LED driving system and driving method

Abstract

The invention discloses an LED driving system. The LED driving system comprises a controller and a plurality of LED driving chips, the controller and the plurality of LED driving chips form a serial communication link, and each LED driving chip is provided with a first data transmission port D1 and a second data transmission port D2; the LED driving system performs data transmission in a two-way communication mode, a second data transmission port control module is arranged in the LED driving chip, and the second data transmission port control module determines whether a second data transmission port is pulled to a low level state or not according to a driving state information representation signal and a last chip identification signal. The abnormal driving state information on the communication link can be quickly output by using the idle output port on the last driving chip in the serial communication link. Therefore, the defect that the upper computer cannot process the abnormal communication state in time in the prior art is overcome.

Description

Technical Field

[0001] The present invention relates to the technical field of LED backlight, and in particular to an LED driving system and a driving method. Background Art

[0002] With the development of display technology, Mini-LED displays, OLED displays and Micro-LED displays have gradually become the three main directions of display technology development based on traditional LCD displays. However, OLED display technology is limited by material properties, and the pixel ablation problem is still difficult to solve. Micro-LED technology still needs to rely on solving the efficiency of mass transfer technology to enable it to be applied to large-size displays at a lower cost. Therefore, as far as the current situation is concerned, LCD displays using direct-type Mini-LED backlight panels are the best display solutions. The so-called direct-type Mini-LED backlight panel refers to a high-density LED array composed of more delicate Mini LED lamp beads (the size is reduced to less than 100 microns), and the entire backlight panel can be divided into multiple backlight partitions, and the number of each backlight partition can be increased from tens of traditional LEDs to hundreds or even thousands. Therefore, how to drive and control a large number of Mini LED lamp beads so that their luminous brightness can better match the display of the liquid crystal panel has become the core issue in the application of Mini-LED backlight panels.

[0003] like Figure 1 As shown, in the single-wire bus LED driving system in the prior art, the LED driving chip has only one input port Din and one output port Dout. The chips are connected in series through the Din / Dout ports, that is, the output port Dout of the previous chip is connected to the input port Din of the next chip. The host computer HOST inputs a signal to the input port Din of the first chip, and then transmits data to the subsequent chips one by one in a serial manner.

[0004] In the above communication link, the driving status information generated by each LED driver chip, such as error information (FAULT), such as LED driver pin open circuit (LED pin Open), LED driver pin short circuit (LED pin Short), LED driver pin overvoltage / undervoltage, etc., will be transmitted to the host computer Host through the serial communication link, and the host computer will perform system processing on the corresponding LED driver chip according to the received error information. For example, whenever the LED pin is short, the corresponding chip will be turned off, and when the LED pin is undervoltage, the DCDC output will be controlled to increase the voltage, etc.

[0005] However, when there are too many LED driver chips connected in series in the LED driver system, or the communication frequency of the host computer HOST is too slow, the driver status information cannot be responded to and processed in time.

[0006] It can be seen that a new LED driving system and driving method are needed in the prior art to enable the host computer to respond promptly to the abnormal state of the LED driving chip. Summary of the invention

[0007] The technical purpose to be achieved by the present invention is to provide an LED driving system and a driving method. The technical purpose of the present invention is to use the output port of the last LED driving chip to quickly obtain the abnormal driving state appearing on the communication link in a two-way communication mode, and enable the host computer to process it in time.

[0008] Based on the above technical objectives, the present invention provides an LED driving system, the LED driving system comprising:

[0009] Controller and multiple LED driver chips;

[0010] The controller and the plurality of LED driver chips form a serial communication link, and the controller acts as a host to send instruction data to the plurality of LED driver chips as slaves;

[0011] Each of the LED driver chips is provided with a first data transmission port D1 and a second data transmission port D2; the LED driver system adopts a bidirectional communication mode for data transmission. When the LED driver chip is powered on, the first data transmission port D1 is set to a data receiving state, and the second data transmission port D2 is set to a data sending state; when the first data transmission port of the LED driver chip completes the reception of a data frame, it is converted to a data sending state, and when the second data transmission port D2 completes the transmission of a data frame, it is converted to a data receiving state;

[0012] The LED driver chip is provided with a second data transmission port control module, and the second data transmission port control module determines whether to pull the second data transmission port to a low level state according to the driving state information characterization signal and the last chip identification signal.

