LED backlight driving system and LED backlight device

Abstract

The invention discloses an LED backlight driving system. The LED backlight driving system comprises a controller and a plurality of LED driving chips, each LED driving chip is provided with a high-voltage driving input pin and a low-voltage driving input and output pin, and a high-voltage LDO (Low Dropout Regulator) module is also arranged in each LED driving chip; a high-voltage driving input pin of the first LED driving chip closest to the controller in the serial communication link is connected with an external high-voltage driving power supply, and an LDO module in the first LED driving chip converts high-voltage driving voltage of the external high-voltage driving power supply into low-voltage driving voltage used for driving internal circuits of the LED driving chips; the low-voltage driving input and output pins of all the LED driving chips are connected to the same driving voltage transmission line, and an external isolation capacitor is arranged between the driving voltage transmission line and the low-potential reference level.

Description

Technical Field

[0001] The present invention relates to the field of image display technology, and in particular to an LED backlight driving system and an LED backlight device. Background Art

[0002] At present, the LED driving technology used in Mini-LED backlight panels generally uses one LED driver chip to control and drive multiple channels of LED light strings, and multiple LED driver chips are connected in series using a single-line chain, such as Figure 1 As shown. Among them, the high driving voltage V DCDC Connect the anode of the LED string, and the cathode of the string is connected to the LED pin of the chip. DCDC The power input pin Vin of the LED driver chip is input, and the high-voltage LDO module inside the LED driver chip converts the high drive voltage V DCDC Convert to low drive voltage V DD , and then use a low drive voltage V DD Provides power to the internal modules of the chip.

[0003] However, the problem in the LED driving system of the prior art is that when each LED driving chip is internally integrated with a high-voltage LDO module and the high-voltage LDO module is used to output a low driving voltage V DD When using the LED driver chip, it is necessary to set pins on the LED driver chip to connect external capacitors. Therefore, when multiple chips are cascaded, more capacitors need to be soldered on the PCB of the backlight panel (such as Figure 1 The capacitors C1 to Cn shown in the figure increase the complexity of PCB design and the cost of PCB use. DCDC When in low voltage applications (such as when the number of LED drivers is relatively small), the high voltage LDO module is not easy to work properly, which brings application limitations to the solution.

[0004] It can be seen that a new LED backlight driving system is needed in the art, which can reduce the use of capacitors in the LED backlight driving system by using a power supply method different from that of the LED driving chip in the prior art. Summary of the invention

[0005] The technical purpose to be achieved by the present invention is to provide an LED backlight driving system and a driving method. The LED backlight driving system and method based on the present invention can solve the problem of excessive number of grounding capacitors used in LED backlight panels with multiple lamps.

[0006] Based on the above technical objectives, the present invention provides an LED backlight driving system, the LED backlight driving system comprising: a controller and a plurality of LED driving chips; the controller and the plurality of LED driving chips form a serial communication link, and the controller acts as a host to send command data to the plurality of LED driving chips as slaves;

[0007] Each of the LED driver chips is provided with a high voltage drive input pin and a low voltage drive input and output pin, and each of the LED driver chips is also provided with a high voltage LDO module;

[0008] The high-voltage drive input pin of the first LED driver chip closest to the controller in the serial communication link is connected to an external high-voltage drive power supply, and the LDO module inside the first LED driver chip converts the high-voltage drive voltage of the external high-voltage drive power supply into a low-voltage drive voltage for driving the internal circuit of the LED driver chip;

[0009] The low voltage driving input and output pins of all the LED driving chips are connected to the same driving voltage transmission line, and an external isolation capacitor is arranged between the driving voltage transmission line and the low potential reference level.

[0010] In one embodiment, high voltage driving input pins of LED driving chips other than the first LED driving chip are also connected to the driving voltage transmission line.

[0011] In one embodiment, each of the LED driver chips has a plurality of LED driver channel pins, and the LED driver channel pins are used to connect an LED light string to directly control the light emission of the LED light string.

