LED driving system and synchronous control method
By introducing synchronization pins on the LED driver chip and coupling them together, the high cost of existing LED synchronous drive systems is solved, and low-cost LED load synchronous control is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SUZHOU NOVOSENSE MICROELECTRONICS CO LTD
- Filing Date
- 2026-05-21
- Publication Date
- 2026-07-21
Smart Images
Figure CN122438221A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of LED driver chip technology, specifically relating to an LED driving system and synchronous control method. Background Technology
[0002] With the continuous development of automotive lighting technology, car lights have evolved from simple illumination functions into interactive display systems with complex animation effects. For example, flowing dynamic lights and breathing lights greatly enhance the visual experience and user interactivity of cars. However, realizing these complex animation effects requires a large number of MCUs (microcontrollers), LED driver chips, and communication chips to ensure timing synchronization between the various light groups.
[0003] Currently, LED headlights in different parts of a car are spaced far apart, and there are a large number of LED driver chips. (Reference) Figure 1 The existing LED driver architecture shown uses multiple LEDs at the same location for display driving via an MCU and PWM (pulse width modulation) control signals. For example, both driver chips LED_Driver11 and LED_Driver12 drive the LED load through multiple PWM control signals output by MCU1. A CAN (controller area network) chip is used for bus communication between LED driver chips at different locations. For example, CAN1 and CAN2 transmit timing synchronization information to ensure that the PWM control signals output by MCU1 and MCU2 remain synchronized. The existing LED driver system's synchronization architecture relies on multiple CAN chips and MCU chips, and when communication latency is high, it cannot guarantee the synchronization of all LED animations, creating a conflict between cost and intelligent synchronized display.
[0004] Therefore, there is an urgent need for a low-cost LED synchronization technology that does not rely on dedicated communication chips. Summary of the Invention
[0005] This application provides an LED driving system and control method to solve the problem of high cost in existing LED synchronous driving solutions.
[0006] According to a first aspect of this application, an LED driving system is provided, comprising: N LED driver chips, each LED driver chip driving an LED load to operate in a cyclic cycle, each LED driver chip having a synchronization pin coupled together, each synchronization pin being used to send and receive a synchronization signal to control the synchronization of the cyclic cycle, wherein N is a natural number greater than or equal to 2; when any LED load is the first to end its current cyclic cycle, the LED driver chip corresponding to the LED load controls the synchronization signal to generate a reset indication, and the LED loads driven by the remaining LED driver chips end their respective current cyclic cycles.
[0007] According to a second aspect of this application, this application provides a synchronous control method for controlling N LED driver chips, wherein each LED driver chip has a synchronization pin to output or receive a synchronization signal, and each LED driver chip drives an LED load to operate in a cyclic cycle. The synchronous control method includes: coupling the synchronization pins of the N LED driver chips together; and each LED driver chip receiving a cyclic parameter and driving its respective LED load to operate in a cyclic cycle according to the cyclic parameter; wherein when any LED driver chip is the first to end its current cyclic cycle, its corresponding synchronization pin outputs a synchronization signal to generate a reset indication; except for the first LED driver chip to end its current cyclic cycle, the remaining LED driver chips receive the reset indication of the synchronization signal through their synchronization pins and end their respective current cyclic cycles under the control of the reset indication, where N is a natural number greater than or equal to 2.
[0008] Through one or more embodiments of the above embodiments of the present invention, at least the following technical effects can be achieved: multiple LED driver chips can be connected together only through synchronization pins to realize the synchronous operation of multiple LED loads, without the need for a dedicated communication chip to transmit synchronization signals, saving chip resources and pin resources, thereby reducing the cost of the LED driver system. Attached Figure Description
[0009] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0010] Figure 1 The intent of existing LED driving systems; Figure 2 A schematic diagram of an LED driving system 200 according to an embodiment of the present invention is provided; Figure 3A schematic diagram of an LED driving system 300 according to an embodiment of the present invention is provided; Figure 4 A schematic diagram of an LED driving system 300 according to an embodiment of the present invention is provided; Figure 5 A schematic diagram of an LED driver chip according to an embodiment of this application is provided; Figure 6 A circuit diagram of an LED driver chip according to an embodiment of this application is provided; Figure 7 Given Figure 1 The waveform diagram of the LED driving system shown is shown below. Figure 8 Given Figure 2 A schematic diagram of the loop effect of the LED driving system 200 shown; Figure 9 A flowchart of an LED driving control method according to an embodiment of this application is provided; Figure 10 A cyclic workflow diagram of an LED driver chip according to an embodiment of this application is provided. Detailed Implementation
[0011] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.
