LED driver chip with composite function pins and LED driver system

Abstract

The present invention discloses an LED driving system, comprising a controller and a plurality of LED driver chips; the controller and the plurality of LED driver chips form a serial communication link, with the controller acting as a host to send instruction data to the plurality of LED driver chips acting as slaves; each of the LED driver chips is provided with a plurality of LED driver channel pins, each of which is used to connect to one end of a plurality of LED light strings to control the light emission of the LED light strings, and the other ends of the plurality of LED light strings are connected to an LED driving power supply; when the instruction data sent by the controller is transmitted step by step in the serial communication link, the LED driver chip at each level is allowed to write status information into the instruction data and pass it to the LED driver chip at the next level; at least one of the LED driver chips is provided with at least one composite function port, which is used to output the status information.

Description

Technical Field

[0001] The present invention relates to the technical field of LED backlight driving, and in particular to an LED driving chip with composite function pins and an LED driving system. Background Art

[0002] With the development of display technology, Mini-LED, OLED, and Micro-LED displays have gradually become the three main directions of display technology development, building on the foundation of traditional LCD displays. However, OLED display technology is limited by material properties, and pixel burn-in remains a difficult problem to solve. Micro-LED technology still needs to improve the efficiency of mass transfer technology to enable more cost-effective application in large-scale displays. Therefore, for the current situation, LCD displays using direct-lit Mini-LED backlight panels are the best display solution. Direct-lit Mini-LED backlight panels are composed of a high-density LED array made of even finer Mini-LED beads (with dimensions reduced to less than 100 microns). The entire backlight panel can be divided into multiple backlight zones, with the number of LEDs in each zone increasing from tens of traditional LEDs to hundreds or even thousands. Therefore, how to drive and control these numerous Mini-LED beads so that their brightness matches the display of the LCD panel becomes a core issue in Mini-LED backlight panel applications.

[0003] like Figure 1 As shown, in the single-bus serial communication link of the LED driver system in the prior art, each LED driver chip is provided with a data input port DI and a data output port DO. The LED driver chips are connected in series through the DI / DO ports, that is, the data output port DO of the previous chip is connected to the data input port DI of the next chip. The upper computer controller inputs instruction data to the data input port DI of the first chip, and then communicates to the subsequent chips in sequence in a serial manner. In this serial communication link, a unidirectional communication method can be used, that is, the data output port of the last chip is transmitted back to the controller, or a bidirectional communication method can be used, that is, the last chip inverts the data and outputs the data to the previous stage, and the data input port DI of each previous chip becomes a data output port, and each data output port DO becomes a data input port, and the data is returned to the controller step by step.

[0004] In existing LED backlight drive systems, the increasing number of backlight zones requires a large number of LED driver chips. When dynamically adjusting the voltage provided by the LED driver power supply based on the needs of the LED driver chips, the controller must adjust the VLED voltage via DAC or PWM output based on feedback from the driver chips. Currently, the communication protocols used by LED driver chips are typically proprietary, and typical controller MCUs lack the hardware to fully support them. This requires the controller MCU to not only use hardware such as SPI / GPIO to simulate the proprietary protocol's transmission waveforms but also to parse the received data to adjust the VLED voltage, which undoubtedly increases the workload of the BCON controller.

[0005] It can be seen from the above that a new LED driver chip and LED driver system are needed in the prior art to reduce the computational dependence on the controller, so that the LED driver chip can directly control the parameters of the LED driver system. Summary of the Invention

[0006] The technical purpose to be achieved by the present invention is to provide a new LED driver chip and LED driver system, so that the LED driver chip can control the LED driver system without relying on the return protocol set by the controller.

[0007] Based on the above technical objectives, the present invention provides an LED driving system, comprising: a controller and a plurality of LED driver chips; the controller and the plurality of LED driver chips form a serial communication link, and the controller acts as a host to send command data to the plurality of LED driver chips as slaves;

[0008] Each of the LED driver chips is provided with at least one first data transmission port and one second data transmission port;

[0009] Each of the LED driver chips is provided with a plurality of LED driver channel pins, each of which is used to connect one end of one of the plurality of LED light strings to control the light emission of the LED light string, and the other end of the plurality of LED light strings is connected to the LED driver power supply;

[0010] When the instruction data sent by the controller is transmitted step by step in the serial communication link, the LED driver chip at each level is allowed to write the status information into the instruction data and pass it to the LED driver chip at the next level;

[0011] At least one of the LED driver chips is provided with at least one composite function port, and the composite function port is used to output the status information.

