LED constant current driver
By integrating charging management, functional protection, light control, and timing adjustment modules into the LED constant current driver, the problems of insufficient protection and unmet discharge curve of solar LED lights are solved, achieving efficient and reliable LED driving and simplifying the system structure.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NANJING ZHIXING ENERGY TECH CO LTD
- Filing Date
- 2025-07-24
- Publication Date
- 2026-05-26
AI Technical Summary
Existing solar LED light drivers do not adequately protect the chips, causing the LEDs to flicker when the battery voltage drops. Furthermore, the discharge curve requirements for different usage scenarios are not met, reducing the efficiency of the application and increasing costs.
An LED constant current driver was designed, which integrates a charging management module, a functional protection module, a light control switch and anti-shake module, a timing adjustment module and a constant current drive module. It integrates multiple protection functions and optimized discharge curve functions, simplifying the complexity of the peripheral system board.
It improves chip reliability and system efficiency, optimizes system board complexity, avoids LED flickering, and meets discharge requirements in different scenarios.
Smart Images
Figure CN224290115U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of electronic circuits and lighting technology, and specifically relates to an LED constant current driver. Background Technology
[0002] With rapid economic development, the demand for energy is increasing daily, and energy shortages have become a significant issue affecting rapid economic growth. Solar energy, as a green and environmentally friendly new energy source, is inexhaustible. Fully utilizing solar energy resources is of positive significance in alleviating the shortage of conventional energy sources.
[0003] Solar-powered LED lights use solar photovoltaic cells to generate electricity. Currently, the technology related to the driver devices in solar-powered LED lights does not adequately protect the internal chips. For example, during LED discharge, as the battery voltage drops to a certain level, the LED will flicker. Furthermore, different application scenarios have different requirements for the LED's discharge curve. These phenomena and requirements are usually addressed by a separate driver control chip in conjunction with a microcontroller, which reduces the efficiency of the overall application and increases the overall system cost.
[0004] Therefore, there is an urgent need for an LED constant current driver that can solve the above problems. Summary of the Invention
[0005] The purpose of this invention is to provide a new LED constant current driver; this LED constant current driver integrates comprehensive protection functions and has a built-in optimized discharge curve function, which can greatly simplify the complexity of the peripheral system board and improve the efficiency of the system.
[0006] To achieve the above objectives, this utility model provides an LED constant current driver for connecting a solar panel, a battery, and an LED. It includes a charging management module, a functional protection module, a light control switch and anti-shake module, a timing adjustment module, and a constant current drive module.
[0007] The input terminals of the charging management module are electrically connected to the solar panel and the functional protection module, respectively, and the first output terminal of the charging management module is electrically connected to the positive terminal BAT of the battery. The charging management module detects the voltage of the solar panel and the battery, and controls the conduction and shutdown of the charging power transistor in the charging management module.
[0008] The first input terminal of the functional protection module is electrically connected to the positive terminal BAT of the battery; the second input terminal of the functional protection module is electrically connected to the first output terminal of the light control switch and the anti-shake module; the first output terminal of the functional protection module is electrically connected to the second input terminal of the charging management module; the second output terminal of the functional protection module is electrically connected to the first input terminal of the constant current drive module; the functional protection module detects the voltage and temperature of the battery during the charging and discharging processes.
[0009] The input terminal of the light control switch and the anti-shake module is electrically connected to the light control enable terminal LS. The first output terminal of the light control switch and the anti-shake module is electrically connected to the second input terminal of the function protection module and the second input terminal of the constant current drive module, respectively. The second output terminal of the light control switch and the anti-shake module is electrically connected to the input terminal of the timing adjustment module. The light control switch and the anti-shake module control the opening and closing of the constant current drive module and the function protection module.
[0010] The input terminal of the timing adjustment module is electrically connected to the second output terminal of the light control switch and the anti-shake module, and the output terminal of the timing adjustment module is electrically connected to the third input terminal of the constant current drive module. The timing adjustment module controls the constant current reference in the constant current drive module. During the timing period, the LED discharges with the maximum current, and after the timing ends, the LED discharges with a smaller current. At the same time, the timing adjustment module works normally during the anti-shake time. When the anti-shake time is exceeded, the timing adjustment module will be reset and the timing will start again.