[0013] In one embodiment, the second data transmission port of the last LED driver chip in the serial communication link is connected to a high-level driving power supply via a resistor.

[0014] In one embodiment, the status information representative signal is the driving status information written by the LED driving chip and contained in the data frame transmitted in the serial communication link.

[0015] In one embodiment, the last chip identification signal is identification information for the LED driver chip to determine whether it is the last driver chip based on the frame header count information included in the data frame and the total number of LED driver chips in the serial communication link.

[0016] In one embodiment, when the status information representation signal is at a high level, it indicates that the data frame contains driving status information indicating that the LED driver chip is in an abnormal state. When the status information representation signal is at a low level, it indicates that the data frame does not contain driving status information indicating that the LED driver chip is in an abnormal state.

[0017] In one embodiment, when the last chip identification signal is at a high level, it indicates that the current LED driver chip is the last LED driver chip, and when the last chip identification signal is at a low level, it indicates that the current LED driver chip is not the last LED driver chip.

[0018] In one embodiment, the second data transmission port control module includes a switch tube and an AND operation unit, and the AND operation unit generates a control signal for controlling the switch tube to turn on according to the input state information characterization signal and the last chip identification signal.

[0019] In one embodiment, each of the LED driver chips has a plurality of LED driver channel pins, and the LED driver channel pins are used to connect an LED light string to directly control the light emission of the LED light string.

[0020] The present invention further provides an LED driving system, the LED driving system comprising:

[0021] A controller and a plurality of LED driver chip serial units, each of which includes an LED driver chip; the controller HOST and each of the LED driver chip serial units 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;

[0022] Each of the LED driver chips is provided with a first data transmission port D1 and a second data transmission port D2; the LED driver system adopts a bidirectional communication mode for data transmission. When the LED driver chip is powered on, the first data transmission port D1 is set to a data receiving state, and the second data transmission port D2 is set to a data sending state; when the first data transmission port of the LED driver chip completes the reception of a data frame, it is converted to a data sending state, and when the second data transmission port D2 completes the transmission of a data frame, it is converted to a data receiving state;

[0023] The LED driver chip is provided with a second data transmission port control module, and the second data transmission port control module determines whether to pull the second data transmission port to a low level state according to the driving state information characterization signal and the last chip identification signal.

[0024] Compared with the prior art, one or more embodiments of the present invention may have the following advantages:

[0025] In the present invention, by utilizing the idle output port on the last driver chip in the serial communication link, the abnormal driving state information on the communication link can be quickly output, thereby solving the defect in the prior art that the host computer cannot process the abnormal communication state in time.

[0026] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] 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:

[0028] Figure 1 It is a schematic diagram of the structure of an LED driving system in the prior art;

[0029] Figure 2 is a schematic structural diagram of an LED driving system according to a first embodiment of the present invention;

[0030] Figure 3 It is a schematic diagram of the data frame structure used by the LED driving system of the present invention;

[0031] Figure 4 is a schematic structural diagram of a second data transmission port control module according to a first embodiment of the present invention;

[0032] Figure 5 Schematic diagram of the structure of the LED driving system according to the second embodiment of the present invention. DETAILED DESCRIPTION

[0033] 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.

[0034] It should be understood that when an element or layer is referred to as "on ...", "adjacent to ...", "connected to" or "coupled to" other elements or layers, it can be directly on, adjacent to, connected to or coupled to other elements or layers, or there can be intervening elements or layers. On the contrary, when an element is referred to as "directly on ...", "directly adjacent to ...", "directly connected to" or "directly coupled to" other elements or layers, there is no intervening element or layer. It should be understood that although the terms first, second, third, etc. can 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 only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present invention, the first element, component, region, layer or part discussed below can be represented as the second element, component, region, layer or part. And when the second element, component, region, layer or part is discussed, it does not indicate that the present invention necessarily has the first element, component, region, layer or part.

