LED drive system

Abstract

We provide LED driving systems. [Solution] The LED driving system 700A includes an LED driver chain 714A-1~K, a controller 706A, and bridge circuits 710A~K. Each LED driver drives a set of LEDs 716A-1~K and communicates with other LED drivers in the LED driver chain through a first communication protocol. The controller controls the LED drivers to drive multiple sets of LEDs and supports a second communication protocol. The bridge circuit receives status information of multiple sets of LEDs from the LED driver chain, generates feedback signals to control the power supplied to the LEDs based on the status information, and includes a first communication interface coupled to the LED driver chain to support the first communication protocol and a second communication interface coupled to the controller to support the second protocol.

Description

[Technical Field]

[0001] Related applications This application claims priority to the U.S. Provisional Application No. 63 / 730,419 filed on 10 December 2024 and claims interest under Section 119(a) of Title 35 of the United States Code (U.S. Patent Act) of Application No. 202511152259.2 filed on 18 August 2025 with the National Intellectual Property Administration of the People's Republic of China, and those applications are incorporated herein by reference in their entirety. [Background technology]

[0002] Figure 1A shows a block diagram of a conventional LED driver system 100A for driving mini light-emitting diodes (LEDs) 116 in a backlight panel 112A. The LED driver system 100A includes a DC / DC converter 102, an MCU (microcontroller unit) 106A, and a backlight panel 112A. The MCU 106A controls the DC / DC converter 102 to power the backlight panel 112A. The backlight panel 112A includes multiple sets of mini LEDs 116 and multiple chains of LED drivers 114A that drive the mini LEDs 116. In Figure 1A, each LED driver is labeled "AMIC" to represent an active matrix integrated circuit. The MCU 106A is a typical MCU that supports the SPI (serial peripheral interface) protocol. The LED driver 114A also supports the SPI protocol so that it can communicate with the MCU 106A. The MCU 106A sends commands and parameters to the LED driver 114A via the SPI interface. The LED driver 114A sends feedback data to the MCU 106A via the SPI interface so that the MCU 106A controls the output power VLED of the DC / DC converter 102 based on the feedback data.

[0003] However, due to the use of the SPI interface, the LED driver 114A occupies a relatively large amount of PCB (printed circuit board) area. More specifically, a standard SPI interface includes at least three pins—a clock pin SCLK, a data input pin SDI, and a data output pin SDO. Figure 2 is a block diagram of a chain of LED drivers 114A that support the SPI protocol. As shown in Figure 2, the LED drivers 114A are connected in a daisy-chain arrangement and communicate with each other using the SPI protocol. Thus, the SPI interface of each LED driver includes four pins—a clock input pin SCLKI, a clock output pin SCLKO, a data input pin SDI, and a data output pin SDO. The LEDs 116 in the backlight panel 112A require multiple LED drivers for operation, and each LED driver includes at least four pins for communication. The large number of pins and associated wiring increase the size of the PCB and the cost of the system, complicating the PCB layout.

[0004] In addition, as shown in Figure 1A, the MCU 106A includes a feedback module 108 (e.g., a digital-to-analog converter (DAC)) that converts feedback data received from the LED driver 114A into an analog feedback signal 104 for controlling the output power VLED of the DC / DC converter 102. The feedback module 108 (e.g., a DAC) may increase the cost of the MCU 106A.

[0005] Furthermore, in some situations, the MCU 106A and LED driver 114A may be located far apart, for example, on different PCBs. In these situations, a driver buffer 110 supporting the SPI protocol is placed / inserted between the MCU 106A and the LED driver 114A. The buffer 110 may further increase the size of the PCB and the cost of the system. Since the buffer 110 only provides basic buffering functionality, including the buffer 110 in the LED driver system 100A may not be cost-effective.

[0006] Figure 1B shows a block diagram of another conventional LED driver system 100B. In LED driver system 100B, the LED drivers in each chain of LED driver 114B communicate with each other using the 1-Wire protocol. The 1-Wire interface of each LED driver includes two pins—signal input pin SDI and signal output pin SDO—two fewer pins than the SPI interface. Therefore, LED driver 114B may occupy a smaller PCB area and cost less compared to LED driver 114A described above. An encode / decode software module 118 is installed on the MCU 106B. The encode / decode software module 118 is configured to convert SPI data to 1-Wire data so that the MCU 106B can communicate with LED driver 114B. However, the encode / decode software module 118 may increase the cost of the MCU 106B. Furthermore, the data conversion process occupies extra time and resources of the MCU 106B, which can increase the power consumption of the MCU 106B and reduce its operational efficiency.

[0007] Furthermore, in the LED driving system 100B, the backlight panel 112B transmits a feedback signal 120 to control the output power VLED of the DC / DC converter 102. Therefore, the aforementioned feedback module 108 (e.g., DAC) in the MCU 106A in Figure 1A can be omitted in the MCU 106B. However, in Figure 1B, the feedback signal 120 is generated by generating adjustment signals (e.g., analog signals) using each of the LED drivers 114B, and by collecting and combining multiple adjustment signals (e.g., analog signals) from multiple chains of LED drivers 114B using the feedback circuit 122.

[0008] More specifically, Figure 3 shows a partial block diagram of the LED driving system 100B. As shown in Figure 3, each LED driver monitors the status of a set of LEDs. For example, LED driver 114-1 monitors the status of LED 116-1, and LED driver 114-2 monitors the status of LED 116-2. Each LED driver includes an input terminal ADJFIN and an output terminal ADJFO. In the chain of LED drivers 114B, the first LED driver may output a first adjustment signal (e.g., an analog signal) at its ADJFO pin indicating the first status of a first set of LEDs driven by the first LED driver. A second LED driver coupled adjacent to the first LED driver may receive the first adjustment signal at its ADJFIN pin, generate a second adjustment signal indicating the first status and the second status of a second set of LEDs driven by the second LED driver, and output the second adjustment signal at its ADJFO pin. Similarly, a third LED driver coupled adjacent to a second LED driver may output a third adjustment signal at its ADJFO pin indicating a first status, a second status, and a third status for a third set of LEDs driven by the third LED driver (in this context, “adjacent coupled” is used to mean that there is no intervening LED driver between adjacent coupled LED drivers, but there may or may not be any other kind of hardware between any two adjacent coupled LED drivers). As a result, an LED driver at the end of the chain of LED driver 114B (e.g., 114-1) may output an adjustment signal from its ADJFO pin to the feedback circuit 122 indicating the status of multiple sets of LEDs driven by the chain of LED driver 114B.

[0009] Similarly, in Figure 1B, each chain of the multiple LED driver 114B can provide its respective adjustment signal to the feedback circuit 122. As a result, the feedback circuit 122 can control the output power VLED of the DC / DC converter 102 based on the status of the LEDs in the backlight panel 112B. However, the numerous ADJFIN and ADJFO pins and associated wiring increase the size and cost of the PCB and complicate the PCB layout.

[0010] Figure 4 shows a block diagram of another conventional LED driver system 400. The LED driver system 400 includes a DC / DC converter 402, a chain of LED drivers 414-1 to 414-N (where N is a natural number), and an MCU 406. The DC / DC converter 402 provides an output voltage VLED for powering multiple sets of LED strings 416-1 to 416-N. Each LED driver 414-1, 414-2, ..., or 414-N drives each set of LED strings S1 to SM (where M is a natural number) and senses its status. The MCU 406 controls the output voltage VLED of the DC / DC converter 402 based on the status of the LED strings 416-1 to 416-N.

[0011] More specifically, each of the LED drivers 414-1 to 414-N includes sense terminals ISEN1 to ISENM coupled to its respective LED string S1 to SM. The LED drivers 414-1 to 414-N can sense the voltage of terminals ISEN1 to ISENM and determine whether to raise or lower the output voltage VLED. For example, if one or more of the voltages of terminals ISEN1 to ISENM are below a reference voltage VREF, the LED drivers 414-1 to 414-N can notify the MCU 406 to raise the output voltage VLED. As a result, the output voltage VLED may be set to a voltage level such that the voltages of terminals ISEN1 to ISENM of all LED drivers 414-1 to 414-N are equal to or greater than the reference voltage VREF. However, in some practical situations, the LED strings S1 to SM may have different forward voltages, for example, because they contain different types of LEDs. If the difference in forward voltage between LED strings S1 to SM is relatively large, this difference can result in wasted power in LED drivers 414-1 to 414-N, potentially leading to thermal issues.

[0012] For example, Figure 5 shows a partial circuit diagram of the LED driving system 400. As shown in Figure 5, the LED driver 414-1 drives each of the LED strings S1 to SM by sinking the respective LED current. In order to set the LED current flowing through the LED strings S1 to SM to a predetermined level, the voltage V across the sense terminals ISEN1 to ISENM is set. ISEN1 ~V ISENM It is required that the voltage is above the voltage threshold. Taking Figure 5 as an example, in order to set the LED current flowing through the LED string S1~SM to 100mA, the voltage V ISEN1 ~V ISENM The voltage is required to be 0.25V or higher. The LED driver 414-1 sets the reference voltage VREF to a voltage level slightly higher than the threshold voltage of 0.25V (for example, 0.3V), and the voltage V ISEN1 ~V ISENMThe output voltage VLED of the DC / DC converter 402 can be controlled (for example, raised or lowered) to 30V so that the reference voltage is 0.3V or higher.

[0013] As shown in Figure 5, a 100mA LED current results in, for example, a forward voltage of 29.7V for LED string S1 and a forward voltage of 28V for LED string S2. As a result, the voltage at sense terminal ISEN2 is V ISEN2 The voltage is 2V, which is significantly higher than the reference voltage of 0.3V. ISEN2 This voltage is applied across the internal transistor Q2 and sense resistor Rs, resulting in relatively high power consumption (including wasted power) and potentially generating a considerable amount of heat in the internal transistor Q2. A backlight panel (e.g., 112A or 112B) may contain multiple sets of LED strings driven by a corresponding number of LED drivers. Therefore, differences in the forward voltage of the LED strings within the backlight panel can result in significant power loss in the LED drivers 414-1 to 414-N, which can lead to thermal problems.

