Low-brightness anti-flicker dimming control method and circuit for LED driving power supply

Abstract

This application relates to a low-brightness flicker-free dimming control method and circuit for LED driver power supplies. The control method includes acquiring a dimming input signal and the operating status data of the LED output current; when entering the lowest brightness stable control mode, determining the target brightness based on the dimming input signal, determining the corresponding distribution strategy, outputting the corresponding continuous current to the LED load through an analog current regulation path, and outputting the corresponding distributed compensation pulse to the LED load through a PWM drive path; sampling the current data output by the LED load and determining whether the sampling result meets the mode exit condition; if so, switching the lowest brightness stable control mode to the conventional PWM dimming mode. This significantly reduces brightness fluctuations and flicker under extremely low brightness conditions, improving output stability and visual comfort while ensuring dimming accuracy, and enhancing adaptability to different loads and application scenarios.

Description

Technical Field

[0001] This application relates to the technical field of LED driver power supply dimming control, and in particular to a method and circuit for low-brightness anti-flicker dimming control of LED driver power supply. Background Technology

[0002] Currently, with the widespread application of LED lighting in bedroom nightlights, hotel ambient lighting, and various auxiliary lighting scenarios, users have placed higher demands on visual comfort in low-brightness conditions. Existing dimming methods typically rely on reducing the duty cycle to control brightness in low-brightness areas. However, under extremely low brightness conditions, this can easily lead to discontinuous changes in output luminous flux, resulting in flickering or brightness instability that is perceptible to the naked eye, affecting the user experience. Furthermore, the load characteristics of different application scenarios and the sensitivity of the human eye to brightness changes vary, making it difficult for existing technologies to simultaneously ensure dimming accuracy and stability and consistency. Therefore, there is an urgent need for a dimming control solution that can balance output continuity and brightness adjustment accuracy under low-brightness conditions to improve overall lighting quality. Summary of the Invention

[0003] To address the issues of flickering caused by discontinuous output luminous flux during low-brightness dimming and the difficulty in balancing brightness accuracy and stability, this application provides a low-brightness anti-flicker dimming control method and circuit for LED driver power supplies.

[0004] A low-brightness flicker-proof dimming control method for LED driver power supplies, the control method comprising: Acquire the dimming input signal and the operating status data of the LED output current; Based on the dimming input signal and operating status data, the stability of the current driving state is determined to generate a corresponding determination result, and the minimum brightness stable control mode is entered when the determination result meets the preset conditions. In the lowest brightness stable control mode, the target brightness is determined based on the dimming input signal. Based on the target brightness and the determination result, the corresponding distribution strategy is determined. The distribution strategy is used to determine the output ratio of the basic sustaining current component and the micro-pulse compensation component. Based on the basic sustaining current component, a corresponding continuous current is output to the LED load through an analog current regulation path, and the LED load is monitored in real time to ensure that it maintains a minimum conduction state. Based on the micro-pulse compensation component, the corresponding distributed compensation pulse is output to the LED load through the PWM drive path; The current data output by the LED load is sampled, and it is determined whether the sampling result meets the mode exit condition. If not, the output ratio of the basic maintenance current component and the micro-pulse compensation component is adjusted according to the sampling result. If yes, the minimum brightness stable control mode is switched to the conventional PWM dimming mode.

[0005] By adopting the above technical solution, and by introducing a driving method that combines continuous base sustaining current with dispersed micro-pulse compensation during the extremely low brightness dimming stage, the LED is always kept in a minimum conduction state and the target brightness difference is finely compensated, thereby significantly reducing the flickering phenomenon caused by current discontinuity while ensuring brightness adjustability.

[0006] Preferably, the step of determining the stability of the current driving state based on the dimming input signal and operating status data to generate a corresponding determination result includes: Based on the operating status data within a continuous time window, a corresponding current conduction state sequence is constructed. Based on the current conduction state sequence, the corresponding discontinuous intervals are identified, and the discontinuity duration parameter and discontinuity distribution density parameter of each discontinuous interval are calculated. The weight values ​​corresponding to each discontinuity interval are generated based on the discontinuity duration parameter and the discontinuity distribution density parameter, and structural judgment parameters for characterizing the continuity of LED output current are generated based on each weight value. By integrating structural judgment parameters and the weight values ​​corresponding to each discontinuous interval, a corresponding judgment result is generated. The structural judgment parameters are used to determine whether the preset conditions are met, and the weight values ​​are used to participate in the generation process of the distribution strategy.

[0007] By adopting the above technical solution, the conduction state of the LED output current is serialized within a continuous time window, and the discontinuous interval and its characteristic parameters are identified based on the sequence. This enables a structured analysis of the current continuity, improving the stability judgment from a single threshold judgment to a multi-dimensional feature judgment, thereby enhancing the judgment accuracy and robustness.

[0008] Preferably, the step of calculating the discontinuity duration parameter and discontinuity distribution density parameter for each discontinuous interval includes: Obtain the duration of each discontinuous interval and generate the corresponding discontinuous duration parameter; Calculate the interval distance between adjacent discontinuous intervals based on their distribution within a preset time window; Based on the matching relationship between the interval distance and the preset reference time scale, the corresponding discontinuous distribution density parameters are generated.

[0009] By adopting the above technical solution, and by introducing the time interval between discontinuous intervals and combining it with a preset reference time scale for matching analysis, the original discontinuity description based solely on duration is expanded into a density representation that includes distribution patterns. This allows for a more comprehensive reflection of the degree of discontinuity aggregation on the time axis and improves the ability to identify flicker risks.

[0010] Preferably, the step of generating weight values ​​corresponding to each discontinuity interval based on the discontinuity duration parameter and the discontinuity distribution density parameter, and generating structural determination parameters for characterizing the continuity of LED output current based on each weight value, includes: Determine the attribute information of the LED load, and map the scene-sensitive weights based on the attribute information to adjust the degree of influence of discontinuous intervals on continuity; The default interval value corresponding to each discontinuous interval is determined based on the discontinuous duration parameter; The distribution weight of each discontinuous interval within a preset time window is determined based on the discontinuous distribution density parameter. Based on scene-sensitive weights and distribution weights, the default interval values ​​of each discontinuous interval are weighted to determine the weight value corresponding to each discontinuous interval. The weight values ​​are then accumulated and processed to generate the corresponding comprehensive discontinuity characterization value. Based on the correspondence between the comprehensive discontinuous characterization value and the preset judgment interval, the corresponding structural judgment parameters are generated.

[0011] By adopting the above technical solution, and by integrating the scene-sensitive weights obtained from the intermittent duration, distribution density, and LED load attribute mapping, weighted modeling is performed on each intermittent interval to generate a comprehensive intermittent characterization value. This enables a differentiated characterization of the impact of different intermittent structures on actual application scenarios, thereby making subsequent control strategies more targeted.

[0012] Preferably, the step of determining the corresponding distribution strategy based on the target brightness and the judgment result includes: Based on the structural judgment parameters in the judgment result, compare them with the structural judgment parameters of the previous control cycle to generate the corresponding change direction; Based on the weight values ​​of each discontinuous interval in the judgment results, the energy allocation parameters and the rate of change of the distribution strategy corresponding to each discontinuous interval are determined. Based on the target brightness, the corresponding driving energy is mapped; Based on the direction of change, energy distribution parameters, rate of change of distribution strategy, and driving energy, a corresponding distribution strategy is constructed.

