Single-line cascaded LED signal spread spectrum transmission method, chip and system

Abstract

The invention provides a single-line cascade LED signal spread spectrum transmission method, an LED driving chip and an LED driving chip cascade system. The single-line cascade LED signal spread spectrum transmission method comprises the following steps: receiving an input signal; performing regeneration processing on the input signal to obtain a regeneration signal; performing spread spectrum modulation on the regenerated signal; and outputting the regenerated signal after the spread spectrum modulation to a next-stage LED driving chip. According to the invention, the special requirements of single-line communication are met, and the frequency expansion of the signal is realized at the same time. Signal energy can be effectively dispersed, energy is prevented from being concentrated on a specific frequency, and therefore the electromagnetic radiation intensity is remarkably reduced.

Description

Technical Field

[0001] The present application relates to the field of communications, and in particular to a single-line cascaded LED signal spread spectrum transmission method, an LED driver chip, and an LED driver chip cascade system. Background Art

[0002] In the single-line cascade LED driver chip data transmission scenario, data and clock information need to be transmitted simultaneously on a single channel. To meet this requirement, a coding method that integrates these two types of information is usually used, such as return-to-zero code.

[0003] However, although this type of encoding method solves the special needs of single-line communication, it has caused new problems. This type of encoding usually has a fixed frequency, which causes the signal energy to be concentrated on a specific frequency and its harmonics. This energy concentration will generate a strong electromagnetic field at these specific frequencies, increasing the intensity of electromagnetic radiation. In addition, multiple cascaded LED driver chips transmit fixed-frequency code streams, which will further concentrate the output spectrum and aggravate the electromagnetic radiation problem. This concentrated electromagnetic radiation has an impact on the surrounding electromagnetic environment that cannot be ignored.

[0004] Therefore, there is an urgent need for a signal transmission method that can maintain the advantages of single-line communication while effectively reducing electromagnetic radiation. Summary of the invention

[0005] Based on this, the present application provides a single-line cascade LED signal spread spectrum transmission method, which is applied to an LED driver chip, including: receiving an input signal; Regenerate the input signal to obtain a regenerated signal; performing spread spectrum modulation on the regenerated signal; The regenerated signal after spread spectrum modulation is output to the next-level LED driver chip.

[0006] In some possible implementations, each bit in the regenerated signal includes an effective level segment for indicating a bit value and a fixed level segment for separating adjacent bits.

[0007] In some possible implementations, the regenerated signal is subjected to spread spectrum modulation, including: For each bit in the regenerated signal: a delay value is selected from a delay value sequence, and the selected delay value is added to the duration of the fixed level segment corresponding to the bit, wherein the delay value sequence includes at least two delay values.

[0008] In some possible implementations, selecting a delay value from a sequence of delay values ​​includes: Randomly select a delay value from the sequence of delay values.

[0009] In some possible implementations, selecting a delay value from a sequence of delay values ​​includes: Select a delay value from the delay value sequence in a cyclic manner.

[0010] In some possible implementations, randomly selecting a delay value from a sequence of delay values ​​includes: A random number is generated using a pseudo-random number generator, and a delay value is selected from a sequence of delay values ​​based on the random number.

[0011] In some possible implementations, the regenerated signal is subjected to spread spectrum modulation, including: For each bit in the regenerated signal: a delay value is cyclically selected in sequence from a predefined delay value sequence, and the selected delay value is added to the duration of the fixed level segment corresponding to the bit, wherein the delay value sequence includes at least two delay values.

[0012] In some possible implementations, each bit in the input signal includes an effective level segment for representing a bit value and a fixed level segment for separating adjacent bits, and regenerating the input signal to obtain a regenerated signal includes: Sampling the input signal to obtain a sampling sequence; Detecting the alternation of effective level segments and fixed level segments in the sampling sequence; Based on the detected alternating changes, determining the start and end positions of each bit; For each bit, determine the bit value corresponding to the bit according to the duration of the valid level segment in the bit; A regenerated signal is generated according to the bit value corresponding to each bit in the sampling sequence.