[0014] Figure 6 illustrates a conventional process in which the MCU 606 sends commands via the driver buffer 610 to a chain of LED drivers labeled, for example, "AMIC-1" to "AMIC-N" in Figure 6, and reads data from that chain. The MCU 606 can be the same as or similar to the MCU 106A, 106B, or 406 described above. The chain of LED drivers AMIC-1 to AMIC-N can be the same as or similar to the chain of LED drivers 114A, 114B, or 414-1 to 414-N described above. The buffer 610 can be the same as or similar to the buffer 110 described above.

[0015] As shown in Figure 6, MCU 606 sends command 624 to buffer 610. Buffer 610 forwards command 624 to LED drivers AMIC-1 to AMIC-N. For example, command 624 labeled "STAT AND Tj READ" is configured to instruct LED drivers AMIC-1 to AMIC-N to send information about the status of the LEDs driven by the LED drivers and information about the junction temperature of the LED drivers to MCU 606. In response to receiving the command "STAT AND Tj READ", LED driver AMIC-1 generates a data packet 626 containing information about the status of the LEDs driven by LED driver AMIC-1 and information about the junction temperature in LED driver AMIC-1. LED driver AMIC-1 sends the command "STAT AND Tj READ" and data packet 626 to the next LED driver AMIC-2. LED driver AMIC-2, in response to receiving the command "STAT AND Tj READ", generates data packet 628 containing information about the status of the LEDs driven by LED drivers AMIC-1 and AMIC-2, and information about the junction temperatures in LED drivers AMIC-1 and AMIC-2. LED driver AMIC-2 sends the command "STAT AND Tj READ" and data packet 628 to the next LED driver AMIC-3. Similarly, LED driver AMIC-N, in response to receiving the command "STAT AND Tj READ", generates data packet 630 containing information about the status of the LEDs driven by LED drivers AMIC-1 to AMIC-N, and information about the junction temperatures in LED drivers AMIC-1 to AMIC-N. LED driver AMIC-N sends data packet 630 to buffer 610. Buffer 610 forwards data packet 630 to MCU 606.Therefore, after the MCU 606 sends the command "STAT AND Tj READ" to the buffer 610, the MCU 606 has to wait for a relatively long time to receive a response from the buffer 610, for example, a data packet 630. This long waiting period may reduce the operation efficiency of the MCU 606. Summary of the Invention Problems to be Solved by the Invention

[0016] Therefore, a solution to address the problems considered with respect to FIGS. 1A - 6 is beneficial. Means for Solving the Problems

[0017] Embodiments of the present invention provide a solution to the above problems.

[0018] In an embodiment, an LED driving system includes a chain of LED drivers, a controller, and a bridge circuit. Each LED driver drives a set of LEDs and communicates with other LED drivers in the chain of LED drivers by a first communication protocol. The controller controls the LED drivers to drive a plurality of sets of LEDs. The controller supports a second communication protocol. The bridge circuit receives status information indicating the status of a plurality of sets of LEDs from the chain of LED drivers, and generates a feedback signal for controlling the power provided to the plurality of sets of LEDs based on the status information. The bridge circuit is coupled to the chain of LED drivers and includes a first communication interface configured to support the first communication protocol, and is coupled to the controller and includes a second communication interface configured to support the second communication protocol. The bridge circuit enables communication between the LED drivers and the controller through the first communication interface and the second communication interface.

[0019] In another embodiment, the LED driving system includes a device and a chain of LED drivers. The device controls a plurality of power converters, including a first power converter and a second power converter. The first power converter provides first power to a first group of LED strings. The second power converter provides second power to a second group of LED strings. Each LED driver in the chain of LED drivers drives a first LED string in the first group of LED strings and a second LED string in the second group of LED strings, and is configured to transmit first information regarding the status of the first LED strings and second information regarding the status of the second LED strings to the device via a communication link including the chain of LED drivers. The device controls first power based on the first information and second power based on the second information.

[0020] In yet another embodiment, the LED driving system includes a chain of LED drivers and a device. Each LED driver in the chain is configured to drive each set of LEDs. The chain of LED drivers includes a first LED driver, a second LED driver, and a third LED driver. The second LED driver receives a first packet of command and data from the first LED driver. In response to receiving the command, the second LED driver generates a first packet of data and a second packet of data based on the status of the second LED driver. The second LED driver also transmits the second packet of command and data to the third LED driver. LED drivers at the ends of the chain of LED drivers, in response to receiving the command, generate a combined packet of data based on the respective status of each LED driver. In a first period, the device stores the previous packet of data received from the chain of LED drivers. In a second period following the first period, the device receives a command from the controller. In response to receiving the command, the device transmits the previous packet of data to the controller. During the second period, the device further forwards commands to the LED driver chain, receives data-combined packets from the LED driver chain, and stores the data-combined packets.

[0021] The features and advantages of the claimed embodiments will become apparent as the following detailed description progresses and by referring to the drawings, where similar numbers indicate similar parts. [Brief explanation of the drawing]

[0022] [Figure 1A] This is a block diagram of a conventional LED driving system. [Figure 1B] This is a block diagram of a conventional LED driving system. [Figure 2] This is a block diagram of the LED driver chain in a conventional LED driving system. [Figure 3]This is a block diagram of a portion of a conventional LED driving system. [Figure 4] This is a block diagram of a conventional LED driving system. [Figure 5] This is a partial circuit diagram of a conventional LED driving system. [Figure 6] This diagram illustrates the conventional process where the MCU sends commands to the LED driver chain and reads data from that chain. [Figure 7A] This is a block diagram of an example of an LED driving system according to an embodiment of the present invention. [Figure 7B] This is a block diagram of an example of an LED driving system according to an embodiment of the present invention. [Figure 7C] This is a block diagram of an example of an LED driving system according to an embodiment of the present invention. [Figure 7D] This is a block diagram of an example of an LED driving system according to an embodiment of the present invention. [Figure 8A] This figure shows a subset of pins / terminals in an example of a bridge circuit in an embodiment of the present invention. [Figure 8B] This figure shows a subset of pins / terminals in an example of a bridge circuit in an embodiment of the present invention. [Figure 9A] This is a partial circuit diagram of an example of a bridge circuit in an embodiment of the present invention. [Figure 9B] This is a partial circuit diagram of an example of a bridge circuit in an embodiment of the present invention. [Figure 10] This is a flowchart illustrating an example of a method for driving multiple sets of LEDs according to an embodiment of the present invention. [Figure 11] This is a block diagram of an example of an LED driving system according to an embodiment of the present invention. [Figure 12] This is a partial circuit diagram of an example of an LED driving system according to an embodiment of the present invention. [Figure 13] This is a flowchart illustrating an example of a method for supplying power to multiple sets of LED strings according to an embodiment of the present invention. [Figure 14]This is a block diagram of an example of an LED driving system according to an embodiment of the present invention. [Figure 15] This diagram shows the process in which a controller sends a command to a chain of LED drivers and reads data from that chain, according to an embodiment of the present invention. [Figure 16] This is a flowchart illustrating an example of a method for transmitting data from an LED driver chain to a controller in an embodiment of the present invention. [Figure 17A] This is a block diagram of an example of an LED driving system according to an embodiment of the present invention. [Figure 17B] This is a block diagram of an example of an LED driving system according to an embodiment of the present invention. [Modes for carrying out the invention]

[0023] Next, references to embodiments of the present invention will be made in detail. While the present invention will be described in relation to these embodiments, it will be understood that these embodiments are not intended to limit the present invention to them. Rather, the present invention is intended to encompass modifications, alterations, and equivalents that may be included within the spirit and scope of the invention as defined by the appended claims.

[0024] Furthermore, in the following detailed description of the present invention, many specific details are described to provide a complete understanding of the invention. However, it will be understood by those skilled in the art that the invention may be carried out without these specific details. In other cases, well-known methods, procedures, components, and circuits are not described in detail so as not to unnecessarily obscure aspects of the invention.

[0025] Embodiments of the present invention provide an LED driving system. The LED driving system includes a plurality of LED drivers configured to drive a plurality of sets of LEDs, a controller configured to command and control the LED drivers, and a bridge circuit configured to enable communication between the controller and the LED drivers and to control the power supplied to the LEDs. In some embodiments of the present invention, the problems discussed with respect to Figures 1A to 6 can be solved by using the bridge circuit.

[0026] Figure 7A shows a block diagram of an example of an LED driver system 700A that can operate to drive a plurality of sets of LEDs 716A-1 to 716A-K (where K is a natural number) in an embodiment of the present invention. The plurality of sets of LEDs 716A-1 to 716A-K can be used in a variety of ways, including but not limited to within a backlight panel 712A. The plurality of sets of LEDs 716A-1 to 716A-K may be referred to as LED sets 716A-1 to 716A-K. As shown in Figure 7A, the LED driver system 700A includes a plurality of LED driver chains 714A-1 to 714A-K, a controller 706A, and a bridge circuit. The bridge circuit includes a chain of bridge circuits 710A-1 to 710A-K coupled between the LED driver chains 714A-1 to 714A-K and the controller 706A. In some embodiments, the backlight panel 712A is used in an active matrix display panel. In these embodiments, LEDs 716A-1 to 716A-K include “mini-LEDs,” and each LED driver in the backlight panel 712A may be referred to as an active-matrix integrated circuit (AMIC).

[0027] LED driver chains 714A-1 to 714A-K can drive LED sets 716A-1 to 716A-K, respectively. More specifically, each LED set 716A-1, 716A-2, ..., or 716A-K contains multiple subsets of LEDs. Each LED driver chain 714A-1, 714A-2, ..., or 714A-K contains a chain of LED drivers (or multiple LED drivers connected in sequence). Each LED driver in the chain of LED drivers can drive each subset of LEDs in the corresponding LED set. For example, LED driver chain 714A-1 can drive LED set 716A-1. LED set 716A-1 may contain multiple subsets of LEDs that are the same as or similar to the multiple subsets of LEDs S1 to SM shown in Figure 4 or Figure 11, for example. Each LED driver in LED driver chain 714A-1 can drive each subset of LEDs.

