be achieved by properly setting R6, R7, R8, and R9, and selecting a low feedback node input voltage V. FB A high-efficiency, radiation-hardened switching regulator can significantly reduce additional power losses in the power resistors R8 and R9 and the switching regulator itself. To prevent excessive power in a single power resistor from causing it to fail and reducing reliability, two power resistors, R8 and R9, are connected in parallel to reduce the power of a single power resistor, thus increasing reliability.

[0027] The total additional power loss across the high-power resistors R8 and R9 is:

[0028] P LOSS-RES =I LED 2 ×(R8 / / R9)

[0029] The additional power loss on the radiation-hardened switching regulator U4 is:

[0030] P LOSS-DC / DC =(I LED 2 ×(R8 / / R9)+I LED ×(VCC_LED + -VCC_LED - ))×(1-η)

[0031] η is the average conversion efficiency of the radiation-hardened switching regulator used.

[0032] (III) Beneficial Effects

[0033] The present invention has the following advantages:

[0034] (1) An integrated switching regulator with high reliability, high conversion efficiency and heat dissipation pad on the bottom is used as the feedback controller. It has the characteristics of high integration and small PCB area. Since the switching regulator has high conversion efficiency and heat dissipation pad on the bottom, a large area of ​​the PCB ground plane can be used as the heat sink of the switching regulator, without the need for additional heat dissipation measures.

[0035] (2) By increasing the external reference voltage V SET The voltage divider network of resistors R6, R7, R8, and R9 effectively reduces the voltage across the power resistors R8 and R9 for high-power LED current regulation, thereby reducing the extra power consumed by the power resistors R8 and R9. Under the same LED driving current conditions, the power consumed by the power resistors is only 1 / 5 of that of the traditional switching regulator driving method, which greatly saves limited space and energy resources.

[0036] (3) The LED supplementary light can be turned on or off according to the ambient light intensity of the space low light camera; the current of the high-power LED can be adjusted by setting the DAC output voltage value according to the observation distance, thereby controlling the brightness of the LED, so as to achieve the purpose of intelligent management of increasing the LED current for long-distance detection and decreasing the LED current for short-distance detection, thereby avoiding the additional resource consumption caused by using the same brightness illumination for both long and short distances. Attached Figure Description

[0037] Figure 1 High-reliability, high-conversion-efficiency high-power LED constant current drive circuit for space applications;

[0038] Figure 2 Traditional linear regulator constant current drive LED circuit;

[0039] Figure 3 Traditional switching regulator constant current drive LED circuit. Detailed Implementation

[0040] The embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0041] like Figure 1As shown, a high-power LED constant current drive circuit for space applications includes a field-programmable gate array (FPGA) U1, a digital-to-analog converter (DAC) U2, an amplifier U3, a radiation-hardened switching regulator U4, a high-speed switching transistor Q1, an inductor L1, resistors R1, R2, R3, R4, R5, R6, R7, R8, and R9, capacitors C1, C2, C3, C4, C5, and C6, and a high-power light-emitting diode (LED). D1; A high-quality, high-efficiency, low-feedback-node-voltage, radiation-resistant step-down synchronous voltage converter with a large-area heat dissipation pad on the bottom is used as the current constant regulation controller for high-power LEDs; the supply current of the high-power LED is adjusted by setting an adjustable voltage at the output of the digital-to-analog converter and followed by an amplifier, thereby controlling the brightness of the high-power LED; the reference voltage output of amplifier U3, together with resistors R6, R7, R8, and R9, provides the feedback input voltage for the radiation-resistant switching regulator U4. The radiation-resistant switching regulator U4 uses an internal voltage feedback loop to maintain a constant voltage at the feedback input terminal FB, thereby maintaining a constant voltage across resistor R7 and reducing the current consumption. The voltage across resistors R8 and R9 reduces their power consumption. Both R8 and R9 are power resistors, and their parallel connection reduces the heat dissipation of each, achieving the goal of not requiring additional heat dissipation measures. The output voltage of amplifier U3 must be greater than the feedback input voltage FB of the radiation-resistant switching regulator U4 to drive the high-power LED. A high-quality, high-speed switching transistor Q1 is used as the enable switch to control the high-power LED's on / off state. The output of amplifier U3 uses an RC filter circuit formed by resistor R5 and capacitor C3 to filter out noise and create a stable reference voltage, thereby ensuring the constant current control accuracy of the high-power LED.