[0013] The present application also provides an LED driver chip, including: Receiving unit: used to receive input signals; Regeneration unit: used to regenerate the input signal to obtain a regenerated signal; Spread spectrum modulation unit: used for performing spread spectrum modulation on the regenerated signal; Transmission unit: used to output the regenerated signal after spread spectrum modulation to the next-level LED driver chip.

[0014] In some possible implementations, each bit in the regenerated signal includes an effective level segment and a fixed level segment, the effective level segment is used to represent the bit value, and the fixed level segment is used to separate adjacent bits, and the spread spectrum modulation unit is specifically used to: For each bit in the regenerated signal: a delay value is randomly selected from a delay value sequence, and the selected delay value is added to the duration of the fixed level segment corresponding to the bit, wherein the delay value sequence includes at least two delay values.

[0015] The present application also provides an LED driver chip cascade system, comprising a plurality of mutually cascaded LED driver chips, wherein each LED driver chip communicates with the next-level LED driver chip via a single line; each LED driver chip executes any of the above-mentioned single-line cascade LED signal transmission methods.

[0016] This application performs spread spectrum modulation on the regenerated signal and then outputs it to the next-level LED driver chip, dispersing the original fixed frequency signal to multiple frequencies, meeting the special needs of single-line communication while also achieving signal frequency expansion. It can effectively disperse signal energy and avoid energy concentration on a specific frequency, thereby significantly reducing the intensity of electromagnetic radiation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] in: Figure 1 It is a schematic diagram of a single-line cascade of LED driver chips provided in this application; Figure 2 It is a schematic block diagram of a single-line cascade LED signal spread spectrum transmission method provided in one embodiment of the present application; Figure 3 is a waveform diagram of an input signal provided by an embodiment of the present application; Figure 4 is a waveform diagram of a regeneration signal provided by an embodiment of the present application; Figure 5 is a schematic block diagram of an LED driver chip provided in one embodiment of the present application; Figure 6 It is a schematic block diagram of an LED driver chip cascade system provided in one embodiment of the present application. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0021] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0022] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0023] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0024] In the data transmission scenario of single-line cascade of LED driver chips, such as Figure 1 As shown, a group of cascaded LED driver chips realize signal transmission through single-line communication, that is, data and clock information are transmitted simultaneously on a single signal line. Therefore, a coding method that can integrate these two types of information is usually adopted, such as return-to-zero code. However, this type of coding method usually has a fixed frequency. When a fixed-frequency code stream is transmitted on the signal line, the signal energy will be concentrated on a specific frequency and its harmonics. This energy concentration phenomenon will cause a strong electromagnetic field to be generated at these frequencies, increasing the radiation intensity. Moreover, in the process of signal transmission from the head end to the end of the LED driver chip cascade system, each LED driver chip transmits a fixed-frequency code stream, which means that the signal energy is superimposed multiple times on a specific frequency and its harmonics, causing more serious electromagnetic radiation problems, which may seriously interfere with the nearby electromagnetic environment.

[0025] Based on this, the present application proposes a single-line cascade LED signal spread spectrum transmission method, which can be applied to single-line cascade LED driver chips. This method receives an input signal, regenerates the input signal to obtain a regenerated signal, performs spread spectrum modulation on the regenerated signal, and outputs the spread spectrum modulated regenerated signal to the next-level LED driver chip. This method can expand the frequency of the code stream when it is transmitted on the signal line, so that the signal energy is no longer concentrated on a specific frequency and its harmonics, thereby reducing the intensity of electromagnetic radiation, and solving the problem of high electromagnetic radiation in the data transmission scenario of single-line cascade LED driver chips.

[0026] It is understandable that the "single-line" or "single-line communication" described in this application refers to a communication method that transmits data information and clock information simultaneously on a single signal line, and is not limited to the case where there is only a single signal line between two LED driver chips. For example, in some special application scenarios, if it is necessary to support the breakpoint resume function, there may be two or more signal lines between the two LED driver chips. However, as long as data information and clock information are transmitted simultaneously on a single signal line, it still belongs to the "single-line" or "single-line communication" described in this application.