[0028] The bridge circuits 710A-1 to 710A-K enable communication between the controller 706A and the LED driver chains 714A-1 to 714A-K so that the controller 706A can send commands and parameters to the LED driver chains 714A-1 to 714A-K and read feedback data from the LED driver chains 714A-1 to 714A-K. The controller 706A can control the LED driver chains 714A-1 to 714A-K to drive the LED sets 716A-1 to 716A-K. The bridge circuits 710A-1 to 710A-K can also use feedback signals 704A (or more feedback signals) to control the power converter 702A (or more power converters) for supplying power to the LED sets 716A-1 to 716A-K. In embodiments, the power converter 702A includes a DC / DC (direct current to direct current) converter. In another embodiment, the power converter 702A may include an AC / DC (alternating current-to-direct current) converter.

[0029] More specifically, each LED driver in the LED driver chain 714A-1, 714A-2, ..., or 714A-K communicates with other LED drivers in the LED driver chain via a first communication protocol, such as the 1-Wire protocol. The controller 706A supports a second communication protocol, such as the SPI (Serial Peripheral Interface) protocol. Each bridge circuit 710A-1, 710A-2, ..., or 710A-K includes a first communication interface (collectively labeled "732A") coupled to its respective LED driver chain 714A-1, 714A-2, ..., or 714A-K and configured to support the first communication protocol, and a second communication interface (collectively labeled "734A") coupled to the controller 706A and configured to support the second communication protocol. Each bridge circuit 710A-1, 710A-2, ..., or 710A-K can enable communication between its respective LED driver chain 714A-1, 714A-2, ..., or 714A-K and the controller 706A through its first communication interface 732A and second communication interface 734A. The SPI protocol may include the standard SPI protocol, dual SPI protocol, quad SPI protocol, octal SPI protocol, etc.

[0030] In addition, the bridge circuit chain 710A-1 to 710A-K can receive status information from the LED driver chain 714A-1 to 714A-K indicating the status of the LED sets 716A-1 to 716A-K, and can generate a feedback signal 704A for controlling the power supplied to the LED sets 716A-1 to 716A-K (including, for example, the supply voltage VLED) based on the status information. In some embodiments, the status of an LED set includes whether the LED set is receiving sufficient power. The status of an LED set may be represented by one or more voltages at one or more sense terminals of the LED driver that drives the LED set. The following description is given with reference to Figures 7A, 8A, and 9A.

[0031] Figure 8A shows a diagram illustrating a subset of pins / terminals in an example of bridge circuit 810A in an embodiment of the present invention. Figure 8A is described in conjunction with Figure 7A. Bridge circuit 810A may be an embodiment of bridge circuits 710A-1, 710A-2, ..., or 710A-K. As shown in Figure 8A, bridge circuit 810A includes a first communication interface 832 having signal input pins / terminals SDI_BMC and signal output pins / terminals SDO_BMC. The first communication interface 832 is configured to transmit and receive BMC-encoded signals. "BMC" may refer to a line coding technique known as bi-phase mark coding. A detailed description of this technique is available in the known techniques and is therefore not included herein. BMC-encoded signals may refer to signals converted from SPI format to BMC format and signals originally generated in BMC format. The bridge circuit 810A also includes a second communication interface 834 having a clock pin / terminal SCLK_SPI, a data input pin / terminal SDI_SPI, and a data output pin / terminal SDO_SPI. The second communication interface 834 is configured to transmit and receive SPI format signals. Furthermore, the bridge circuit 810A includes an adjustment signal input pin / terminal ADJFIN and an adjustment signal output pin / terminal ADJFO. The input pin / terminal ADJFIN of the bridge circuit 810A can receive an adjustment signal FBIN from a bridge circuit coupled to the input pin / terminal ADJFIN. The output pin / terminal ADJFO of the bridge circuit 810A can output another adjustment signal FBO to another bridge circuit or power converter 702A coupled to the output pin / terminal ADJFO.

[0032] Figure 9A shows a partial circuit diagram of an example of a bridge circuit 810A in an embodiment of the present invention. Figure 9 is described in conjunction with Figures 7A and 8A. As shown in Figure 9A, the bridge circuit 810A includes a signal conversion circuit 936A, a regulated signal setting circuit 954A (including, for example, a data setting circuit 938 and a DAC 940), and a selector 942 (including, for example, a multiplexer MUX).

[0033] The signal conversion circuit 936A can convert signals from the first communication interface 832 to signals from the second communication interface 834. That is, the signal conversion circuit 936A can convert BMC-encoded signals to SPI-formatted signals and SPI-formatted signals to BMC-encoded signals. For example, the signal conversion circuit 936A includes an encoder and decoder circuit configured to convert BMC-encoded signals from the first communication interface 832 to SPI-formatted signals from the second communication interface 834. The encoder and decoder circuit 936A can also extract a set of status bits STAT_ADD and STAT_MINUS from data packets received at the first communication interface 832. The status bits STAT_ADD and STAT_MINUS may indicate whether the power supplied to LEDs driven by a chain of LED drivers coupled to the first communication interface 832 should be increased or decreased. The data setting circuit 938 receives the status bits STAT_ADD and STAT_MINUS and can set adjustment data 944 according to the status bits STAT_ADD and STAT_MINUS. DAC 940 can convert adjustment data 944 into an internal adjustment signal 950. In other words, the adjustment signal setting circuit 954A can set the internal adjustment signal 950 according to the status bits STAT_ADD and STAT_MINUS.

[0034] In some embodiments, the status bits STAT_ADD and STAT_MINUS may each have a value of "0" or "1". The status bit STAT_ADD may be used to indicate whether the LED supply voltage should be increased. The status bit STAT_MINUS may be used to indicate whether the LED supply voltage should be decreased. For example, if the status bits STAT_ADD and STAT_MINUS are "1" and "0" respectively, it may indicate that the supply voltage should be increased. If the status bits STAT_ADD and STAT_MINUS are "0" and "1" respectively, it may indicate that the supply voltage should be decreased. If both status bits STAT_ADD and STAT_MINUS are "0", it may indicate that the unchanged supply voltage should be maintained. In some embodiments, the status bits STAT_ADD and STAT_MINUS may not both be "1" at the same time. A status bit STAT_ADD of "1" can override the status bit STAT_MINUS of "1" and be set to "0".

[0035] The selector 942 receives an internal adjustment signal 950 from the DAC 940 and an external adjustment signal FBIN from another bridge circuit coupled to the adjustment signal input pin / terminal ADJFIN of the bridge circuit 810A, and can select a signal from the external adjustment signal FBIN and the internal adjustment signal 950 as the output signal 952 of the selector 942. In an embodiment, the bridge circuit 810A may include a buffer or voltage follower, for example labeled "BUF" in Figure 9A, which receives the output signal 952 and generates an adjustment signal FBO of the voltage level of the output signal 952 at the adjustment signal output pin / terminal ADJFO of the bridge circuit 810A.

[0036] In some embodiments, each of the bridge circuits 710A-1 to 710A-K in Figure 7A includes the pins / terminals and circuit structure of bridge circuit 810A and performs functions similar to those of bridge circuit 810A. Bridge circuits 710A-K can generate an adjustment signal FBO based on the status of LED set 716A-K. The signal FBO output from bridge circuit 710A-K can be an external adjustment signal FBIN (similar to the signal FBIN in Figure 9A) which is input to bridge circuit 710A-(K-1) (not explicitly shown in Figure 7A) adjacent to bridge circuit 710A-K (in this specification, "adjacent to" in this context is used to mean, for example, that there is no bridge circuit interposed between bridge circuit 710A-(K-1) and bridge circuit 710A-K, but there may or may not be any other kind of hardware between these or any two adjacent to each other bridge circuits). Bridge circuit 710A-(K-1) can generate an internal adjustment signal (similar to signal 950 in Figure 9A) based on the status of LED set 716A-(K-1). Bridge circuit 710A-(K-1) can also generate an adjustment signal (similar to signal FBO in Figure 9A) based on an external adjustment signal and an internal adjustment signal. The adjustment signal FBO output from bridge circuit 710A-(K-1) may indicate the status of LED sets 716A-(K-1) and 716A-K. Similarly, bridge circuit 710A-1 at the end of the chain of bridge circuits 710A-1 to 710A-K can generate an adjustment signal FBO based on its internal adjustment signal and an external adjustment signal FBIN received from bridge circuit 710A-2. In other words, each of the bridge circuits 710A-1 to 710A-K can communicate with other bridge circuits in the same bridge circuit using adjustment signals (e.g., the internal and / or external adjustment signals described above) that indicate the status of the LEDs driven by the LED driver chains in the same LED driver chains 714A-1 to 714A-K.As a result, the adjustment signal FBO output from the bridge circuit 710A-1 is generated based on the status of the LED sets 716A-1 to 716A-K. The adjustment signal FBO output from the bridge circuit 710A-1 can function as a feedback signal 704A for controlling the power converter 702A that supplies power to the LED sets 716A-1 to 716A-K. The feedback signal 704A is determined according to the adjustment signal FBO output from the bridge circuits 710A-1 to 710A-K.

