Constant current detection control circuit for DC-DC LED dimming power supply

Abstract

The invention relates to the technical field of LED illumination, and provides a constant current detection control circuit and device for a DC-DC LED dimming power supply. Comprising an MOS driving module; the driving module is used for receiving dimming control signals and generating driving voltage; a BUCK voltage reduction module; the voltage reduction module is used for reducing the driving voltage to generate an equivalent voltage signal; the peak current acquisition module is used for transmitting the LED output current to the MCU processor and determining a driving pulse width correction signal; and the current compensation calculation module is used for determining a compensation control signal according to the driving pulse width correction signal. The MCU is adopted as a control chip, an independent programming mode is adopted, and a corresponding peripheral acquisition circuit is matched to replace a drive control circuit with a BUCK drive IC as a core, so that the flexibility of BUCK drive application design is improved, and the BUCK drive circuit is not limited by the defects of a drive chip.

Description

Technical Field

[0001] The invention relates to the field of power supply detection, and in particular to a constant current detection control circuit for a DC-DC LED dimming power supply. Background Art

[0002] Currently, if Figure 3 As shown, the conventional BUCK constant current control method of LED driving uses a constant current buck driver IC for control. In the process of controlling the buck circuit buck, the IC samples the output current through an external resistor, and obtains an equivalent voltage by multiplying the current flowing through the resistor by the resistor. The current equivalent voltage set by the comparator unit inside the IC is compared to form a current closed-loop feedback loop to achieve the purpose of constant current control. The current equivalent voltage value can be changed through an external control signal (PWM signal, analog voltage signal), thereby controlling the output current of the buck circuit and achieving the purpose of adjusting the output brightness of the LED light by the LED power driver.

[0003] In the traditional solution, the driving current of the BUCK circuit is completely controlled by the BUCK driver IC. In the circuit application scenario, there are many limitations. During the design process, it is impossible to adjust the external circuit parameters to deal with the internal defects of the driver IC, such as low-brightness step feeling, output current jitter during fixed-point dimming, etc. Summary of the invention

[0004] The present invention discloses a constant current detection control circuit for a DC-DC LED dimming power supply, which is used to solve the problem that the driving current of a BUCK circuit is completely controlled by a BUCK driver IC. In the circuit application scenario, there are many limitations. In the design process, it is impossible to adjust external circuit parameters to handle the internal defects of the driver IC, such as low brightness step feeling and output current jitter problems during fixed-point dimming.

[0005] The present invention proposes a constant current detection control circuit for a DC-DC LED dimming power supply, comprising: MOS driving module; used to receive dimming control signals and generate driving voltage; BUCK step-down module; used to step down the driving voltage to generate LED output current; Peak current acquisition module: used to transmit the LED output current to the MCU processor to determine the drive pulse width correction signal; Current compensation calculation module: used to determine the compensation control signal according to the drive pulse width correction signal.

[0006] Furthermore, the peak current acquisition module includes: A signal amplifying circuit, used for receiving an equivalent voltage signal and converting it into a preset voltage range; The comparator is used to compare the LED output current with the expected current value and output a comparison signal; wherein the expected current value signal is sent by the MCU processor.

[0007] Further, the comparison signal includes a first signal and a second signal; Wherein, when the comparison signal is the first signal, the LED output current is higher than the expected current value, and the comparator outputs a rising edge signal; When the comparison signal is the second signal, the LED output current is lower than the expected current value, and the comparator outputs a falling edge signal.

[0008] Further, the signal amplification circuit includes: an eleventh resistor, a tenth resistor, a ninth resistor, an eighth resistor, a seventh resistor, a sixth resistor, a fourth capacitor, a fifth capacitor, a fifth resistor, a third capacitor and a signal amplifier; One end of the eleventh resistor is used to collect the LED output current and is connected to the positive input end of the signal amplifier through the seventh resistor; The other end of the eleventh resistor is connected to the negative input terminal of the signal amplifier through the eighth resistor; The eleventh resistor is connected in parallel with the tenth resistor and the ninth resistor; The negative input terminal of the signal amplifier is also grounded through a fourth capacitor, and the positive input terminal of the signal amplifier is also grounded through a fifth capacitor; A fifth resistor is connected in parallel between the negative input terminal and the output terminal of the signal amplifier, and a third capacitor and a sixth resistor which are connected in series are also connected in parallel between the negative input terminal and the output terminal.