[0012] The LED driver chip in the serial communication link also includes:

[0013] The composite function port of at least one LED driver chip is connected to the LED driver power supply, and the composite function port transmits voltage adjustment information to the LED driver power supply;

[0014] or

[0015] The composite function port of at least one LED driver chip is connected to the controller to transmit error information or terminal information to the controller.

[0016] In one embodiment, the serial communication link means that the first data transmission port of each LED driver chip is connected to the second data transmission port of the LED driver chip of the previous level adjacent to the LED driver chip, and the second data transmission port of each LED driver chip is connected to the first data transmission port of the LED driver chip of the next level adjacent to the LED driver chip.

[0017] In one embodiment, the serial communication link adopts a unidirectional communication mode or a bidirectional communication mode.

[0018] In one embodiment, the LED driver chip in the serial communication link includes a driver chip with a port having a composite function and a driver chip without a port having a composite function, and the driver chip with the port having a composite function is set as the first or last LED driver chip in the serial communication link.

[0019] The present invention further provides an LED driving system, comprising: a controller and a plurality of LED driving chips; the controller and the plurality of LED driving chips form a serial communication link, and the controller acts as a host to send instruction data to the plurality of LED driving chips as slaves;

[0020] Each of the LED driver chips is provided with at least one first data transmission port and one second data transmission port;

[0021] Each of the LED driver chips is provided with a plurality of LED driver channel pins, and the plurality of LED driver channel pins are respectively used to connect one end of one of the R-LED light string, the G-LED light string and the B-LED light string, or to connect one end of one of the R-LED light string, the G-LED light string, the B-LED light string and the W-LED light string; the other end of the R-LED light string, the G-LED light string, the B-LED light string or the W-LED light string is connected to one of the plurality of LED driver power supplies;

[0022] When the instruction data sent by the controller is transmitted step by step in the serial communication link, the LED driver chip at each level is allowed to write the status information into the instruction data and pass it to the LED driver chip at the next level;

[0023] At least one of the LED driver chips is provided with at least one composite function port, and the composite function port is used to output the status information.

[0024] The LED driver chip in the serial communication link also includes:

[0025] The composite function port of at least one LED driver chip is connected to the LED driver power supply, and the composite function port transmits voltage adjustment information to the LED driver power supply;

[0026] or

[0027] The composite function port of at least one LED driver chip is connected to the controller to transmit error information or terminal information to the controller.

[0028] In one embodiment, the serial communication link means that the first data transmission port of each LED driver chip is connected to the second data transmission port of the LED driver chip of the previous level adjacent to the LED driver chip, and the second data transmission port of each LED driver chip is connected to the first data transmission port of the LED driver chip of the next level adjacent to the LED driver chip.

[0029] In one embodiment, the serial communication link adopts a unidirectional communication mode or a bidirectional communication mode.

[0030] In one embodiment, the LED driver chip in the serial communication link includes a driver chip with a port having a composite function and a driver chip without a port having a composite function, and the driver chip with the port having a composite function is set as the first or last LED driver chip in the serial communication link.

[0031] The present invention also provides an LED driver chip, wherein the LED driver chip is provided with inter-chip interconnection pins and external pins, wherein the inter-chip interconnection pins are used to realize interconnection communication between LED driver chips;

[0032] The external pins include: LED drive pins, shared pins and composite function pins; wherein, the LED drive pins are used to connect LED light strings, and control the brightness of the LED light strings by adjusting the current or switching the LED light strings; the shared pins are used to connect the high-voltage drive power supply VCC, the chip drive power supply VDD or the common ground or negative voltage terminal;

[0033] The LED driver chip is further provided with at least one composite function pin, and each composite function pin is configured to output only one type of status information.

[0034] In one embodiment, the status information includes a voltage adjustment signal, an error signal, an interrupt signal, or an overvoltage / undervoltage signal.

[0035] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purposes and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0037] Figure 1 It is a schematic diagram of the structure of the LED driving system in the prior art;

[0038] Figure 2 1 is a schematic structural diagram of an LED driving system according to a first embodiment of the present invention;

[0039] Figure 3 is a schematic structural diagram of an LED driving system according to a second embodiment of the present invention;

[0040] Figure 4 Schematic diagram of the pin arrangement of the LED driver chip according to the third embodiment of the present invention. DETAILED DESCRIPTION

[0041] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings.