[0027] like Figure 2 As shown, the technical solution of this method is as follows: 101. Receiving input signal In this embodiment, the source of the input signal depends on the position of the chip in the cascade sequence. For the first LED driver chip in the cascade sequence, the input signal usually comes from the LED controller, which can be a main control unit responsible for generating the initial input signal and transmitting the input signal to the first LED driver chip through the signal line. These signals may include control instructions for LED lighting effects, such as brightness, color, dynamic changes, etc. For other LED driver chips in the cascade sequence, the input signal comes from the LED driver chip at the previous level.

[0028] It can be understood that for the first LED driver chip in the cascade sequence, the input signal usually comes from the LED controller, so the input signal can be a signal after spread spectrum modulation or a signal that has not been spread spectrum modulated. For other LED driver chips in the cascade sequence, the input signal comes from the LED driver chip of the previous level, so the input signal is a signal after spread spectrum modulation by the upper-level LED driver chip. Although the signal sources are different, the signal format and protocol received by all chips can be consistent. Therefore, the method provided in the present application can be applied to LED driver chips in different positions, whether it is the first chip directly connected to the controller or any other chip in the cascade sequence, it can correctly receive and process the input signal.

[0029] In some embodiments, in order to simultaneously transmit clock information and data information on a single signal line, each bit in the input signal may include an effective level segment for representing the bit value, and a fixed level segment for separating adjacent bits, and the order of the effective level segment and the fixed level segment is fixed, for example, the effective level segment is followed by the fixed level segment, so that the fixed level segment can effectively divide different bits. The duration of the effective level segment can be used to represent different bit values, for example, a longer duration can be used to represent "1", and a shorter duration can be used to represent "0". The fixed level segment appears fixedly in each bit and is used to separate adjacent bits, so the fixed level segment and the effective level segment can adopt different level states, for example, the fixed level is a low level and the effective level is a high level.

[0030] As an example, Figure 3 As shown, Figure 3 , which shows a waveform diagram of an input signal, including 4 waveform segments, each of which corresponds to a bit ( Figure 3 In the figure, each waveform segment is marked with a dotted line), each waveform segment includes a valid level segment (high level part) and a fixed level segment (low level part). The corresponding bit value can be obtained based on the duration of the valid level segment (high level part) of each waveform segment. A longer valid level duration represents "1", and a shorter valid level duration represents "0".

[0031] It can be understood that the above examples are only for illustration, and the present application does not limit the effective level segment and the fixed level segment. For example, the effective level segment can be a low level, and the fixed level segment can be a high level; the effective level segment can also be a negative level, and the fixed level segment can be a zero level.

[0032] In this embodiment, the effective level segment of each bit in the input signal is used to represent the bit value, and the fixed level segment is used to divide the bits, so that the input signal can carry data information and clock information at the same time, which can meet the special requirements of LED single-line communication.

[0033] 102. Regenerate the input signal to obtain a regenerated signal In this embodiment, the regenerated signal is obtained by regenerating the input signal, and the regenerated signal retains the data information and clock information of the input signal.

[0034] In some embodiments, the step of “regenerating the input signal to obtain a regenerated signal” may specifically include: (11) Sampling the input signal to obtain a sampling sequence; (12) Detecting the alternation of effective level segments and fixed level segments in the sampling sequence; (13) determining the start and end positions of each bit based on the detected alternating changes; (14) For each bit, determine the bit value corresponding to the bit according to the duration of the valid level segment in the bit; (15) Generate a regenerated signal according to the bit value corresponding to each bit in the sampling sequence.

[0035] In this embodiment, the input signal is first sampled, for example, using an analog-to-digital converter or other sampling circuits to obtain a sampling sequence. The sampling sequence is a digitized sequence that represents a discrete representation of the input signal in time.