[0009] Further, the PA2 end of the comparator is electrically connected to the output end of the signal amplification circuit through a fourth resistor, and the PA0 end of the comparator is electrically connected to the MCU processor through a secondary RC filter circuit, and receives a PWM wave sent by the MCU processor, wherein the PWM wave is equivalent to the expected current value; The output end of the comparator is electrically connected to the MCU processor and is used to output a driving pulse width correction signal.

[0010] Furthermore, the secondary RC filter circuit includes: a first resistor, a second resistor and a third resistor connected in series, wherein the second resistor is connected in parallel with a twelfth resistor and a first capacitor connected in series; and a grounded second capacitor is connected between the third resistor and the PA0 port of the comparator.

[0011] Furthermore, the step of passing the LED output current through the MCU processor further includes: Based on the LED output current interruption, a peak current distribution curve is generated, and the signal timing and amplitude characteristics of each peak and each valley are extracted through the peak-valley algorithm; According to the peak current distribution curve, the LED current signal is converted, and VMD decomposition is performed after the conversion to determine the distribution entropy value of each peak value and each valley value; Inputting the spread entropy value and the signal timing into the first PAC model to determine whether the LED output current corresponding to the signal timing needs to be compensated; When the LED output current corresponding to the signal timing needs to be compensated, the spread entropy value and the amplitude characteristic are input into the second PAC model to determine the required correction value of the LED output current corresponding to the signal timing.

[0012] Furthermore, the step of determining whether the LED output current corresponding to the signal timing needs to be compensated comprises the following steps: Inputting the spread entropy value into the first PAC model according to the signal timing sequence to determine the property characteristics of the LED current of each signal timing sequence; Based on the signal timing, calculate the fluctuation data of LED current at different signal timings; Determine the long-range correlation of LED current based on fluctuation data and expected current value; Among them, when the LED current belongs to the expected negative correlation, it means that the LED output current needs to be corrected; Among them, when the LED current belongs to the expected positive correlation, it means that the LED output current does not need to be corrected; Among them, when the LED current has no expected correlation, it means that the MOS driver module is driving fault.

[0013] Furthermore, the step of determining whether the LED output current corresponding to the signal timing needs to be compensated further includes: Inputting the LED output current and the spread entropy value at each moment into the second PAC model to determine the compensation interval of the LED output current at each moment; According to the compensation interval, determine the adjustable curve of LED output current; According to the adjustable curve and the expected current value, determine whether the LED output current compensation is an expected current value that exceeds the compensation interval; Wherein, when there is an ambiguous value, the time when the ambiguous value occurs is determined, and whether the driving current of the MOS driving module is abnormal is determined, and when the driving current of the MOS driving module is abnormal, the MOS driving module is controlled to reset; When there is no ambiguity, the correction value corresponding to each moment is determined.

[0014] Further, the determining the compensation control signal includes: Pre-set the expected equivalent network; Input the driving pulse width correction signal into the expected equivalent network for equivalent calculation to determine the capacitance and inductance parameter values ​​at each moment; Perform fitting calculation on the capacitance and inductance parameter values ​​at each moment and the preset constant current compensation conditions, and determine the fitting value corresponding to the fitting calculation; The fitting value is converted into a compensation control signal to compensate the dimming control signal.

[0015] The beneficial effects of the present invention are: The MCU of the present invention can accurately collect the actual output current size, and make a correct judgment based on the result after comparing it with the expected output current size, and can correctly control the opening and closing of the BUCK driving waveform to achieve the purpose of constant output current.

[0016] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings.

[0017] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0019] In the attached picture: Figure 1 It is a composition diagram of a constant current detection control circuit for a DC-DC LED dimming power supply in an embodiment of the present invention; Figure 2 A peak current acquisition circuit corresponding to the peak current acquisition module in the embodiment of the present invention; Figure 3 1 is a conventional circuit composition diagram of a constant current detection control circuit for a DC-DC LED dimming power supply in an embodiment of the present invention. DETAILED DESCRIPTION

[0020] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0021] like Figure 1 As shown, this embodiment provides a constant current detection control circuit for a DC-DC LED dimming power supply, which is characterized by comprising: MOS driving module; used to receive dimming control signals and generate driving voltage; BUCK step-down module; used to step down the driving voltage to generate LED output current; Peak current acquisition module: used to transmit the LED output current to the MCU processor to determine the drive pulse width correction signal; Current compensation calculation module: used to determine the compensation control signal according to the drive pulse width correction signal.