[0011] The first input terminal of the constant current drive module is electrically connected to the second output terminal of the functional protection module. The second input terminal of the constant current drive module is electrically connected to the first output terminal of the light control switch and the anti-shake module. The third input terminal of the constant current drive module is electrically connected to the output terminal of the timing adjustment module. The output terminal of the constant current drive module is electrically connected to the LED port to realize constant current discharge of the LED.
[0012] Compared with the prior art, the present invention has the following beneficial effects:
[0013] This utility model discloses a new solar LED driver control chip that integrates multiple protection functions and has a built-in optimized discharge curve function, which can greatly simplify the complexity of the peripheral system board, improve the system efficiency, improve the chip's reliability, and optimize the system board's complexity. Attached Figure Description
[0014] Figure 1 A schematic diagram of the LED constant current driver control circuit of this utility model is shown;
[0015] Figure 2 A schematic diagram of the charging management module is shown;
[0016] Figure 3 A schematic diagram of the functional protection module is shown;
[0017] Figure 4 A schematic diagram of the light control switch and the image stabilization module is shown;
[0018] Figure 5 A schematic diagram of the timing adjustment module is shown;
[0019] Figure 6A schematic diagram of the constant current drive module is shown;
[0020] Figure 7 The timing diagram for adjusting the over-discharge protection circuit is shown;
[0021] Figure 8 The timing diagram for stabilization and timing adjustment is shown. Detailed Implementation
[0022] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this application will be clearly and completely described below in conjunction with the accompanying drawings.
[0023] This utility model discloses an LED constant current driver for connecting a solar panel, a battery, and an LED. (See reference...) Figure 1 , Figure 1 A schematic diagram of an LED constant current driver control circuit is shown. The LED constant current driver includes a charging management module, a function protection module, a light control switch and anti-shake module, a timing adjustment module, and a constant current drive module.
[0024] The input terminals of the charging management module are electrically connected to the solar panel and the functional protection module, respectively, and the first output terminal of the charging management module is electrically connected to the positive terminal BAT of the battery. The charging management module is used to detect the voltage of the solar panel and the battery, and to control the conduction and shutdown of the charging power transistor in the charging management module.
[0025] The functional protection module is used to detect the voltage and temperature of the battery during charging and discharging. The first input terminal of the functional protection module is electrically connected to the positive terminal (BAT) of the battery; the second input terminal of the functional protection module is electrically connected to the first output terminal of the light control switch and the anti-shake module; the first output terminal of the functional protection module is electrically connected to the second input terminal of the charging management module; and the second output terminal of the functional protection module is electrically connected to the first input terminal of the constant current drive module.
[0026] The input terminal of the light-controlled switch and anti-shake module is electrically connected to the light-controlled enable terminal LS. The first output terminal of the light-controlled switch and anti-shake module is electrically connected to the second input terminal of the function protection module and the second input terminal of the constant current drive module, respectively. The second output terminal of the light-controlled switch and anti-shake module is electrically connected to the input terminal of the timing adjustment module. The light-controlled switch and anti-shake module controls the opening and closing of the constant current drive module and the function protection module, reducing the power consumption of the chip and preventing the LED from flickering due to low battery voltage during discharge.
[0027] The input terminal of the timing adjustment module is electrically connected to the second output terminal of the light control switch and the anti-shake module, and the output terminal of the timing adjustment module is electrically connected to the third input terminal of the constant current drive module. The timing adjustment module controls the constant current reference in the constant current drive module. During the timing period, the LED discharges with the maximum current, and after the timing ends, the LED discharges with a smaller current. At the same time, the timing adjustment module works normally during the anti-shake time. When the anti-shake time is exceeded, the timing adjustment module will be reset and the timing will start again.
[0028] The first input terminal of the constant current drive module is electrically connected to the second output terminal of the functional protection module. The second input terminal of the constant current drive module is electrically connected to the first output terminal of the light control switch and the anti-shake module. The third input terminal of the constant current drive module is electrically connected to the output terminal of the timing adjustment module. The output terminal of the constant current drive module is electrically connected to the LED port to realize constant current discharge of the LED.
[0029] The specific connection methods and working principles between the above modules are described below.