[0013] By adopting the above technical solution, the stability determination result is transformed into the change direction, energy distribution parameters and distribution strategy change rate, and the distribution strategy is constructed by combining the driving energy obtained from the target brightness mapping. This enables the system to dynamically adjust the energy ratio between the basic maintenance current and the micro-pulse compensation under different stable states, thereby achieving synergistic optimization of brightness control and stability.

[0014] Preferably, the step of comparing the structural determination parameters in the determination result with the structural determination parameters of the previous control cycle to generate the corresponding change direction includes: Based on the current structural judgment parameters in the judgment results, the current structural judgment parameters are subtracted from the structural judgment parameters of the previous control cycle to generate the corresponding deviation vector. If the deviation vector is positive, determine the direction of change used to increase the proportion of the base sustaining current component; If the deviation vector is negative, a change direction is generated to reduce the proportion of the base sustaining current component.

[0015] By adopting the above technical solution, the deviation vector is obtained by differential calculation of the structural judgment parameters within the continuous control cycle, and the adjustment direction of the basic maintenance current ratio is determined according to the deviation direction. This enables the system to perform feedforward adjustment according to the changing trend of current continuity, thereby improving the response speed to the process of flicker deterioration or improvement.

[0016] Preferably, the step of determining the energy allocation parameters and the rate of change of the distribution strategy corresponding to each discontinuous interval based on the weight values ​​of each discontinuous interval in the judgment result includes: Based on the weight values ​​of each discontinuous interval, the target energy allocation parameters corresponding to each discontinuous interval are determined according to the preset weight mapping relationship. The comparison results between the weight values ​​and the preset weight threshold range are calculated to determine the corresponding rate of change of the distribution strategy.

[0017] By adopting the above technical solution, and by using the weight values ​​of each discontinuous interval to determine the corresponding energy allocation parameters and the rate of change of the distribution strategy, a graded response to the severity of discontinuity in different time intervals can be achieved. This enables energy allocation to not only have overall adjustment capabilities, but also local optimization capabilities for specific discontinuous structures.

[0018] Preferably, the step of calculating the comparison result between the weight value and the preset weight threshold interval to determine the corresponding distribution strategy change rate includes: The comparison between the weight value and the preset weight threshold range is calculated to generate the corresponding initial rate value; Determine the minimum preset update interval required when updating between two adjacent discontinuous intervals; Based on a preset minimum update interval, all initial rate values ​​are corrected to determine the corresponding distribution strategy change rate.

[0019] By adopting the above technical solution, the initial rate value is corrected by introducing a minimum update interval constraint in the calculation of the rate of change, thus avoiding frequent adjustments to the distribution strategy due to short-term fluctuations in the weight value, thereby improving the stability of the system operation and reducing control jitter.

[0020] A low-brightness anti-flicker dimming control circuit for an LED driver power supply is provided, which uses a low-brightness anti-flicker dimming control method for an LED driver power supply. The control circuit includes a dimming input interface module, a current sampling module, a control processing module, an analog current adjustment module, a PWM drive module, and a mode control module. The dimming input interface module is used to receive dimming input signals; The signal input terminal of the current sampling module is connected to a detection node in the current loop of the LED load. The first signal input terminal of the control processing module is connected to the signal output terminal of the dimming input interface module, and the second signal input terminal of the control processing module is connected to the signal output terminal of the current sampling module. The first signal input terminal of the analog current regulation module is connected to the first signal output terminal of the control processing module, and the signal output terminal of the analog current regulation module is connected to an input node of the current loop in which the LED load is located, so that the analog current regulation module outputs the basic maintenance current component to the current loop. The first signal input terminal of the PWM drive module is connected to the second signal output terminal of the control processing module, and the signal output terminal of the PWM drive module is connected to another input node of the current loop where the LED load is located, so that the PWM drive module outputs a micro-pulse compensation component to the current loop. The signal input terminal of the mode control module is connected to the third signal output terminal of the control processing module, the first signal output terminal of the mode control module is connected to the second signal input terminal of the analog current regulation module, and the second signal output terminal of the mode control module is connected to the second signal input terminal of the PWM drive module.

[0021] By adopting the above technical solution, and by constructing a control circuit that includes a dimming input interface, current sampling, control processing, and dual-path drive of analog current and PWM, a complete hardware closed loop from signal acquisition and stability determination to distributed strategy execution is achieved, enabling continuous current and compensation pulses to work together to improve the low-brightness flicker problem.

[0022] Preferably, the PWM drive module includes a gated pulse generation unit, a duty cycle modulation unit, and a drive output unit; The signal input terminal of the duty cycle modulation unit is connected to the second signal output terminal of the control processing module to receive the corresponding micropulse compensation component parameters. The signal output terminal of the pulse generation unit is connected to the first signal input terminal of the duty cycle modulation unit, and is used to provide a reference pulse signal to the duty cycle modulation unit; The first signal output terminal of the duty cycle modulation unit is connected to the first signal input terminal of the drive output unit; The signal output terminal of the drive output unit is connected to another input node of the current loop where the LED load is located, and is used to output the modulated pulse signal to the current loop to form a micro-pulse compensation component. The first signal input terminal of the gating unit is connected to the second signal output terminal of the mode control module, and the second signal input terminal of the gating unit is connected to the second signal output terminal of the duty cycle modulation unit. The signal output terminal of the gating unit is connected to the signal input terminal of the drive output unit, and is used to enable or disable the modulated pulse signal according to the control signal of the mode control module, so as to control the start and stop status of the PWM drive module.

[0023] By adopting the above technical solution, and by setting functional units such as pulse generation, duty cycle modulation, gating control and drive output in the PWM drive path, the compensation pulse can not only be generated according to the set parameters, but also achieve precise start-stop and modulation under the action of the mode control signal, thereby improving the controllability of the compensation pulse output and the overall stability of the system.

[0024] In summary, this application includes at least one of the following beneficial technical effects: This application analyzes the operating state of the LED output current through a continuous time window to identify the discontinuous characteristics of the current on the time axis, and uses this to determine the stability of the current driving state, thereby determining whether to enter a stable control mode specifically for extremely low brightness. In this mode, instead of relying solely on a single dimming method, the driving demand corresponding to the target brightness is transformed into a distribution strategy. The driving energy is reorganized in the time dimension, dividing the overall output into two parts: a continuously existing base sustaining current and a discretely distributed micro-pulse compensation. The base sustaining current is used to keep the LED in a minimum conducting state throughout the entire control cycle to avoid prolonged current interruption, while the micro-pulse compensation is used to make up for the brightness difference without disrupting continuity. At the same time, through continuous sampling feedback of the output current, the ratio of the above two parts is dynamically corrected, enabling the driving structure to adaptively adjust according to the actual operating state. By using this composite driving method of "continuous current base and dispersed pulse compensation", the intermittent conduction structure that was originally prone to flickering is transformed into an output form with continuous conduction as the main function and local compensation as the auxiliary function. This significantly reduces brightness fluctuation and flicker under extremely low brightness conditions, improves output stability and visual comfort while ensuring dimming accuracy, and enhances adaptability to different loads and application scenarios. Attached Figure Description

[0025] Figure 1 This is a flowchart of a low-brightness anti-flicker dimming control method for an LED driver power supply according to one embodiment of this application; Figure 2This is a flowchart illustrating a low-brightness anti-flicker dimming control circuit for an LED driver power supply according to one embodiment of this application. Figure 3 This is a partial circuit diagram of the dimming input interface module in a low-brightness anti-flicker dimming control circuit for an LED driver power supply according to one embodiment of this application. Figure 4 This is a partial circuit diagram of the current sampling module in a low-brightness anti-flicker dimming control method for an LED driver power supply according to an embodiment of this application. Figure 5 This is a schematic diagram of the analog current regulation circuit structure in a low-brightness anti-flicker dimming control method for an LED driver power supply according to one embodiment of this application. Detailed Implementation

[0026] The present application will be further described in detail below with reference to the accompanying drawings.