[0022] The principle of the above technical solution is: The present invention proposes to use MCU as the control chip, independently program it, and cooperate with the corresponding peripheral acquisition circuit to replace the driving control circuit with BUCK driver IC as the core, so as to improve the flexibility of BUCK driver application design without being limited by the defects of the driver chip itself.

[0023] In the actual implementation process, the MOS driver module is used to receive the dimming control signal and generate the driving voltage of the dimming control drive. The BUCK buck module uses a constant current buck control method to output the LED output current to perform dimming control. The peak current acquisition module of the present invention will collect the LED output current, and the collected current will be processed by the MCU to determine whether there is a dimming deviation. If there is a dimming deviation, the corresponding driving pulse width correction signal will be output, and then the compensation signal will be determined by the current compensation calculation module for the driving pulse width correction signal. That is: the constant current control method adopted converts the output current signal into a voltage signal through the peak current acquisition module and transmits it to the MCU. Through the collected voltage signal, the MCU performs real-time correction on the driving pulse width.

[0024] The beneficial effects of the above technical solution are: The DC-DC digital dimming power supply device introduced in the present invention changes the method of using the BUCK driver IC as the current control device in the existing solution, and selects to monitor the output current change through the MCU. The advantage of the above method is that it can realize the driving and constant current control of the BUCK circuit through MCU programming without relying on the BUCK driver IC.

[0025] As an embodiment of the present invention: the peak current acquisition module includes: A signal amplifying circuit, used for receiving an equivalent voltage signal and converting it into a preset voltage range; The comparator is used to compare the LED output current with the expected current value and output a comparison signal; wherein the expected current value signal is sent by the MCU processor.

[0026] The principle of the above technical solution is: In the peak current acquisition module of the present invention, the signal amplification circuit is used for signal acquisition to determine whether the equivalent voltage signal corresponding to the LED output current is within a preset voltage range. The comparator is used to compare the LED output current with the expected current value to determine whether compensation is required.

[0027] As an embodiment of the present invention: the comparison signal includes a first signal and a second signal; Wherein, when the comparison signal is the first signal, the LED output current is higher than the expected current value, and the comparator outputs a rising edge signal; When the comparison signal is the second signal, the LED output current is lower than the expected current value, and the comparator outputs a falling edge signal.

[0028] The principle of the above technical solution is: When the present invention is implemented, compensation display is performed through the current signal, and the rising edge and falling edge signals can clearly display the specific compensation value.

[0029] As an embodiment of the present invention: the signal amplification circuit includes: an eleventh resistor R11, a tenth resistor R10, a ninth resistor R9, an eighth resistor R8, a seventh resistor R7, a sixth resistor R6, a fourth capacitor C4, a fifth capacitor C5, a fifth resistor R5, a third capacitor C3 and a signal amplifier ARI; One end of the eleventh resistor R11 is used to collect the LED output current, and is connected to the positive input end of the signal amplifier ARI through the seventh resistor R7; Another section of the eleventh resistor R11 is connected to the negative input terminal of the signal amplifier ARI through the eighth resistor R8; The eleventh resistor R11 is connected in parallel with the tenth resistor R10 and the ninth resistor R9; The negative input terminal of the signal amplifier ARI is also grounded via a fourth capacitor C4, and the positive input terminal of the signal amplifier ARI is also grounded via a fifth capacitor C5; A fifth resistor R5 is connected in parallel between the negative input terminal and the output terminal of the signal amplifier ARI, and a third capacitor C3 and a sixth resistor R6 connected in series are also connected in parallel between the negative input terminal and the output terminal.

[0030] The principle of the above technical solution is: like Figure 2As shown, the current acquisition input terminal is CUR_FEEDBACK (right end). After the current flows through this terminal, it is converted into a voltage signal through the eleventh resistor R11, the tenth resistor R10, and the ninth resistor R9. Since the output current of the LED power supply is generally mA, the equivalent voltage converted after flowing through three Ω-level sampling resistors is mV, so signal amplification processing is required. The operational amplifier AR1 is used to amplify the collected current signal to a voltage range that can be more easily recognized by the microcontroller, so an amplification factor of 11 times is used. The amplified signal enters the negative end of the comparator.