[0030] A schematic diagram of the charging management module is shown below. Figure 2 As shown, it includes a comparator CMP1, a logic circuit 1, and a charging power transistor P0; the first input terminal of the comparator CMP1 is electrically connected to the positive terminal SBAT of the solar panel, the second input terminal of the comparator CMP1 is electrically connected to the positive terminal BAT of the battery, and the output terminal of the comparator CMP1 is electrically connected to the first input terminal of the logic circuit 1; the second input terminal of the logic circuit 1 is electrically connected to the OV_CH signal, and the output terminal of the logic circuit 1 is electrically connected to the gate of the charging power transistor P0, wherein the OV_CH signal comes from the first output terminal of the functional protection module; the source of the charging power transistor P0 is electrically connected to the positive terminal SBAT of the solar panel, and the drain of the charging power transistor P0 is electrically connected to the positive terminal BAT of the battery.
[0031] In the charging management module, the charging power transistor P0 will only be turned on when the voltage of the positive terminal SBAT of the solar panel is higher than the voltage of the positive terminal BAT of the battery. At this time, the solar panel will charge the battery through the charging power transistor P0. When the voltage of the positive terminal BAT of the battery rises to a certain value, overcharge protection will be triggered. The logic of the overcharge protection signal OV_CH will change and turn off the charging power transistor P0, and the solar panel will stop charging the battery.
[0032] A schematic diagram of the functional protection module is shown below. Figure 3As shown, it includes comparator CMP2, logic circuit 2, over-temperature protection module, comparator CMP3, and RS flip-flop; the first input terminal of comparator CMP2 is electrically connected to the positive terminal BAT of the battery, the second input terminal of comparator CMP2 is electrically connected to the first threshold voltage Vth1, and the output terminal of comparator CMP2 is electrically connected to the first input terminal of logic circuit 2; the second input terminal of logic circuit 2 is electrically connected to the first output terminal of the over-temperature protection module, and the output terminal of logic circuit 2 is the first output terminal of the functional protection module, outputting the OV_CH signal; the over-temperature protection module outputs the first output terminal signal OTP according to the temperature detection result. 1. The second output terminal signal OTP2; the first input terminal of comparator CMP3 is electrically connected to the second threshold voltage Vth2, the second input terminal of comparator CMP3 is electrically connected to the positive terminal BAT of the battery, and the output terminal of comparator CMP3 is electrically connected to the first input terminal of RS flip-flop; the second input terminal of RS flip-flop is electrically connected to the LS_EN signal, which comes from the first output terminal of the light control switch and anti-shake module; the third input terminal of RS flip-flop is electrically connected to the second output terminal of the over-temperature protection module, and the output terminal of RS flip-flop is the second output terminal of the functional protection module, outputting the OV_DIS signal.
[0033] This protection module includes three types of protection: battery overcharge protection, battery over-discharge protection, and battery over-temperature protection. Overcharge protection is triggered when the BAT voltage exceeds the first threshold voltage Vth1, causing the OV_CH logic signal level to flip and shutting down the charging power transistor P0. During LED discharge, over-discharge protection is triggered when the BAT voltage falls below the second threshold voltage Vth2, causing the OV_DIS logic voltage to flip and shutting down the LED constant current drive module, stopping the BAT discharge.
[0034] The chip temperature is monitored during both battery charging and discharging. OTP1 and OTP2 are output signals for over-temperature protection, which control the charging and discharging processes respectively. When over-temperature protection occurs, the charging or discharging state will be shut down.
[0035] A schematic diagram of the light control switch and the image stabilization module is shown below. Figure 4As shown, it includes a comparator CMP4, a timing unit, and an oscillator 1; the first input terminal of the comparator CMP4 is electrically connected to the light control enable terminal LS, the second input terminal of the comparator CMP4 is electrically connected to the third threshold voltage Vth3, the third input terminal of the comparator CMP4 is electrically connected to the fourth threshold voltage Vth4; the output terminal of the comparator CMP4 is the first output terminal of the light control switch and the anti-shake module, outputting the LS_EN signal; the first input terminal of the timing unit is electrically connected to the output terminal of the comparator CMP4, the second input terminal of the timing unit is electrically connected to the output terminal of the oscillator 1, and the output terminal of the timing unit is the second output terminal of the light control switch and the anti-shake module, outputting the Tjitter signal.