[0037] Therefore, in some embodiments, the LED drivers of the LED driver system 700A use a 1-Wire interface for communication, and each of these 1-Wire interfaces requires two fewer pins than an SPI interface. Thus, the LED driver system 700A can occupy a smaller PCB area, reduce costs, and have a simpler PCB layout compared to the conventional LED driver system 100A in Figure 1A. In addition, since the bridge circuits 710A-1 to 710A-K can generate feedback signals 704A for controlling the power converter 702A, the feedback module 108 (e.g., DAC) in the MCU 106A in Figure 1A can be omitted from the controller 706A of the LED driver system 700A, which can reduce the cost of the controller 706A. Furthermore, the ADJFIN and ADJFO pins of each LED driver in the conventional LED driver system 100B can be omitted from the LED driver in the LED driver system 700A, which can also reduce the size and cost of the PCB and simplify the PCB layout. Furthermore, the bridge circuits 710A-1 to 710A-K can be configured to perform a buffering function, eliminating the need for additional driver buffers and thereby improving the cost-effectiveness of the LED driving system 700A. In addition, since the bridge circuits 710A-1 to 710A-K can convert between BMC-encoded signals and SPI-formatted signals, the encode / decode software module 118 installed on the MCU 106B in Figure 1B can be omitted in the controller 706A, which can further reduce the cost and power consumption of the controller 706A and improve the operating efficiency of the controller 706A.

[0038] In some embodiments, the bridge circuits 710A-1 to 710A-K can be incorporated into separate IC packages and can be coupled to each other through pins such as ADJFIN and ADJFO shown in Figure 8A. In some other embodiments, the bridge circuits 710A-1 to 710A-K can be incorporated into an IC package and can be coupled to each other through terminals ADJFIN and ADJFO.

[0039] In the example shown in Figure 7A, the power converter 702A receives a feedback signal 704A and outputs a supply voltage VLED to the backlight panel 712A. However, the present invention is not limited thereto. In some embodiments of the present invention, multiple power converters may receive multiple feedback signals and output multiple supply voltages for powering LEDs in the backlight panel.

[0040] Figure 7B shows a block diagram of an example of an LED driving system 700B in another embodiment of the present invention. Figure 7B is described in conjunction with Figures 7A, 8A, and 9A. In the example of Figure 7B, the backlight panel 712B may include different types of LEDs, for example, LEDs of different colors such as red, green, and blue. The LED driver chains 714B-1 to 714B-K can transmit status information of three types of LEDs (or referred to as three groups of LEDs) to the bridge circuits 710B-1 to 710B-K so that the bridge circuits 710B-1 to 710B-K generate feedback signals 704-1, 704-2, and 704-3 for controlling power converters 702-1, 702-2, and 702-3, respectively. Each of the power converters 702-1, 702-2, and 702-3 can output supply voltages VLED1, VLED2, or VLED3 at the voltage level required by each group of LEDs. In some embodiments, different types of LEDs may have different forward voltages when the same current level flows through each LED. Using multiple power converters (e.g., 702-1, 702-2, and 702-3) to power different types of LEDs may reduce power losses in the LED driving system 700B.

[0041] Figure 8B shows a diagram illustrating a subset of pins / terminals in an example of bridge circuit 810B in an embodiment of the present invention. Figure 8B is described in conjunction with Figures 7A, 7B, and 8A. Bridge circuit 810B may be embodiments of bridge circuits 710B-1 to 710B-K in Figure 7B. In some embodiments, the functions of the pins / terminals SDI_BMC, SDO_BMC, SCLK_SPI, SDI_SPI, and SDO_SPI of bridge circuit 810B are the same as or similar to those of bridge circuit 810A in Figure 8A. In the example in Figure 8B, the bridge circuit 810B includes multiple adjustment signal input pins / terminals ADJFIN1 to ADJFIN3 configured to receive multiple adjustment signals FBIN1 to FBIN3 from a bridge circuit coupled to adjustment signal input pins / terminals ADJFIN1 to ADJFIN3, and multiple adjustment signal output pins / terminals ADJFO1 to ADJFO3 configured to output multiple adjustment signals FBO1 to FBO3 to another bridge circuit or power converters 702-1 to 702-3 coupled to adjustment signal output pins / terminals ADJFO1 to ADJFO3.

[0042] Figure 9B shows a partial circuit diagram of an example of the bridge circuit 810B in an embodiment of the present invention. Figure 9B is described in conjunction with Figures 7A, 7B, 8A, 8B, and 9A.

[0043] In some embodiments, the signal conversion circuit 936B in Figure 9B is similar to the signal conversion circuit 936A in Figure 9A, except that it can extract multiple sets of status bits STAT_ADD1~3 and STAT_MINUS1~3 from a data packet received at the first communication interface. For example, in the multiple sets of status bits, the first set includes status bits STAT_ADD1 and STAT_MINUS1, the second set includes status bits STAT_ADD2 and STAT_MINUS2, and the third set includes status bits STAT_ADD3 and STAT_MINUS3. The three sets of status bits could, for example, indicate the status of three groups of LEDs, including a group of red LEDs, a group of blue LEDs, and a group of green LEDs. The adjustment signal setting circuit 954B can generate three internal adjustment signals (similar to signal 950 in Figure 9A, for example) and provide the signals to selectors 942-1~942-3. The functions of selectors 942-1 to 942-3 are the same as those of selector 942 in Figure 9A. Each of selectors 942-1 to 942-3 can select a signal as its output signal from its respective external adjustment signal (e.g., FBIN1, FBIN2, or FBIN3) and internal adjustment signal. As a result, the bridge circuit 810B can generate adjustment signals FBO1 to FBO3 at the adjustment signal output pins / terminals ADJFO1 to ADJFO3 according to the output signals of selectors 942-1 to 942-3.

[0044] In the embodiments described above, the bridge circuit includes a plurality of bridge circuits connected in a daisy-chain configuration. Each bridge circuit includes a first communication interface coupled to its respective LED driver chain and a second communication interface coupled to the controller. However, the present invention is not limited thereto. In other embodiments, the bridge circuit may include a circuit having a plurality of first communication interfaces coupled to a plurality of LED driver chains and one or more second communication interfaces coupled to the controller.

[0045] Figure 7C shows a block diagram of an example of an LED driver system 700C in another embodiment of the present invention. Figure 7C is described in conjunction with Figures 7A, 7B, 8A, 8B, 9A, and 9B. As shown in Figure 7C, the LED driver system 700C includes a plurality of LED driver chains 714C-1 to 714C-K, a power conversion circuit 702C, a controller 706C, and a bridge circuit 710C.

[0046] The LED driver chains 714C-1 to 714C-K can be the same as or similar to the LED driver chains 714A-1 to 714A-K or 714B-1 to 714B-K described above. The power conversion circuit 702C may include one or more power converters the same as or similar to the power converters 702A and 702-1 to 702-3 described above. The controller 706C can be similar to the controller 706A described above, except that the controller 706C includes one or more SPI interfaces, and the total number of SPI interfaces may be less than K, which is the total number of LED driver chains 714C-1 to 714C-K. For example, the controller 706C may include one SPI interface, as shown in Figure 7C. As another example, the controller 706C may include two or more SPI interfaces.

[0047] For example, a bridge circuit 710C, called a "giant-bridge device," may include a number of first communication interfaces (collectively labeled "732C") coupled to LED driver chains 714C-1 to 714C-K, respectively. The first communication interface 732C can be the same as or similar to the first communication interface 732A described above. The first communication interface 732C may support the 1-Wire protocol. The bridge circuit 710C may also include a second communication interface 734C coupled to the controller 706C. The second communication interface 734C may support SPI protocols such as the standard SPI protocol, dual SPI protocol, quad SPI protocol, or octal SPI protocol. The bridge circuit 710C can enable communication between the controller 706C and the LED driver chains 714C-1 to 714C-K by converting signals in the first communication interface 732C and the second communication interface 734C. In addition, the bridge circuit 710C can each receive multiple instances of status information from the first communication interface 732C. Each instance of status information is generated by each of the LED driver chains among the LED driver chains 714C-1 to 714C-K and indicates the status of the LEDs driven by each LED driver chain. For example, each instance of status information may include status bits similar to the status bits STAT_ADD and STAT_MINUS or status bits STAT_ADD1 to 3 and STAT_MINUS1 to 3 described above. Based on multiple instances of status information, the bridge circuit 710C can generate, for example, one or more feedback signals 704C similar to the feedback signal 704A or feedback signals 704-1 to 704-3 described above.More specifically, based on status information received at the first communication interface 732C, the bridge circuit 710C can determine whether all LEDs driven by the LED driver chains 714C-1 to 714C-K are receiving sufficient power. If they are not, the bridge circuit 710C can adjust one or more feedback signals 704C to control the power conversion circuit 702C to increase the power supplied to the LEDs.

[0048] In another embodiment, the bridge circuit 710C may include two or more interfaces that are the same as or similar to the second communication interface 734C. For example, the bridge circuit 710C may include two second communication interfaces 734C. In this example, the LED driver chains 714C-1 to 714C-K may be divided into two parts, for example, called the "first part" and the "second part". The bridge circuit 710C may enable communication between the controller 706C and the first part of the LED driver chains 714C-1 to 714C-K by their respective first communication interfaces and one of the second communication interfaces, and enable communication between the controller 706C and the second part of the LED driver chains 714C-1 to 714C-K by their respective first communication interfaces and the other of the second communication interfaces. Similarly, the LED driver chains 714C-1 to 714C-K may be divided into three or more parts, each with its own communication interface.

[0049] Figure 7D shows a block diagram of an example of an LED driver system 700D in another embodiment of the present invention. Figure 7D is described in conjunction with Figure 7C. The LED driver system 700D may include a plurality of bridge devices. In the example of Figure 7D, the LED driver system 700D includes two bridge devices 710D-1 and 710D-2. In another example, the LED driver system 700D may include three or more bridge devices. In embodiments, each of the bridge devices 710D-1 and 710D-2 includes the same or similar circuitry as the bridge circuit 710C in Figure 7C. In addition, the bridge devices 710D-1 and 710D-2 can communicate with each other in the same manner as the bridge circuits 710A-1 to 710A-K or 710B-1 to 710B-K described above. Thus, the bridge device 710D-1 can generate one or more feedback signals 704C to control the power conversion circuit 702C so that all LEDs driven by the LED driver chain receive sufficient power.

[0050] Figure 10 shows a flowchart 1000 of an example of a method for driving multiple sets of LEDs in an embodiment of the present invention. Figure 10 is described in conjunction with Figures 7A, 7B, 8A, 8B, 9A, and 9B.