[0012] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.
[0013] It should be understood that, in the following description, "circuit" refers to a conductive loop consisting of at least one element or sub-circuit connected by an electrical or electromagnetic link. When an element or circuit is said to be "connected to" or "coupled to" another element, or when an element / circuit is said to be "connected" between two nodes, it can be directly coupled to or connected to the other element, or there may be intermediate elements. The connection between elements can be physical, logical, or a combination thereof. Conversely, when an element is said to be "directly coupled to" or "directly connected to" another element, it means that there are no intermediate elements between them.
[0014] Figure 2 A schematic diagram of an LED driving system 200 according to an embodiment of the present invention is provided. Figure 2 As shown, the LED driving system 200 includes N LED driver chips, denoted as IC1 to ICN. Each LED driver chip has a synchronization pin SN and multiple drive pins LED1-LEDX. The synchronization pin SN is used to send and receive the synchronization signal SYNC. Each LED driver chip receives the power supply voltage VS as its chip power supply voltage. In this embodiment, each drive pin is coupled to an LED load, and multiple drive pins drive multiple LED loads. The LED driving system 200 drives multiple LED loads to operate in a cycle. The cycle refers to the LED load operating within a preset period. Within the preset period, the current flowing through the LED load and the time can be preset according to programming. For example, the operating current of each LED driver chip driving the LED load increases from zero to a preset current value and then decreases back to zero within a preset period, and this process is repeated for multiple preset periods. Each synchronization pin SN is used to send and receive the synchronization signal SYNC. The synchronization pins SN of the N LED driver chips are coupled together to control the synchronization of the N LED loads, where N is a natural number greater than or equal to 2. When any LED driver chip, driving multiple LED loads, is the first to finish its current cycle, it controls the SYNC synchronization signal to generate a reset indication. This reset indication then controls the remaining LED driver chips to finish their respective current cycles. For example, when LED driver chip IC1's multiple LED loads finish their current cycle first, IC1 controls the SYNC synchronization signal to generate a reset indication. The reset indication of the SYNC synchronization signal is transmitted to IC2 through ICN via the synchronization pins SN, causing the remaining LED loads to finish their respective current cycles. In one embodiment, the SYNC synchronization signal is a single-pulse signal, and the reset indication includes a rising edge, a falling edge, and a preset duration of logic low or logic high. In another embodiment, the SYNC synchronization signal is a multi-pulse signal, and the reset indication includes a preset M groups of pulses, where M is a natural number greater than or equal to 2. Figure 2In the embodiments shown, the LED load is a single string of LEDs or multiple strings of LEDs.
[0015] Figure 3 A schematic diagram of an LED driving system 300 according to an embodiment of this application is provided. Figure 3 As shown, the LED driving system 300 provided in this embodiment and Figure 2 The LED driving system 200 shown is similar, but in this embodiment, the synchronization pins SN of N LED driver chips are connected together through resistors RC1 to RCN. Its operation is similar to... Figure 2 The embodiments shown are the same and will not be described again here.
[0016] Figure 4 A schematic diagram of an LED driving system 400 according to an embodiment of this application is provided. Figure 4 As shown, the LED driving system 400 provided in this embodiment is similar to the LED driving system 300, but in this embodiment, the multiple LED loads driven by each LED driving chip are correspondingly coupled between the driving pin and the power supply voltage VS.
[0017] The above embodiment achieves synchronous operation of multiple LED loads driven by N LED driver chips by coupling the synchronization pins SN together and triggering the synchronization signal SYNC to generate a reset indication, thereby saving MCU chip and pin resources and reducing the cost of the synchronization system.