[0036] In the light-controlled switch and anti-shake module, the light-control enable LS is compared with two threshold voltages Vth3 and Vth4 (e.g., Vth3 > Vth4), and an LS_EN signal is output to determine whether the external environment is daytime or nighttime, and to control the on / off state of the constant current drive. When the LS voltage is greater than Vth3, it is considered daytime, and the LED constant current drive is turned off; when the LS voltage is less than Vth4, it is considered nighttime, and the LED constant current drive is turned on to provide nighttime lighting. To prevent frequent switching of the LED current, the light-controlled switch and anti-shake module also have a jitter detection function. When external light interference occurs at night and the interference time is less than the internally set time, the LED current remains constant; when the external light interference time is greater than the internally set time, the LED current will switch.
[0037] A schematic diagram of the timing adjustment module is shown below. Figure 5 As shown, it includes an oscillator 2, a counting circuit, and a duration adjustment module; the output terminal of the oscillator 2 is electrically connected to the first input terminal of the counting circuit; the second input terminal of the counting circuit is electrically connected to the second output terminal of the light control switch and the anti-shake module; the third input terminal of the counting circuit is electrically connected to the output terminal of the duration adjustment module; and the output terminal of the counting circuit is the output terminal of the timing adjustment module, outputting the Tcont signal.
[0038] The timing adjustment module primarily relies on the CLK2 clock of oscillator 2 for frequency division and counting. The output signal Tcont is also affected by the anti-jitter output signal Tjitter and the duration adjustment output signal. When the Tjitter logic level remains constant, the timing signal Tcont will be output according to the set duration. When the Tjitter logic level changes, the logic level of the timing signal Tcont will also change. Simultaneously, Tcont is also affected by the duration adjustment module; that is, the duration of Tcont's timing can be adjusted by the duration adjustment module, which can be configured for internal or external chip adjustment.
[0039] A schematic diagram of the constant current drive module is shown below. Figure 6As shown, it includes a reference selection module, an operational amplifier (OPA), a power transistor (N0), and a resistor (R0). The first input terminal of the reference selection module is electrically connected to the output terminal of the timing adjustment module, the second input terminal of the reference selection module is electrically connected to the first reference voltage REF1, the third input terminal of the reference selection module is electrically connected to the second reference voltage REF2, and the output terminal of the reference selection module is electrically connected to the first input terminal of the operational amplifier (OPA). The second input terminal of the operational amplifier (OPA) is electrically connected to the source of the power transistor N0 and one end of the resistor (R0), respectively. The third input terminal of the operational amplifier (OPA) is connected to the optical... The first output terminal of the control switch and anti-shake module is electrically connected; the fourth input terminal of the operational amplifier OPA is electrically connected to the second output terminal of the functional protection module; the output terminal of the operational amplifier OPA is electrically connected to the gate of the power transistor N0; the drain of the power transistor N0 is electrically connected to the LED; the source of the power transistor N0 is electrically connected to the second input terminal of the operational amplifier OPA and one end of the resistor R0; one end of the resistor R0 is electrically connected to the source of the power transistor N0 and the second input terminal of the operational amplifier OPA, and the other end of the resistor R0 is grounded; the resistor R0 can be built into the chip or externally, depending on the application requirements.
[0040] The constant current drive module relies on the clamping resistor of the operational amplifier (OPA) to ensure that the positive voltage of the OPA equals the negative voltage, thus driving the power transistor N0 to conduct. The LED current is equal to the positive voltage of the OPA divided by the resistance value at the negative terminal of the OPA, which can be set inside or outside the chip.
[0041] The constant current drive module's switching on and off is also controlled by the output signal LS_EN from the light-controlled switch and the over-discharge protection signal OV_DIS. When the external environment is daytime, the output LS_EN will turn off the LED driver output; when the external environment is nighttime and the BAT voltage is lower than the second threshold voltage Vth2, over-discharge protection will be triggered, and the OV_DIS signal will turn off the LED driver output. Additionally, the LED current of the constant current drive module is controlled by the timing adjustment signal Tcont. During the timing period, the LED current is a certain value; after the timing ends, the LED current is another fixed value.
[0042] The timing diagram for adjusting the over-discharge protection circuit in this invention is as follows: Figure 7As shown. When the external environment is nighttime, the LS_EN level (e.g., low level) output by the light control switch and anti-shake module turns on the LED constant current driver, and the current flowing through it is ILED. The battery BAT voltage gradually decreases during discharge. When the BAT voltage falls below the threshold voltage Vth2, over-discharge protection is triggered, thus turning off the LED constant current driver. Afterward, even if the BAT voltage rises or falls, the LED constant current driver cannot be turned on again. Then, LS_EN changes from low to high, and the external environment changes from nighttime to daytime. During the day, the LED constant current driver is forcibly turned off, while the solar panel charges the battery. When daytime turns back to nighttime, LS_EN changes from high to low, and the LED constant current driver is turned on again. In other words, when the BAT voltage is too low and triggers over-discharge protection, the LED constant current driver will remain off until the following night, preventing frequent LED flickering caused by low BAT voltage and interference.