[0051] In step 1002, a controller, for example, a 706A or 706C, controls a chain of LED drivers, for example, a 714A-1, a 714B-1, a 714C-1, etc., to drive multiple sets of LEDs, for example, a 716A-1, a 716B-1, etc. Each LED driver in the chain of LED drivers is configured to drive a set of LEDs in the multiple sets of LEDs and to communicate with other LED drivers in the chain of LED drivers by a first communication protocol, such as the 1-Wire protocol. The controller supports a second communication protocol, such as the SPI protocol.

[0052] In step 1004, a bridge circuit, for example, including circuits 710A-1 to 710A-K, circuits 710B-1 to 710B-K, circuit 710C, or circuits 710D-1 and 710D-2, enables communication between the controller and the LED driver chain. The bridge circuit includes a first communication interface, e.g., 732A or 732C, coupled to the LED driver chain and configured to support a first communication protocol, and a second communication interface, e.g., 734A or 734C, coupled to the controller and configured to support a second communication protocol.

[0053] In step 1006, the LED driver chain transmits status information to the bridge circuit indicating the status of multiple sets of LEDs.

[0054] In step 1008, the bridge circuit generates feedback signals, such as 704A, 704-1, 704-2, 704-3, or 704C, to control the power supplied to multiple sets of LEDs, such as VLED, VLED1, VLED2, or VLED3, based on status information.

[0055] Figure 11 shows a block diagram of an example of an LED driving system 1100 in an embodiment of the present invention. Figure 11 is described in conjunction with Figures 7B, 7C, 7D, 8B, and 9B. As shown in Figure 11, the LED driving system 1100 includes a device 1110 and a chain of LED drivers 1114-1 to 1114-N (where N is a natural number). In some embodiments, device 1110 includes a bridge circuit, for example, 710B-1 in Figure 7B, 810B in Figure 8B, 710C in Figure 7C, or 710D-1 in Figure 7D. In some other embodiments, device 1110 may include a controller, such as an MCU. In some embodiments, the chain of LED drivers 1114-1 to 1114-N can be the same as or similar to the LED driver chains 714B-1, 714B-2, ..., or 714B-K in Figure 7B, or the LED driver chains 714C-1, 714C-2, ..., or 714C-K in Figure 7C.

[0056] Device 1110 can control multiple power converters, for example, DC / DC converters or AC / DC converters. In the example in Figure 11, the multiple power converters include a first power converter 1102-1, a second power converter 1102-2, and a third power converter 1102-3. The first power converter 1102-1 can provide a first power, for example, a supply voltage VLED1, to a first group of LED strings, for example, LED strings S1 and S4 shown in Figure 11. The second power converter 1102-2 can provide a second power, for example, a supply voltage VLED2, to a second group of LED strings, for example, LED string S2 shown in Figure 11. The third power converter 1102-3 can provide a third power, for example, a supply voltage VLED3, to a third group of LED strings, for example, LED strings S3 and SM shown in Figure 11. In some embodiments, the LED strings include one or more LEDs.

[0057] As shown in Figure 11, each of the LED drivers 1114-1 to 1114-N is configured to drive each set of LED strings S1 to SM (where M is a natural number). Each set of LED strings S1 to SM includes one or more LED strings from a first group of LED strings powered by a first power converter 1102-1, one or more LED strings from a second group of LED strings powered by a second power converter 1102-2, and one or more LED strings from a third group of LED strings powered by a third power converter 1102-3. Furthermore, each of the LED drivers 1114-1 to 1114-N can sense the status of its respective set of LED strings S1 to SM and generate first information regarding the status of the LED string powered by the first power converter 1102-1, second information regarding the status of the LED string powered by the second power converter 1102-2, and third information regarding the status of the LED string powered by the third power converter 1102-3. Each of the LED drivers 1114-1 to 1114-N can also transmit the first, second, and third information to device 1110 via a communication link including the LED drivers 1114-1 to 1114-N.

[0058] More specifically, in some embodiments, the LED drivers 1114-1 to 1114-N are connected in a daisy-chain configuration, forming a communication link. The LED drivers 1114-1 to 1114-N can transmit information to device 1110 via the communication link. For example, if first information generated by LED driver 1114-1 indicates that an LED string driven by LED driver 1114-1 and powered by the first power converter 1102-1 requires more power, then the first information from LED driver 1114-1 can be relayed to device 1110 through LED drivers 1114-2, 1114-3, ..., and 1114-N. Similarly, if the first information generated by the LED driver 1114-2 indicates that an LED string driven by the LED driver 1114-2 and powered by the first power converter 1102-1 requires more power, the first information from the LED driver 1114-2 can be relayed to device 1110 through LED drivers 1114-3, 1114-4, ..., and 1114-N.

[0059] In some embodiments, if first information from LED drivers 1114-1 to 1114-N indicates that all LED strings powered by power converter 1102-1 will receive sufficient power, device 1110 may control power converter 1102-1 to either keep the supply voltage VLED1 unchanged or lower the supply voltage VLED1. If one or more first information from LED drivers 1114-1 to 1114-N indicates that one or more LED strings powered by power converter 1102-1 require more power, device 1110 may control power converter 1102-1 to raise the supply voltage VLED1. Device 1110 may similarly control supply voltages VLED2 and VLED3 based on second and third information.

[0060] In some embodiments, each of the first, second, and third groups of LED strings includes the same number of LEDs. Additionally, in some embodiments, the first, second, and third groups of LED strings include different types of LEDs. For example, the first group of LED strings can include red-emitting LEDs, the second group can include green-emitting LEDs, and the third group can include blue-emitting LEDs. Thus, when the first, second, and third groups of LED strings are driven at the same current level, their respective forward voltages can be different. Advantageously, by controlling power converters 1102-1 to 1102-3 to supply power to the three groups of LED strings based on the respective statuses of the three groups of LED strings, the power efficiency of the LED driving system 1100 can be improved, and heat problems in the LED drivers 1114-1 to 1114-N can be avoided.

[0061] For example, FIG. 12 shows a partial circuit diagram of an example of the LED driving system 1100 in an embodiment of the present invention. FIG. 12 is described in combination with FIG. 11. As shown in FIG. 12, the LED driver 1114-1 drives the LED string S1 by turning on the internal transistor Q1 to draw the current I LED1 flowing through the LED string S1, and drives the LED string S2 by turning on the internal transistor Q2 to draw the current I LED2 flowing through the LED string S2, and drives the LED string S3 by turning on the internal transistor Q3 to draw the current I LED3The LED string S3 can be driven by drawing in a current. In the example in Figure 12, the currents flowing through the LED strings S1, S2, and S3 are controlled to be substantially the same, for example, 100mA, while the forward voltages Vf1, Vf2, and Vf3 of the LED strings S1, S2, and S3 are different from each other. For example, the forward voltages of the LED strings S1, S2, and S3 may be 28V, 28.7V, and 29.7V, respectively, and the device 1110 can control the supply voltages VLED1, VLED2, and VLED3 to be 28.5V, 29V, and 30V, respectively. Thus, in this example, the internal transistors Q1, Q2, and Q3 are driven by a current, for example, by the voltage V applied to their drain terminals. ISEN1 , V ISEN2 , and V ISEN3 These can be 0.5V, 0.3V, and 0.3V, respectively. In other words, device 1110 can control the output power of power converters 1102-1 to 1102-3 such that the voltage applied to the drain terminals of the internal transistors of the LED driver 1114-1 is equal to or slightly higher than the reference voltage VREF, for example, 0.3V in the example of Figure 12. The voltage applied to the drain terminals of the internal transistors (e.g., Q1, Q2, or Q3) (e.g., V ISEN1 , V ISEN2 , or V ISEN3 When the reference voltage VREF is greater than or equal to the reference voltage VREF, it indicates that the LED string coupled to its internal transistor will receive sufficient power. As a result, device 1110 can control all LED strings driven by LED driver 1114-1 to receive sufficient power while minimizing power loss in the internal transistor of LED driver 1114-1.

[0062] Therefore, in some embodiments, the first current (for example, I) flowing through the first LED string (for example, S1) of the LED strings S1~SM LED1) and the second current (for example, I) flowing through the second LED string (for example, S2) of the LED strings S1~SM LED2 ) are controlled to be substantially the same current level, and if the first forward voltage (e.g., Vf1) of the first LED string (e.g., S1) is higher than the second forward voltage (e.g., Vf2) of the second LED string (e.g., S2), device 1110 can control the first power (e.g., supply voltage VLED1) supplied to the first LED string (e.g., S1) to be greater than the second power (e.g., supply voltage VLED2) supplied to the second LED string (e.g., S2). When used herein, "the currents are controlled to be substantially the same current level" means that there may be a difference between the current levels due to the non-ideal nature of the circuit components, and that the difference is relatively small and negligible.

[0063] In some embodiments, similar to the bridge circuits described above, e.g., 710B-1, 810B, 710C, or 710D-1, device 1110 may include a first communication interface configured to be coupled to a chain of LED drivers 1114-1 to 1114-N and to support a first communication protocol such as the 1-Wire protocol. Device 1110 may also include a second communication interface configured to be coupled to a controller (e.g., the same or similar controller 706A or 706C) and to support a second communication protocol such as the SPI protocol. Device 1110 can enable communication between the controller and the chain of LED drivers 1114-1 to 1114-N through the first and second communication interfaces.

[0064] Furthermore, in some embodiments, device 1110 includes a signal conversion circuit (not shown in Figure 11) and an adjustment signal setting circuit (not shown in Figure 11). Similar to the signal conversion circuit 936B in Figure 9B, the signal conversion circuit of device 1110 in Figure 11 can convert signals in a first communication interface to signals in a second communication interface. The signal conversion circuit of device 1110 receives status data from the LED driver 1114-N and can extract from the status data multiple sets of status bits, similar to the status bits STAT_ADD1~3 and STAT_MINUS1~3 described in relation to Figure 9B. Similar to the adjustment signal setting circuit 954B in Figure 9B, the adjustment signal setting circuit of device 1110 in Figure 11 can receive multiple sets of status bits from the signal conversion circuit and generate multiple adjustment signals FBO1~FBO3. Each adjustment signal FBO1, FBO2, or FBO3 is generated according to each set of status bits from a plurality of sets of status bits and is configured to control each power converter 1102-1, 1102-2, or 1102-3.

