LED backlight system with low power consumption mode

Abstract

The invention discloses an LED backlight system with a low power consumption mode. The LED backlight system comprises a controller and a plurality of LED driving chips, each LED driving chip is provided with an LDO unit, a logic operation unit and a low-power-consumption control module. The low-power-consumption control module comprises an input signal detection unit and an LDO enable signal generation unit. The input signal detection unit is used for detecting whether instruction data is input to an input port of the LED driving chip and correspondingly generating an input signal judgment signal; the LDO enable signal generation unit correspondingly generates an LDO enable signal according to the input signal judgment signal and a low-power-consumption starting signal generated by the logical operation unit so as to control whether the LDO unit works or not; and the LDO unit converts an external high-voltage driving power supply into a low-voltage driving power supply under the control of the LDO enable signal so as to drive a logical operation unit in the LED driving chip to work.

Description

Technical Field

[0001] The present invention relates to the field of image display technology, and in particular to an LED backlight system with a low power consumption mode. 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] The existing LED backlight driver chip will enter the normal working mode after power-on. Once the system does not communicate for a long time and the backlight is set to off, the LED backlight chip system can shut down some functions, but the power supply part, such as the LDO unit, still consumes a lot of power and does not completely enter the low power state.

[0004] It can be seen that there is a need in the art for an LED backlight system with a low power consumption mode, which can further reduce power consumption when the LED driver chip is in a low power consumption state by shutting down the power supply part inside the chip. Summary of the invention

[0005] The present invention provides an LED backlight system with a low power consumption mode. The method can realize that when the LED driver chip enters the low power consumption mode, the LDO unit inside the LED driver chip is turned off to further reduce the overall power consumption of the LED driver chip, and can also realize that when data is input, the LDO unit is awakened in time to provide low voltage power supply for the internal circuit of the LED driver chip.

[0006] Based on the above technical objectives, the present invention provides an LED backlight system with a low power consumption mode, the method comprising:

[0007] A controller and a plurality of LED driver chips; the controller and the plurality of LED driver chips form a serial communication link, and the controller acts as a host to send command data to the plurality of LED driver chips as slaves;

[0008] Each of the LED driver chips is provided with an LDO unit, a logic operation unit and a low power consumption control module;

[0009] The low power consumption control module includes an input signal detection unit and an LDO enable signal generation unit;

[0010] The input signal detection unit is used to detect whether there is instruction data input to the input port of the LED driver chip and generate an input signal determination signal accordingly;

[0011] The LDO enable signal generating unit generates an LDO enable signal according to the input signal determination signal and the low power startup signal generated by the logic operation unit to control whether the LDO unit works;

[0012] The LDO unit converts the external high-voltage driving power into a low-voltage driving power under the control of the LDO enable signal to drive the logic operation unit inside the LED driving chip to work.

[0013] In one embodiment, the input signal detection unit is composed of a Schmitt trigger circuit. When the data input port of the LED driver chip receives instruction data, the input signal determination signal maintains a high level 1; when no instruction data is received, the input signal determination signal maintains a low level 0.

[0014] In one embodiment, the LDO enable signal generating unit is composed of an RS trigger circuit. When the input signal determines that the signal is a low level 0 and the low power start signal is a low level 0, the LDO enable signal generating unit generates an enable signal for shutting down the LDO unit. When the input signal determines that the signal is a high level 1, the LDO enable signal generating unit generates an enable signal for starting the LDO unit.

[0015] In one embodiment, each of the LED driver chips is provided with a high-voltage drive input pin and a low-voltage drive input and output pin; 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.

[0016] In one embodiment, 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 provided between the driving voltage transmission line and the low potential reference level.

[0017] 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.

[0018] 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.

[0019] Compared with the prior art, one or more embodiments of the present invention may have the following advantages:

[0020] By setting a low-power control module, the present invention can further turn off not only the logic operation circuit inside the driver chip but also the LDO power conversion circuit inside the driver chip in the low-power mode, thereby further reducing the power consumption of the chip. At the same time, the low-power control module of the present invention can detect the input instruction data and restore the LDO power conversion module in time, so as not to affect the power supply of the LDO module to the logic operation module.

[0021] 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, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] 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:

[0023] Figure 1 It is a schematic diagram of the structure of an LED backlight system in the prior art;

[0024] Figure 2 It is a schematic diagram of the structure of the LED backlight system of the present invention;

[0025] Figure 3 It is a structural schematic diagram of a low power consumption control module of the present invention;

[0026] Figure 4 It is a schematic diagram of the structure of the input signal detection unit of the present invention;

[0027] Figure 5 It is a schematic diagram of the structure of the LDO enable signal generating unit of the present invention; DETAILED DESCRIPTION

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] Example 1

[0033] like Figure 2The 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.