[0042] It should be understood that when an element or layer is referred to as being "on," "adjacent to," "connected to," or "coupled to" another element or layer, it can be directly on, adjacent to, connected to, or coupled to the other element or layer, or there can be intervening elements or layers. Conversely, when an element is referred to as being "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" another element or layer, there can be no intervening elements or layers. It should be understood that while the terms first, second, third, etc. may be used to describe various elements, components, regions, layers, and / or parts, these elements, components, regions, layers, and / or parts should not be limited by these terms. These terms are merely used to distinguish one element, component, region, layer, or part from another. Thus, without departing from the teachings of the present invention, a first element, component, region, layer, or part discussed below may be represented as a second element, component, region, layer, or part. Furthermore, when a second element, component, region, layer, or part is discussed, it does not necessarily mean that the first element, component, region, layer, or part is present in the present invention.

[0043] Spatially relative terms such as "under," "beneath," "below," "under," "above," "above," etc., may be used herein for convenience of description to describe the relationship of an element or feature shown in the figures to other elements or features. It should be understood that in addition to the orientations shown in the figures, the spatially relative terms are intended to include different orientations of the device in use and operation. For example, if the device in the drawings is flipped, then the elements or features described as "under the other elements" or "under it" or "under it" will be oriented as "on" the other elements or features. Thus, the exemplary terms "under" and "under" may include both upper and lower orientations. The device may be oriented otherwise (rotated 90 degrees or in other orientations) and the spatial descriptors used herein are interpreted accordingly.

[0044] The purpose of the terms used herein is only to describe specific embodiments and is not intended to limit the present invention. When used herein, the singular forms "a", "an", and "the" are intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "comprising" and / or "comprising", when used in this specification, determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0045] Example 1

[0046] like Figure 2 As shown, the LED driving system of this embodiment includes: a controller and multiple LED driving chips; the controller and the multiple LED driving chips form a serial communication link, and the controller acts as a host to send command data to the multiple LED driving chips as slaves.

[0047] Each of the LED driver chips is provided with at least one first data transmission port DI and a second data transmission port DO. The serial communication link means that the first data transmission port DI of each LED driver chip is connected to the second data transmission port DO of the LED driver chip of the previous level adjacent to the LED driver chip, and the second data transmission port DO of each LED driver chip is connected to the first data transmission port DI of the LED driver chip of the next level adjacent to the LED driver chip. The first LED driver chip in the serial communication link is connected to the transmission port TX / RX of the controller. In the unidirectional communication mode, the second data transmission port of the last LED driver chip is connected to the control transmission port to transmit the return data back to the controller, such as Figure 2 Optionally, in bidirectional communication mode, the second data transmission port of the last LED driver chip is not connected to the controller, but the returned data is inverted and transmitted to the preceding LED driver chip through the first data transmission port, and the returned data is then transmitted to the controller through the first data transmission port of the first LED driver chip step by step.

[0048] In this embodiment, as the command data sent by the controller is transmitted step by step along the serial communication link, the LED driver chip at each stage is allowed to write status information into the command data and pass it on to the LED driver chip at the next stage. The status information includes voltage adjustment signals, error signals, interrupt signals, overvoltage / undervoltage signals, etc.

[0049] In this embodiment, each of the LED driver chips is provided with a plurality of LED driver channel pins, and the LED driver channel pins are respectively used to connect one end of one of the plurality of LED light strings to control the light emission of the LED light string, and the other end of the plurality of LED light strings is connected to the LED driver power supply DCDC.

[0050] In this embodiment, each LED driver chip is provided with at least one composite function port, and the composite function port is used to output the status information. Figure 2 As shown, in this embodiment, the composite function port of the last LED driver chip is connected to the LED driver power supply DCDC. The composite function port of the last LED driver chip outputs a voltage adjustment signal to the LED driver power supply DCDC. The LED driver power supply DCDC increases or decreases the voltage value of the LED light string according to the voltage adjustment signal. In this embodiment, the composite function port of the LED driver chip before the last LED driver chip directly transmits other types of status information, such as voltage adjustment signal, back to the controller. Figure 2 As shown, the LED driver chip (N-1) transmits an error signal back to the controller, and the LED driver chip (N-2) transmits an interrupt signal back to the controller.