[0035] Spatially relative terms such as "under", "beneath", "below", "under", "above", "above", etc., may be used here for convenience of description to describe the relationship between an element or feature shown in the figure and other elements or features. It should be understood that in addition to the orientation shown in the figure, the spatial relationship terms are intended to also include different orientations of the device in use and operation. For example, if the device in the accompanying drawings is turned over, then the elements or features described as "under other elements" or "under it" or "under it" will be oriented as "on" other elements or features. Therefore, the exemplary terms "under" and "under" may include both upper and lower orientations. The device can be oriented otherwise (rotated 90 degrees or other orientations) and the spatial descriptors used herein are interpreted accordingly.

[0036] The purpose of the terms used herein is only to describe specific embodiments and is not intended to be limiting of the present invention. When used herein, the singular forms "one", "an" and "said / the" are also intended to include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "consisting of" 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.

[0037] Example 1

[0038] like Figure 2The LED driving system of the present invention shown in the figure comprises: a controller HOST and a plurality of LED driving chips Chip1 to Chip4; the controller HOST and the plurality of LED driving chips Chip1 to Chip4 form a serial communication link, and the controller acts as a host to send instruction data to the plurality of LED driving chips Chip1 to Chip4 acting as slaves.

[0039] Each of the LED driving chips has a plurality of LED driving channel pins LED1 to LED4, and the LED driving channel pins are used to connect an LED light string to directly control the light emission of the LED light string.

[0040] Each LED driver chip is provided with a first data transmission port D1 and a second data transmission port D2. The serial communication link means that the first data transmission port D1 of each LED driver chip is connected to the second data transmission port D2 of the LED driver chip of the previous level adjacent to the LED driver chip, and the second data transmission port D2 of each LED driver chip is connected to the first data transmission port D1 of the LED driver chip of the next level adjacent to the LED driver chip, and the first LED driver chip in the serial communication link is connected to the transmission port TX / RX of the controller HOST.

[0041] In this example, the LED driving system adopts a two-way communication mode for data transmission, that is, when the LED driving chip is powered on, the first data transmission port D1 is set to a data receiving state, and the second data transmission port D2 is set to a data sending state. When the first data transmission port of the LED driving chip completes the reception of a data frame, it is converted to a data sending state, and when the second data transmission port D2 completes the transmission of a data frame, it is converted to a data receiving state.

[0042] In the present invention, the structure of the data frame is as follows: Figure 3 As shown, the data frame includes a frame header bit (Start_Bits), a control command bit (Command), a register address bit (Reg_Addr), an echo data bit (Echo), a data packet length bit (Data_Len), and a backlight brightness data bit (DATA). The order of the control command bit (Command), the register address bit (Reg_Addr), the echo data bit (Echo), and the data packet length bit (Data_Len) can be switched at will.

[0043] The data frame header bit (Start_Bits) is used to identify the physical sequence position of the driver chip that currently receives the data frame on the serial communication link. The data format of the initial data frame header bit (Start_Bits) sent by the controller HOST is in the form of "Bit S+Bit 1". When each LED driver chip receives the data frame header bit, it will automatically add a data bit to the header bit, and the header bit will become "Bit S+Bit 0+Bit 1". The "Bit 0" represents that the physical sequence position of the driver chip Chip1 on the serial communication link is the first. Correspondingly, when the driver chip Chip1 identifies its own sequence position through the header bit, it collects the first brightness data packet in the subsequent backlight brightness data bit as the backlight brightness data that needs to be driven and displayed by itself.

[0044] Similarly, the frame header bit received by the first input end of the driver chip Chip2 is "Bit S+Bit 0+Bit 1", and the driver chip Chip2 adds a data bit to it, changing the frame header bit to "Bit S+Bit 0+Bit 0+Bit 1". The two "Bit 0"s represent that the physical sequence position of the driver chip Chip2 on the serial communication link is the second. Correspondingly, when the driver chip Chip2 identifies its own sequence position through the frame header bit, it collects the second brightness data packet in the subsequent backlight brightness data bit as the backlight brightness data that it needs to drive and display. And so on until all n driver chips correspondingly obtain the brightness data packet in the backlight brightness data bit as the backlight brightness data that it needs to drive and display.