[0031] As an embodiment of the present invention: the PA2 terminal of the comparator U1 is electrically connected to the output terminal of the signal amplification circuit through the fourth resistor R4, the PA0 terminal of the comparator U1 is electrically connected to the MCU processor through the secondary RC filter circuit, and receives the PWM wave sent by the MCU processor, wherein the PWM wave is equivalent to the expected current value; The output end of the comparator U1 is electrically connected to the MCU processor for outputting a driving pulse width correction signal.

[0032] The principle of the above technical solution is: In the present invention, the positive terminal of the comparator U1 is connected to a PWM wave (PWM2) equivalent to the expected current value, which is emitted by the MCU.

[0033] As an embodiment of the present invention: the secondary RC filter circuit includes: a first resistor R1, a second resistor R2 and a third resistor R3 connected in series, wherein the second resistor R2 is connected in parallel with a twelfth resistor R12 and a first capacitor R1 in series; a grounded second capacitor C2 is connected between the third resistor R3 and the PA0 port of the comparator U1.

[0034] The principle of the above technical solution is: In the present invention, after the PWM2 signal passes through the secondary RC filtering circuit, the PWM wave is converted into a DC signal. The DC signal is equivalent to the voltage signal after the expected current value is converted and connected to the positive end of the comparator. The comparator will generate a rising edge or falling edge signal at the output end of the comparator by comparing the magnitude relationship between the feedback current and the expected current.

[0035] In the specific implementation process: If the actual current value fed back exceeds the expected output current value, the output result of the comparator will change from low level to high level, generating a rising edge signal. Conversely, if the actual current value is lower than the expected output current value, the output result of the comparator will change from high level to low level, generating a falling edge signal. After the microcontroller receives the rising edge and falling edge signals, it can perform corresponding opening or closing operations on the output drive.

[0036] If it is detected that the output current at the current moment is higher than the expected current, after the comparator generates a rising edge signal, the microcontroller detects the rising edge and turns off the drive signal in advance, and then restores the drive signal in the next cycle to reduce the current and ensure that the feedback current is always kept within the small error range of the expected current, thereby achieving the purpose of constant current.

[0037] As an embodiment of the present invention: the step of passing the LED output current through the MCU processor further includes: Based on the LED output current interruption, a peak current distribution curve is generated, and the signal timing and amplitude characteristics of each peak and each valley are extracted through the peak-valley algorithm; According to the peak current distribution curve, the LED current signal is converted, and VMD decomposition is performed after the conversion to determine the distribution entropy value of each peak value and each valley value; Inputting the spread entropy value and the signal timing into the first PAC model to determine whether the LED output current corresponding to the signal timing needs to be compensated; When the LED output current corresponding to the signal timing needs to be compensated, the spread entropy value and the amplitude characteristic are input into the second PAC model to determine the required correction value of the LED output current corresponding to the signal timing.

[0038] The principle of the above technical solution is: The present invention includes four steps, the first of which is the generation of a peak current distribution curve: the LED output current is monitored by the MCU processor, and a series of peak current distributions are generated when the LED output current is generated. These peak currents are caused by the operation of the LED dimming control signal in the voltage control process, and each peak and valley represents a current pulse.

[0039] Then, there is the peak-to-valley algorithm. Through the peak-to-valley algorithm, the signal timing (i.e., the time point when the peak and valley occur) and amplitude characteristics (i.e., the size of the peak and valley) of each peak and valley can be extracted.

[0040] Subsequently, the LED current signal is converted and VMD decomposed to convert the peak current distribution curve into a format suitable for analysis, and then the current signal is decomposed using the variational mode decomposition (VMD) technique. VMD can decompose the complex current signal into multiple intrinsic mode functions (IMFs), each of which represents the current fluctuations of different frequency components. Through VMD decomposition, the spread entropy value of each peak and valley value is determined, which reflects the complexity and randomness of the current signal.

[0041] Finally, PAC model judgment: The first PAC model is used to determine whether the LED output current corresponding to the signal timing needs compensation. The PAC model is based on the probability approximation correctness theory and can determine whether the model is accurate with a high probability. If the first PAC model determines that compensation is needed, the second PAC model is used to determine the specific correction value. The second PAC model takes into account the spread entropy value and amplitude characteristics to more accurately estimate the required correction value.