[0036] Next, the alternating changes of the effective level segment and the fixed level segment are detected in the sampling sequence, and the starting and ending positions of each bit are determined based on the detected alternating changes, that is, the changes of the effective level and the fixed level are identified. Specifically, by analyzing the alternating changes of the effective level segment and the fixed level segment, the boundary of each bit period can be identified. For example, if the effective level segment is followed by a fixed level, the start of the bit usually corresponds to a transition from a fixed level to an effective level, and the end corresponds to the next transition from a fixed level to an effective level. This embodiment establishes timing synchronization through this step. As an example, with Figure 3 As an example, Figure 3 In the example, the effective level is a high level and the fixed level is a low level. Then the first rising edge from low level to high level, that is, the first rising edge, can be taken as the beginning of the first bit, and the second rising edge can be taken as the end of the first bit and the beginning of the second bit.

[0037] For each bit, the bit value corresponding to the bit is determined according to the duration of the valid level segment in the bit. In this step, after the boundary of each bit is determined, the bit value corresponding to the bit is determined according to the duration of the valid level segment in each bit period. For example, a longer valid level segment may represent "1", while a shorter valid level segment may represent "0". The system determines the value of each bit by measuring the duration of the valid level segment and comparing it with a preset threshold.

[0038] Finally, the regenerated signal is generated according to the bit value corresponding to each bit in the sampling sequence. At this time, the frequency of each bit in the regenerated signal is consistent. The regenerated signal is similar to the input signal. Each bit in the regenerated signal also includes an effective level segment for representing the bit value and a fixed level segment for separating adjacent bits. For example, you can refer to Figure 4 , Figure 4 The effective level section of the regenerated signal is the high level section, and the fixed level section is the low level section. For the effective level section and the fixed level section, reference can be made to the above description of the input signal, and the present embodiment will not be repeated.

[0039] In some embodiments, each chip first extracts the portion of data sent to it. The chip then re-encodes the remaining data into a regenerated signal in the same format as the input signal.

[0040] In this embodiment, since the frequency of the input signal may vary, the length of the waveform segment corresponding to each bit also changes accordingly. In this case, the fixed level segment provides a clear boundary mark for each bit, so that the next-level LED driver chip can accurately determine the start and end position of each bit. Not only does it improve the identifiability of the signal, but it also enhances the accuracy and reliability of data transmission. Even when the frequency changes and the waveform length varies, the receiving end can still accurately demodulate the original digital signal, thereby effectively realizing the spread spectrum transmission of the signal while ensuring the integrity and correctness of the data.

[0041] 103. Spread spectrum modulation of the regenerated signal In this embodiment, the regenerated signal is spread spectrum modulated, and the spread spectrum modulation makes the regenerated signal no longer concentrated on a certain frequency, but disperses the signal energy into a wider spectrum range. Specifically, a delay value sequence can be predefined, for example [t1, t2, t3 。。。 tn], indicating that the delay value sequence includes n delay values. For each bit in the regenerated signal, a delay value is selected from the predefined delay value sequence, and the selected delay value is added to the duration of the fixed level segment corresponding to the bit. The delay value sequence includes at least two different delay values ​​to ensure the effectiveness of the modulation.

[0042] In some embodiments, a random selection method can be used to generate a random number using a pseudo-random number generator, and a delay value can be selected from a delay value sequence based on the random number, which can significantly improve the randomness of the modulation. For example, a pseudo-random number generator can be used to generate a code corresponding to a delay value sequence, and a delay value in the delay value sequence can be determined based on the code.

[0043] As an example, Figure 4 As shown, Figure 4 Schematic diagram of the waveform of the regenerated signal before spread spectrum modulation is included, the regenerated signal includes 4 bits, the period of each bit is T, and the delay value sequence is [t1, t2, t3, t4].

[0044] Assume that the results of random selection are as follows: the first bit selects t2; the second bit selects t3; the third bit selects t4; and the fourth bit selects t3.

[0045] After applying these delay values, the duration of the fixed level segment for each bit will increase accordingly. Figure 4 As shown, Figure 4 The figure includes a waveform diagram of the regenerated signal after spread spectrum modulation. The fixed level segment of the first bit is t2 longer than the original one, so the new period is T1=T+t2; the fixed level segment of the second bit is t3 longer than the original one, so the new period is T2=T+t3; the fixed level segment of the third bit is t4 longer than the original one, so the new period is T3=T+t4; the fixed level segment of the fourth bit is t3 longer than the original one, so the new period is T4=T+t3.