[0051] In this embodiment, if the LED driver system adopts a bidirectional communication mode, the composite function port of the LED driver chip outputs status information when returning data. If the LED driver system adopts a unidirectional communication mode, the composite function port of the LED driver chip will output status information through the composite function port when the LED driver chip sends instruction data to the next-level LED driver chip. It should be noted that in the unidirectional communication mode, the status information output by the LED driver chip does not include the status information of the subsequent LED driver chip, for example Figure 2As shown, when the LED driver chip (N-1) transmits an error signal back to the controller, if the last LED driver chip N also generates an error signal, the error signal cannot be transmitted back to the controller.

[0052] In this embodiment, the multi-function port of any LED driver chip on the serial communication link can be selected to output status information. Specifically, in bidirectional communication mode, the status information contained within the return data time window includes complete information for all LED driver chips on the entire serial communication link. Therefore, any LED driver chip can be selected to output complete status information. For example, if the circuit design requires that the LED driver power supply DCDC be located near the primary LED driver chip, the multi-function port of the primary LED driver chip can be selected to output a voltage adjustment signal to the LED driver power supply DCDC.

[0053] In this embodiment, each of the LED driver chips can be provided with a plurality of composite function ports, and each composite function port outputs a type of status information. For example, composite function port a outputs voltage adjustment information, composite function port b outputs error information, composite function port c outputs interrupt information, and so on. However, since a large number of LED driver chips are required in the LED backlight system, and the increase in the number of LED driver chip ports (pins) will increase the manufacturing cost of the LED driver chip, the specific composite function ports on the LED driver chip can be adjusted according to cost requirements. Therefore, further improvements can be made in this embodiment, that is, two types of LED driver chips are provided in the serial communication link, and the LED driver chip with the composite function port is only provided at a specific position, such as the first or last position, while the LED driver chips at other positions use conventional chips that do not have a composite function port.

[0054] Furthermore, in this embodiment, when the serial communication link adopts a bidirectional communication mode, the second data transmission port of the last LED driver chip is in an idle state. In this case, the second data transmission port of the last LED driver chip can be used as a composite function port.

[0055] Implementation 2

[0056] like Figure 3 As shown, the LED driving system of this embodiment includes: a controller and multiple LED driving chips; the controller and the multiple LED driving chips form a serial communication link, and the controller acts as a host to send command data to the multiple LED driving chips as slaves.

[0057] Each of the LED driver chips is provided with at least one first data transmission port DI and a second data transmission port DO. The serial communication link means that the first data transmission port DI of each LED driver chip is connected to the second data transmission port DO of the LED driver chip of the previous level adjacent to the LED driver chip, and the second data transmission port DO of each LED driver chip is connected to the first data transmission port DI of the LED driver chip of the next level adjacent to the LED driver chip. The first LED driver chip in the serial communication link is connected to the transmission port TX / RX of the controller. In the unidirectional communication mode, the second data transmission port of the last LED driver chip is connected to the control transmission port to transmit the return data back to the controller, such as Figure 3 Optionally, in bidirectional communication mode, the second data transmission port of the last LED driver chip is not connected to the controller, but the returned data is inverted and transmitted to the preceding LED driver chip through the first data transmission port, and the returned data is then transmitted to the controller through the first data transmission port of the first LED driver chip step by step.

[0058] In this embodiment, as the command data sent by the controller is transmitted step by step along the serial communication link, the LED driver chip at each stage is allowed to write status information into the command data and pass it on to the LED driver chip at the next stage. The status information includes voltage adjustment signals, error signals, interrupt signals, overvoltage / undervoltage signals, etc.

[0059] In this embodiment, each of the LED driver chips is provided with a plurality of LED driver channel pins, and the plurality of LED driver channel pins are respectively used to connect one end of one of the R-LED light string, G-LED light string and B-LED light string (i.e. one of the red, green and blue LED light strings), or to connect one end of one of the R-LED light string, G-LED light string, B-LED light string and W-LED light string (i.e. one of the red, green, blue and white LED light strings). The other end of the RGB light string is respectively connected to the R-LED driver power supply, B-LED driver power supply and G-LED driver power supply. Figure 3 As shown, in this embodiment, each of the LED driver chips is provided with three LED driver channel pins, and the three LED driver channel pins are used to connect the R-LED light string, the G-LED light string, and the B-LED light string, respectively. The R-LED light string is connected to the R-LED driving power supply, the G-LED light string is connected to the G-LED driving power supply, and the B-LED light string is connected to the B-LED driving power supply. Optionally, since the red LED has a different luminous efficiency than the green and blue LEDs, the R-LED light string can also be connected to the R-LED driving power supply, while the G-LED light string and the B-LED light string are simultaneously connected to the same GB-LED driving power supply.