[0042] Specifically, FPGA U1 outputs a control signal LED_EN, which is connected to the first terminal of resistor R3. The second terminal of resistor R3 is connected to the base of high-speed switching transistor Q1. The first terminal of resistor R1 is connected to the external input power supply VCC_IN, and the second terminal of resistor R1 is connected to the second terminal of resistor R3. The first terminal of resistor R2 is connected to the external input power supply VCC_IN, and the second terminal of resistor R2 is connected to the collector of high-speed switching transistor Q1. The first terminal of resistor R4 is connected to the second terminal of resistor R3, and the second terminal of resistor R4 is connected to ground. The emitter of high-speed switching transistor Q1 is connected to ground. The first terminal of capacitor C1 is connected to the external input power supply VCC_IN, and the second terminal of capacitor C1 is connected to the first terminal of capacitor C2. The second terminal of capacitor C2 is connected to ground. The SPI control bus of FPGA U1 is connected to the input terminal of digital-to-analog converter U2. The output terminal of digital-to-analog converter U2 is connected to the non-inverting input terminal of amplifier U3, and the inverting input terminal of amplifier U3 is connected to the output terminal of amplifier U3. Terminals; the first terminal of resistor R5 is connected to the output terminal of amplifier U3, and the first terminal of capacitor C3 is connected to the second terminal of resistor R5; the second terminal of resistor R6 is connected to the first terminal of capacitor C3, and the first terminal of resistor R6 is connected to the feedback input terminal FB of radiation-hardened switching regulator U4; the voltage input terminal VIN of radiation-hardened switching regulator U4 is connected to the external input power supply VCC_IN, the enable input terminal EN of radiation-hardened switching regulator U4 is connected to the collector of the high-speed switching transistor, the ground input terminal GND of radiation-hardened switching regulator U4 is connected to ground, the voltage output terminal VOUT of radiation-hardened switching regulator U4 is connected to the first terminal of inductor L1, the second terminal of inductor L1 is connected to the first terminal of capacitor C4, the second terminal of capacitor C4 is connected to the second terminal of resistor R7, and the first terminal of resistor R7 is connected to the feedback input terminal FB of radiation-hardened switching regulator U4; the first terminals of resistors R8 and R9 are connected to the second terminal of resistor R7, and the second terminals of resistors R8 and R9 are connected to ground; high-power LED The anode of D1 is connected to the first terminal of capacitor C4, and the cathode of high-power LED D1 is connected to the second terminal of capacitor C4; the first terminal of capacitor C5 is connected to the second terminal of inductor L1, the second terminal of capacitor C5 is connected to the first terminal of capacitor C6, and the second terminal of capacitor C6 is connected to ground; the first terminal of capacitor C4, VCC_LED+, is the positive output of the high-power LED current, and the second terminal of capacitor C4, VCC_LED-, is the negative input of the high-power LED current.

[0043] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any transformations or substitutions that can be conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A high-power LED constant current driving circuit for space applications, characterized in that: The circuit includes a field-programmable gate array (FPGA) U1, a digital-to-analog converter (DAC) U2, an amplifier U3, a radiation-resistant switching regulator U4, a high-speed switching transistor Q1, an inductor L1, resistors R1, R2, R3, R4, R5, R6, R7, R8, and R9, capacitors C1, C2, C3, C4, C5, and C6, and a high-power light-emitting diode (LEDD1). Among them, the radiation-resistant switching regulator U4 uses a radiation-resistant step-down synchronous voltage converter with a large-area heat dissipation pad at the bottom as the current constant regulation controller for the high-power light-emitting diode LED D1. This current constant regulation controller has the characteristics of high conversion efficiency and low feedback node voltage. The amplifier U3 outputs a reference voltage, which, together with resistors R6, R7, R8 and R9, provides the feedback input voltage for the radiation-hardened switching regulator U4. The radiation-hardened switching regulator U4 uses an internal voltage feedback loop to maintain a constant voltage at its feedback input terminal FB, thereby maintaining a constant voltage across resistor R7, which reduces the voltage across resistors R8 and R9 and lowers the power consumption of resistors R8 and R9. The SPI control bus of the field programmable gate array (FPGA) U1 is connected to the input of the digital-to-analog converter (DAC) U2, and the output of the DAC U2 is connected to the positive input of the amplifier U3. The field-programmable gate array (FPGA) U1 outputs a control signal LED_EN, which is connected to the enable input terminal EN of the radiation-hardened switching regulator U4 through an enable control circuit composed of resistors R1, R2, R3, R4 and a high-speed switching transistor Q1, to control its operating state; when the voltage output by the amplifier U3 is greater than the voltage at the feedback input terminal FB of the radiation-hardened switching regulator U4, it drives the high-power light-emitting diode LED D1 to light up. The voltage output terminal VOUT of the radiation-resistant switching regulator U4 supplies power to the high-power light-emitting diode LED D1 through inductor L1 and a filter network composed of capacitors C4, C5, and C6.