[0045] The data in the brightness data packet is the voltage and current information for driving the LED light string when DC dimming is used, and is the pulse modulation frequency information for driving the LED switch, such as the PWM duty cycle, when PWM dimming is used.

[0046] At the same time, the data frame also includes information recording the number of LED driver chips in the entire serial communication link. For example, this information can be set in the control command bit.

[0047] In this embodiment, the data frame also transmits the driving status information written by each LED driver chip to the data frame, such as LED driver pin open (LED pin Open), LED driver pin short circuit (LED pin Short), LED driver pin overvoltage / undervoltage information, etc. The driving status information is written into the control command bit by the LED driver chip, that is, when the LED driver chip has an LED abnormal state included in the above driving status information, the corresponding driving status information is actively written to the data frame, and the driving status information already written by other previous LED driver chips in the data frame is overwritten. If the LED driver chip does not have an LED abnormal state included in the above driving status information, no driving status information is written to the data frame.

[0048] According to the above serial communication link, the second data transmission port D2 of the last LED driver chip in this embodiment is in an idle state. And because the data transmission is carried out in a two-way communication mode in this embodiment, that is, after the data frame is transmitted to the last LED driver chip, the driving state information contained in the data frame needs to be inverted and then transmitted to the controller HOST through the two-way communication mode. If there are a large number of LED driver chips in the serial communication link, or the data processing frequency of the controller HOST is low, or the controller HOST cannot provide enough time window to receive reverse transmission data due to the frequency requirement of data transmission, the driving state information in the data frame cannot be obtained by the controller in time and processed accordingly.

[0049] Therefore, in this embodiment, Figure 4 As shown, the LED driver chip is provided with a second data transmission port control module, and the second data transmission port control module includes a switch tube, namely an AND gate, and the gate control end of the switch tube is connected to the output end of the AND gate. One input end of the AND gate inputs a drive status information characterization signal, which is a high level signal if there is drive status information in the data frame, otherwise it is a low level signal. The other input end is a signal for identifying that the current LED driver chip is the last chip, which is a high level 1 if the current LED driver chip is the last chip, and a low level 0 if not. The source and drain of the switch tube, one of which is grounded, and the other is connected to the second data transmission port inside the LED driver chip. Therefore, when the LED driver chip is simultaneously satisfied with judging itself as the last LED driver chip, and there is drive status information in the data frame, the second data transmission port of the last LED driver chip will be pulled to a low level. When the second data transmission port of the last LED driver chip is externally connected to a high level V CC When the second data transmission port is pulled down to a low level state, it will be detected immediately. Thus, the controller HOST can quickly obtain the driving state information in the data frame.

[0050] In this embodiment, since the two data transmission ports are pulled down to a low level to express only one type of driving state information, the last LED driver chip is required to filter and process the driving state information in the data frame. For example, only the undervoltage state information in the data frame is processed. When the undervoltage state information is written into the data frame, the driving state information characterization signal input to the second data transmission port control module is a high level signal.

[0051] Example 2

[0052] like Figure 5 The LED driving system of the present embodiment shown in the figure comprises: a controller HOST and a plurality of LED driving chip serial units, each of which comprises LED driving chips Chip1 to Chip4; the controller HOST and each of the LED driving chip serial units form a serial communication link, and the controller acts as a host to send command data to the plurality of LED driving chips Chip1 to Chip4 acting as slaves.

[0053] Each of the LED driving chips has a plurality of LED driving channel pins LED1 to LED4, and the LED driving channel pins are used to connect an LED light string to directly control the light emission of the LED light string.