[0065] For example, multiple sets of status bits may include a first set of status bits STAT_ADD1 and STAT_MINUS1, a second set of status bits STAT_ADD2 and STAT_MINUS2, and a third set of status bits STAT_ADD3 and STAT_MINUS3. The first set of status bits can indicate whether the power output from power converter 1102-1 should be increased or decreased, the second set of status bits can indicate whether the power output from power converter 1102-2 should be increased or decreased, and the third set of status bits can indicate whether the power output from power converter 1102-3 should be increased or decreased. Device 1110 can set the values ​​of adjustment signals FBO1 to FBO3 according to the first, second, and third sets of status bits, respectively.

[0066] Figure 13 shows a flowchart 1300 of an example of a method for supplying power to multiple sets of LED strings in an embodiment of the present invention. Figure 13 will be described in conjunction with Figures 11 and 12.

[0067] In step 1302, a first power converter, for example 1102-1, provides first power, including, for example, a supply voltage VLED1, to a first group of LED strings, including, for example, LED strings S1, S4, etc.

[0068] In step 1304, a second power converter, for example 1102-2, provides a second power, including, for example, a supply voltage VLED2, to a second group of LED strings, including, for example, LED strings S2, S5, etc.

[0069] In step 1306, the LED driver chain, for example, 1114-1 to 1114-N, drives the first and second groups of the LED string. For example, in step 1308, each LED driver in the chain, for example, 1114-1 to 1114-N, is controlled to drive the first LED string of the first group of the LED string. In step 1310, the LED driver is further controlled to drive the second LED string of the second group of the LED string.

[0070] In step 1312, the LED driver transmits first information regarding the status of a first LED string and second information regarding the status of a second LED string to a device, for example, 1110, via a communication link including a chain of LED drivers, for example, 1114-1 to 1114-N.

[0071] In step 1314, device 1110 controls the first power based on the first information.

[0072] In step 1316, device 1110 controls the second power based on the second information.

[0073] Figure 14 shows a block diagram of an example of an LED driving system 1400 in an embodiment of the present invention. Figure 14 is described in conjunction with Figures 7A, 7B, 7C, 7D, 8A, 8B, 9A, 9B, and 11. As shown in Figure 14, the LED driving system 1400 includes a controller 1406 (e.g., an MCU), a device 1410 (e.g., a bridge circuit), and a chain of LED drivers AMIC-1 to AMIC-N (where N is a natural number).

[0074] The controller 1406 can send command 1424 to LED drivers AMIC-1 to AMIC-N via device 1410. Command 1424 can instruct LED drivers AMIC-1 to AMIC-N to send their respective status information to device 1410. Command 1424 can also cause device 1410 to respond to the controller 1406 with the status information of LED drivers AMIC-1 to AMIC-N. In some embodiments, each LED driver AMIC-1 to AMIC-N in Figure 14 can drive each set of LEDs, as can LED drivers 714A-1 to 714A-K in Figure 7A, LED drivers 714B-1 to 714B-K in Figure 7B, and LED drivers 1114-1 to 1114-N in Figure 11. As used herein, the status information of an LED driver may include the status of the LED driver and / or the status of the set of LEDs driven by the LED driver.

[0075] In some embodiments, controller 1406 may periodically send command 1424. During the current period, device 1410 can receive command 1424 and forward it to LED drivers AMIC-1 to AMIC-N. In response to receiving command 1424, LED drivers AMIC-1 to AMIC-N can send their current status information 1430 to device 1410. In response to receiving command 1424, device 1410 can send previously stored status information 1456 to controller 1406 and wait to receive the current status information 1430 from LED drivers AMIC-1 to AMIC-N. The previously stored status information 1456 includes the status information of LED drivers AMIC-1 to AMIC-N that was stored in storage unit 1458 (e.g., including registers) during the previous period. During the current period, device 1410 can store current status information 1430 received from LED drivers AMIC-1 to AMIC-N in storage unit 1458. The “previous period” may be called the first period, and the “current period” may be called the second period following the first period. The following description is given with reference to Figures 14 and 15. Figure 15 shows a diagram of the process in which a controller 1406 sends commands to a chain of LED drivers AMIC-1 to AMIC-N and reads data from that chain in an embodiment of the present invention.

[0076] As shown in Figures 14 and 15, the LED drivers AMIC-1 to AMIC-N include a first LED driver, e.g., AMIC-1, a second LED driver, e.g., AMIC-2, and a third LED driver, e.g., AMIC-3. During the second period 1562 (which follows the first period 1560, e.g., either immediately after or some time later), device 1410 receives command 1424 from controller 1406 and forwards command 1424 to LED drivers AMIC-1 to AMIC-N. In response to receiving command 1424, the first LED driver AMIC-1 generates a first packet 1426 of data according to the status of LED driver AMIC-1. The second LED driver AMIC-2 receives command 1424 and the first packet 1426 of data from the first LED driver AMIC-1. The second LED driver AMIC-2, in response to receiving command 1424, generates the first data packet 1426 and a second data packet 1428 based on the status of the second LED driver AMIC-2. The second LED driver AMIC-2 also sends command 1424 and the second data packet 1428 to the third LED driver AMIC-3. LED drivers AMIC-3 to AMIC-N can perform similar operations. Thus, LED driver AMIC-N, at the end of the chain of LED drivers AMIC-1 to AMIC-N, can, in response to receiving command 1424, generate a combined data packet 1430 based on the respective statuses of each of the LED drivers AMIC-1 to AMIC-N. Device 1410 receives the combined data packet 1430 and stores it in the storage unit 1458.

[0077] In addition, as shown in Figures 14 and 15, during the first period 1560, device 1410 and LED drivers AMIC-1 to AMIC-N perform operations similar to those described in relation to the second period 1562. Thus, device 1410 can store the previous packet 1456 of the data received from LED drivers AMIC-1 to AMIC-N. During the second period 1562, in response to receiving command 1424, device 1410 sends the previous packet 1456 of the data to controller 1406. Thus, after controller 1406 sends command 1424 to device 1410, controller 1406 does not need to wait a relatively long time to receive a response from device 1410. Device 1410 can send the previous packet 1456 of the data to controller 1406. Thus, the operational efficiency of controller 1406 can be improved compared to MCU 606 mentioned in Figure 6.

[0078] In the example in Figure 15, command 1424 may be labeled "STAT AND Tj READ". "STAT" can represent the status bit, and "Tj" can represent the junction temperature. In some embodiments, each LED driver AMIC-1, AMIC-2, ..., or AMIC-N can generate a data packet based on the LED driver status in response to receiving the command "STAT AND Tj READ". The LED driver status may include the LED driver junction temperature. The LED driver status is measured by the LED driver's sense terminal (e.g., the voltage V shown in Figure 12, similar to the terminals ISEN1~ISENM shown in Figure 12). ISEN1 , V ISEN2 , and V ISEN3This may also include voltage levels (similar to those mentioned above). Each sense terminal is configured to sense the status of an LED string driven by an LED driver. The voltage status of those sense terminals may be represented by one or more sets of status bits similar to the status bits STAT_ADD and STAT_MINUS mentioned in relation to Figure 9A, and the status bits STAT_ADD1-3 and STAT_MINUS1-3 mentioned in relation to Figures 9B and 11.

[0079] For example, the first LED driver AMIC-1 can drive a first set of LEDs. In the first embodiment, the first set of LEDs may be powered by a single power converter (similar to power converter 702A in Figure 7A, for example). In the first embodiment, the first packet 1426 of data generated by the first LED driver AMIC-1 may include information about the junction temperature Tj1 of the first LED driver AMIC-1 and a set of status bits STAT_ADD and STAT_MINUS. In the second embodiment, the first set of LEDs may include multiple subsets of LEDs powered by different power converters (similar to power converters 1102-1 to 1102-3 in Figure 11, for example). In the second embodiment, the first packet 1426 of data generated by the first LED driver AMIC-1 may include information about the junction temperature Tj1 of the first LED driver AMIC-1 and a multiple set of status bits STAT_ADD1 to 3 and STAT_MINUS1 to 3.

[0080] Taking the first embodiment as an example, the values ​​of the status bits STAT_ADD and STAT_MINUS in the first data packet 1426, for example, "10" and "01", may indicate whether the voltage at the sense terminal of the first LED driver AMIC-1 is higher than the reference voltage VREF, thereby indicating whether the power supplied to the first set of LEDs should be increased or decreased. The second LED driver AMIC-2 can drive a second set of LEDs. The first and second sets of LEDs may be powered by the same power converter. The second LED driver AMIC-2 generates a second data packet 1428 based on the status of the first data packet 1426 and the second LED driver AMIC-2. The second data packet 1428 may include information about the junction temperature Tj1 of the first LED driver AMIC-1 and information about the junction temperature Tj2 of the second LED driver AMIC-2. The second data packet 1428 may also include the status bits STAT_ADD and STAT_MINUS. The status bits STAT_ADD and STAT_MINUS in the second packet 1428 of the data may indicate whether the power supplied to the first and second sets of LEDs should be increased or decreased. LED drivers AMIC-3 to AMIC-N can similarly generate their respective packets of data. As a result, LED driver AMIC-N generates a combined packet of data that includes information about the respective junction temperatures of each of the LED drivers AMIC-1 to AMIC-N (e.g., Tj1, Tj2, Tj3, ..., TjN) and information indicating whether the power supplied to the LEDs driven by LED drivers AMIC-1 to AMIC-N should be increased or decreased.