[0042] In the specific implementation process: The MCU processor monitors the LED output current in real time and records the current data when the output current is detected to be disconnected. The peak current distribution curve is generated: When the LED output is disconnected, a peak current distribution curve is generated. For example, the current waveform may generate a spike each time the LED is switched on and off. Using the peak-to-valley algorithm, 10 peaks and corresponding valleys are extracted, and their occurrence time and current amplitude are recorded. The current signal is converted into a format suitable for VMD processing and decomposed to obtain 5 IMFs. Each IMF is analyzed to extract the spread entropy value. For example, the spread entropy value of the first IMF is 0.8. The signal timing and spread entropy value are input into the first PAC model, and the model determines that the current of the third peak needs to be compensated. The spread entropy value and amplitude characteristics of the third peak are input into the second PAC model, and the model outputs a correction value of +50mA. The LED drive current is adjusted according to the correction value to compensate for the detected current fluctuations to ensure the stability of the brightness and dimming effect of the LED light strip.

[0043] As an embodiment of the present invention: determining whether the LED output current corresponding to the signal timing needs to be compensated includes the following steps: Inputting the spread entropy value into the first PAC model according to the signal timing sequence to determine the property characteristics of the LED current of each signal timing sequence; Based on the signal timing, calculate the fluctuation data of LED current at different signal timings; Determine the long-range correlation of LED current based on fluctuation data and expected current value; Among them, when the LED current belongs to the expected negative correlation, it means that the LED output current needs to be corrected; Among them, when the LED current belongs to the expected positive correlation, it means that the LED output current does not need to be corrected; Among them, when the LED current has no expected correlation, it means that the MOS driver module is driving fault.

[0044] The principle of the above technical solution is: In the process of inputting the distributed entropy value into the first PAC model to determine whether compensation is required, the distributed entropy value is a quantitative indicator of signal complexity and randomness. The distributed entropy value is input into the first PAC model according to the signal timing, and the model will analyze the LED current property characteristics of each signal timing, such as stability, volatility, etc. The LED current fluctuation data is calculated, which is based on the signal timing and calculates the fluctuation data of the LED current at different timings. This involves analyzing the change amplitude and frequency of the current signal to understand the stability of the current. The long-range correlation of the LED current is determined, and its long-range correlation refers to the correlation of the signal on different time scales. By comparing the fluctuation data and the expected current value, the long-range correlation of the LED current can be determined. Expected negative correlation, which means that if the change of the LED current is negatively correlated with the expected current value, that is, the current fluctuation causes the brightness to be lower than the expected value, then correction is required. Expected positive correlation, which means that if the change of the LED current is positively correlated with the expected current value, that is, the current fluctuation will not affect the brightness stability, then correction is not required. No expected correlation, which means that if the LED current has no correlation with the expected current value, it may indicate that there is a driving fault in the MOS driving module.

[0045] In the specific implementation process: Step 1: The MCU processor collects LED output current data and calculates the dispersion entropy values ​​of 10 different signal timing points.

[0046] Step 2: Input the 10 spread entropy values ​​into the first PAC model according to the signal timing, and obtain the current property characteristics at each timing point through model analysis.

[0047] Step 3: Based on the signal timing, calculate the current fluctuation data of each timing point. For example, the current fluctuation at the fifth timing point is ±20mA.

[0048] Step 4: Compare the fluctuation data with the expected current value (assuming 500mA), and find that the current fluctuation at the fifth timing point causes the actual current to be lower than 500mA, which is negatively correlated.

[0049] The current fluctuation at the third timing point is positively correlated with the expected current value, and the fluctuation will not affect the brightness stability.

[0050] The current fluctuation at the eighth timing point has no correlation with the expected current value, which may indicate a fault in the MOS driver module.

[0051] Step 5: For the fifth timing point, since the LED current is in the expected negative correlation, it is determined that the LED output current needs to be corrected. The correction value may be +20mA to compensate for the fluctuation.

[0052] For the third timing point, since the LED current is in the expected positive correlation, no correction is required.

[0053] For the eighth timing point, since the LED current has no expected correlation, the system issues a warning and instructs to check the MOS driver module.

[0054] As an embodiment of the present invention: the step of determining whether the LED output current corresponding to the signal timing needs to be compensated further includes: Inputting the LED output current and the spread entropy value at each moment into the second PAC model to determine the compensation interval of the LED output current at each moment; According to the compensation interval, determine the adjustable curve of LED output current; According to the adjustable curve and the expected current value, determine whether the LED output current compensation is an expected current value that exceeds the compensation interval; Wherein, when there is an ambiguous value, the time when the ambiguous value occurs is determined, and whether the driving current of the MOS driving module is abnormal is determined, and when the driving current of the MOS driving module is abnormal, the MOS driving module is controlled to reset; When there is no ambiguity, the correction value corresponding to each moment is determined.