[0027] In one embodiment, such as Figure 1 As shown, this application discloses a low-brightness anti-flicker dimming control method for LED driver power supplies. The control method includes: S10. Acquire the dimming input signal and the operating status data of the LED output current; S20. Based on the dimming input signal and operating status data, the stability of the current driving state is determined to generate the corresponding determination result, and the minimum brightness stable control mode is entered when the determination result meets the preset conditions. S30. In the minimum brightness stable control mode, the target brightness is determined based on the dimming input signal. According to the target brightness and the judgment result, the corresponding distribution strategy is determined. The distribution strategy is used to determine the output ratio of the basic sustaining current component and the micro-pulse compensation component. S40. Based on the basic sustaining current component, the corresponding continuous current is output to the LED load through the analog current regulation path, and the LED load is monitored in real time to ensure that it maintains the minimum conduction state. S50. Based on the micro-pulse compensation component, the corresponding distributed compensation pulse is output to the LED load through the PWM drive path; S60. Sample the current data output by the LED load and determine whether the sampling result meets the mode exit condition. If not, adjust the output ratio of the basic maintenance current component and the micro-pulse compensation component according to the sampling result. If yes, switch the minimum brightness stable control mode to the conventional PWM dimming mode.

[0028] In this embodiment, the dimming input signal can be understood as a brightness adjustment command input from an external control terminal to the drive system. It can originate from buttons, knobs, potentiometers, or digital communication interfaces, and its essence is to characterize the user's desired target luminous intensity. After entering the system, this signal is typically converted into a corresponding numerical value to participate in subsequent calculations. The LED output current operating status data is a set of dynamic electrical information obtained by real-time detection of the current loop containing the LED load. This information includes not only the instantaneous current value but also the trend characteristics of current changes over time, reflecting whether the LED is in a continuous or intermittent conducting state. Stability determination refers to the determination based on the target brightness requirement corresponding to the dimming input signal and the operating... The process of comprehensively analyzing the actual current behavior reflected by the state data to determine whether there are significant fluctuations or discontinuities in the current drive output, and its output result is the judgment result. This judgment result is essentially a marker indicating whether the current output state meets the requirements for stable light emission. The preset condition is the judgment standard used to trigger mode switching, which can correspond to a certain stability threshold range. When the judgment result meets this standard, the system enters the lowest brightness stable control mode. This mode is a control state specifically optimized for current continuity under low brightness conditions. In this state, the system's control objective changes from simple brightness adjustment to coordinated control of brightness and stability. The target brightness is the desired output brightness level obtained by converting the dimming input signal. It is typically converted into the corresponding driving energy demand through a mapping relationship; the distribution strategy is the core scheduling parameter in the entire control process, which describes the distribution of driving energy among different output forms within a control cycle. This strategy is not a single proportional value, but a comprehensive control scheme that coordinates the allocation of continuous output and pulse output based on the current judgment result; the base sustaining current component refers to a portion of the current continuously output throughout the driving process, and its amplitude is usually set at a level that ensures the LED just maintains conduction, in order to avoid complete current interruption and thus eliminate the intermittent phenomenon under low brightness; the micro-pulse compensation component is a set of time-discretely distributed pulse currents superimposed on the base current, which is used to supplement the target brightness and The difference in brightness provided by the base current consists of pulses that typically have short durations and low energy densities, distributed in a dispersed manner along the time axis. The analog current regulation path can be understood as a drive path for outputting continuous current. It can employ linear regulation circuits or current source structures internally to achieve stable current output by adjusting the operating state of the conducting device. The PWM drive path is a path for outputting pulsed current. It generates corresponding pulse signals through periodic switching control and superimposes these pulses into the current loop to create a compensation effect. The minimum conduction state refers to the LED being in a state where it is just turned on but the brightness is extremely low. In this state, the current remains continuous but the energy is low, which is a key operating point to avoid flickering.The sampling result is feedback information obtained after re-detecting the output current, used to determine whether the current control strategy is effective; the mode exit condition is the criterion used to determine whether it can recover from the lowest brightness stable control mode to the normal dimming mode. Mode switching is triggered when the system detects that the current continuity has met the normal dimming requirements; the normal PWM dimming mode refers to the standard dimming method used under non-extremely low brightness conditions, which mainly relies on changes in the duty cycle to achieve brightness adjustment.

[0029] For example, in the application scenario of a bedroom nightlight, when the user adjusts the brightness to an extremely low level using a knob, the target brightness corresponding to the dimming input signal is low. At this time, the system detects a significant discontinuity in the LED output current and enters the lowest brightness stable control mode based on stability judgment. In this mode, the system allocates a portion of the energy to the basic maintenance current, keeping the LED in a slightly conductive state. At the same time, multiple micro-pulses are distributed and superimposed on the time axis through the PWM drive path to supplement the brightness. When changes in the environment or dimming signal cause the current continuity to recover, the system judges that the mode exit condition is met based on the sampling results, and automatically switches back to the conventional PWM dimming mode to achieve a smooth transition and stable light emission.

[0030] Furthermore, the step of determining the stability of the current driving state based on the dimming input signal and operating status data to generate a corresponding determination result includes: S201. Based on the operating status data within a continuous time window, construct the corresponding current conduction state sequence; S202. Based on the current conduction state sequence, identify the corresponding discontinuous intervals and calculate the discontinuity duration parameter and discontinuity distribution density parameter of each discontinuous interval. S203. Generate weight values ​​corresponding to each discontinuous interval based on the discontinuity duration parameter and the discontinuity distribution density parameter, and generate structural judgment parameters to characterize the continuity of LED output current based on each weight value. S204. Integrate the structural judgment parameters and the weight values ​​corresponding to each discontinuous interval to generate the corresponding judgment result. The structural judgment parameters are used to determine whether the preset conditions are met, and the weight values ​​are used to participate in the generation process of the distribution strategy.

[0031] Furthermore, the steps for calculating the discontinuity duration parameter and discontinuity distribution density parameter for each discontinuous interval include: S2021. Obtain the duration of each discontinuous interval and generate the corresponding discontinuous duration parameter; S2022. Calculate the interval distance between adjacent discontinuous intervals based on the distribution location of the discontinuous intervals within the preset time window. S2023. Generate the corresponding discontinuous distribution density parameters based on the matching relationship between the interval distance and the preset reference time scale.