[0081] In some embodiments, device 1410 includes bridge circuits, such as bridge circuits 710A-1, ..., or 710A-K in Figure 7A, bridge circuits 710B-1, ..., or 710B-K in Figure 7B, bridge circuit 810A in Figure 8A, bridge circuit 810B in Figure 8B, bridge circuit 710C in Figure 7C, bridge circuit 710D-1 or 710D-2 in Figure 7D, and so on. Device 1410 may include a first communication interface coupled to the chain of LED drivers AMIC-1 to AMIC-N and configured to support a first communication protocol such as the 1-Wire protocol. Device 1410 may also include a second communication interface coupled to the controller 1406 and configured to support a second communication protocol such as the SPI protocol. Device 1410 can enable communication between the controller 1406 and the chain of LED drivers AMIC-1 to AMIC-N through the first and second communication interfaces. Device 1410 may include signal conversion circuits (for example, including the BMC-to-SPI module and SPI-to-BMC module shown in Figure 14) configured to convert signals in a first communication interface (for example, BMC-encoded signals) to signals in a second communication interface (for example, SPI-formatted signals). Storage unit 1458 can receive and store status information (for example, including the preceding packet 1456 and the combined packet 1430 of the data described above) from the signal conversion circuits.

[0082] Figure 16 shows a flowchart 1600 of an example of a method for transmitting data from a chain of LED drivers, e.g., AMIC-1 to AMIC-N, to a controller, e.g., 1406, according to an embodiment of the present invention. Figure 16 is described in conjunction with Figures 14 and 15.

[0083] In step 1602, each LED driver in the chain of LED drivers AMIC-1 to AMIC-N drives its respective set of LEDs. LED drivers AMIC-1 to AMIC-N include a first LED driver, e.g., AMIC-1, a second LED driver, e.g., AMIC-2, and a third LED driver, e.g., AMIC-3.

[0084] In step 1604, during the first period (for example, 1560), device 1410 stores the previous packet 1456 of the data received from LED drivers AMIC-1 to AMIC-N.

[0085] In step 1606, during a second period (for example, 1562) following the first period, the device 1410 and LED drivers AMIC-1 to AMIC-N perform operations including, for example, steps 1608 to 1622, as follows:

[0086] In step 1608, device 1410 receives command 1424 from controller 1406.

[0087] In step 1610, device 1410, in response to receiving command 1424, sends packet 1456 preceding the data to controller 1406.

[0088] In step 1612, device 1410 forwards command 1424 to LED drivers AMIC-1 to AMIC-N.

[0089] In step 1614, the second LED driver AMIC-2 receives command 1424 and the first data packet 1426 from the first LED driver AMIC-1.

[0090] In step 1616, the second LED driver AMIC-2, in response to receiving command 1424, generates the first packet 1426 of data and the second packet 1428 of data based on the status of the second LED driver AMIC-2.

[0091] In step 1618, the second LED driver AMIC-2 sends command 1424 and a second packet 1428 of data to the third LED driver AMIC-3.

[0092] In step 1620, an LED driver at the end of the chain of LED drivers AMIC-1 to AMIC-N, for example AMIC-N, responds to the receipt of command 1424 by generating a combined data packet 1430 based on the respective status of each of the LED drivers AMIC-1 to AMIC-N.

[0093] In step 1622, device 1410 stores the combined data packet 1430 in a storage unit, for example, 1458.

[0094] Figure 17A shows a block diagram of an example of an LED driving system 1700A in an embodiment of the present invention. Figure 17A is described in conjunction with Figure 14. Device 1410A in Figure 17A may be an embodiment of device 1410 in Figure 14. AMIC-1 in Figure 17A may be an embodiment of AMIC-1 in Figure 14.

[0095] As shown in Figure 17A, device 1410A has a value of F 1WCLK The system includes a communication circuit, for example, a signal transmitting circuit 1764 and a signal receiving circuit 1766, configured to communicate with a chain of LED drivers AMIC-1 to AMIC-N at a communication clock frequency 1780A, which can be represented by F. In other words, the communication circuit communicates with a communication clock frequency F. 1WCLKThe device can send signals to LED driver AMIC-1 and receive signals from LED driver AMIC-N. Device 1410A also includes an oscillator (OSO) 1768A configured to generate an operating clock signal 1770A to support the operation of the communication circuit. Communication clock frequency F 1WCLK The frequency value F of the operating clock signal 1770A is CLK (Hereafter, the operating frequency F CLK It is set based on the communication clock frequency F. 1WCLK The operating frequency F CLK It may be proportional to [something].

[0096] Similarly, each LED driver from AMIC-1 to AMIC-N has a communication clock frequency F 1WCLK The device may include a communication circuit configured to communicate with adjacently coupled devices, for example, a signal receiving circuit 1772 and a signal transmitting circuit 1774, and may include an oscillator 1776A configured to generate an operating clock signal 1778A to support the operation of the communication circuit.

[0097] In the example in Figure 17A, the communication frequency F 1WCLK The frequency is set relatively low, for example, below 2 MHz, thereby reducing electromagnetic interference (EMI) during communication. However, this not only reduces the communication speed but also limits the number of LED drivers AMIC-1 to AMIC-N that the LED driver system 1700A can support. Therefore, an LED driver system in another embodiment of the present invention is given as follows.

[0098] Figure 17B shows a block diagram of an example of an LED driving system 1700B in another embodiment of the present invention. Figure 17B is described in conjunction with Figures 14 and 17A. Device 1410B in Figure 17B may be an embodiment of device 1410 in Figure 14. AMIC-1 in Figure 17B may be an embodiment of AMIC-1 in Figure 14.

[0099] Device 1410B in Figure 17B is similar to device 1410A in Figure 17A, except that it uses a spread spectrum clock generator (SSCG) 1768B to generate an operating clock signal 1770B to support the operation of a communication circuit, including modules 1764 and 1766. The spread spectrum clock generator 1768B uses the spread spectrum clocking technique to generate the operating frequency F of the operating clock signal 1770B. SSCLK By alternately raising and lowering (for example, slowly increasing and decreasing the speed), the operating frequency F SSCLK This can be varied within a predetermined range. A detailed description of spread-spectrum clock technology is available in the known art and is therefore not included herein.

[0100] Communication frequency F 1WCLK The operating frequency F SSCLK It can change as the communication frequency F changes. 1WCLK Furthermore, it is possible for the frequency to alternately rise and fall within a predetermined frequency range (for example, for the speed to slowly rise and fall). As a result, the electromagnetic energy generated during communication between device 1410B and LED drivers AMIC-1 and AMIC-N is diffused over a predetermined frequency range, thereby significantly reducing EMI. Therefore, the communication frequency F 1WCLK This can be set to a relatively high value, such as approximately 12 MHz. More specifically, the communication frequency F 1WCLK For example, the communication clock frequency F may slowly rise and fall within a range from 3% of 12MHz minus 12MHz to 3% of 12MHz plus 12MHz. Similarly, each LED driver from AMIC-1 to AMIC-N utilizes a spread spectrum clock generator 1776B to generate the operating clock signal 1778B to support its operation. The LED driver uses a communication clock frequency F that slowly changes within a predetermined range. 1WCLKIt can communicate with adjacent connected devices. Communication clock frequency F 1WCLK Since this can be set to be relatively high, higher communication speeds can be achieved, and a relatively large number of LED drivers AMIC-1 to AMIC-N can be supported.

[0101] While the above description and drawings represent embodiments of the present invention, it will be understood that various additions, modifications, and substitutions may be made in those embodiments without departing from the spirit and scope of the principles of the invention as defined in the appended claims. Those skilled in the art will understand that the present invention may be used with many modifications, such as form, structure, arrangement, size, materials, elements, and components used in the implementation of the invention, which are particularly suited to specific environmental and operational requirements without departing from the principles of the invention. Accordingly, the embodiments disclosed herein should be considered illustrative and not restrictive in all respects, and the scope of the invention is indicated by the appended claims and their legal equivalents, and is not limited to the above description. [Explanation of symbols]

[0102] 100A Conventional LED driving system 100B Another conventional LED driving system 102 DC / DC Converter 104 Analog Feedback Signal 106A MCU 106B MCU 108 Feedback Module 110 Driver Buffer 112A Backlight Panel 112B Backlight Panel 114A LED Driver 114B LED Driver 114-1 LED Driver 114-2 LED Driver 116 Mini LED 116-1 LED 116-2 LED 118 Encode / Decode Software Modules 120 Feedback signal 122 Feedback Circuit 400 Another conventional LED driving system 402 DC / DC Converter 406 MCU 414-1~414-N LED Driver 416-1~416-N LED String Set 606 MCU 610 Driver Buffer 624 command 626 data packets 628 data packets 630 data packets 700A LED drive system 700B LED driving system 700C LED drive system 702A Power Converter 702C Power Conversion Circuit 700D LED drive system 702-1, 702-2, 702-3 Power Converters 704A Feedback signal 704C Feedback Signal 704-1, 704-2, 704-3 Feedback Signal 706A Controller 706C controller 710A-1~710A-K Bridge Circuit 710B-1~710B-K Bridge Circuit 710C bridge circuit 710D-1, 710D-2 Bridge Device 712A Backlight Panel 712B Backlight Panel 714A-1~714A-K LED Driver Chain 714B-1~714B-K LED Driver Chain 714C-1~714C-K LED Driver Chain 716A-1~716A-K LED set, LED set 716B-1 LED set 732A First communication interface 732C First communication interface 734A Second communication interface 734C Second communication interface 810A Bridge Circuit 810B bridge circuit 832 First communication interface 834 Second communication interface 936A Signal Conversion Circuit 936B Signal Conversion Circuit 938 Data setting circuit 940 DAC 942 Selector 942-1~942-3 Selector 944 Adjustment Data 950 Internal adjustment signal 952 Output signal 954A Adjustment signal setting circuit 954B Adjustment signal setting circuit 1000 flowcharts 1100 LED drive system 1102-1 First Power Converter 1102-2 Second Power Converter 1102-3 Third Power Converter 1110 devices 1114-1~1114-N LED Driver 1300 Flowchart 1400 LED drive system 1406 Controller, MCU 1410 devices 1410A device 1424 command 1426 The first packet of data 1428 Second packet of data 1430 Data-combined packets 1430 Current Status Information 1456 Previously stored status information, previous packet of data 1458 Storage Units 1560 First period 1562 Second period 1600 Flowchart 1700A LED drive system 1700B LED driving system 1764 Signal transmission circuit 1766 Signal receiving circuit 1768A Oscillator 1768B Spread Spectrum Clock Generator 1770A Operating Clock Signal 1770B Operating Clock Signal 1772 Signal receiving circuit 1774 Signal transmission circuit 1776A Oscillator 1776B Spread Spectrum Clock Generator 1778A Operating clock signal 1778B Operating clock signal 1780A Communication clock frequency

