LED driving circuit and lighting system

Abstract

This application provides an LED driver circuit and lighting system. The parameter acquisition module can simultaneously acquire the charging state parameters of the energy storage path and the valley value parameters of the load path. The logic control circuit controls the discharge process in real time based on these parameters, ensuring that the valley value in the load path remains stable. By stabilizing the valley value, the current phase angle offset problem caused by the capacity difference of energy storage devices in the prior art is fundamentally solved, ensuring the stability of the LED driving current waveform. Secondly, it significantly improves the consistency and reliability of the LED driver circuit in mass production, reduces the dependence on component precision, and effectively controls production costs.

Description

Technical Field

[0001] This application relates to the field of electronic circuit technology, and more specifically, to an LED driver circuit and lighting system. Background Technology

[0002] LED driver circuits are the core components of LED lighting products. Their core function is to convert AC mains power into DC power suitable for LED operation and provide LEDs with a constant and reliable driving current. Their performance determines the luminous efficacy, lifespan, and overall lighting quality of LEDs.

[0003] Existing technologies commonly employ linear drive schemes based on specific control chips. While these schemes are structurally simple, they share a common technical flaw: the current phase angle shifts with the actual capacitance of the electrolytic capacitor in the circuit. Specifically, when the electrolytic capacitor's capacitance is too large due to manufacturing tolerances, the capacitor cannot fully discharge within each operating cycle. This causes the initial charging voltage to rise at the arrival of the next half-wave, delaying the charging process and ultimately resulting in a phase lag between the drive current waveform and the input voltage waveform. This problem leads to inconsistencies in the performance of LED lamps between production batches, severely impacting product standardization and reliability. Utility Model Content

[0004] In view of this, the purpose of this application is to provide an LED driver circuit and lighting system to overcome the problems in the prior art.

[0005] In a first aspect, embodiments of this application provide an LED driving circuit, including: a rectifier circuit, an energy storage path composed of an energy storage capacitor and a diode, and a load path composed of an LED and a constant current source; further comprising: The parameter acquisition module is used to acquire the charging status parameters of the energy storage path and the valley parameters of the load path. A logic control circuit is used to control the discharge process of the energy storage path to the load path according to the charging state parameters and the valley value parameters, so as to keep the valley value in the load path stable.

[0006] In some technical solutions of this application, the above-mentioned parameter acquisition module includes: The first current acquisition module is used to acquire the operating current of the energy storage path; The second voltage acquisition module is used to acquire the valley voltage across the constant current source.

[0007] In some technical solutions of this application, the above-mentioned circuit includes: The first current acquisition module is used to acquire the operating current of the energy storage path; The second voltage acquisition module is used to acquire the valley voltage across the constant current source.

[0008] In some technical solutions of this application, the above-mentioned circuit includes: The first current acquisition module is used to acquire the operating current of the energy storage path; The second current acquisition module is used to obtain the valley current of the load path.

[0009] In some technical solutions of this application, the above-mentioned circuit includes: The first voltage acquisition module is used to acquire the operating voltage of the diode; The second voltage acquisition module is used for the valley voltage across the constant current source; The logic control circuit is used to adjust the target voltage difference and thus adjust the delay time for the start of discharge of the energy storage path; wherein the target voltage difference is the difference between the threshold voltage characterizing the completion of charging and the bus voltage.

[0010] In some technical solutions of this application, the above-mentioned circuit includes: The first voltage acquisition module is used to acquire the operating voltage of the diode; The second current acquisition module is used for the valley current of the load path; The logic control circuit is used to adjust the target voltage difference and thus adjust the delay time for the start of discharge of the energy storage path; wherein the target voltage difference is the difference between the threshold voltage characterizing the completion of charging and the bus voltage.

[0011] In some technical solutions of this application, the above-mentioned circuit includes: The first current acquisition module is used to acquire the operating current of the energy storage path; The second voltage acquisition module is used to acquire the valley voltage between the output terminal of the rectifier circuit and ground.

[0012] In some technical solutions of this application, the above-mentioned circuit includes: The first voltage acquisition module is used to acquire the operating voltage of the diode; The second voltage acquisition module is used for the valley voltage between the output terminal of the rectifier circuit and ground. The logic control circuit is used to adjust the target voltage difference and thus adjust the delay time for the start of discharge of the energy storage path; wherein the target voltage difference is the difference between the threshold voltage characterizing the completion of charging and the bus voltage.