[0012] The present invention also provides an LED backlight driving system, the LED backlight driving system comprising: a controller and a plurality of LED driving chips; the controller and the plurality of LED driving chips form a serial communication link, the controller as a host sends instruction data to the plurality of LED driving chips as slaves;

[0013] Each of the LED driver chips is provided with a high voltage drive input pin and a low voltage drive input and output pin, and each of the LED driver chips is also provided with a high voltage LDO module;

[0014] A high-voltage driving input pin of one of the plurality of LED driving chips is connected to an external high-voltage driving power supply, and an LDO module inside the LED driving chip connected to the external high-voltage driving power supply converts a high-voltage driving voltage of the external high-voltage driving power supply into a low-voltage driving voltage for driving an internal circuit of the LED driving chip;

[0015] The low voltage driving input and output pins of all the LED driving chips are connected to the same driving voltage transmission line, and an external isolation capacitor is arranged between the driving voltage transmission line and the low potential reference level.

[0016] In one embodiment, high voltage driving input pins of LED driving chips other than the first LED driving chip are also connected to the driving voltage transmission line.

[0017] In one embodiment, each of the LED driver chips has a plurality of LED driver channel pins, and the LED driver channel pins are used to connect an LED light string to directly control the light emission of the LED light string.

[0018] The present invention also provides an LED backlight driving system, the LED backlight driving system comprising: a controller and a plurality of LED driving chips; the controller and the plurality of LED driving chips form a serial communication link, the controller as a host sends instruction data to the plurality of LED driving chips as slaves;

[0019] Each of the LED driver chips has a plurality of LED driver channel pins, and the LED driver channel pins are used to connect an LED light string to directly control the light emission of the LED light string; and the number of LED elements on the LED light string is less than a first threshold;

[0020] Each LED driver chip is also provided with a low voltage driving input and output pin; the low voltage driving input and output pins of all LED driver chips are connected to the same driving voltage transmission line; and the driving voltage transmission line is connected to an external driving voltage.

[0021] In one embodiment, each of the LED driver chips is further provided with a high-voltage drive input pin, and the high-voltage drive input pins of all LED driver chips are also connected to the drive voltage transmission line.

[0022] Compared with the prior art, one or more embodiments of the present invention may have the following advantages:

[0023] The present invention utilizes low-voltage drive input and output pins to be set on the LED driver chip, and inputs the low-voltage drive voltage generated by one LED driver chip on the serial communication link to other LED driver chips, thereby avoiding the defect of using a large number of capacitor elements caused by the need to connect each LED driver chip to a high-voltage external drive power supply.

[0024] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0026] Figure 1 It is a schematic diagram of the structure of an LED backlight driving system in the prior art;

[0027] Figure 2 is a schematic structural diagram of an LED backlight driving system according to a first embodiment of the present invention;

[0028] Figure 3 is a schematic structural diagram of an LED backlight driving system according to a second embodiment of the present invention;

[0029] Figure 4 is a schematic structural diagram of an LED backlight driving system according to a third embodiment of the present invention;

[0030] Figure 5 is a schematic structural diagram of an LED backlight driving system according to a fourth embodiment of the present invention; DETAILED DESCRIPTION

[0031] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings.

[0032] It should be understood that when an element or layer is referred to as "on ...", "adjacent to ...", "connected to" or "coupled to" other elements or layers, it can be directly on, adjacent to, connected to or coupled to other elements or layers, or there can be intervening elements or layers. On the contrary, when an element is referred to as "directly on ...", "directly adjacent to ...", "directly connected to" or "directly coupled to" other elements or layers, there is no intervening element or layer. It should be understood that although the terms first, second, third, etc. can be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present invention, the first element, component, region, layer or part discussed below can be represented as the second element, component, region, layer or part. And when the second element, component, region, layer or part is discussed, it does not indicate that the present invention necessarily has the first element, component, region, layer or part.

[0033] Spatially relative terms such as "under", "beneath", "below", "under", "above", "above", etc., may be used here for convenience of description to describe the relationship between an element or feature shown in the figure and other elements or features. It should be understood that in addition to the orientation shown in the figure, the spatial relationship terms are intended to also include different orientations of the device in use and operation. For example, if the device in the accompanying drawings is turned over, then the elements or features described as "under other elements" or "under it" or "under it" will be oriented as "on" other elements or features. Therefore, the exemplary terms "under" and "under" may include both upper and lower orientations. The device can be oriented otherwise (rotated 90 degrees or other orientations) and the spatial descriptors used herein are interpreted accordingly.

[0034] The purpose of the terms used herein is only to describe specific embodiments and is not intended to be limiting of the present invention. When used herein, the singular forms "one", "an" and "said / the" are also intended to include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "consisting of" and / or "comprising", when used in this specification, determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0035] Example 1

[0036] like Figure 2 The LED backlight driving system of the present embodiment shown in the figure comprises: a controller HOST and a plurality of LED driving chips Chip1 to Chipn; the controller HOST and the plurality of LED driving chips Chip1 to Chipn form a serial communication link, and the controller acts as a host to send instruction data to the plurality of LED driving chips Chip1 to Chipn acting as slaves.