Claims

1. A first chain of LED drivers, wherein each LED driver in the first chain of LED drivers is configured to drive a set of LEDs and communicate with other LED drivers in the first chain of LED drivers by a first communication protocol, A controller configured to control a first chain of LED drivers to drive a first set of LEDs, the controller supporting a second communication protocol, A bridge circuit coupled between a first chain of the LED driver and the controller, configured to receive status information from the first chain of the LED driver indicating the status of a first set of LEDs, and configured to generate a feedback signal for controlling the power supplied to the first set of LEDs based on the status information, A first communication interface coupled to the first chain of the LED driver and configured to support the first communication protocol, and A second communication interface coupled to the controller and configured to support the second communication protocol. Includes, A bridge circuit and a second communication interface are further configured to enable communication between the first chain of the LED driver and the controller through the first and second communication interfaces. LED driving system, including

2. The LED driving system according to claim 1, wherein the first communication protocol includes the 1-Wire protocol, and the second communication protocol includes the SPI (Serial Peripheral Interface) protocol.

3. The LED driving system according to claim 1, wherein the bridge circuit includes an encoder and decoder circuit configured to convert signals in the first communication interface to signals in the second communication interface.

4. The LED driving system further includes a second chain of LED drivers configured to drive a second set of LEDs, and the bridge circuit is A first bridge circuit coupled to the second chain of the LED driver and configured to generate a first adjustment signal based on the status of a second set of LEDs driven by the second chain of the LED driver, A second bridge circuit is coupled to the first chain of the LED driver, coupled adjacent to the first bridge circuit, and configured to receive the first adjustment signal, generate an internal adjustment signal based on the status of the first set of LEDs, and generate a second adjustment signal based on the first adjustment signal and the internal adjustment signal. It further includes, The LED driving system according to claim 1, wherein the feedback signal is determined according to at least the first adjustment signal and the second adjustment signal.

5. The second bridge circuit described above, The LED driving system according to claim 4, comprising a tuning signal setting circuit configured to set the internal tuning signal based on a set of status bits received from the first communication interface, wherein the set of status bits indicates whether the power supplied to the first set of LEDs should be increased or decreased.

6. The LED driving system according to claim 5, further comprising the selector, the second bridge circuit configured to receive the internal adjustment signal and the first adjustment signal and to select a signal from the first adjustment signal and the internal adjustment signal as the output signal of the selector, wherein the second adjustment signal includes the level of the output signal.

7. The LED driving system according to claim 5, wherein the second bridge circuit further includes a signal conversion circuit configured to convert signals in the first communication interface to signals in the second communication interface, and the adjustment signal setting circuit receives the set of status bits from the signal conversion circuit.

8. A plurality of LED driver chains, wherein each chain of the plurality of LED driver chains includes a chain of LED drivers, and the plurality of LED driver chains further includes a first chain of LED drivers, The bridge circuit includes a chain of bridge circuits, each of which is configured to enable communication between the controller and each of the LED driver chains of the plurality of LED driver chains, and is also configured to communicate with other bridge circuits in the chain of the bridge circuit using adjustment signals that indicate the status of the LEDs driven by the LED driver chains of the plurality of LED driver chains. The first bridge circuit is located at the end of the chain of the bridge circuit, The LED driving system according to claim 1, wherein the feedback signal controls a power converter that supplies power to the LEDs driven by the plurality of LED driver chains.

9. A plurality of LED driver chains, wherein each chain of the plurality of LED driver chains includes a chain of LED drivers, and the plurality of LED driver chains further includes a first chain of LED drivers, The bridge circuit includes a plurality of first communication interfaces, each coupled to the plurality of LED driver chains. The bridge circuit is configured to enable communication between the controller and the plurality of LED driver chains by converting signals from the plurality of first communication interfaces and signals from the second communication interface. Each of the bridge circuits is configured to receive multiple instances of status information from the multiple first communication interfaces, and each instance of the multiple instances of status information is generated by each of the multiple LED driver chains and indicates the status of the LEDs driven by each of the LED driver chains. The LED driving system according to claim 1, wherein the bridge circuit is further configured to generate the feedback signal based on a plurality of instances of the status information.

10. A device configured to control a plurality of power converters, including a first power converter and a second power converter, wherein the first power converter is configured to provide first power to a first group of LED strings, and the second power converter is configured to provide second power to a second group of LED strings. A chain of LED drivers coupled to the device, wherein each LED driver in the chain of LED drivers is configured to drive a first LED string of a first group of the LED string and a second LED string of a second group of the LED string, and to transmit first information regarding the status of the first LED string and second information regarding the status of the second LED string to the device via a communication link including the chain of LED drivers. Includes, An LED driving system in which the device is configured to control the first power based on the first information and the second power based on the second information.

11. The LED driver system according to claim 10, wherein the LED driver is configured to drive the first LED string by drawing in a first current flowing through the first LED string and to drive the second LED string by drawing in a second current flowing through the second LED string, the first current and the second current are controlled to be substantially the same current level, and the device is configured to control the first power to be greater than the second power if the first forward voltage of the first LED string is higher than the second forward voltage of the second LED string.

12. The LED driving system according to claim 10, wherein the device is further configured to receive a plurality of sets of status bits from an LED driver at the end of the chain of LED drivers, each set of the plurality of status bits indicating whether the output power of each of the plurality of power converters should be increased or decreased, and the device is also configured to generate a plurality of adjustment signals for controlling each of the plurality of power converters, each of the plurality of adjustment signals being generated according to each set of status bits of the plurality of sets of status bits.

13. The aforementioned device A first communication interface, coupled to the LED driver chain and configured to support a first communication protocol, A second communication interface coupled to the controller and configured to support a second communication protocol, Includes, The LED driving system according to claim 10, wherein the device is further configured to enable communication between the controller and the chain of LED drivers through the first communication interface and the second communication interface.

14. The aforementioned device A signal conversion circuit configured to convert signals in the first communication interface and signals in the second communication interface, A tuning signal setting circuit configured to receive multiple sets of status bits from the signal conversion circuit and generate multiple tuning signals, wherein each of the multiple tuning signals is generated according to each set of status bits in the multiple sets of status bits and is configured to control each of the multiple power converters. The LED driving system according to claim 13, further comprising:

15. A chain of LED drivers, wherein each LED driver in the chain is configured to drive each set of LEDs, and the chain of LED drivers includes a first LED driver, a second LED driver, and a third LED driver, the second LED driver is The first LED driver receives a first packet of command and data, In response to receiving the command, a second packet of data is generated based on the first packet of data and the status of the second LED driver. The second packet of the command and the data is configured to be sent to the third LED driver. An LED driver chain, wherein the LED drivers at the ends of the LED driver chain are configured to generate a combined data packet based on the status of each of the LED drivers in response to the reception of the command, Coupled to the LED driver chain, The previous packet of data received from the LED driver chain during the first period is stored. The command is received from the controller during the second period following the first period. In response to receiving the aforementioned command, it is configured to send the packet preceding the data to the controller. During the second period, a device is configured to transfer the command to the LED driver chain, receive the combined data packets from the LED driver chain, and store the combined data packets. LED driving system, including

16. During the aforementioned period 1, The device is configured to transfer the previous command from the controller to the LED driver chain. The aforementioned second LED driver, The first LED driver receives the preceding first packet of the preceding command and data, In response to receiving the aforementioned command, a preceding second packet of data is generated based on the preceding first packet of data and the status of the second LED driver. The configuration is configured to send the preceding command and the preceding second packet of data to the third LED driver. The LED driver system according to claim 15, wherein the LED driver at the end of the LED driver chain is configured to generate the previous packet of data in response to the reception of the previous command.

17. The LED driving system according to claim 15, wherein the status of the second LED driver includes at least one of the first status and the second status, the first status includes a voltage level of a sense terminal of the second LED driver that senses the status of at least one LED driven by the second LED driver, and the second status includes the temperature of the second LED driver.

18. The LED driver system according to claim 15, wherein the combined data packet includes information regarding the junction temperature of each of the LED drivers in the LED driver chain, and information indicating whether the power supplied to a plurality of sets of LEDs driven by the LED driver chain should be increased or decreased.

19. The aforementioned device A first communication interface, coupled to the LED driver chain and configured to support a first communication protocol, The system includes a second communication interface coupled to the controller and configured to support a second communication protocol, The LED driving system according to claim 15, wherein the device is configured to enable communication between the controller and the LED driver chain through the first communication interface and the second communication interface.

20. The aforementioned device A signal conversion circuit configured to convert signals in the first communication interface and signals in the second communication interface, A storage unit coupled to the signal conversion circuit and configured to receive and store the previous packet of data from the signal conversion circuit during the first period, The LED driving system according to claim 19, further comprising:

21. The aforementioned device A communication circuit configured to communicate with the LED driver chain at a communication clock frequency, A spread spectrum clock generator coupled to the communication circuit, which generates an operating clock signal to support the operation of the communication circuit, and is configured to change the operating frequency within a predetermined range by alternately raising and lowering the operating frequency of the operating clock signal, wherein the communication clock frequency changes when the operating frequency changes. The LED driving system according to claim 15, including the following:

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