[0043] The timing diagram for the anti-shake and timing adjustment in this utility model is as follows: Figure 8 As shown. When the external environment is at night, the LED constant current driver is turned on, and the current is ILED2. Due to interference from other external lights, the voltage of the light control enable terminal LS becomes unstable, and the potential of the output Tjitter of the anti-shake module is also unstable. When the duration of external light interference is less than the internally set time, the LED current will remain unchanged; when the duration of external light interference is greater than the internally set time, that is, when the Tjitter maintains a high level for a longer period than the internally set time, the LED current will switch from the original ILED2 to ILED1.
[0044] After switching, the current of ILED1 remains constant during the timing period. After the timing period ends, ILED1 switches to ILED2. The timing period is controlled by a duration adjustment module, which can be configured for internal or external adjustment within the chip.
[0045] The LED constant current driver disclosed in this utility model integrates multiple protection functions through a control chip and has a built-in optimized discharge curve function, which can greatly simplify the complexity of the peripheral system board, improve the efficiency of the system, improve the reliability of the chip, and optimize the complexity of the system board.
[0046] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.
Claims
1. An LED constant current driver, connecting a solar panel, a battery, and an LED, characterized in that, The LED constant current driver includes a charging management module, a functional protection module, a light control switch and anti-shake module, a timing adjustment module and a constant current driving module; The input terminal of the charging management module is electrically connected to the solar panel and the functional protection module, respectively, and the first output terminal of the charging management module is electrically connected to the positive terminal BAT of the battery. The charging management module detects the voltage of the solar panel and the battery, and controls the conduction and shutdown of the charging power transistor in the charging management module. The first input terminal of the functional protection module is electrically connected to the positive terminal BAT of the battery; the second input terminal of the functional protection module is electrically connected to the first output terminal of the light control switch and the anti-shake module; the first output terminal of the functional protection module is electrically connected to the second input terminal of the charging management module; the second output terminal of the functional protection module is electrically connected to the first input terminal of the constant current drive module; the functional protection module detects the voltage and temperature of the battery during the charging and discharging processes. The input terminal of the light-controlled switch and the anti-shake module is electrically connected to the light-controlled enable terminal LS. The first output terminal of the light-controlled switch and the anti-shake module is electrically connected to the second input terminal of the function protection module and the second input terminal of the constant current drive module, respectively. The second output terminal of the light-controlled switch and the anti-shake module is electrically connected to the input terminal of the timing adjustment module. The light-controlled switch and the anti-shake module control the opening and closing of the constant current drive module and the function protection module. The input terminal of the timing adjustment module is electrically connected to the second output terminal of the light control switch and the anti-shake module, and the output terminal of the timing adjustment module is electrically connected to the third input terminal of the constant current drive module. The timing adjustment module controls the constant current reference in the constant current drive module. During the timing period, the LED discharges with the maximum current, and after the timing ends, the LED discharges with a smaller current. At the same time, the timing adjustment module works normally during the anti-shake time. When the anti-shake time is exceeded, the timing adjustment module will be reset and the timing will start again. The first input terminal of the constant current drive module is electrically connected to the second output terminal of the functional protection module, the second input terminal of the constant current drive module is electrically connected to the first output terminal of the light control switch and the anti-shake module, the third input terminal of the constant current drive module is electrically connected to the output terminal of the timing adjustment module, and the output terminal of the constant current drive module is electrically connected to the LED port to realize constant current discharge of the LED.
2. The LED constant current driver according to claim 1, characterized in that, The charging management module includes a comparator CMP1, a logic circuit 1, and a charging power transistor P0. The first input terminal of the comparator CMP1 is electrically connected to the positive terminal SBAT of the solar panel, the second input terminal of the comparator CMP1 is electrically connected to the positive terminal BAT of the battery, and the output terminal of the comparator CMP1 is electrically connected to the first input terminal of the logic circuit 1. The second input terminal of the logic circuit 1 is electrically connected to the OV_CH signal, and the output terminal of the logic circuit 1 is electrically connected to the gate of the charging power transistor P0. The OV_CH signal comes from the first output terminal of the functional protection module. The source of the charging power transistor P0 is electrically connected to the positive terminal SBAT of the solar panel, and the drain of the charging power transistor P0 is electrically connected to the positive terminal BAT of the battery.