[0032] Furthermore, the step of generating weight values ​​corresponding to each discontinuity interval based on the discontinuity duration parameter and the discontinuity distribution density parameter, and generating structural judgment parameters for characterizing the continuity of LED output current based on each weight value, includes: S2031. Determine the attribute information of the LED load, and map the scene-sensitive weights based on the attribute information to adjust the degree of influence of the discontinuous interval on the continuity. S2032. Determine the default interval value corresponding to each discontinuous interval based on the discontinuous duration parameter; S2033. Determine the distribution weight of each discontinuous interval within a preset time window based on the discontinuous distribution density parameter. S2034. Based on scene-sensitive weights and distribution weights, the default interval values ​​of each discontinuous interval are weighted and calculated to determine the weight value corresponding to each discontinuous interval. The weight values ​​are then accumulated and processed to generate the corresponding comprehensive discontinuity characterization value. S2035. Generate corresponding structural judgment parameters based on the correspondence between the comprehensive discontinuous characterization value and the preset judgment interval.

[0033] In this embodiment, the continuous time window can be understood as a continuous sampling time range selected by the control processing module when performing a stability analysis. This time range is not a single instantaneous sampling point, but a time segment covering several sampling cycles, used to observe whether the LED output current remains continuously conducting, whether there is a short-term power outage, or whether there is periodic discontinuity. The length of the continuous time window can be preset according to the PWM frequency of the LED driver power supply, the target brightness level, and the sensitivity characteristics of the human eye in low-brightness scenarios. For example, it can cover multiple PWM control cycles, so that the control processing module can obtain a sufficient number of current change samples and will not misjudge the current driving state due to noise at a certain instantaneous sampling point. The operating status data is the data set formed by the current sampling module after collecting the LED output current within the continuous time window. It can include multiple current sampling values ​​arranged in chronological order, or intermediate data such as current amplitude changes, conduction status, and low current persistence obtained by preprocessing the sampling values. The current conduction state sequence is a time-seriesd state result constructed by the control processing module based on the operating state data. It can mark each sampling moment or each sampling interval within a continuous time window as either a conduction state or a non-conducting state, thereby converting the originally continuously changing current waveform into a state sequence that is easy to identify as discontinuous. Here, the conduction state does not require the LED to be in its rated brightness operating state, but rather refers to the LED output current reaching the minimum current level that can maintain effective conduction of the LED load; the non-conducting state usually corresponds to the LED output current being lower than this minimum conduction requirement, or the current being close to zero, which may cause brightness interruption.

[0034] A discontinuous interval refers to a time segment in a current-conducting state sequence consisting of one or more consecutive non-conducting states. Essentially, it represents a current gap in the LED output current along the time axis, rather than a spatial interval. The appearance of a discontinuous interval indicates that the LED load has failed to continuously receive sufficient conducting current during that time period. If such intervals are prolonged or repeatedly occur within a continuous time window, they are prone to manifesting as brightness fluctuations or flickering in low-brightness lighting environments. A series of discontinuous intervals should be understood as consecutively formed discontinuous intervals, i.e., multiple discontinuous time periods obtained by merging adjacent non-conducting sampling points. The discontinuity duration parameter describes the duration of each discontinuous interval in the time dimension. It can be determined by the time difference between the start and end sampling times of the discontinuous interval, or by multiplying the number of consecutive non-conducting sampling points within the interval by the sampling period. This parameter reflects the degree to which a single discontinuous interval disrupts the continuous light emission of the LED. The longer the discontinuity duration, the longer the LED loses continuous conduction within that interval, and the more significant the impact on low-brightness stability.

[0035] The discontinuous distribution density parameter describes the density of multiple discontinuous intervals within a preset time window. It doesn't simply count the number of discontinuous intervals, but also considers the time interval between adjacent intervals. Distribution location refers to the temporal position of each discontinuous interval within a continuous time window; for example, the start and end times of a given interval within the window. Interval distance refers to the time interval between two adjacent discontinuous intervals, typically determined by the difference between the end time of the previous interval and the start time of the next. Short intervals indicate frequent discontinuities in the LED output current within a short period; long and dispersed intervals indicate relatively sparse discontinuities. The preset reference time scale is a reference time base used to measure whether the discontinuous interval significantly affects low-brightness visual stability. This time scale can be determined by combining the LED driving cycle, low-brightness control cycle, the human eye's sensitivity to flicker, or product test calibration results. Matching relationships refer to the rules for comparing, mapping, or classifying interval distances with a reference time scale. For example, when the interval distance between adjacent discontinuous intervals is close to or less than the reference time scale, these discontinuous phenomena can be considered to be more concentrated in time and have a stronger impact on continuity; when the interval distance is significantly greater than the reference time scale, the discontinuous phenomena can be considered to be more dispersed and have a relatively weaker impact on visual stability. The resulting discontinuity distribution density parameter can reflect the degree of clustering of discontinuous intervals on the time axis, enabling the system to not only know how long the discontinuity lasts, but also whether the discontinuity occurs frequently and repeatedly.

[0036] The weight value is a range-level influence representation for each discontinuous interval, indicating the degree to which the discontinuity disrupts the continuity of the LED output current and its impact on subsequent distribution strategies. Unlike simple duration or frequency, the weight value typically integrates factors such as discontinuity duration, discontinuity distribution density, and LED load attributes, thus distinguishing the importance of different discontinuity intervals. The structural judgment parameter is an overall judgment quantity obtained by further summing the weight values ​​of multiple discontinuous intervals, used to characterize the stability of the current LED output current's continuity structure as a whole. Here, "structure" does not refer to physical structure, but rather to the combination of conduction and discontinuity of the LED output current over time, such as whether it is dominated by continuous low current or frequent interruptions. The structural judgment parameter can be used to determine whether the current driving state has reached the trigger condition for entering the minimum brightness stable control mode, while the weight values ​​corresponding to each discontinuous interval can continue to serve as the range-level basis for generating subsequent distribution strategies, enabling the system to perform differentiated energy allocation for discontinuity intervals of varying severity.

[0037] The attribute information of an LED load can be understood as characteristic information related to the LED load itself and its application scenario, such as LED chip type, rated current range, minimum conducting current, low-brightness luminous characteristics, lamp application, optical diffusion structure, or series / parallel connection form. Different LED loads have different sensitivities to current discontinuity at low brightness. For example, bedroom nightlights or hotel ambient lights are usually used in dark environments, and users are more likely to perceive slight brightness fluctuations. Therefore, the same discontinuity interval may need to be given a higher degree of influence under this type of load or application scenario. The scenario sensitivity weight is a correction factor obtained by mapping the attribute information of the LED load, used to adjust the evaluation intensity of the impact of the discontinuity interval on the continuity. The default interval value is a basic evaluation value initially determined for each discontinuity interval based on the discontinuity duration parameter, which mainly reflects the degree of influence corresponding to the duration of the discontinuity interval itself. The distribution weight is a correction weight determined based on the discontinuity distribution density parameter, used to reflect the distribution state of the discontinuity interval within the entire preset time window and its dense relationship with other discontinuity intervals. The comprehensive discontinuity characterization value is an overall measure of discontinuity obtained by accumulating the weights of each discontinuity interval. It is used to combine the influence of multiple local discontinuity intervals into a single overall result that can be used for stability assessment. The preset judgment interval is a pre-defined range that divides the comprehensive discontinuity characterization value into different stability or risk levels, such as stable, slightly unstable, and significantly unstable states. The control processing module determines which judgment interval the comprehensive discontinuity characterization value falls into and generates the corresponding structural judgment parameters.