[0037] Each of the LED driving chips has a plurality of LED driving channel pins LED1 to LEDn, and the LED driving channel pins are used to connect an LED light string to directly control the light emission of the LED light string.

[0038] Each of the LED driver chips is provided with a first data transmission port DI and a second data transmission port DO. The serial communication link means that the first data transmission port DI of each LED driver chip is connected to the second data transmission port DO of the LED driver chip of the previous level adjacent to the LED driver chip, and the second data transmission port DO of each LED driver chip is connected to the first data transmission port DI of the LED driver chip of the next level adjacent to the LED driver chip, the first data transmission port DI of the first LED driver chip in the serial communication link is connected to the output port TX of the controller HOST, and the second data transmission port DO of the last LED driver chip is connected to the input port RX of the controller HOST.

[0039] Each of the LED driver chips is also provided with a high-voltage drive input pin and a low-voltage drive input and output pin, and each of the LED driver chips is also provided with a high-voltage LDO module.

[0040] In this embodiment, in the LED backlight drive system, the high-voltage drive input pin of the first LED driver chip is connected to an external high-voltage drive power supply, and the high-voltage drive voltage (for example, 24V) is converted into a low-voltage drive voltage (such as 5V) for driving the internal circuit of the LED driver chip through the LDO module inside the first LED driver chip.

[0041] In this embodiment, in the LED backlight driving system, the low-voltage driving input and output pins of all the LED driving chips are connected to the same driving voltage transmission line, so that the low-voltage driving input and output pins of the first LED driving chip transmit the low-voltage driving voltage to each LED driving chip on the serial communication link except the first LED driving chip.

[0042] At the same time, in this embodiment, an external capacitor is set between the low voltage driving input and output pin of the first LED driving chip and the low potential reference level. The low voltage driving input and output pins of the remaining LED driving chips other than the first LED driving chip no longer need to be set with an external capacitor between the low potential reference level. Thus, compared with the LED backlight driving system of the prior art, a large amount of external capacitors are saved.

[0043] In this embodiment, it is not limited to the first LED driver chip being connected to the external high-voltage driver power supply. Any LED driver chip on the serial communication link can be selected to connect to the external high-voltage driver power supply according to the actual needs of PCB wiring, and an external capacitor can be set at any position of the drive voltage output line connected to all the low-voltage drive input and output pins to still achieve the purpose of the invention.

[0044] Example 2

[0045] like Figure 3 The LED backlight driving system of the present embodiment shown in the figure comprises: a controller HOST and a plurality of LED driving chips Chip1 to Chipn; the controller HOST and the plurality of LED driving chips Chip1 to Chipn form a serial communication link, and the controller acts as a host to send instruction data to the plurality of LED driving chips Chip1 to Chipn acting as slaves.

[0046] Each of the LED driving chips has a plurality of LED driving channel pins LED1 to LEDn, and the LED driving channel pins are used to connect an LED light string to directly control the light emission of the LED light string.

[0047] Each of the LED driver chips is provided with a first data transmission port DI and a second data transmission port DO. The serial communication link means that the first data transmission port DI of each LED driver chip is connected to the second data transmission port DO of the LED driver chip of the previous level adjacent to the LED driver chip, and the second data transmission port DO of each LED driver chip is connected to the first data transmission port DI of the LED driver chip of the next level adjacent to the LED driver chip, the first data transmission port DI of the first LED driver chip in the serial communication link is connected to the output port TX of the controller HOST, and the second data transmission port DO of the last LED driver chip is connected to the input port RX of the controller HOST.

[0048] Each of the LED driver chips is also provided with a high-voltage drive input pin and a low-voltage drive input and output pin, and each of the LED driver chips is also provided with a high-voltage LDO module.

[0049] In this embodiment, in the LED backlight drive system, the high-voltage drive input pin of the first LED driver chip is connected to an external high-voltage drive power supply, and the high-voltage drive voltage (for example, 24V) is converted into a low-voltage drive voltage (such as 5V) for driving the internal circuit of the LED driver chip through the LDO module inside the first LED driver chip.