[0013] In some technical solutions of this application, the above-mentioned logic control circuit includes a logic control unit, a switching transistor, and a MOS driver; the load path also includes a detection resistor.

[0014] Secondly, embodiments of this application provide an LED lighting system, including the aforementioned LED driving circuit.

[0015] The technical solutions provided by the embodiments of this application may include the following beneficial effects: The LED driving circuit in this application includes: a rectifier circuit, an energy storage path composed of an energy storage capacitor and a diode, and a load path composed of an LED and a constant current source; it also includes: a parameter acquisition module for acquiring the charging state parameters of the energy storage path and the valley value parameters of the load path; and a logic control circuit for controlling the discharge process of the energy storage path to the load path according to the charging state parameters and the valley value parameters, so as to keep the valley value in the load path stable.

[0016] The parameter acquisition module of this application can simultaneously acquire the charging state parameters of the energy storage path and the valley value parameters of the load path. The logic control circuit then controls the discharge process in real time based on these parameters, ensuring that the valley value in the load path remains stable. By stabilizing the valley value, the current phase angle offset problem caused by the capacity difference of energy storage devices in the prior art is fundamentally solved, ensuring the stability of the LED driving current waveform. Secondly, it significantly improves the consistency and reliability of LED driving circuits in mass production, reduces the dependence on component precision, and effectively controls production costs.

[0017] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic diagram of an LED driving circuit provided in an embodiment of this application is shown; Figure 2 The illustration shows a schematic diagram of a prior art solution provided in an embodiment of this application; Figure 3 A schematic diagram of another prior art solution provided by an embodiment of this application is shown; Figure 4 A schematic diagram of another LED driving circuit provided in an embodiment of this application is shown; Figure 5 A schematic diagram illustrating the effect of an LED driving circuit provided in an embodiment of this application is shown. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the accompanying drawings in this application are for illustrative and descriptive purposes only and are not intended to limit the scope of protection of this application. Furthermore, it should be understood that the schematic drawings are not drawn to scale. The flowcharts used in this application illustrate operations implemented according to some embodiments of this application. It should be understood that the operations in the flowcharts may not be implemented in sequence, and steps without logical contextual relationships may be reversed or implemented simultaneously. In addition, those skilled in the art, guided by the content of this application, may add one or more other operations to the flowcharts, or remove one or more operations from the flowcharts.

[0021] Furthermore, the described embodiments are merely some, not all, of the embodiments of this application. The components of the embodiments of this application described and illustrated herein can typically be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0022] It should be noted that the term "comprising" will be used in the embodiments of this application to indicate the presence of the features declared thereafter, but does not exclude the addition of other features.

[0023] LED driver circuits are the core components of LED lighting products. Their core function is to convert AC mains power into DC power suitable for LED operation and provide LEDs with a constant and reliable driving current. Their performance determines the luminous efficacy, lifespan, and overall lighting quality of LEDs.

[0024] Existing technologies, such as Figure 2 The scheme shown has two constant current sources with different thresholds inside the chip, which drive the LED through the charging and discharging of capacitor C1. When the capacitance of the electrolytic capacitor is too large, the electrolytic capacitor is not fully discharged, resulting in delayed charging of the electrolytic capacitor after the next half-wave cycle, ultimately causing a delay in the current phase angle.

[0025] same, Figure 3 The scheme shown discharges the load through the electrolytic capacitor after the voltage V(GND-COUT) reaches a fixed value of 35V. However, if the electrolytic capacitor has a large capacitance, incomplete discharge will also cause a phase angle delay.

[0026] This problem leads to batch-to-batch inconsistencies in LED lighting production due to variations in electrolytic capacitor capacitance, impacting product performance and market competitiveness. Therefore, there is an urgent need for an LED driver solution that can eliminate the influence of electrolytic capacitor capacitance differences on the current phase angle.

[0027] Based on this, this application provides an LED driving circuit and a lighting system, which are described below through embodiments. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0028] like Figure 1 As shown, the LED driving circuit in this embodiment includes: a rectifier circuit, an energy storage path composed of an energy storage capacitor and a diode, and a load path composed of an LED and a constant current source. The rectifier circuit converts AC power into DC power and provides power to both the energy storage path and the load path. The energy storage path stores energy, while the load path provides operating current to the LED. This embodiment also adds a parameter acquisition module and a logic control circuit. The parameter acquisition module is responsible for real-time monitoring of two important parameters: one is the charging status parameter of the energy storage path, which can be the magnitude of the operating current flowing to the energy storage device or the operating voltage of the diode, used to determine whether the charging of the energy storage device is complete. Specifically, it can be a status parameter during the charging process or a status parameter when charging is complete. For example, the voltage V1 of the diode at time t1 during the charging process can be calculated from t1 and V1 to obtain the voltage V2 when the diode is fully charged at time t2. For another example, if the diode voltage is detected to be V2 at time t2, charging is complete. Second, the valley parameter of the load path. Here, the valley value refers to the lowest point in the periodically changing waveform. Specifically, it can be the valley current of the load path or the valley voltage of a certain point in the load path (the valley voltage across the constant current source, the voltage between the output terminal of the rectifier circuit and ground).