[0018] Figure 5 This is a schematic diagram of an LED driver chip according to an embodiment of this application. Figure 5As shown, the LED driver chip includes a cycle control circuit 210 and a synchronization signal generation circuit 220. The cycle control circuit 210 receives a synchronization signal SYNC and cycle parameters, and generates a cycle end signal SYOUT based on the cycle parameters or the synchronization signal SYNC. The synchronization signal generation circuit 220 receives the cycle end signal SYOUT and generates a synchronization signal SYNC based on the cycle end signal SYOUT. When the cycle parameters control the LED driver chip to end its cycle, the cycle end signal SYOUT changes from a first state to a second state, and the synchronization signal SYNC generates a reset indication. When the synchronization signal SYNC received by the cycle control circuit 210 generates a reset indication, the cycle parameters of the LED driver chip are initialized. Specifically, cycle parameter initialization means, for example, when the LED driver chip drives the corresponding LED load to increase from zero to a preset current value within a preset cycle time for one cycle, if the cycle control circuit 210 receives a reset indication, the cycle control circuit 210 drives the corresponding LED load to end the current cycle and start the next cycle. In one embodiment, the loop parameters may include the number of steps ST of the loop cycle duration, the duration T of the steps, and the current ΔI flowing through the LED load at each step.
[0019] like Figure 5 As shown, the synchronization signal generation circuit 220 is used to receive the cycle end signal SYOUT and generate a reset indication of the synchronization signal SYNC based on the cycle end signal. The synchronization signal generation circuit 220 includes a first terminal and a second terminal, wherein the first terminal is coupled to the loop control circuit 210 and the second terminal is coupled to the synchronization pin SN; the loop control circuit 210 is used to run a program that drives the LED load to work in a loop, including multiple output terminals coupled to multiple drive pins LED1-LEDX, multiple input terminals that receive multiple loop parameters, and a synchronization signal receiving terminal PIN coupled to the synchronization pin SN and a cycle end signal output terminal POUT coupled to the first terminal of the synchronization signal generation circuit 220. Before the end of the current loop cycle, if the synchronization pin SN receives a reset indication of the synchronization signal SYNC, the loop control circuit 210 ends the current loop cycle according to the received synchronization signal SYNC and initializes the loop parameters to run the next loop cycle. When the current cycle ends, if the synchronization pin 101 does not receive a reset indication from the synchronization signal SYNC, the cycle end signal SYOUT output by the cycle control circuit 210 will switch from the first state to the second state to drive the synchronization signal generation circuit 220 to trigger the synchronization signal SYNC to generate a reset indication and output it to the synchronization pin SN.
[0020] Figure 6This is a circuit diagram of an LED driver chip according to an embodiment of this application. In the LED driver chip provided in this application, the synchronization signal generation circuit 220 includes a driving unit 221 and a switching unit 222. The driving unit 221 has a first terminal and a second terminal, wherein the first terminal is coupled to the loop control circuit 210 to receive the cycle end signal SYOUT, and the second terminal is coupled to the switching unit 222. The switching unit 222 has a first terminal, a second terminal, and a controlled terminal, wherein the first terminal is used to receive the power supply voltage VS, the second terminal is coupled to the synchronization pin SN and coupled to the reference ground through a grounding resistor R0, and the controlled terminal is coupled to the second terminal of the driving unit 221. When the second terminal of the driving unit 221 outputs a logic high level, the switching unit 222 is controlled to turn on. Figure 6 In this circuit, when the cycle end signal SYOUT transitions from a first state (e.g., logic low) to a second state (e.g., logic high), the synchronization signal transitions from the first state (e.g., logic low) to the second state (e.g., logic high). In one embodiment, the synchronization signal generation circuit 220 includes a first transistor, a first resistor, a second transistor, and a second resistor. The first transistor has a source, a drain, and a gate, wherein the source is coupled to a reference ground, and the gate receives the cycle end signal; the first resistor is coupled between a power supply and the drain of the first transistor. The second transistor has a source, a drain, and a gate, wherein the source is coupled to a power supply, and the gate is coupled to the drain of the first transistor; the second resistor is coupled between a reference ground and the drain of the second transistor.