[0038] The corresponding working principle can be understood as follows: the control processing module does not directly determine the stability of the LED based on a single instantaneous current value. Instead, it observes the changes in the conduction state of the LED output current within a continuous time window, converting the current waveform into a conduction state sequence. This allows it to identify time periods with insufficient or interrupted current on the time axis. Subsequently, the system analyzes these discontinuous intervals in two dimensions: firstly, it calculates the duration of each discontinuous interval to determine the severity of a single discontinuity; secondly, it calculates the interval distance between adjacent discontinuous intervals and, combined with a preset reference time scale, determines whether these discontinuities occur in a concentrated manner within a short period, indicating whether the discontinuity phenomenon has a perceptible clustering. After obtaining the duration and distribution density, the system further incorporates the attribute information of the LED load for scenario-based correction, enabling the same current discontinuity to receive different evaluation intensities under different lighting fixtures or different low-brightness application scenarios. In other words, in loads or scenarios with higher requirements for visual comfort, even slight discontinuities may be assigned a higher weight; while in loads with lower sensitivity to low-brightness flicker, the same discontinuity may only have a lower weight. Finally, the control processing module accumulates the effects of each discontinuous interval to form a comprehensive discontinuity characterization value. This value is then converted into structural judgment parameters through a preset judgment interval. This allows stability assessment to move beyond simple current threshold comparisons and instead be based on a comprehensive judgment of the continuous structure of the LED output current over time. This enables more accurate identification of flicker risks caused by current discontinuity, dense discontinuity, or load sensitivity at extremely low brightness levels, and provides a more reliable basis for generating distribution strategies for the subsequent basic sustaining current component and micro-pulse compensation component.

[0039] Furthermore, the step of determining the corresponding distribution strategy based on the target brightness and the judgment result includes: S301. Based on the structural judgment parameters in the judgment result, compare them with the structural judgment parameters of the previous control cycle to generate the corresponding change direction; S302. Based on the weight values ​​of each discontinuous interval in the judgment result, determine the energy allocation parameters and distribution strategy change rate corresponding to each discontinuous interval. S303. Map the corresponding driving energy based on the target brightness; S304. Based on the direction of change, energy distribution parameters, distribution strategy change rate, and driving energy, construct the corresponding distribution strategy.

[0040] In this embodiment, by converting the stability determination result into the change direction, energy allocation parameters and distribution strategy change rate, and combining the driving energy obtained from the target brightness mapping to construct the distribution strategy, the system can dynamically adjust the energy ratio between the basic maintenance current and the micro-pulse compensation under different stable states, thereby achieving synergistic optimization of brightness control and stability.

[0041] Furthermore, the step of comparing the structural judgment parameters in the judgment result with the structural judgment parameters of the previous control cycle to generate the corresponding change direction includes: S3011. Based on the current structural judgment parameters in the judgment results, subtract the current structural judgment parameters from the structural judgment parameters of the previous control cycle to generate the corresponding deviation vector. S3012. If the deviation vector is positive, determine the direction of change used to increase the proportion of the base sustaining current component; S3013. If the deviation vector is negative, generate the direction of change to reduce the proportion of the base sustaining current component.

[0042] Furthermore, the step of determining the energy allocation parameters and distribution strategy change rate corresponding to each discontinuous interval based on the weight values ​​of each discontinuous interval in the judgment result includes: S3021. Based on the weight values ​​of each discontinuous interval, determine the target energy allocation parameters corresponding to each discontinuous interval according to the preset weight mapping relationship. S3022. Calculate the comparison results between the weight value and the preset weight threshold range to determine the corresponding distribution strategy change rate.

[0043] Furthermore, the step of calculating the comparison results between the weight values ​​and the preset weight threshold interval to determine the corresponding rate of change of the distribution strategy includes: S30221. Calculate the comparison result between the weight value and the preset weight threshold range, and generate the corresponding initial rate value; S30222 Determine the minimum preset update interval required when updating between two adjacent discontinuous intervals; S30223. Based on the preset minimum update interval, all initial rate values ​​are corrected to determine the corresponding distribution strategy change rate.

[0044] In this implementation, the target brightness can be understood as the desired luminous level calculated by the control processing module based on the external dimming input. It is not directly equivalent to a fixed current value, but rather represents the low-brightness output target that the LED load should achieve within the current control cycle. The judgment result is the comprehensive state information output by the stability judgment process. It can simultaneously include structural judgment parameters and the weight values ​​corresponding to each discontinuous interval, enabling the control processing module to determine whether the current LED output current is generally stable and to identify which discontinuous intervals have a more significant impact on current continuity. The distribution strategy is the energy scheduling rule generated by the control processing module in the minimum brightness stable control mode. It determines how the driving energy corresponding to the target brightness is distributed between the basic sustaining current component and the micro-pulse compensation component, and how this distribution relationship changes in different control cycles. Here, distribution does not refer to spatial location distribution, but rather to the distribution method of driving energy in the time dimension and output form. For example, part of the driving energy is continuously output in the form of a small current, while another part of the driving energy compensates for the brightness difference in the form of dispersed pulses.

[0045] The structural judgment parameter is a quantitative result of the overall continuity state of the LED output current, reflecting whether the current output structure tends towards continuous stability or discontinuous instability. The structural judgment parameter of the previous control cycle refers to the structural judgment parameter calculated and stored by the control processing module in the previous control loop. This parameter is used to compare with the structural judgment parameter of the current control cycle to determine whether the current continuity state is improving or deteriorating. The change direction is an adjustment direction indicator generated based on the change trend of the current structural judgment parameter relative to the previous control cycle. It indicates whether the distribution strategy should be adjusted towards increasing the proportion of the base sustaining current or towards decreasing the proportion of the base sustaining current and increasing the participation of micro-pulse compensation. The deviation vector is the difference between the current structural judgment parameter and the structural judgment parameter of the previous control cycle, reflecting the magnitude and direction of change in the current continuity state between adjacent control cycles. When the structural judgment parameter is set such that a larger value indicates a higher degree of discontinuity, a positive deviation vector indicates that the current continuity is worse than the previous control cycle. Therefore, it is necessary to increase the proportion of the base holding current component to enhance the continuous conduction capability. A negative deviation vector indicates that the current continuity is improved. Therefore, the proportion of the base holding current component can be appropriately reduced to allow the system to gradually transition to a more efficient pulse compensation or conventional PWM.

[0046] The weight value of the discontinuous interval is the interval-level influence generated for each discontinuous time period, reflecting the degree to which the discontinuous interval disrupts the continuity of the LED output current. The energy allocation parameter is a control parameter determined based on the weight value of the discontinuous interval, used to indicate how much drive energy adjustment should correspond to a certain discontinuous interval or a certain type of discontinuous state. This parameter can further participate in the calculation of the ratio of the basic sustaining current component and the micro-pulse compensation component. The target energy allocation parameter is the target value of the energy allocation parameter within the current control cycle, which can be converted from the weight value of the discontinuous interval according to the preset weight mapping relationship. The preset weight mapping relationship is a correspondence pre-set or calibrated in the control processing module, used to convert the weight value of the discontinuous interval into the corresponding energy adjustment target. For example, a larger weight value indicates a more severe discontinuous interval, and the mapped target energy allocation parameter can make more drive energy tend towards the basic sustaining current component; a smaller weight value indicates a weaker discontinuous effect, and more micro-pulse compensation ratio can be retained. The distribution strategy change rate refers to how quickly the distribution strategy adjusts between adjacent control cycles. It controls the rate of change in the output ratio of the base sustaining current component and the micro-pulse compensation component, rather than directly representing the frequency or duty cycle of a single pulse. By setting the distribution strategy change rate, the system can avoid immediately and drastically changing the output ratio after detecting intermittent changes, thereby reducing brightness abrupt changes and control jitter.