3. The LED constant current driver according to claim 2, characterized in that, The functional protection module includes comparator CMP2, logic circuit 2, over-temperature protection module, comparator CMP3, and RS flip-flop; The first input terminal of the comparator CMP2 is electrically connected to the positive terminal BAT of the battery, the second input terminal of the comparator CMP2 is electrically connected to the first threshold voltage Vth1, and the output terminal of the comparator CMP2 is electrically connected to the first input terminal of the logic circuit 2. The second input terminal of the logic circuit 2 is electrically connected to the first output terminal of the over-temperature protection module, and the output terminal of the logic circuit 2 is the first output terminal of the functional protection module, outputting the OV_CH signal; The over-temperature protection module outputs a first output signal OTP1 and a second output signal OTP2 based on the temperature detection result. The first input terminal of the comparator CMP3 is electrically connected to the second threshold voltage Vth2, the second input terminal of the comparator CMP3 is electrically connected to the positive terminal BAT of the battery, and the output terminal of the comparator CMP3 is electrically connected to the first input terminal of the RS flip-flop. The second input terminal of the RS flip-flop is electrically connected to the LS_EN signal, which comes from the first output terminal of the light control switch and the anti-shake module; the third input terminal of the RS flip-flop is electrically connected to the second output terminal of the over-temperature protection module, and the output terminal of the RS flip-flop is the second output terminal of the functional protection module, which outputs the OV_DIS signal.
4. The LED constant current driver according to claim 3, characterized in that, The light-controlled switch and anti-shake module include a comparator CMP4, a timing unit, and an oscillator 1; The first input terminal of the comparator CMP4 is electrically connected to the light control enable terminal LS; the second input terminal of the comparator CMP4 is electrically connected to the third threshold voltage Vth3; the third input terminal of the comparator CMP4 is electrically connected to the fourth threshold voltage Vth4; the output terminal of the comparator CMP4 is the first output terminal of the light control switch and the anti-shake module, and outputs the LS_EN signal. The first input terminal of the timing unit is electrically connected to the output terminal of the comparator CMP4, the second input terminal of the timing unit is electrically connected to the output terminal of the oscillator 1, and the output terminal of the timing unit is the second output terminal of the light control switch and the anti-shake module, outputting a Tjitter signal.
5. An LED constant current driver according to claim 4, characterized in that, The timing adjustment module includes an oscillator 2, a counting circuit, and a duration adjustment module; The output terminal of the oscillator 2 is electrically connected to the first input terminal of the counting circuit; The second input terminal of the counting circuit is electrically connected to the second output terminal of the light control switch and the anti-shake module, the third input terminal of the counting circuit is electrically connected to the output terminal of the duration adjustment module, and the output terminal of the counting circuit is the output terminal of the timing adjustment module, outputting the Tcont signal.
6. The LED constant current driver according to claim 5, characterized in that, The constant current drive module includes a reference selection module, an operational amplifier OPA, a power transistor N0, and a resistor R0. The first input terminal of the reference selection module is electrically connected to the output terminal of the timing adjustment module, the second input terminal of the reference selection module is electrically connected to the first reference voltage REF1, the third input terminal of the reference selection module is electrically connected to the second reference voltage REF2, and the output terminal of the reference selection module is electrically connected to the first input terminal of the operational amplifier OPA. The second input terminal of the operational amplifier OPA is electrically connected to the source of the power transistor N0 and one end of the resistor R0, respectively. The third input terminal of the operational amplifier OPA is electrically connected to the first output terminal of the light control switch and the anti-shake module. The fourth input terminal of the operational amplifier OPA is electrically connected to the second output terminal of the function protection module. The output terminal of the operational amplifier OPA is electrically connected to the gate of the power transistor N0. The drain of the power transistor N0 is electrically connected to the LED, and the source of the power transistor N0 is electrically connected to the second input terminal of the operational amplifier OPA and one end of the resistor R0, respectively. One end of the resistor R0 is electrically connected to the source of the power transistor N0 and the second input terminal of the operational amplifier OPA, respectively, and the other end of the resistor R0 is grounded.