[0021] The driving unit 221 in the aforementioned synchronization signal generation circuit 220 includes an N-channel field-effect transistor T1, i.e., a first transistor, and a driving resistor R1, i.e., a first resistor. The gate of the N-channel field-effect transistor T1 is the first terminal of the driving unit 221, the drain is the second terminal of the driving unit 221, and it is coupled to the power supply voltage VS through the driving resistor R1. The source is coupled to the reference ground. The switching unit 222 is a P-channel field-effect transistor T2, i.e., a second transistor. Its gate is the controlled terminal of the switching unit 222, its source is the first terminal of the switching unit 222, and its drain is the second terminal of the switching unit 222. When the gate voltage of the N-channel MOSFET T1 is negative, i.e., when the first terminal of the driving unit 221 receives a logic high level, the N-channel MOSFET T1 is turned on. The power supply voltage VS applies a logic high level to the gate of the P-channel MOSFET T2 through the driving resistor R1, thereby turning on the P-channel MOSFET T2. The power supply voltage VS, through the grounding resistor R0, i.e., the second resistor, raises the voltage of the synchronization pin SN, generating a rising edge reset indication. It should be understood that the MOSFETs and resistors used in the driving unit 221 and the switching unit 222 in this embodiment are not intended to limit the scope of protection of the independent claims. Any electronic components that can realize the functions of the driving unit 221 and the switching unit 222 can be selected by those skilled in the art.
[0022] like Figure 6 As shown, the loop control circuit 210 in the above embodiment includes at least a plurality of transistors corresponding to multiple drive pins LED1-LEDX. The circuit receives duty cycle signals PWM1-PWMX through the gate terminals of the transistors, thereby driving the multiple LED loads to operate according to the preset duty cycle signals PWM1-PWMX. In one embodiment, the loop control circuit generates N duty cycle signals based on loop parameters to control the current flowing through the LED loads. For example, based on the timing information required for the cyclic operation of a single string of LEDs or an LED array, the duty cycle size and operating frequency of PWM1-PWMX are preset and transmitted to the corresponding transistors. The timing information may include the loop period length.
[0023] In the above embodiment, when all LED loads operate in a cycle, a loop animation is formed. The loop parameters are used to determine the loop mode of the LED load's operation, and the loop mode information is transmitted to the multiple drive pins LED1-LEDX via duty cycle signals PWM1-PWMX. When the synchronization pin SN receives a reset indication from the synchronization signal SYNC, the loop control circuit 210 immediately stops the current loop cycle and initializes the loop parameters to the values at the start of the next loop cycle. When the duty cycle signals PWM1-PWMX have completely driven the LED load to complete the current loop cycle, the loop control circuit 210 generates a cycle end signal SYOUT, causing the cycle end signal SYOUT to transition from a first state to a second state. In this embodiment, the cycle end signal SYOUT is the gate control signal of the N-channel field-effect transistor T1, with the first state being a logic low level and the second state being a logic high level.
[0024] In the above embodiments, the loop modes include at least a breathing mode, a flowing mode, and a blinking mode. Taking the breathing mode as an example, when the loop parameters are preset to the breathing mode, for example, the loop cycle length is 2 seconds, then within a single loop cycle, the duty cycle signals PWM1-PWMX generated by the loop control circuit 210 according to the loop parameters of the breathing mode are: in the first second, the duty cycle gradually increases from 0% to 100%, and in the next second, the duty cycle gradually decreases from 100% to 0%. In some embodiments, the loop control circuit 210 can use a hardware timer (such as the TIM module of STM32) or a programmable logic device to write an interrupt instruction that responds to the SYNC reset indication through embedded development. If the synchronization pin SN receives the SYNC reset indication before the end of the current loop cycle, the loop control circuit 210 interrupts the reception of the loop parameters of the current loop cycle according to the received SYNC reset indication. The synchronization process of the above LED loop animation does not rely on bus communication or MCU communication between the two driver chips, and each LED driver chip only occupies one pin to achieve the synchronization function, which can significantly save chip resources and pin resources.
[0025] Figure 7 For existing technology Figure 1 The diagram shows the waveform of the LED driver system 100 during operation. Because each driver chip drives its corresponding LED load in a cyclic operation, the length of each cycle has a very small error. The accumulated error over multiple cycles results in a significant time difference in the animations displayed by different LED loads. For example... Figure 7 As shown, taking the cyclic operation in breathing mode as an example, the total current of the LED load corresponding to LED driver chip IC#1 and LED driver chip IC#2 are I_IC1 and I_IC2, respectively. When the power supply voltage VS is powered on at time t0, the change period length of the total current I_IC1 of the LED load corresponding to LED driver chip IC#1 is T_IC1, and the change period length of the total current I_IC2 of the LED load corresponding to LED driver chip IC#2 is T_IC2. T_IC2 is slightly larger than T_IC1. However, when the system works to the fourth cycle, the cumulative time difference TD when the duty cycle is 100% is nearly four times the difference between T_IC2 and T_IC1, and the synchronous visual effect of the breathing animation is significantly reduced.