[0029] The logic control circuit precisely controls the discharge process from the energy storage path to the load path based on the parameters acquired by the parameter acquisition module. Its core control objective is to maintain the valley value in the load path within a preset range. Specifically, when the valley value parameter deviates from the target range, the logic control circuit adjusts the discharge process accordingly.

[0030] This closed-loop control method stabilizes the valley value, ensuring a fixed initial voltage for the energy storage device at the start of each operating cycle, thus completely resolving the current phase angle shift problem caused by differences in the energy storage device's capacity. This not only improves the operational stability of the LED driver circuit but also significantly enhances product consistency during mass production.

[0031] In an optional implementation, the energy storage path specifically comprises an energy storage capacitor and a diode. The energy storage capacitor is typically an electrolytic capacitor, whose main function is to store energy when the circuit is operating. The diode, as a unidirectional conducting element, is connected in series with the energy storage capacitor to form a complete charging circuit. Its core function is to ensure that the current can only flow in one direction to charge the energy storage capacitor, while preventing the energy stored in the energy storage capacitor from being discharged in the reverse direction through the rectifier circuit.

[0032] The load path consists of an LED and a constant current source. The LED serves as the light-emitting load and energy consumer of the circuit; the constant current source is connected in series with the LED to form a complete discharge circuit. Its main function is to provide a stable and continuous driving current for the LED, ensuring that the LED maintains a constant brightness under different operating conditions, while protecting the LED from the effects of current fluctuations.

[0033] The specific implementation of the logic control circuit includes a logic control unit and switching transistors. The logic control unit is the core of the control system, typically implemented using a dedicated integrated circuit or microprocessor. It is responsible for processing signals from the parameter acquisition module, executing preset control algorithms, and outputting control commands. The switching transistors are usually semiconductor switching devices such as MOSFETs. They are controlled by the control signals output from the logic control unit. Through changes in their on or off states, they control the connection and disconnection of the discharge circuit between the energy storage path and the load path, thereby achieving precise timing management of the discharge process.

[0034] In actual circuit connections, such as Figure 4 As shown, one end of the energy storage capacitor is connected to the anode of the diode, and the other end is connected to the anode of the rectifier circuit output; the cathode of the diode is connected to the ground terminal of the rectifier circuit output. The anode of the LED is connected to the anode of the rectifier circuit output, and the cathode is connected to the input of the constant current source; the switching transistor is placed in the discharge circuit of the energy storage capacitor, and its control terminal is connected to the drive output of the logic control unit. This structural configuration allows the logic control unit to intelligently manage the charging and discharging process of the energy storage capacitor by precisely controlling the turn-on and turn-off timing of the switching transistor, ultimately achieving the technical effect of stabilizing the operating parameters of the load path.

[0035] In an optional implementation, the parameter acquisition module includes a first acquisition module and a second acquisition module. The first acquisition module includes a first current acquisition module and a first voltage acquisition module; the second acquisition module includes a second current acquisition module and a second voltage acquisition module. In specific implementations, these modules can be freely combined. For example, the parameter acquisition module may include a first current acquisition module and a second voltage acquisition module; a first current acquisition module and a second current acquisition module; a first voltage acquisition module and a second voltage acquisition module; or a first voltage acquisition module and a second current acquisition module. In actual circuit design, any combination of two modules can be integrated into the same chip or implemented as discrete functional units. In a specific implementation, the second voltage acquisition module has two different acquisition positions. One position detects the rectified bus voltage Vbulk, and the other position detects the voltage valley value at the DRAIN terminal of the constant current source power transistor, reflecting the operating state of the constant current source.