[0047] Drive energy is the energy requirement mapped from the target brightness, representing the total drive quantity required to reach the LED load within one or more control cycles to achieve the target brightness. This drive energy can be calculated based on the target brightness level, the LED load current-brightness relationship, the supply voltage, and the control cycle length. It is subsequently decomposed into the base sustaining current component and the micro-pulse compensation component according to a distribution strategy. The preset weighted threshold range is a set of thresholds used to determine the severity range of the discontinuous interval weight value. It can include low-weight, medium-weight, and high-weight intervals, each corresponding to different rate-of-change adjustment rules. The comparison result is the level or interval assignment result obtained by matching the weight value with the preset weighted threshold range, indicating whether the discontinuous interval is slightly discontinuous, moderately discontinuous, or severely discontinuous. The initial rate value is a preliminary candidate value for the rate of change determined based on this comparison result. For example, a high-weight discontinuous interval can correspond to a higher initial rate value to quickly enhance continuous current support; a low-weight discontinuous interval can correspond to a lower initial rate value to avoid over-response. The preset minimum update interval is the minimum time interval that must be satisfied between two adjacent discontinuous intervals or two adjacent strategy updates. It is used to limit the update frequency of the distribution strategy change rate. This parameter prevents the control processing module from continuously and rapidly updating the distribution strategy when multiple discontinuous intervals are too close together, thereby avoiding frequent fluctuations in the output ratios of the base sustaining current component and the micro-pulse compensation component. The distribution strategy change rate, corrected by the preset minimum update interval, can maintain a smooth overall output change while ensuring timely response to severe discontinuities.

[0048] The corresponding working principle can be understood as follows: after obtaining the target brightness, the control processing module does not simply convert the target brightness into a fixed current or a fixed PWM duty cycle. Instead, it first judges the stability trend of the LED output current based on the current judgment result. If the current structural judgment parameter increases compared to the previous control cycle, it indicates that the discontinuity of the LED output current is worsening. At this time, the system sets the direction of change to increase the proportion of the basic holding current component, so that more driving energy is output in the form of continuous current, thereby enhancing the continuous conduction capability of the LED load. If the current structural judgment parameter decreases, it indicates that the current continuity is improving. The system can then gradually reduce the proportion of the basic holding current component to avoid maintaining an excessively high continuous current and reducing dimming efficiency. At the same time, the control processing module also determines the energy allocation parameters and distribution strategy change rate according to the weight value of each discontinuity interval, so that the severe discontinuity interval corresponds to a larger energy adjustment target and a faster strategy response speed, while the slight discontinuity interval corresponds to a smaller energy adjustment target and a slower response speed. To prevent frequent changes in the output ratio due to localized short-term discontinuities or densely packed adjacent discontinuity intervals, the control processing module further corrects the initial rate value by setting a minimum update interval, ensuring a necessary time interval between adjacent strategy updates. Ultimately, the system integrates the direction of change, energy distribution parameters, change rate, and driving energy obtained from the target brightness mapping into a distribution strategy. This allows the basic sustaining current component and the micro-pulse compensation component to be dynamically adjusted according to the current continuity state, thus balancing continuous conduction, brightness accuracy, and output smoothness in low-brightness scenarios.

[0049] like Figure 2-5 As shown, a low-brightness anti-flicker dimming control circuit for an LED driver power supply is disclosed, which uses a low-brightness anti-flicker dimming control method for an LED driver power supply. The control circuit includes a dimming input interface module, a current sampling module, a control processing module, an analog current adjustment module, a PWM drive module, and a mode control module. The dimming input interface module is used to receive dimming input signals; The signal input terminal of the current sampling module is connected to a detection node in the current loop of the LED load. The first signal input terminal of the control processing module is connected to the signal output terminal of the dimming input interface module, and the second signal input terminal of the control processing module is connected to the signal output terminal of the current sampling module. The first signal input terminal of the analog current regulation module is connected to the first signal output terminal of the control processing module, and the signal output terminal of the analog current regulation module is connected to an input node of the current loop in which the LED load is located, so that the analog current regulation module outputs the basic maintenance current component to the current loop. The first signal input terminal of the PWM drive module is connected to the second signal output terminal of the control processing module, and the signal output terminal of the PWM drive module is connected to another input node of the current loop where the LED load is located, so that the PWM drive module outputs a micro-pulse compensation component to the current loop. The signal input terminal of the mode control module is connected to the third signal output terminal of the control processing module, the first signal output terminal of the mode control module is connected to the second signal input terminal of the analog current regulation module, and the second signal output terminal of the mode control module is connected to the second signal input terminal of the PWM drive module.

[0050] Furthermore, the PWM drive module includes a gate control unit, a pulse generation unit, a duty cycle modulation unit, and a drive output unit; The signal input terminal of the duty cycle modulation unit is connected to the second signal output terminal of the control processing module to receive the corresponding micropulse compensation component parameters. The signal output terminal of the pulse generation unit is connected to the first signal input terminal of the duty cycle modulation unit, and is used to provide a reference pulse signal to the duty cycle modulation unit; The first signal output terminal of the duty cycle modulation unit is connected to the first signal input terminal of the drive output unit; The signal output terminal of the drive output unit is connected to another input node of the current loop where the LED load is located, and is used to output the modulated pulse signal to the current loop to form a micro-pulse compensation component. The first signal input terminal of the gating unit is connected to the second signal output terminal of the mode control module, and the second signal input terminal of the gating unit is connected to the second signal output terminal of the duty cycle modulation unit. The signal output terminal of the gating unit is connected to the signal input terminal of the drive output unit, and is used to enable or disable the modulated pulse signal according to the control signal of the mode control module, so as to control the start and stop status of the PWM drive module.

[0051] In one specific embodiment, the dimming input interface module includes an input terminal J1, a resistor R1, a resistor R2, a filter capacitor C1, and an operational amplifier U1A. The input terminal J1 is used to receive external dimming input signals. The first end of the resistor R1 is connected to the input terminal J1. The second end of the resistor R1 is connected to the first end of the resistor R2, the first end of the filter capacitor C1, and the non-inverting input terminal of the operational amplifier U1A. The second end of the resistor R2 is grounded, the second end of the filter capacitor C1 is grounded, and the inverting input terminal of the operational amplifier U1A is connected to the output terminal of the operational amplifier U1A to form a voltage follower buffer structure. The output terminal of the operational amplifier U1A serves as the signal output terminal of the dimming input interface module and is connected to the first signal input terminal of the control processing module U2. Thus, the external dimming input signal is input to the control processing module U2 after voltage division, filtering, and buffering.