[0026] Figure 8 For the purposes of this application Figure 2The diagram shows the cycling effect of the LED driving system 200. In this application, the synchronization pin SN of LED driver chip IC1 and the synchronization pin SN of LED driver chip IC2 are directly connected or connected through a resistor. If the cycle length of LED driver chip IC1 is slightly less than the cycle length of LED driver chip IC2, then before the end of each cycle, the synchronization pin SN of LED driver chip IC2 can receive a reset indication of the synchronization signal SYNC from the synchronization pin SN of LED driver chip IC1. Figure 8 In the process, at the end of the cycle, i.e., when the current I1 of the LED load corresponding to LED driver chip IC#1 is zero, the reset indication of the synchronization signal SYNC, i.e., the rising edge, arrives. Under the control of the reset indication of the synchronization signal SYNC, LED driver chip IC#2 ends the current cycle, even if the current I2 of the LED load corresponding to LED driver chip IC#2 has not completely dropped to zero, i.e., the corresponding PWM is 5%. In some other embodiments, the reset indication of the synchronization signal SYNC can be set as a pulse group according to the cycle end signal SYOUT output by the cycle control circuit 210.
[0027] This application also provides a synchronization control method for controlling N LED driver chips, wherein each LED driver chip has a synchronization pin to output or receive a synchronization signal, and each LED driver chip drives an LED load to operate in a cyclic cycle. The synchronization control method includes: coupling the synchronization pins of the N LED driver chips together; each LED driver chip receiving a cyclic parameter and driving its respective LED load to operate in the cyclic cycle according to the cyclic parameter; wherein when any LED driver chip is the first to end its current cyclic cycle, its corresponding synchronization pin outputs a synchronization signal to generate a reset indication; except for the first LED driver chip to end its current cyclic cycle, the remaining LED driver chips receive the reset indication of the synchronization signal through their synchronization pins and end their respective current cyclic cycles under the control of the reset indication, where N is a natural number greater than or equal to 2.
[0028] Figure 9 This is a flowchart of an LED driving control method provided in this application. Figure 9 As shown, in step S1: the synchronization pins SN of N LED driver chips are directly connected together or connected together through resistors; in step S2: the first LED driver chip to end the current cycle outputs a reset indication of the synchronization signal SYNC on its corresponding synchronization pin; in step S3: except for the first LED driver chip to end the current cycle, the remaining LED driver chips receive the reset indication of the synchronization signal SYNC through the synchronization pin SN, and end the current cycle according to the reset indication.
[0029] In some embodiments, the SYNC synchronization signal is a single-pulse signal, and the reset indication of the SYNC synchronization signal includes a rising edge, a falling edge, a preset duration of logic low, or a preset duration of logic high. In other embodiments, the SYNC synchronization signal is a multi-pulse signal, and the reset indication of the SYNC synchronization signal includes a preset M groups of pulses, where M is a natural number greater than or equal to 2.
[0030] In the above embodiments, the LED load includes a single string of LEDs or multiple strings of LEDs.
[0031] Figure 10 This is a flowchart illustrating the cyclic operation of the LED driver chip described in this application. Figure 10 As shown, when the LED driver system 200 is powered on, each LED driver chip, when executing the current cycle, according to the above-mentioned LED driving control method, further includes: before the end of the current cycle, if the synchronization pin SN of the LED driver chip receives a reset indication of the synchronization signal SYNC, then the cycle control circuit 210 of the LED driver chip controls the LED load to end the current cycle and run the next cycle; otherwise, the cycle control circuit 210 controls the LED load to continue executing the current cycle; when the current cycle ends, if the synchronization pin SN of the LED driver chip still has not received a reset indication of the synchronization signal SYNC, then the cycle control circuit 210 of the LED driver chip outputs a cycle end signal SYOUT to the synchronization signal generation circuit 220; the synchronization signal generation circuit 220 outputs a reset indication of the synchronization signal SYNC to the synchronization pin SN.