[0055] The principle of the above technical solution is: In the process of determining the current demand compensation value through the second PAC model, First, the LED output current and the spread entropy value at each moment are input into the second PAC model, which will analyze these data to determine the possible compensation range of the LED output current at each moment. The compensation range refers to the range in which the current can be adjusted without affecting the performance and life of the LED.

[0056] Then, according to the compensation interval, the adjustable curve of the LED output current is drawn. This curve represents the limit within which the LED output current can be adjusted within the compensation interval.

[0057] Then, the adjustable curve and the expected current value are compared to determine whether there is a difference beyond the compensation interval. The difference refers to the difference between the actual current value and the expected current value, and the difference exceeds the compensation interval defined by the adjustable curve.

[0058] If there is an ambiguous value, the system will determine the time when the ambiguous value occurs and further check whether the driving current of the MOS driving module is abnormal. If it is detected that the driving current of the MOS driving module is abnormal, the system will control the MOS driving module to reset to eliminate the abnormal state.

[0059] If there is no ambiguity, the system will determine the corresponding correction value at each moment according to the adjustable curve to adjust the LED output current to meet the expected current value.

[0060] As an embodiment of the present invention: determining the compensation control signal includes: Pre-set the expected equivalent network; Input the driving pulse width correction signal into the expected equivalent network for equivalent calculation to determine the capacitance and inductance parameter values ​​at each moment; Perform fitting calculation on the capacitance and inductance parameter values ​​at each moment and the preset constant current compensation conditions, and determine the fitting value corresponding to the fitting calculation; The fitting value is converted into a compensation control signal to compensate the dimming control signal.

[0061] The principle of the above technical solution is to further supplement the method of determining the compensation control signal, which includes presetting the expected equivalent network, performing equivalent calculation on the driving pulse width correction signal, determining the capacitance and inductance parameter values ​​at each moment, and fitting these values ​​with the preset constant current compensation conditions to determine the corresponding fitting values. This fitting value is then converted into a compensation control signal, and the dimming control signal is compensated. This can not only make the current compensation more accurate, but also ensure the real-time and accuracy of the compensation control, further improving the performance and reliability of the system. Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A constant current detection control circuit for a DC-DC LED dimming power supply, characterized in that: include: MOS driver module; Used to receive dimming control signals and generate driving voltages; BUCK step-down module; Used to step down the driving voltage to generate LED output current; Peak current acquisition module: used to transmit the LED output current to the MCU processor to determine the drive pulse width correction signal; Current compensation calculation module: used to determine the compensation control signal according to the drive pulse width correction signal.

2. A constant current detection control circuit for a DC-DC LED dimming power supply as claimed in claim 1, characterized in that: The peak current acquisition module comprises: A signal amplifying circuit, used for receiving an equivalent voltage signal and converting it into a preset voltage range; The comparator U1 is used to compare the LED output current with the expected current value and output a comparison signal; wherein the expected current value signal is sent by the MCU processor.

3. A constant current detection control circuit for a DC-DC LED dimming power supply as claimed in claim 2, characterized in that: The comparison signal includes a first signal and a second signal; Wherein, when the comparison signal is the first signal, the LED output current is higher than the expected current value, and the comparator outputs a rising edge signal; When the comparison signal is the second signal, the LED output current is lower than the expected current value, and the comparator outputs a falling edge signal.

4. A constant current detection control circuit for a DC-DC LED dimming power supply as claimed in claim 2, characterized in that: The signal amplifying circuit includes: an eleventh resistor R11, a tenth resistor R10, a ninth resistor R9, an eighth resistor R8, a seventh resistor R7, a sixth resistor R6, a fourth capacitor C4, a fifth capacitor C5, a fifth resistor R5, a third capacitor C3 and a signal amplifier ARI; One end of the eleventh resistor R11 is used to collect the LED output current, and is connected to the positive input end of the signal amplifier ARI through the seventh resistor R7; The other end of the eleventh resistor R11 is connected to the negative input end of the signal amplifier ARI through the eighth resistor R8; The eleventh resistor R11 is connected in parallel with the tenth resistor R10 and the ninth resistor R9; The negative input terminal of the signal amplifier ARI is also grounded via a fourth capacitor C4, and the positive input terminal of the signal amplifier ARI is also grounded via a fifth capacitor C5; A fifth resistor R5 is connected in parallel between the negative input terminal and the output terminal of the signal amplifier ARI, and a third capacitor C3 and a sixth resistor R6 connected in series are also connected in parallel between the negative input terminal and the output terminal.