[0036] The logic control circuit executes an intelligent control strategy based on the collected parameters. Specifically, it adjusts the discharge process in two basic ways: First, it adjusts the delay time for the energy storage path to begin discharging; that is, after detecting the completion of charging, it does not immediately start discharging but waits for an adjustable time interval T. Second, it adjusts the target voltage difference, thereby adjusting the delay time for the energy storage path to begin discharging; where the target voltage difference is the difference between the threshold voltage representing the completion of charging and the bus voltage. Both adjustment methods are based on the closed-loop control principle. The logic control circuit continuously monitors the valley current or valley voltage in the load path and compares it with the target value, then dynamically adjusts the delay time T or the target voltage difference to ensure that these valley values ​​remain stable within a preset range. Finally, the logic control circuit controls the discharge process by controlling the switching transistor to turn on and off. When the discharge conditions are met, the switching transistor is turned on, allowing the energy stored in the energy storage capacitor to be released to the LED load; when a valley parameter is detected or other shutdown conditions are met, the switching transistor is turned off in time, ending the discharge process. This precise control mechanism ensures that the entire system maintains stable performance under different operating conditions, particularly addressing the current phase angle shift problem caused by differences in component parameters. Its adjustment effect is as follows: Figure 5 As shown.

[0037] In an optional implementation, a first current acquisition module is used to acquire the operating current signal of the energy storage path, while a second voltage acquisition module is used to acquire the valley voltage signal across the constant current source. Based on these acquired signals, the logic control circuit achieves precise control by adjusting the delay time at which the energy storage path begins discharging.

[0038] The specific control process is as follows: When the first current acquisition module detects that the operating current flowing through the energy storage capacitor C1 has decreased to near zero, it indicates that the capacitor charging process is basically complete. At this time, the logic control circuit starts timing, and after an adjustable delay time T, it outputs a control signal to turn on the switching transistor Q1, allowing the electrical energy stored in C1 to begin discharging to the LED load. The value of the delay time T is limited to a reasonable range, i.e., Tmin ≤ T ≤ Tmax. During operation, the second voltage acquisition module continuously monitors the voltage change at the constant current source DRAIN terminal. The logic control circuit dynamically adjusts the delay time T based on the deviation between the detected valley voltage at the DRAIN terminal and the first target voltage value. If the valley voltage is too high, the value of T is appropriately decreased; if the valley voltage is too low, the value of T is increased accordingly. Through this closed-loop adjustment mechanism, the valley voltage at the constant current source DRAIN terminal can be stabilized within the first range. When the second voltage acquisition module detects that the voltage at the DRAIN terminal has reached the valley value, the logic control circuit immediately outputs a turn-off signal, turning off the switching transistor Q1, thereby ending the current discharge process.

[0039] In one optional implementation, a first current acquisition module is used to acquire the operating current of the energy storage path; a second current acquisition module is used to acquire the valley current of the load path. The logic control circuit achieves precise closed-loop control by adjusting the delay time at which the energy storage path begins discharging.

[0040] The specific workflow is as follows: When the first current acquisition module detects that the operating current of the energy storage capacitor C1 has dropped to near zero, it indicates that the capacitor has completed charging. At this time, the logic control circuit starts timing. After an adjustable delay time T (satisfying Tmin≤T≤Tmax), it outputs a control signal to turn on the switching transistor Q1, causing the energy stored in C1 to begin discharging to the LED load. During this process, the second current acquisition module continuously monitors the current signal on the detection resistor RCS connected in the load path. The logic control circuit dynamically adjusts the delay time T according to the detected RCS current valley value. If the current valley value deviates from the second range, the value of T is adjusted accordingly. This feedback adjustment mechanism ensures that the output current valley value of the constant current source is stable within the second range. When the detected RCS current reaches the valley value, the logic control circuit immediately outputs a turn-off signal, turning off the switching transistor Q1, thereby ending the current discharge cycle.

[0041] In an optional implementation, a first voltage acquisition module is used to acquire the operating voltage of the diode; a second voltage acquisition module is used to acquire the valley voltage across the constant current source. The logic control circuit achieves precise control by adjusting the target voltage difference, thereby adjusting the delay time for the start of discharge in the energy storage path, wherein the target voltage difference is the difference between the threshold voltage representing the completion of charging and the bus voltage.

[0042] In practice, the first voltage acquisition module continuously monitors the voltage V(GND-GND1) across D5. When the target voltage difference reaches a preset threshold, the logic control circuit immediately outputs a control signal to turn on the switching transistor Q1, causing C1 to begin discharging the LED load. During operation, the second voltage acquisition module simultaneously monitors the voltage change at the DRAIN terminal of the constant current source. The logic control circuit dynamically adjusts the target voltage difference based on the deviation between the detected valley voltage at the DRAIN terminal and the target voltage value. When the valley voltage at the DRAIN terminal is too high, the target voltage difference is appropriately reduced; when the valley voltage at the DRAIN terminal is too low, the target voltage difference is correspondingly increased. Through this closed-loop adjustment mechanism, the valley voltage at the DRAIN terminal of the constant current source is ensured to remain stable within the first range. When a valley voltage is detected at the DRAIN terminal, the logic control circuit turns off the switching transistor Q1.