[0034] 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.

[0035] 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.

[0036] Each of the LED driver chips is also provided with a high-voltage driver input pin VIN and a low-voltage driver input and output pin VDD, and each of the LED driver chips is also provided with a high-voltage LDO module.

[0037] 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.

[0038] 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. And 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.

[0039] 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.

[0040] 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.

[0041] In this embodiment, in order to turn off the LDO module inside the LED driver chip to further reduce the power consumption of the LED driver chip in a low power state, as shown in FIG. Figure 3 As shown, a low power consumption control module is provided inside the LED driver chip. The low power consumption control module includes an input signal detection unit and an LDO enable signal generation unit. The input signal detection unit is as shown in FIG. Figure 4 As shown, it is composed of a Schmitt trigger circuit, having an input end and an output end, the input end inputs the transmission data input by the first data transmission port DI, and the Schmitt trigger circuit delays the high level of the transmission data to generate a high-level input signal determination signal S and outputs it from the output end, that is, when the first data transmission port DI receives high-low level transmission data, the input signal determination signal S maintains a high level 1, and when no high-low level transmission data is received, the input signal determination signal S maintains a low level 0. Figure 5 As shown, the LDO enable signal generating unit is composed of an RS trigger, and the R port of the RS trigger inputs the input signal determination signal S generated by the input signal detection unit; the S port of the RS trigger inputs the low power mode start signal R generated by the logic operation unit inside the LED driver chip. The logic truth table of the RS trigger is shown in Table 1 below:

[0042] S R Y Function 0 0 0 / 1 Keep 0 1 0 Clear 1 0 1 Set 1 1 -- prohibit

[0043] Table 1

[0044] Thus, when the logic operation unit inside the LED driver chip determines that there is no actual driving data input according to the state of the first data transmission port DI, the LED driver chip is started to enter the low power mode, and the low power mode start signal R is input to the LDO enable signal generation unit, and the LDO enable signal generation unit outputs the enable signal Y for stopping the LDO unit from working according to the low power mode start signal R and the input signal determination signal S. When the first data transmission port DI receives the transmission data of high and low levels, the input signal determination signal S becomes a high level 1, at which time the LDO enable signal generation unit will immediately generate the enable signal Y for starting the LDO unit to work to restore the VDD power supply to the entire LED driver chip.

[0045] 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 system with a low power consumption mode, characterized in that: A controller and a plurality of LED driver chips; the controller and the plurality of LED driver chips form a serial communication link, and the controller acts as a host to send command data to the plurality of LED driver chips as slaves; Each of the LED driver chips is provided with an LDO unit, a logic operation unit and a low power consumption control module; The low power consumption control module includes an input signal detection unit and an LDO enable signal generation unit; The input signal detection unit is used to detect whether there is instruction data input to the input port of the LED driver chip and generate an input signal determination signal accordingly; The LDO enable signal generating unit generates an LDO enable signal according to the input signal determination signal and the low power startup signal generated by the logic operation unit to control whether the LDO unit works; The LDO unit converts the external high-voltage driving power into a low-voltage driving power under the control of the LDO enable signal to drive the logic operation unit inside the LED driving chip to work.

2. The LED backlight system according to claim 1, characterized in that: The input signal detection unit is composed of a Schmitt trigger circuit. When the data input port of the LED driver chip receives instruction data, the input signal determination signal maintains a high level 1; when no instruction data is received, the input signal determination signal maintains a low level 0.

3. The LED backlight system according to claim 1, characterized in that: The LDO enable signal generating unit is composed of an RS trigger circuit. When the input signal determines that the signal is a low level 0 and the low power startup signal is a low level 0, the LDO enable signal generating unit generates an enable signal for shutting down the LDO unit. When the input signal determines that the signal is a high level 1, the LDO enable signal generating unit generates an enable signal for starting the LDO unit.

4. The LED backlight system according to claim 1, characterized in that: Each of the LED driver chips is provided with a high-voltage drive input pin and a low-voltage drive input and output pin; 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.

5. The LED backlight system according to claim 1, characterized in that: 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.

6. The LED backlight system according to claim 1, characterized in that: 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.

7. The LED backlight 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.

8. The LED backlight 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.

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

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

Images