[0054] Each LED driver chip is provided with a first data transmission port D1 and a second data transmission port D2. The serial communication link means that the first data transmission port D1 of each LED driver chip is connected to the second data transmission port D2 of the LED driver chip of the previous level adjacent to the LED driver chip, the second data transmission port D2 of each LED driver chip is connected to the first data transmission port D1 of the LED driver chip of the next level adjacent to the LED driver chip, and the first LED driver chip in the LED driver chip serial unit is connected to the transmission port TX / RX of the controller HOST.

[0055] Similarly, in this example, the LED driving system adopts a two-way communication mode for data transmission, that is, when the LED driving chip is powered on, the first data transmission port D1 is set to a data receiving state, and the second data transmission port D2 is set to a data sending state. When the first data transmission port of the LED driving chip completes the reception of a data frame, it is converted to a data sending state, and when the second data transmission port D2 completes the transmission of a data frame, it is converted to a data receiving state.

[0056] The data frame format used in this embodiment and the second data transmission port control module provided in the LED driver chip are consistent with those in the aforementioned embodiment 1.

[0057] The present invention may be a system, method and / or computer program product at any possible level of integrated technical detail. The computer program product may include a computer-readable storage medium (or multiple media) having computer-readable program instructions thereon for causing a processor to perform various aspects of the present invention.

[0058] A computer readable storage medium may be a tangible device that can retain and store instructions used by an instruction execution device. The computer readable storage medium may be, for example, but not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of computer readable storage media includes the following: a portable computer floppy disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a portable compact disk read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanical encoding device such as a punch card or a raised structure in a groove on which instructions are recorded, and any suitable combination of the above. A computer readable storage medium, as used herein, should not be interpreted as a transient signal itself, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagating through a waveguide or other transmission medium (e.g., a light pulse through a fiber optic cable), or an electrical signal transmitted by a wire.

[0059] The computer-readable program instructions described herein may be downloaded from a computer-readable storage medium to a corresponding computing / processing device, or downloaded to an external computer or external storage device via a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network may include copper transmission cables, optical transmission fibers, wireless transmissions, routers, firewalls, switches, gateway computers, and / or edge servers. The network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions to be stored in a computer-readable storage medium within the corresponding computing / processing device.

[0060] The computer-readable program instructions for performing the operation of the present invention may be assembler instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, configuration data for integrated circuits, or source code or object code written in any combination of one or more programming languages ​​and process programming languages. The computer-readable program instructions may be executed entirely on the user's computer, partially on the user's computer, as an independent software package, partially on the user's computer, partially on a remote computer, or entirely on a remote computer or server. In the latter case, the remote computer may be connected to the user's computer by any type of network including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., by using the Internet of an Internet service provider). In certain embodiments, the electronic circuit including, for example, a programmable logic circuit, a field programmable gate array (FPGA) or a programmable logic array (PLA) may execute the computer-readable program instructions by utilizing the state information of the computer-readable program instructions to personalize the electronic circuit, thereby performing aspects of the present invention.

[0061] Various aspects of the present invention are described herein with reference to flowcharts and / or block diagrams of methods, devices (systems) and computer program products according to embodiments of the present invention. It is understood that each block of the flowchart illustration and / or block diagram, and the combination of blocks in the flowchart illustration and / or block diagram, can be implemented by computer-readable program instructions.

[0062] These computer-readable program instructions may be provided to a processor of a computer or other programmable data processing device to produce a machine so that the instructions executed by the processor of the computer or other programmable data processing device create instructions for implementing the flowcharts and / or block diagrams. Figure 1 These computer-readable program instructions may also be stored in a computer-readable storage medium capable of booting a computer, a programmable data processing device and / or other device that operates in a specific manner, so that the computer-readable storage medium having the instructions stored therein includes a manufactured product that includes instructions that implement aspects of the functions / actions specified in the flowchart and / or block diagram blocks.

[0063] Computer readable program instructions may also be loaded into a computer, other programmable data processing device, or other device to cause a series of operating steps to be performed on the computer, other programmable devices or other devices for producing a computer-implemented process, so that the instructions executed on the computer, other programmable device or other device implement the functions / actions specified in the flowchart and / or block diagram blocks.