[0043] In an optional implementation, a first voltage acquisition module is used to acquire the operating voltage of the diode, while a second current acquisition module is used to acquire the valley current of the load path. The logic control circuit adjusts the delay time for the energy storage path to begin discharging by adjusting the target voltage difference.

[0044] The specific working process is as follows: When the first voltage acquisition module detects that the voltage V(GND-GND1) across D5 reaches the preset threshold voltage Vth (where Vth-min≤Vth≤Vth-max), the logic control circuit immediately outputs a control signal to turn on the switching transistor Q1, allowing the electrical energy stored in C1 to begin discharging to the LED load. Simultaneously, the second current acquisition module continuously monitors the current signal on the detection resistor RCS connected in the load path. The logic control circuit dynamically adjusts the target voltage difference based on the deviation between the detected RCS current valley and the target current value. If the current valley is too high, the target voltage difference is appropriately reduced; if the current valley is too low, the target voltage difference is correspondingly increased. Through this closed-loop adjustment mechanism, the output current valley of the constant current source is ensured to remain stable within the second range. When the second current acquisition module detects the current valley, the logic control circuit turns off the switching transistor Q1.

[0045] In an optional implementation, the first current acquisition module is used to acquire the operating current of the energy storage path, while the second voltage acquisition module is used to acquire the valley voltage Vbulk of the rectified bus. The logic control circuit achieves precise control of the system by adjusting the delay time at which the energy storage path discharges.

[0046] The specific control process is as follows: When the first current acquisition module detects that the operating current of the energy storage capacitor C1 has dropped to near zero, it indicates that the capacitor has completed the charging process. At this time, the logic control circuit starts timing. After an adjustable delay time T (satisfying Tmin≤T≤Tmax), it outputs a control signal to turn on the switching transistor Q1, allowing the energy stored in C1 to begin discharging to the LED load. During this process, the second voltage acquisition module continuously monitors the change in the rectified bus voltage Vbulk. The logic control circuit dynamically adjusts the delay time T based on the deviation between the detected Vbulk valley voltage and the second target voltage value. If the Vbulk valley voltage is too high, the value of T is appropriately reduced; if the Vbulk valley voltage is too low, the value of T is increased accordingly. Through this closed-loop adjustment mechanism, it is ensured that the valley value of the rectified bus voltage Vbulk can be stabilized within the third range. When the second voltage acquisition module detects that the Vbulk voltage has reached the valley value, the logic control circuit immediately turns off the switching transistor Q1.

[0047] In an optional implementation, a first voltage acquisition module is used to acquire the operating voltage of the diode; a second voltage acquisition module is used to acquire the valley voltage between the output terminal of the rectifier circuit and ground, specifically the voltage V(GND-GND1) across D5 and the bus voltage Vbulk. The logic control circuit adjusts the delay time for the start of discharge of the energy storage path by adjusting the target voltage difference; wherein, the target voltage difference is the difference between the threshold voltage characterizing the completion of charging and the bus voltage to achieve precise system control.

[0048] The specific control process is as follows: When the first voltage acquisition module detects the voltage V(GND-GND1) across D5, and the target voltage difference reaches the preset difference threshold, the logic control circuit immediately outputs a control signal to turn on the switch Q1, allowing the stored energy in C1 to begin discharging to the LED load. During this process, the second voltage acquisition module continuously monitors the valley value change of the rectified bus voltage Vbulk. The logic control circuit dynamically adjusts the target voltage difference based on the deviation between the detected Vbulk valley voltage and the second target voltage value. If the Vbulk valley voltage is too high, the target voltage difference is appropriately reduced; if the Vbulk valley voltage is too low, the target voltage difference is correspondingly increased. Through this bus voltage feedback-based adjustment mechanism, the valley value of the rectified bus voltage Vbulk is ensured to remain stable within the third range. When the Vbulk valley voltage is detected, the logic control circuit turns off the switch Q1.