[0052] The current sampling module includes a sampling resistor R3, an operational amplifier U1B, resistors R4 and R5, and a filter capacitor C2. The sampling resistor R3 is connected in series between the detection node of the current loop of the LED load LED1 and ground. The first end of the sampling resistor R3 is connected to the detection node of the current loop of the LED load LED1, and the second end of the sampling resistor R3 is grounded. The first end of the resistor R4 is connected to the first end of the sampling resistor R3, and the second end of the resistor R4 is connected to the non-inverting input of the operational amplifier U1B. The first end of the filter capacitor C2 is connected to the non-inverting input of the operational amplifier U1B, and the second end of the filter capacitor C2 is grounded. The inverting input of the operational amplifier U1B is connected to the first end of the resistor R5 and the output end of the operational amplifier U1B, respectively. The second end of the resistor R5 is grounded. The output end of the operational amplifier U1B serves as the signal output end of the current sampling module and is connected to the second signal input end of the control processing module U2 to convert the LED output current into a corresponding sampling voltage and output it to the control processing module U2.

[0053] The control processing module can be implemented using a microcontroller U2. The microcontroller U2 includes at least a first ADC input terminal ADC1, a second ADC input terminal ADC2, a first control output terminal DAC1 or PWM1, a second control output terminal PWM2, and a third control output terminal GPIO1. ADC1 is connected to the output terminal of operational amplifier U1A to receive the dimming input signal, ADC2 is connected to the output terminal of operational amplifier U1B to receive the LED output current sampling signal, DAC1 or PWM1 is connected to the analog current adjustment module as the first signal output terminal, PWM2 is connected to the PWM drive module as the second signal output terminal, and GPIO1 is connected to the mode control module as the third signal output terminal.

[0054] The analog current regulation module includes a digital-to-analog converter filter resistor R6, a filter capacitor C3, an operational amplifier U1C, a power MOSFET Q1, and a current sampling resistor R7. The first terminal of resistor R6 is connected to the first signal output terminal of the control processing module U2. The second terminal of resistor R6 is connected to both the first terminal of the filter capacitor C3 and the non-inverting input terminal of the operational amplifier U1C. The second terminal of the filter capacitor C3 is grounded. The output terminal of the operational amplifier U1C is connected to the gate of the power MOSFET Q1. The drain of the power MOSFET Q1 is connected to an input node of the current loop containing the LED load LED1. The source of the power MOSFET Q1 is connected to the first terminal of the current sampling resistor R7. The second terminal of the current sampling resistor R7 is grounded. The inverting input terminal of the operational amplifier U1C is connected to the source of the power MOSFET Q1. Therefore, the basic sustaining current control signal output by the control processing module U2 is smoothed by R6 and C3 and then input to the operational amplifier U1C. The operational amplifier U1C adjusts the conduction level of Q1 to make the sampling voltage on R7 follow the input reference voltage, thereby outputting a continuous basic sustaining current component to the current loop containing the LED load LED1.

[0055] The PWM drive module includes a pulse generation unit, a duty cycle modulation unit, a gating unit, and a drive output unit. In the minimum hardware implementation, the pulse generation unit can be implemented using a reference pulse provided by the internal timer of the control processing module U2, or it can be implemented using an external oscillator U3. If an external oscillator U3 is used, its output is connected to the first signal input of the duty cycle modulation unit U4. The duty cycle modulation unit U4 can be implemented using a comparator. The non-inverting input of comparator U4A is connected to the second signal output of the control processing module U2 to receive the micro-pulse compensation component parameters. The inverting input of comparator U4A is connected to the sawtooth wave output of the oscillator U3. The output of comparator U4A outputs the modulated PWM pulse signal. The gating unit can be implemented using an AND gate chip U5A. The output of comparator U4A is connected to the first input of AND gate chip U5A. The second signal output of the mode control module is connected to the second input of AND gate chip U5A. The output of AND gate chip U5A is connected to the input of the drive output unit U6. The drive output unit U6 can be a MOS driver chip or a transistor driver circuit. The output terminal of the drive output unit U6 is connected to the gate of the power MOS transistor Q2. The drain of the power MOS transistor Q2 is connected to the other input node of the current loop where the LED load LED1 is located. The source of the power MOS transistor Q2 is grounded. Alternatively, the power MOS transistor Q2 can be connected in series in the low-side loop of the LED load LED1 to inject the micro-pulse compensation component into the current loop where the LED load LED1 is located when the gating is enabled.

[0056] The mode control module may include resistor R8, transistor Q3, pull-up resistor R9, and logic output node EN1. The third signal output terminal of control processing module U2 is connected to the first terminal of resistor R8, the second terminal of resistor R8 is connected to the base of transistor Q3, the emitter of transistor Q3 is grounded, the collector of transistor Q3 is connected to the first terminal of pull-up resistor R9 and logic output node EN1, the second terminal of pull-up resistor R9 is connected to control power supply VCC, and logic output node EN1 is connected to the second signal input terminal of analog current regulation module and the second input terminal of gate control unit U5A in PWM drive module. Therefore, control processing module U2 can control Q3 to turn on or off through GPIO1, thereby changing the level state of EN1, and synchronously control the operating state of analog current regulation module and PWM drive module through EN1.

[0057] In actual operation, the dimming input signal input by J1 is processed by R1, R2, C1 and U1A and then sent to U2. The output current of the LED load LED1 is converted into a sampling voltage by R3 and amplified by U1B before being sent to U2. U2 generates a basic sustaining current control quantity and a micro-pulse compensation control quantity based on the sampling result. The basic sustaining current control quantity forms a continuous constant current output through R6, C3, U1C, Q1 and R7. The micro-pulse compensation control quantity is modulated by U4A and gated by U5A, and then output to the current loop of the LED load LED1 through U6 and Q2. When U2 determines that it needs to enter the minimum brightness stable control mode, the GPIO1 drive mode control module outputs an enable signal, so that the analog current adjustment path and the PWM micro-pulse compensation path work together, so that the LED load LED1 can maintain continuous conduction under extremely low brightness and supplement brightness through scattered pulses.

[0058] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A low-brightness anti-flicker dimming control method for LED driver power supply, characterized in that, The control method includes: Acquire the dimming input signal and the operating status data of the LED output current; Based on the dimming input signal and the operating status data, the stability of the current driving state is determined to generate a corresponding determination result, and when the determination result meets the preset conditions, the minimum brightness stable control mode is entered. In the minimum brightness stabilization control mode, the target brightness is determined based on the dimming input signal, and a corresponding distribution strategy is determined according to the target brightness and the determination result. The distribution strategy is used to determine the output ratio of the basic sustaining current component and the micro-pulse compensation component. Based on the aforementioned basic sustaining current component, a corresponding continuous current is output to the LED load through an analog current regulation path, and the LED load is monitored in real time to ensure that it maintains a minimum conduction state. Based on the micro-pulse compensation component, a corresponding distributed compensation pulse is output to the LED load through the PWM drive path; The current data output by the LED load is sampled, and it is determined whether the sampling result meets the mode exit condition. If not, the output ratio of the basic holding current component and the micro-pulse compensation component is corrected according to the sampling result. If yes, the minimum brightness stabilization control mode is switched to the conventional PWM dimming mode.