[0064] The flowcharts and block diagrams in the accompanying drawings illustrate the possible implementation architecture, functions and operations of the system, method and computer program product according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagram may represent a module, segment or portion of an instruction, which includes one or more executable instructions for implementing a specified logical function. In some optional implementations, the functions indicated in the block may occur outside the order indicated in the figure. For example, in fact, two blocks shown in succession can be completed as a step, and depending on the functions involved, they can be executed concurrently, substantially concurrently, in a partially or fully time-overlapping manner, or sometimes these blocks can be executed in reverse order. It will also be noted that each block of the block diagram and / or flowchart illustration, as well as the combination of blocks in the block diagram and / or flowchart illustration, can be implemented by a dedicated hardware-based system that performs a specified function or action or performs a combination of dedicated hardware and computer instructions.

[0065] The embodiments of the present application are described with reference to the flowcharts and / or block diagrams of the methods, apparatuses (devices) and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0066] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0067] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

Claims

1. An LED driving system, comprising: Controller and multiple 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 instruction data to the plurality of LED driver chips as slaves; characterized in that: Each of the LED driver chips is provided with a first data transmission port D1 and a second data transmission port D2; the LED driver system adopts a bidirectional communication mode for data transmission. When the LED driver chip is powered on, the first data transmission port D1 is set to a data receiving state, and the second data transmission port D2 is set to a data sending state; when the first data transmission port of the LED driver chip completes the reception of a data frame, it is converted to a data sending state, and when the second data transmission port D2 completes the transmission of a data frame, it is converted to a data receiving state; The LED driver chip is provided with a second data transmission port control module, and the second data transmission port control module determines whether to pull the second data transmission port to a low level state according to the driving state information characterization signal and the last chip identification signal.

2. The LED driving system according to claim 1, characterized in that: The second data transmission port of the last LED driving chip in the serial communication link is connected to a high-level driving power supply via a resistor.

3. The LED driving system according to claim 1, characterized in that: The state information characterizing signal is the driving state information written by the LED driving chip and contained in the data frame transmitted in the serial communication link.

4. The LED driving system according to claim 1, characterized in that: The last chip identification signal is identification information for the LED driver chip to determine whether it is the last driver chip based on the frame header count information contained in the data frame and the total number of LED driver chips in the serial communication link.

5. The LED driving system according to claim 1, characterized in that: The second data transmission port control module includes a switch tube and an AND operation unit, and the AND operation unit generates a control signal for controlling the switch tube to be turned on according to the input state information characterization signal and the last chip identification signal.

6. The LED driving system according to claim 1, characterized in that: Each of the LED driver chips has a plurality of LED driver channel pins, and the LED driver channel pins are used to connect an LED light string to directly control the light emission of the LED light string.

7. The LED driving system according to claim 3, characterized in that: The driving state information includes an open circuit state of an LED driving pin, a short circuit state of an LED driving pin, or an overvoltage / undervoltage state of an LED driving pin.

8. An LED driving system, characterized in that: The LED driving system comprises: A controller and a plurality of LED driver chip serial units, each of which includes an LED driver chip; the controller HOST and each of the LED driver chip serial units 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; Each of the LED driver chips is provided with a first data transmission port D1 and a second data transmission port D2; the LED driver system adopts a bidirectional communication mode for data transmission. When the LED driver chip is powered on, the first data transmission port D1 is set to a data receiving state, and the second data transmission port D2 is set to a data sending state; when the first data transmission port of the LED driver chip completes the reception of a data frame, it is converted to a data sending state, and when the second data transmission port D2 completes the transmission of a data frame, it is converted to a data receiving state; The LED driver chip is provided with a second data transmission port control module, and the second data transmission port control module determines whether to pull the second data transmission port to a low level state according to the driving state information characterization signal and the last chip identification signal.

9. An LED backlight panel, comprising a plurality of LED driving units and a plurality of LED light groups, wherein the LED driving unit is formed by the LED driving system according to any one of claims 1 to 8.

10. An LED display device, comprising the backlight panel according to claim 9.

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