[0046] In this embodiment, a delay value is selected from a delay value sequence by random selection, and the delay value is added to a fixed level segment of each bit of the regenerated signal, so that each LED driver chip outputs signals of different frequencies, and the overall spectrum distribution is more discrete. This discrete spectrum characteristic effectively reduces the energy concentration on a single frequency.

[0047] In other embodiments, a sequential cyclic selection scheme may be used, for example, each value in the delay value sequence may be cyclically used in a predetermined order.

[0048] As an example, the regenerated signal contains 5 bits, and the delay value sequence is [t1, t2, t3, t4]. The first bit selects the first delay value t1 of the sequence; the second bit selects t2 in turn; the third bit selects t3 in turn; the fourth bit selects t4 in turn; the fifth bit returns to the beginning of the sequence and selects t5.

[0049] In this embodiment, a sequential cyclic selection scheme is used to ensure that all delay values ​​are used evenly, so that all available frequencies can be fully utilized and signal energy can be effectively dispersed. This method avoids energy concentration on a specific frequency and its harmonics, and also increases spectrum utilization efficiency.

[0050] It can be understood that the more delay values ​​there are in the delay value sequence, the flatter the spectrum of the modulated regenerated signal will be, which means that the spread spectrum effect will be better, the signal power density within a single frequency will be reduced, and the corresponding electromagnetic radiation will also be reduced accordingly, but the more delay values ​​there are, the more likely it is that the frequency range of the communication system will be exceeded. Therefore, the specific number of delay values ​​in the delay value sequence and the specific value of the delay value can be selected according to actual conditions, and this application does not limit this.

[0051] It should be noted that, in this embodiment, the spread spectrum modulation process keeps the duration of the effective level segment of the same bit in the regenerated signal unchanged, because this is the basis for distinguishing different bit values. Therefore, in order to achieve frequency change, the present application innovatively adjusts the duration of the fixed level. This method can achieve three goals at the same time in a single-line communication scenario: transmitting data information, maintaining clock information, and realizing signal spread spectrum. The embodiment of the present application encodes the data information in the duration of the effective level, and adjusts the signal frequency by changing the duration of the fixed level segment. These two aspects are relatively independent, which makes this method have significant advantages: even if the signal frequency changes, the next-level LED driver chip can still accurately identify the data information, and this design improves communication reliability.

[0052] Furthermore, the reason why the delay value is increased in the present application, that is, the period of each bit is increased by increasing the duration of the fixed level segment, rather than reducing the period of each bit by reducing the duration of the fixed level segment, is that for the LED driver chip, reducing the duration of the fixed level segment means that the effective level needs to be triggered in advance during the fixed level segment, for example, the high level needs to be triggered in advance during the low level period, which requires predicting or caching the upcoming signal, which is very difficult in a real-time system. Therefore, the embodiment of the present application adopts the method of increasing the delay value, which can be implemented without complex hardware, reducing hardware complexity and cost.

[0053] 104. Output the regenerated signal after spread spectrum modulation to the next-level LED driver chip.

[0054] In the embodiment of the present application, the regenerated signal after spread spectrum modulation is output to the next-stage LED driver chip.

[0055] The embodiment of the present application performs spread spectrum modulation on the regenerated signal and then outputs it to the next-level LED driver chip, so that the original fixed frequency signal is dispersed to multiple frequencies, which not only meets the special needs of single-line communication, but also realizes the frequency expansion of the signal. It can effectively disperse the signal energy and avoid the energy being concentrated on a specific frequency, thereby significantly reducing the intensity of electromagnetic radiation.

[0056] like Figure 5 As shown, the present application also provides an LED driver chip 200, and the LED driver chip 200 includes: Receiving unit 210: used to receive an input signal; Regeneration unit 220: used to regenerate the input signal to obtain a regenerated signal; Spread spectrum modulation unit 230: used to perform spread spectrum modulation on the regenerated signal; Transmission unit 240: used to output the regenerated signal after spread spectrum modulation to the next-stage LED driver chip.