[0050] In this embodiment, in the LED backlight driving system, the low-voltage driving input and output pins of all the LED driving chips are connected to the same driving voltage transmission line. Thus, the low-voltage driving input and output pins of the first LED driving chip transmit the low-voltage driving voltage to each LED driving chip except the first LED driving chip on the serial communication link. Different from the aforementioned embodiment 1, in this embodiment, the high-voltage driving input pins of each LED driving chip except the first LED driving chip are also connected to the driving voltage transmission line.

[0051] At the same time, in this embodiment, an external capacitor is set between the low voltage driving input and output pin of the first LED driving chip and the low potential reference level. The low voltage driving input and output pins of the remaining LED driving chips other than the first LED driving chip no longer need to be set with an external capacitor between the low potential reference level. Thus, compared with the LED backlight driving system of the prior art, a large amount of external capacitors are saved.

[0052] In this embodiment, it is not limited to the first LED driver chip being connected to the external high-voltage driver power supply. Any LED driver chip on the serial communication link can be selected to connect to the external high-voltage driver power supply according to the actual needs of PCB wiring, and an external capacitor can be set at any position of the drive voltage output line connected to all the low-voltage drive input and output pins to still achieve the purpose of the invention.

[0053] Example 3

[0054] like Figure 4 The LED backlight driving system of the present embodiment shown in the figure comprises: a controller HOST and a plurality of LED driving chips Chip1 to Chipn; the controller HOST and the plurality of LED driving chips Chip1 to Chipn form a serial communication link, and the controller acts as a host to send instruction data to the plurality of LED driving chips Chip1 to Chipn acting as slaves.

[0055] Each of the LED driver chips has a plurality of LED driver channel pins LED1 to LEDn, and the LED driver channel pins are used to connect an LED light string to directly control the light emission of the LED light string. The number of LED elements on the LED light string is less than a first threshold value; for example, the first threshold value is 3, that is, the number of LED elements that each LED driver channel needs to drive is less than three.

[0056] Each of the LED driver chips is provided with a first data transmission port DI and a second data transmission port DO. The serial communication link means that the first data transmission port DI of each LED driver chip is connected to the second data transmission port DO of the LED driver chip of the previous level adjacent to the LED driver chip, and the second data transmission port DO of each LED driver chip is connected to the first data transmission port DI of the LED driver chip of the next level adjacent to the LED driver chip, the first data transmission port DI of the first LED driver chip in the serial communication link is connected to the output port TX of the controller HOST, and the second data transmission port DO of the last LED driver chip is connected to the input port RX of the controller HOST.

[0057] Each of the LED driver chips is also provided with low voltage drive input and output pins.

[0058] In this embodiment, in the LED backlight driving system, the low voltage driving input and output pins of all the LED driving chips are connected to the same driving voltage transmission line. And the driving voltage transmission line is connected to the external driving voltage V DCDC In this embodiment, since the number of LED elements that each LED driving channel needs to drive is small, the external driving voltage V DCDC The voltage is relatively low, for example, 3 to 6 V. Therefore, the external driving voltage can be directly connected to the low-voltage driving input and output pins to realize the power supply of the LED driver chip, thereby avoiding the need for external capacitor components in the LDO unit.

[0059] Example 4

[0060] like Figure 5 The LED backlight driving system of the present embodiment shown in the figure comprises: a controller HOST and a plurality of LED driving chips Chip1 to Chipn; the controller HOST and the plurality of LED driving chips Chip1 to Chipn form a serial communication link, and the controller acts as a host to send instruction data to the plurality of LED driving chips Chip1 to Chipn acting as slaves.

[0061] Each of the LED driver chips has a plurality of LED driver channel pins LED1 to LEDn, and the LED driver channel pins are used to connect an LED light string to directly control the light emission of the LED light string. The number of LED elements on the LED light string is less than a first threshold value; for example, the first threshold value is 3, that is, the number of LED elements that each LED driver channel needs to drive is less than three.

[0062] Each of the LED driver chips is provided with a first data transmission port DI and a second data transmission port DO. The serial communication link means that the first data transmission port DI of each LED driver chip is connected to the second data transmission port DO of the LED driver chip of the previous level adjacent to the LED driver chip, and the second data transmission port DO of each LED driver chip is connected to the first data transmission port DI of the LED driver chip of the next level adjacent to the LED driver chip, the first data transmission port DI of the first LED driver chip in the serial communication link is connected to the output port TX of the controller HOST, and the second data transmission port DO of the last LED driver chip is connected to the input port RX of the controller HOST.