[0032] Although the invention has been described with reference to illustrative embodiments, this specification is not intended to be limiting. Various modifications and combinations of illustrative embodiments, as well as other embodiments of the invention, will be apparent to those skilled in the art when referring to the specification. Therefore, it is intended that the appended claims cover all such modifications or embodiments.
Claims
1. An LED driving system, comprising: There are N LED driver chips, each driving an LED load to operate in a cycle. Each LED driver chip has a synchronization pin and each synchronization pin is coupled together. Each synchronization pin is used to send and receive synchronization signals to control the synchronization of the cycle, where N is a natural number greater than or equal to 2. When any LED load is the first to finish its current cycle, the LED driver chip corresponding to that LED load generates a reset indication by controlling the synchronization signal, and the LED loads driven by the remaining LED driver chips finish their respective current cycles.
2. The LED driving system as described in claim 1, wherein the synchronization signal is a single pulse signal, and the reset indication of the synchronization signal includes a rising edge, a falling edge, a preset duration of logic low, or a preset duration of logic high.
3. The LED driving system as described in claim 1, wherein the synchronization signal is a multi-pulse signal, and the reset indication of the synchronization signal includes a preset set of M pulses, where M is a natural number greater than or equal to 2.
4. The LED driving system as described in claim 1, wherein the LED load comprises a single string of LEDs or multiple strings of LEDs.
5. The LED driving system as described in claim 1, wherein each LED driving chip has multiple driving pins, and each LED load is coupled between the driving pin and the reference ground.
6. The LED driving system as described in claim 1, wherein each LED driving chip has multiple driving pins, and each LED load is coupled between the driving pins and the power supply.
7. The LED driving system as described in claim 1, wherein the LED driver chip comprises: The loop control circuit receives the synchronization signal and loop parameters, and generates a cycle end signal based on the loop parameters or the synchronization signal. The synchronization signal generation circuit receives the cycle end signal and generates a reset indication for the synchronization signal based on the cycle end signal; When the cycle of the LED driver chip controlled by the cycle parameter ends, the cycle end signal changes from the first state to the second state, and the synchronization signal generates a reset indication. When the synchronization signal received by the loop control circuit generates a reset indication, the loop parameters of the LED driver chip are initialized.
8. The LED driving system of claim 7, wherein the synchronization signal generation circuit comprises: A drive unit has a first terminal and a second terminal, wherein the first terminal is coupled to a loop control circuit to receive a cycle end signal; as well as Switching unit; It has a first terminal, a second terminal and a controlled terminal, wherein the first terminal is coupled to the power supply voltage, the second terminal is coupled to the synchronization pin, and the controlled terminal is coupled to the second terminal of the drive unit 221; When the cycle end signal transitions from the first state to the second state, the synchronization signal also transitions from the first state to the second state.
9. The LED driving system as claimed in claim 7, wherein the cycle control circuit further generates N duty cycle signals according to the cycle parameters to control the current flowing through the LED load.
10. The LED driving system of claim 7, wherein the cycle parameters include the number of steps in the cycle period, the duration of the steps, and the current flowing through the LED load at each step.
11. A synchronization control method for controlling N LED driver chips, wherein each LED driver chip has a synchronization pin to output or receive a synchronization signal, and each LED driver chip drives an LED load to operate in a cyclic period, the synchronization control method comprising: Couple the synchronization pins of N LED driver chips together; as well as Each LED driver chip receives the cycle parameters and drives its respective LED load to work in the cycle period according to the cycle parameters; When any LED driver chip is the first to finish the current cycle, its corresponding synchronization pin outputs a synchronization signal to generate a reset indication. Except for the first LED driver chip that ends its current cycle, the other LED driver chips receive a reset instruction from the synchronization signal through the synchronization pin and end their respective current cycles under the control of the reset instruction, where N is a natural number greater than or equal to 2.
12. The synchronization control method as described in claim 11, wherein the synchronization signal is a single pulse signal, and the reset indication of the synchronization signal includes a rising edge, a falling edge, a preset duration of logic low, or a preset duration of logic high.
13. The synchronization control method as described in claim 11, wherein the synchronization signal is a multi-pulse signal, and the reset indication of the synchronization signal includes a preset M groups of pulses, where M is a natural number greater than or equal to 2.
14. The synchronous control method as described in claim 11, wherein the LED load comprises a single string of LEDs or multiple strings of LEDs.