2. The LED driver power supply low-brightness anti-flicker dimming control method according to claim 1, characterized in that, The step of determining the stability of the current driving state based on the dimming input signal and the operating state data to generate a corresponding determination result includes: Based on the operating state data within a continuous time window, a corresponding current conduction state sequence is constructed. Based on the current conduction state sequence, the corresponding discontinuous intervals are identified, and the discontinuity duration parameter and discontinuity distribution density parameter of each discontinuous interval are calculated. The weight values ​​corresponding to each discontinuity interval are generated based on the discontinuity duration parameter and the discontinuity distribution density parameter, and structural judgment parameters for characterizing the continuity of LED output current are generated based on each weight value. By integrating the structural judgment parameters and the weight values ​​corresponding to each discontinuous interval, a corresponding judgment result is generated. The structural judgment parameters are used to determine whether the preset conditions are met, and the weight values ​​are used to participate in the generation process of the distribution strategy.

3. The LED driver power supply low-brightness anti-flicker dimming control method according to claim 2, characterized in that, The step of calculating the discontinuity duration parameter and discontinuity distribution density parameter of each of the discontinuous intervals includes: The duration of each discontinuous interval is obtained respectively, and the corresponding discontinuous duration parameter is generated; Calculate the interval distance between adjacent discontinuous intervals based on the distribution location of the discontinuous intervals within a preset time window; Based on the matching relationship between the interval distance and the preset reference time scale, the corresponding discontinuous distribution density parameters are generated.

4. The LED driver power supply low-brightness anti-flicker dimming control method according to claim 2, characterized in that, The step of generating weight values ​​corresponding to each discontinuity interval based on the discontinuity duration parameter and the discontinuity distribution density parameter, and generating structural determination parameters for characterizing the continuity of LED output current based on each weight value, includes: Determine the attribute information of the LED load, and map out the scene-sensitive weights based on the attribute information to adjust the degree of influence of the discontinuous interval on the continuity. The default interval value corresponding to each discontinuous interval is determined based on the discontinuous duration parameter; The distribution weight of each discontinuous interval within a preset time window is determined based on the discontinuous distribution density parameter. Based on the scenario-sensitive weight and the distribution weight, the default interval values ​​of each discontinuous interval are weighted and calculated to determine the weight value corresponding to each discontinuous interval. The weight values ​​are then accumulated and processed to generate the corresponding comprehensive discontinuity characterization value. Based on the correspondence between the comprehensive discontinuity characterization value and the preset judgment interval, corresponding structural judgment parameters are generated.

5. The LED driver power supply low-brightness anti-flicker dimming control method according to claim 1, characterized in that, The step of determining the corresponding distribution strategy based on the target brightness and the determination result includes: Based on the structural determination parameters in the determination result, they are compared with the structural determination parameters of the previous control cycle to generate the corresponding change direction; Based on the weight values ​​of each discontinuous interval in the judgment results, the energy allocation parameters and distribution strategy change rate corresponding to each discontinuous interval are determined. Based on the target brightness, the corresponding driving energy is mapped; Based on the change direction, the energy allocation parameters, the change rate of the distribution strategy, and the driving energy, a corresponding distribution strategy is constructed.

6. The LED driver power supply low-brightness anti-flicker dimming control method according to claim 5, characterized in that, The step of comparing the structural determination parameters in the determination result with the structural determination parameters of the previous control cycle to generate the corresponding change direction includes: Based on the current structural judgment parameters in the judgment result, the current structural judgment parameters are subtracted from the structural judgment parameters of the previous control cycle to generate the corresponding deviation vector. If the deviation vector is positive, determine the direction of change used to increase the proportion of the base sustaining current component; If the deviation vector is negative, a change direction is generated to reduce the proportion of the base sustaining current component.

7. The LED driver power supply low-brightness anti-flicker dimming control method according to claim 5, characterized in that, The step of determining the energy allocation parameters and distribution strategy change rate corresponding to each discontinuous interval based on the weight values ​​of each discontinuous interval in the determination result includes: Based on the weight values ​​of each discontinuous interval, the target energy allocation parameters corresponding to each discontinuous interval are determined according to a preset weight mapping relationship. The comparison result between the weight value and the preset weight threshold range is calculated to determine the corresponding distribution strategy change rate.

8. The LED driver power supply low-brightness anti-flicker dimming control method according to claim 7, characterized in that, The step of calculating the comparison result between the weight value and the preset weight threshold interval to determine the corresponding distribution strategy change rate includes: Calculate the comparison result between the weight value and the preset weight threshold range, and generate the corresponding initial rate value; Determine the preset minimum update interval required when updating between two adjacent discontinuous intervals; Based on the preset minimum update interval, all the initial rate values ​​are corrected to determine the corresponding distribution strategy change rate.

9. A low-brightness anti-flicker dimming control circuit for an LED driver power supply, characterized in that, Using the LED driver power supply low brightness anti-flicker dimming control method according to any one of claims 1-8, the control circuit includes a dimming input interface module, a current sampling module, a control processing module, an analog current adjustment module, a PWM drive module, and a mode control module; The dimming input interface module is used to receive dimming input signals; The signal input terminal of the current sampling module is connected to a detection node in the current loop of the LED load. The first signal input terminal of the control processing module is connected to the signal output terminal of the dimming input interface module, and the second signal input terminal of the control processing module is connected to the signal output terminal of the current sampling module. The first signal input terminal of the analog current regulation module is connected to the first signal output terminal of the control processing module, and the signal output terminal of the analog current regulation module is connected to an input node of the current loop in which the LED load is located, so that the analog current regulation module outputs the basic sustaining current component to the current loop. The first signal input terminal of the PWM drive module is connected to the second signal output terminal of the control processing module, and the signal output terminal of the PWM drive module is connected to another input node of the current loop where the LED load is located, so that the PWM drive module outputs a micro-pulse compensation component to the current loop; The signal input terminal of the mode control module is connected to the third signal output terminal of the control processing module, the first signal output terminal of the mode control module is connected to the second signal input terminal of the analog current regulation module, and the second signal output terminal of the mode control module is connected to the second signal input terminal of the PWM drive module.

10. The LED driver power supply low-brightness anti-flicker dimming control circuit according to claim 9, characterized in that, The PWM drive module includes a gated pulse generation unit, a duty cycle modulation unit, and a drive output unit; The signal input terminal of the duty cycle modulation unit is connected to the second signal output terminal of the control processing module, and is used to receive the corresponding micropulse compensation component parameters. The signal output terminal of the pulse generation unit is connected to the first signal input terminal of the duty cycle modulation unit, and is used to provide a reference pulse signal to the duty cycle modulation unit. The first signal output terminal of the duty cycle modulation unit is connected to the first signal input terminal of the drive output unit; The signal output terminal of the drive output unit is connected to another input node of the current loop where the LED load is located, and is used to output the modulated pulse signal to the current loop to form the micro-pulse compensation component. The first signal input terminal of the gating unit is connected to the second signal output terminal of the mode control module, and the second signal input terminal of the gating unit is connected to the second signal output terminal of the duty cycle modulation unit. The signal output terminal of the gating unit is connected to the signal input terminal of the drive output unit, and is used to enable or disable the modulated pulse signal according to the control signal of the mode control module, so as to control the start and stop state of the PWM drive module.

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