[0063] Each of the LED driver chips is also provided with a high voltage drive input pin and a low voltage drive input and output pin.

[0064] In this embodiment, in the LED backlight driving system, the high voltage driving input pins and low voltage driving input and output pins of all the LED driving chips are connected to the same driving voltage transmission line. And the driving voltage transmission line is connected to the external driving voltage V DCDC In this embodiment, since the number of LED elements that each LED driving channel needs to drive is small, the external driving voltage V DCDC The voltage is relatively low, for example, 3 to 6 V. Therefore, the external driving voltage can be directly connected to the low-voltage driving input and output pins to realize the power supply of the LED driver chip, thereby avoiding the need for external capacitor components in the LDO unit.

[0065] The above description is only a specific implementation case of the present invention, and the protection scope of the present invention is not limited thereto. Any modification or replacement of the present invention by any technician familiar with the present technology within the technical specifications described in the present invention should be within the protection scope of the present invention.

Claims

1. An LED backlight driving system, characterized in that: The LED backlight driving system comprises: a controller and a plurality of LED driving chips; the controller and the plurality of LED driving chips form a serial communication link, and the controller acts as a host to send instruction data to the plurality of LED driving chips as slaves; Each of the LED driver chips is provided with a high-voltage drive input pin and a low-voltage drive input and output pin, and each of the LED driver chips is also provided with a high-voltage LDO module; The high-voltage drive input pin of the first LED driver chip closest to the controller in the serial communication link is connected to an external high-voltage drive power supply, and the LDO module inside the first LED driver chip converts the high-voltage drive voltage of the external high-voltage drive power supply into a low-voltage drive voltage for driving the internal circuit of the LED driver chip; The low voltage driving input and output pins of all the LED driving chips are connected to the same driving voltage transmission line, and an external isolation capacitor is arranged between the driving voltage transmission line and the low potential reference level.

2. The LED backlight driving system according to claim 1, characterized in that: The high-voltage driving input pins of the LED driving chips other than the first LED driving chip are also connected to the driving voltage transmission line.

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

4. An LED backlight driving system, characterized in that: The LED backlight driving system comprises: a controller and a plurality of LED driving chips; the controller and the plurality of LED driving chips form a serial communication link, and the controller acts as a host to send instruction data to the plurality of LED driving chips as slaves; Each of the LED driver chips is provided with a high-voltage drive input pin and a low-voltage drive input and output pin, and each of the LED driver chips is also provided with a high-voltage LDO module; A high-voltage driving input pin of one of the plurality of LED driving chips is connected to an external high-voltage driving power supply, and an LDO module inside the LED driving chip connected to the external high-voltage driving power supply converts a high-voltage driving voltage of the external high-voltage driving power supply into a low-voltage driving voltage for driving an internal circuit of the LED driving chip; The low voltage driving input and output pins of all the LED driving chips are connected to the same driving voltage transmission line, and an external isolation capacitor is arranged between the driving voltage transmission line and the low potential reference level.

5. The LED backlight driving system according to claim 4, characterized in that: The high-voltage driving input pins of the LED driving chips other than the first LED driving chip are also connected to the driving voltage transmission line.

6. The LED backlight driving system according to claim 4, characterized in that: Each of the LED driver chips has a plurality of LED driver channel pins, and the LED driver channel pins are used to connect an LED light string to directly control the light emission of the LED light string.

7. An LED backlight driving system, characterized in that: The LED backlight driving system comprises: a controller and a plurality of LED driving chips; the controller and the plurality of LED driving chips form a serial communication link, and the controller acts as a host to send instruction data to the plurality of LED driving chips as slaves; Each of the LED driver chips has a plurality of LED driver channel pins, and the LED driver channel pins are used to connect an LED light string to directly control the light emission of the LED light string; and the number of LED elements on the LED light string is less than a first threshold; Each LED driver chip is also provided with a low voltage driving input and output pin; the low voltage driving input and output pins of all LED driver chips are connected to the same driving voltage transmission line; and the driving voltage transmission line is connected to an external driving voltage.

8. The LED backlight driving system according to claim 7, characterized in that: Each of the LED driver chips is also provided with a high-voltage drive input pin, and the high-voltage drive input pins of all the LED driver chips are also connected to the drive voltage transmission line.

9. An LED backlight panel, comprising the LED backlight driving system according to any one of claims 1 to 8.

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

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