5. A constant current detection control circuit for a DC-DC LED dimming power supply as claimed in claim 2, characterized in that: The PA2 terminal of the comparator U1 is electrically connected to the output terminal of the signal amplification circuit through the fourth resistor R4, and the PA0 terminal of the comparator U1 is electrically connected to the MCU processor through the secondary RC filter circuit, and receives the PWM wave sent by the MCU processor, wherein the PWM wave is equivalent to the expected current value; The output end of the comparator U1 is electrically connected to the MCU processor for outputting a driving pulse width correction signal.

6. A constant current detection control circuit for a DC-DC LED dimming power supply as claimed in claim 5, characterized in that: The secondary RC filter circuit includes: a first resistor R1, a second resistor R2 and a third resistor R3 connected in series, wherein the second resistor R2 is connected in parallel with a twelfth resistor R12 and a first capacitor R1 connected in series; a grounded second capacitor C2 is connected between the third resistor R3 and the PA0 port of the comparator U1.

7. A constant current detection control circuit for a DC-DC LED dimming power supply as claimed in claim 1, characterized in that: The LED output current is passed through the MCU processor, and further includes: Based on the LED output current interruption, a peak current distribution curve is generated, and the signal timing and amplitude characteristics of each peak and each valley are extracted through the peak-valley algorithm; According to the peak current distribution curve, the LED current signal is converted, and VMD decomposition is performed after the conversion to determine the distribution entropy value of each peak value and each valley value; Inputting the spread entropy value and the signal timing into the first PAC model to determine whether the LED output current corresponding to the signal timing needs to be compensated; When the LED output current corresponding to the signal timing needs to be compensated, the spread entropy value and the amplitude characteristic are input into the second PAC model to determine the required correction value of the LED output current corresponding to the signal timing.

8. A constant current detection control circuit for a DC-DC LED dimming power supply as claimed in claim 7, characterized in that: The step of judging whether the LED output current corresponding to the signal timing needs to be compensated comprises the following steps: Inputting the spread entropy value into the first PAC model according to the signal timing sequence to determine the property characteristics of the LED current of each signal timing sequence; Based on the signal timing, calculate the fluctuation data of LED current at different signal timings; Determine the long-range correlation of LED current based on fluctuation data and expected current value; Among them, when the LED current belongs to the expected negative correlation, it means that the LED output current needs to be corrected; Among them, when the LED current belongs to the expected positive correlation, it means that the LED output current does not need to be corrected; Among them, when the LED current has no expected correlation, it means that the MOS driver module is driving fault.

9. A constant current detection control circuit for a DC-DC LED dimming power supply as claimed in claim 8, characterized in that: The step of determining whether the LED output current corresponding to the signal timing needs to be compensated further includes: Inputting the LED output current and the spread entropy value at each moment into the second PAC model to determine the compensation interval of the LED output current at each moment; According to the compensation interval, determine the adjustable curve of LED output current; According to the adjustable curve and the expected current value, determine whether the LED output current compensation is an expected current value that exceeds the compensation interval; Wherein, when there is an ambiguous value, the time when the ambiguous value occurs is determined, and whether the driving current of the MOS driving module is abnormal is determined, and when the driving current of the MOS driving module is abnormal, the MOS driving module is controlled to reset; When there is no ambiguity, the correction value corresponding to each moment is determined.

10. A constant current detection control circuit for a DC-DC LED dimming power supply as claimed in claim 1, characterized in that: The determining of the compensation control signal comprises: Pre-set the expected equivalent network; Input the driving pulse width correction signal into the expected equivalent network for equivalent calculation to determine the capacitance and inductance parameter values ​​at each moment; Perform fitting calculation on the capacitance and inductance parameter values ​​at each moment and the preset constant current compensation conditions, and determine the fitting value corresponding to the fitting calculation; The fitting value is converted into a compensation control signal to compensate the dimming control signal.

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