[0049] In an optional embodiment, this application also provides an LED lighting system, which uses the LED driving circuit from any of the foregoing embodiments as the core driving component. The LED lighting system specifically includes an LED driving circuit, an LED light source, a power interface, and a lamp housing. The LED driving circuit can employ the aforementioned technical solution, achieving precise control of the energy storage path discharge process through the coordinated operation of a parameter acquisition module and a logic control circuit, ensuring the stability of the valley value in the load path. The LED light source, as the system's light-emitting component, maintains an electrical connection with the load path of the LED driving circuit, and is provided with a stable and reliable driving current by the driving circuit. The power interface is located externally to the system, used to connect to external power sources such as AC mains and transmit electrical energy to the LED driving circuit. The lamp housing, as the system's physical support structure, provides mechanical protection and heat dissipation for the LED driving circuit and LED light source, while ensuring electrical insulation safety between components. This LED lighting system, by adopting an innovative driving scheme, not only effectively solves the current phase angle shift problem caused by differences in electrolytic capacitor capacity in traditional LED drivers, but also significantly improves the system's stability and reliability, while possessing good electromagnetic compatibility characteristics, and can be widely applied to various lighting scenarios such as indoor lighting, road lighting, and commercial lighting.

[0050] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In addition, the terms "first", "second", "third", etc. are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0051] Finally, it should be noted that the above-described embodiments are merely specific implementations of this application, used to illustrate the technical solutions of this application, and not to limit them. The protection scope of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the scope of the technology disclosed in this application; and these modifications, changes, 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. All should be covered within the protection scope of this application. Therefore, the protection scope of this application should be determined by the protection scope of the claims.

Claims

1. An LED driving circuit, characterized in that, include: The energy storage path consists of a rectifier circuit, an energy storage capacitor, and a diode; the load path consists of an LED and a constant current source. Also includes: The parameter acquisition module is used to acquire the charging status parameters of the energy storage path and the valley parameters of the load path. A logic control circuit is used to control the discharge process of the energy storage path to the load path according to the charging state parameters and the valley value parameters, so as to keep the valley value in the load path stable.

2. The LED driving circuit according to claim 1, characterized in that, The parameter acquisition module includes: The first acquisition module is used to acquire the charging status parameters of the energy storage path; The second acquisition module is used to acquire the valley parameters of the load path; The logic control circuit is used to control the discharge process by adjusting the delay time of the discharge start of the energy storage path by controlling the switching transistor to turn it on and off.

3. The LED driving circuit according to claim 2, characterized in that, include: The first current acquisition module is used to acquire the operating current of the energy storage path; The second voltage acquisition module is used to acquire the valley voltage across the constant current source.

4. The LED driving circuit according to claim 2, characterized in that, include: The first current acquisition module is used to acquire the operating current of the energy storage path; The second current acquisition module is used to obtain the valley current of the load path.

5. The LED driving circuit according to claim 2, characterized in that, include: The first voltage acquisition module is used to acquire the operating voltage of the diode; The second voltage acquisition module is used for the valley voltage across the constant current source; The logic control circuit is used to adjust the target voltage difference and thus adjust the delay time for the start of discharge of the energy storage path; wherein the target voltage difference is the difference between the threshold voltage characterizing the completion of charging and the bus voltage.

6. The LED driving circuit according to claim 2, characterized in that, include: The first voltage acquisition module is used to acquire the operating voltage of the diode; The second current acquisition module is used for the valley current of the load path; The logic control circuit is used to adjust the target voltage difference and thus adjust the delay time for the start of discharge of the energy storage path; wherein the target voltage difference is the difference between the threshold voltage characterizing the completion of charging and the bus voltage.

7. The LED driving circuit according to claim 2, characterized in that, include: The first current acquisition module is used to acquire the operating current of the energy storage path; The second voltage acquisition module is used to acquire the valley voltage between the output terminal of the rectifier circuit and ground.

8. The LED driving circuit according to claim 2, characterized in that, include: The first voltage acquisition module is used to acquire the operating voltage of the diode; The second voltage acquisition module is used for the valley voltage between the output terminal of the rectifier circuit and ground. The logic control circuit is used to adjust the target voltage difference and thus adjust the delay time for the start of discharge of the energy storage path; wherein the target voltage difference is the difference between the threshold voltage characterizing the completion of charging and the bus voltage.

9. The LED driving circuit according to claim 1, characterized in that, The logic control circuit includes a logic control unit, a switching transistor, and a MOS driver; the load path also includes a sensing resistor.

10. An LED lighting system, characterized in that, include: The LED driving circuit as described in any one of claims 1-9.

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