[0060] In this embodiment, each LED driver chip is provided with at least one composite function port, and the composite function port is used to output the status information. Figure 3 As shown, in this embodiment, the composite function port of the last LED driver chip N is connected to the R-LED driver power supply. The composite function port of the last LED driver chip N outputs a voltage adjustment signal to the R-LED driver power supply. The R-LED driver power supply increases or decreases the voltage value driving the R-LED light string according to the voltage adjustment signal. Similarly, the composite function port of LED driver chip N-1 is connected to the G-LED driver power supply. The composite function port of LED driver chip N-1 outputs a voltage adjustment signal to the G-LED driver power supply. The G-LED driver power supply increases or decreases the voltage value driving the G-LED light string according to the voltage adjustment signal. The composite function port of LED driver chip N-2 is connected to the B-LED driver power supply. The composite function port of LED driver chip N-2 outputs a voltage adjustment signal to the B-LED driver power supply. The B-LED driver power supply increases or decreases the voltage value driving the B-LED light string according to the voltage adjustment signal.

[0061] In this embodiment, the composite function port of the preceding LED driver chip including the LED driver chip N-2 can directly transmit other types of status information except the voltage adjustment signal back to the controller. For example, the LED driver chip (N-3) can transmit an error signal back to the controller, and the LED driver chip (N-4) can transmit an interrupt signal back to the controller.

[0062] In this embodiment, if the LED driver system adopts a bidirectional communication mode, the composite function port of the LED driver chip outputs status information when transmitting data back. If the LED driver system adopts a unidirectional communication mode, the composite function port of the LED driver chip will simultaneously output status information through the composite function port when the LED driver chip sends instruction data to the next-level LED driver chip. It should be noted that in the unidirectional communication mode, the status information output by the LED driver chip does not include the status information of the subsequent LED driver chip. For example, when the LED driver chip (N-3) transmits an error signal back to the controller, if the last LED driver chip N to N-2 also generates an error signal, the error signal cannot be transmitted back to the controller.

[0063] In this embodiment, the multi-function port of any LED driver chip on the serial communication link can be selected to output status information. Specifically, in bidirectional communication mode, the status information contained within the return data time window includes complete information for all LED driver chips on the entire serial communication link. Therefore, any LED driver chip can be selected to output complete status information. For example, if the circuit design requires that the LED driver power supply be located near the primary LED driver chip, the multi-function port of the primary LED driver chip can be selected to output the voltage adjustment signal to the LED driver power supply.

[0064] In this embodiment, each of the LED driver chips can be provided with multiple composite function ports, each of which outputs a type of status information. For example, composite function port a outputs R-LED voltage adjustment information, composite function port b outputs G-LED voltage adjustment information, composite function port c outputs B-LED voltage adjustment information, and so on. However, since a large number of LED driver chips are required in the LED backlight system, and the increase in LED driver chip ports (pins) will increase the manufacturing cost of the LED driver chip, the specific composite function ports on the LED driver chip can be adjusted according to cost requirements. Therefore, further improvements can be made to this embodiment, that is, two LED driver chips are provided in the serial communication link, and the LED driver chip with the composite function port is only provided at a specific position, such as the first or last position, while the LED driver chips at other positions use conventional chips without composite function ports.

[0065] Furthermore, in this embodiment, when the serial communication link adopts a bidirectional communication mode, the second data transmission port of the last LED driver chip is in an idle state. In this case, the second data transmission port of the last LED driver chip can be used as a composite function port.

[0066] Example 3

[0067] like Figure 4 As shown, the LED driver chip of the present invention is provided with inter-chip interconnection pins and external pins. The inter-chip interconnection pins are used to realize interconnection communication between LED driver chips. For example, each LED driver chip is provided with a first data transmission port DI and a second data transmission port DO. One of the first data transmission port DI and the second data transmission port DO is used for data input, and the other is used for data output.

[0068] The external pins include LED driver pins, shared pins, and composite function pins. The LED driver pins are used to connect to LED light strings, controlling their brightness by adjusting their current or switching them on and off. The shared pins are used to connect to the high-voltage driver power supply VCC, the chip driver power supply VDD, or a common ground or negative voltage terminal. The composite function pins are used to output status information, including voltage adjustment signals, error signals, interrupt signals, and overvoltage / undervoltage signals.