[0057] In some embodiments, the waveform segment corresponding to each bit in the regenerated signal includes an effective level and a fixed level, the effective level is used to represent the bit value, and the fixed level is used to separate adjacent bits. The spread spectrum modulation unit 230 is specifically used to: For each bit in the regenerated signal: a delay value is randomly selected from a delay value sequence, and the selected delay value is added to the duration of the fixed level corresponding to the bit, wherein the delay value sequence includes at least two delay values.

[0058] like Figure 6 As shown, the present application also provides an LED driver chip cascade system 300, including multiple mutually cascaded LED driver chips 200, wherein each LED driver chip 200 communicates with the next-level LED driver chip 200 in a single-line manner; each LED driver chip 200 executes the single-line cascade LED signal transmission method in the above-mentioned method embodiment.

[0059] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0060] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0061] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0062] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0063] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A single-line cascade LED signal spread spectrum transmission method, characterized in that: Applied to LED driver chips, including receiving an input signal; Performing regeneration processing on the input signal to obtain a regenerated signal; Performing spread spectrum modulation on the regenerated signal; The regenerated signal after spread spectrum modulation is output to the next-level LED driving chip.

2. The LED signal spread spectrum transmission method according to claim 1, characterized in that: Each bit in the regenerated signal includes an effective level segment for indicating a bit value and a fixed level segment for separating adjacent bits.

3. The LED signal spread spectrum transmission method according to claim 2, characterized in that: Performing spread spectrum modulation on the regenerated signal, comprising: For each bit in the regenerated signal: select a delay value from a delay value sequence, and add the selected delay value to the duration of the fixed level segment corresponding to the bit, wherein the delay value sequence includes at least two delay values.

4. The LED signal spread spectrum transmission method according to claim 3, characterized in that: The step of selecting a delay value from the delay value sequence comprises: A delay value is randomly selected from the delay value sequence.

5. The LED signal spread spectrum transmission method according to claim 4, characterized in that: The randomly selecting a delay value from the delay value sequence comprises: A random number is generated using a pseudo-random number generator, and the delay value is selected from the delay value sequence based on the random number.

6. The LED signal spread spectrum transmission method according to claim 3, characterized in that: The step of selecting a delay value from the delay value sequence comprises: One of the delay values ​​is selected cyclically from the delay value sequence.

7. The method according to claim 1, characterized in that Each bit in the input signal includes an effective level segment for indicating a bit value and a fixed level segment for separating adjacent bits, and the regenerating the input signal to obtain a regenerated signal includes: Sampling the input signal to obtain a sampling sequence; Detecting the alternating changes of the effective level segment and the fixed level segment in the sampling sequence; Based on the detected alternating changes, determining the start and end positions of each bit; For each bit, determine the bit value corresponding to the bit according to the duration of the valid level segment in the bit; A regenerated signal is generated according to the bit value corresponding to each bit in the sampling sequence.

8. An LED driver chip, characterized in that: include: Receiving unit: used to receive input signals; Regeneration unit: used for regenerating the input signal to obtain a regenerated signal; Spread spectrum modulation unit: used for performing spread spectrum modulation on the regenerated signal; Transmission unit: used to output the regenerated signal after spread spectrum modulation to the next-level LED driver chip.

9. The LED driver chip according to claim 8, characterized in that: Each bit in the regenerated signal includes an effective level segment and a fixed level segment, the effective level segment is used to represent the bit value, and the fixed level segment is used to separate adjacent bits, and the spread spectrum modulation unit is specifically used to: For each bit in the regenerated signal: a delay value is selected from a delay value sequence, and the selected delay value is added to the duration of the fixed level segment corresponding to the bit, wherein the delay value sequence includes at least two of the delay values.

10. An LED driver chip cascade system, characterized in that: It includes a plurality of mutually cascaded LED driver chips, wherein each LED driver chip communicates with the next-level LED driver chip via a single line; Each of the LED driver chips executes the single-line cascade LED signal transmission method according to any one of claims 1 to 7.

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