2. The high-power LED constant current driving circuit for space applications according to claim 1, characterized in that: The field-programmable gate array (FPGA) U1 configures the digital-to-analog converter (DAC) U2, outputs an adjustable voltage, and after passing through the amplifier U3 and buffer, adjusts the power supply current of the high-power light-emitting diode (LED) D1, thereby controlling the brightness of the high-power LED D1.

3. The high-power LED constant current driving circuit for space applications according to claim 1, characterized in that: Both resistors R8 and R9 are power resistors, and they are connected in parallel to reduce the heat power of each resistor.

4. The high-power LED constant current driving circuit for space applications according to claim 1, characterized in that: A high-speed switching transistor Q1 is used as an enable switch to control the turning on and off of a high-power light-emitting diode LED D1.

5. The high-power LED constant current driving circuit for space applications according to claim 1, characterized in that: The output of amplifier U3 uses an RC filter circuit formed by resistor R5 and capacitor C3 to filter out noise and form a stable reference voltage, thereby ensuring the constant current control accuracy of the high-power light-emitting diode LED D1.

6. The high-power LED constant current driving circuit for space applications according to claim 1, characterized in that: The FPGA U1 outputs a control signal LED_EN to the first terminal of resistor R3. The second terminal of resistor R3 is connected to the base of high-speed switching transistor Q1. The first terminal of resistor R1 is connected to the external input power supply VCC_IN, and the second terminal of resistor R1 is connected to the second terminal of resistor R3. The first terminal of resistor R2 is connected to the external input power supply VCC_IN, and the second terminal of resistor R2 is connected to the collector of high-speed switching transistor Q1. The first terminal of resistor R4 is connected to the second terminal of resistor R3, and the second terminal of resistor R4 is connected to ground. The emitter of high-speed switching transistor Q1 is connected to ground. The first terminal of capacitor C1 is connected to the external input power supply VCC_IN, and the second terminal of capacitor C1 is connected to the first terminal of capacitor C2. The second terminal of capacitor C2 is connected to ground.

7. The high-power LED constant current driving circuit for space applications according to claim 1, characterized in that: The inverting input terminal of amplifier U3 is connected to the output terminal of amplifier U3; the first terminal of resistor R5 is connected to the output terminal of amplifier U3, the first terminal of capacitor C3 is connected to the second terminal of resistor R5, and the second terminal of resistor R6 is connected to the first terminal of capacitor C3.

8. A high-power LED constant current driving circuit for space applications according to claim 1, characterized in that: The first terminal of resistor R6 is connected to the feedback input terminal FB of the radiation-hardened switching regulator U4; the voltage input terminal VIN of the radiation-hardened switching regulator U4 is connected to the external input power supply VCC_IN; the enable input terminal EN of the radiation-hardened switching regulator U4 is connected to the collector of the high-speed switching transistor Q1; the ground input terminal GND of the radiation-hardened switching regulator U4 is connected to ground; the voltage output terminal VOUT of the radiation-hardened switching regulator U4 is connected to the first terminal of inductor L1; the second terminal of inductor L1 is connected to the first terminal of capacitor C4; the second terminal of capacitor C4 is connected to the second terminal of resistor R7; the first terminal of resistor R7 is connected to the feedback input terminal FB of the radiation-hardened switching regulator U4; the first terminals of resistors R8 and R9 are connected to the second terminal of resistor R7; and the second terminals of resistors R8 and R9 are connected to ground.

9. A high-power LED constant current driving circuit for space applications according to claim 1, characterized in that: The anode of high-power LED D1 is connected to the first terminal of capacitor C4, and the cathode of high-power LED D1 is connected to the second terminal of capacitor C4; the first terminal of capacitor C5 is connected to the second terminal of inductor L1, the second terminal of capacitor C5 is connected to the first terminal of capacitor C6, and the second terminal of capacitor C6 is connected to ground; the first terminal of capacitor C4, VCC_LED+, is the positive output of the current of high-power LED D1, and the second terminal of capacitor C4, VCC_LED-, is the negative input of the current of high-power LED D1.

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