[0069] In this embodiment, the LED driver chip is provided with one composite function pin, and each composite function pin of each LED driver chip is configured to output only one type of status information. Alternatively, each LED driver chip may be provided with multiple composite function pins. However, since a large number of LED driver chips are required in LED backlight systems, the increase in LED driver chip ports (pins) will increase the manufacturing cost of the LED driver chip. Therefore, the specific composite function pins on the LED driver chip can be adjusted based on cost requirements.

[0070] As described above, 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 above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. However, 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.

Claims

1. An LED driving system, characterized in that: The LED driving system includes: a controller and a plurality of LED driving chips; the controller and the plurality of LED driving chips form a serial communication link, and the controller acts as a host to send command data to the plurality of LED driving chips as slaves; Each of the LED driver chips is provided with at least one first data transmission port and one second data transmission port; Each of the LED driver chips is provided with a plurality of LED driver channel pins, each of which is used to connect one end of one of the plurality of LED light strings to control the light emission of the LED light string, and the other end of the plurality of LED light strings is connected to the LED driver power supply; When the command data sent by the controller is transmitted step by step in the serial communication link, the LED driver chip at each level is allowed to write the status information into the command data and pass it to the LED driver chip at the next level; At least one of the LED driver chips is provided with at least one composite function port, and the composite function port is used to output the status information; the status information includes a voltage adjustment signal, an error signal, an interrupt signal or an overvoltage / undervoltage signal; The LED driver chip in the serial communication link also includes: The composite function port of at least one LED driver chip is connected to the LED driver power supply, and the composite function port transmits voltage adjustment information to the LED driver power supply; as well as; The composite function port of at least one LED driver chip is connected to the controller to transmit error information or terminal information to the controller.

2. The LED driving system according to claim 1, wherein: The serial communication link means that the first data transmission port of each LED driver chip is connected to the second data transmission port of the LED driver chip of the previous level adjacent to the LED driver chip, and the second data transmission port of each LED driver chip is connected to the first data transmission port of the LED driver chip of the next level adjacent to the LED driver chip.

3. The LED driving system according to claim 1, wherein: The serial communication link adopts a unidirectional communication mode or a bidirectional communication mode.

4. The LED driving system according to claim 1, wherein: The LED driver chips in the serial communication link include driver chips with ports having composite functions and driver chips without ports having composite functions. The driver chips with ports having composite functions are set as the first or last LED driver chips in the serial communication link.

5. An LED driving system, characterized in that: The LED driving system includes: a controller and a plurality of LED driving chips; the controller and the plurality of LED driving chips form a serial communication link, and the controller acts as a host to send command data to the plurality of LED driving chips as slaves; Each of the LED driver chips is provided with at least one first data transmission port and one second data transmission port; Each of the LED driver chips is provided with a plurality of LED driver channel pins, and the plurality of LED driver channel pins are respectively used to connect one end of one of the R-LED light string, the G-LED light string and the B-LED light string, or to connect one end of one of the R-LED light string, the G-LED light string, the B-LED light string and the W-LED light string; the other end of the R-LED light string, the G-LED light string, the B-LED light string or the W-LED light string is connected to one of the plurality of LED driver power supplies; When the command data sent by the controller is transmitted step by step in the serial communication link, the LED driver chip at each level is allowed to write the status information into the command data and pass it to the LED driver chip at the next level; At least one of the LED driver chips is provided with at least one composite function port, and the composite function port is used to output the status information; the status information includes a voltage adjustment signal, an error signal, an interrupt signal or an overvoltage / undervoltage signal; The LED driver chip in the serial communication link also includes: The composite function port of at least one LED driver chip is connected to the LED driver power supply, and the composite function port transmits voltage adjustment information to the LED driver power supply; as well as; The composite function port of at least one LED driver chip is connected to the controller to transmit error information or terminal information to the controller.

6. The LED driving system according to claim 5, characterized in that: The serial communication link means that the first data transmission port of each LED driver chip is connected to the second data transmission port of the LED driver chip of the previous level adjacent to the LED driver chip, and the second data transmission port of each LED driver chip is connected to the first data transmission port of the LED driver chip of the next level adjacent to the LED driver chip.

7. The LED driving system according to claim 5, characterized in that: The serial communication link adopts a unidirectional communication mode or a bidirectional communication mode.

8. The LED driving system according to claim 5, wherein: The LED driver chips in the serial communication link include driver chips with ports having composite functions and driver chips without ports having composite functions. The driver chips with ports having composite functions are set as the first or last LED driver chips in the serial communication link.

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