CN114449699B

CN114449699B - Display driving chip and LED lamp panel

Info

Publication number: CN114449699B
Application number: CN202011212352.5A
Authority: CN
Inventors: 李晓; 王伙荣
Original assignee: Xi'an Ti Pt Sr Electronic Technology Co ltd
Current assignee: Xi'an Ti Pt Sr Electronic Technology Co ltd
Priority date: 2020-11-03
Filing date: 2020-11-03
Publication date: 2024-06-07
Anticipated expiration: 2040-11-03
Also published as: CN114449699A

Abstract

The embodiment of the invention discloses a display driving chip and an LED lamp panel. The display driving chip includes: the voltage detection circuits are used for connecting a plurality of corresponding LED lamp strings; a detection output circuit connected to the plurality of voltage detection circuits; each voltage detection circuit is used for detecting the voltage value of the corresponding LED lamp string to obtain a measured voltage value, comparing the measured voltage value with a target voltage threshold to obtain a voltage comparison signal and outputting the voltage comparison signal to the detection output circuit, and the detection output circuit is used for generating a voltage detection signal output based on the voltage comparison signal output by each voltage detection circuit. The display driving chip disclosed by the embodiment of the invention can realize automatic detection of the channel voltage.

Description

Display driving chip and LED lamp panel

Technical Field

The invention relates to the technical field of display control, in particular to a display driving chip and an LED lamp panel.

Background

At present, the inside LED array, power chip and the display driver chip that are provided with of LED lamp plate, the LED array is all connected to display driver chip and power chip, and wherein power chip output voltage is to the LED array of its connection to thereby make the LED array give out light under the drive control of display driver chip realize the display of image. However, in the practical application process, there is often a situation that the output voltage of the power chip is unreasonable, so that the problem occurs in the LED lamp panel, for example, the voltage output by the power chip is too high, which results in that the voltage of an output point of a certain channel in the LED array is too high, so that the power consumption is increased, and the problem that the display driving chip generates heat seriously is also caused, for example, because each LED emits light, a certain starting voltage is required, when the output voltage of the power chip is too low, some LEDs in the LED array cannot be normally lightened.

Therefore, providing a solution for implementing automatic detection of the channel voltage is a current urgent problem to be solved.

Disclosure of Invention

Therefore, in order to solve the defects and shortcomings of the prior art, the embodiment of the invention provides a display driving chip and an LED lamp panel.

In one aspect, an embodiment of the present invention provides a display driving chip, including: the voltage detection circuits are used for connecting a plurality of corresponding LED lamp strings; a detection output circuit connected to the plurality of voltage detection circuits; each voltage detection circuit is used for detecting the voltage value of the corresponding connected LED lamp string to obtain a measured voltage value, comparing the measured voltage value with a target voltage threshold to obtain a voltage comparison signal and outputting the voltage comparison signal to the detection output circuit, and the detection output circuit is used for generating a voltage detection signal output based on the voltage comparison signal output by each voltage detection circuit.

Through setting up a plurality of voltage detection circuits that are used for connecting a plurality of LED lamp cluster and connect a plurality of voltage detection circuit's detection output circuit in the display driver chip, can realize automatic detection channel circuit, on the one hand can avoid appearing the channel voltage in the prior art too high, cause the consumption to rise, the serious phenomenon of display driver chip generates heat, on the other hand can avoid the channel voltage too low, lead to the phenomenon that some LEDs can not normally light, ensure to reduce the channel voltage as far as under the circumstances that display driver chip normally works and LED normally lights, thereby furthest's reduction display driver chip's consumption has improved display driver chip's performance.

In one embodiment of the present invention, the display driving chip further includes: a control circuit and a threshold selection circuit connecting the control circuit and the plurality of voltage detection circuits, wherein the threshold selection circuit is used for receiving a plurality of input voltage thresholds, selecting the target voltage threshold from the plurality of voltage thresholds based on a voltage selection signal input by the control circuit and outputting the target voltage threshold to each of the voltage detection circuits; each of the voltage detection circuits includes: and the voltage comparison module is connected with the control circuit, the corresponding LED lamp string, the threshold selection circuit and the detection output circuit and is used for comparing the measured voltage value with the target voltage threshold to obtain the voltage comparison signal and outputting the voltage comparison signal to the detection output circuit.

By arranging the control circuit and the threshold selection circuit in the display driving chip and arranging the voltage comparison module in each voltage detection circuit, the target voltage threshold can be adjusted according to actual requirements, and the flexibility of voltage detection is improved.

In one embodiment of the invention, the threshold selection module includes: the threshold selection circuit includes: a multiplexer, wherein a multiplexing voltage input end of the multiplexer receives the input voltage thresholds, and a voltage selection input end of the multiplexer is connected with the control circuit so as to select the target voltage threshold from the voltage thresholds based on the voltage selection signal and output the target voltage threshold through a selection output end of the multiplexer; the voltage comparison module includes: a first switching element and a comparator; the first input end of the first switching element is connected with the corresponding LED lamp string, and the first control end of the first switching element is connected with the control circuit; the positive input end of the comparator is connected with the first output end of the first switching element, the negative input end of the comparator is connected with the selection output end of the multiplexer, the comparison output end of the comparator is connected with the detection output circuit, and the voltage comparison signal is obtained by comparing the measured voltage value with the target voltage threshold value under the condition that the first switching element is conducted and is output to the detection output circuit through the comparison output end.

In one embodiment of the present invention, the display driving chip further includes: a first port; and the output control circuit is connected between the detection output circuit and the first port and is used for transmitting the voltage detection signal output by the detection output circuit to the first port for output.

By providing an output control circuit between the detection output circuit and the first port, it is possible to establish an electrical connection between the first port and the internal circuit of the display driving chip.

In one embodiment of the present invention, the display driving chip further includes a current adjusting circuit connected to the detection output circuit; a second port connected to the current regulation circuit; a drive enhancing circuit connected between the first port and the detection output circuit; the detection output circuit is further used for receiving a processed voltage detection signal input by the first port through the drive enhancement circuit and outputting a current regulation signal to the current regulation circuit based on the processed voltage detection signal; the current regulation circuit is used for regulating input current based on the current regulation signal so as to obtain target current to be output through the second port.

By arranging the current adjusting circuit connected with the detection output circuit in the display driving chip and arranging the drive enhancing circuit between the first port and the detection output circuit, current adjustment based on the processed voltage detection signal can be realized, and thus automatic detection of channel voltage and automatic adjustment of channel voltage are realized.

In one embodiment of the present invention, the output control circuit includes: the inverting input end of the inverter is connected with the detection output circuit; the second control end of the second switching element is connected with the inverting output end of the inverter, the second output end of the second switching element is connected with the grounding end, and the second input end of the second switching element is connected with the first port.

In one embodiment of the present invention, the current regulation circuit includes: a current input module for receiving the input current; and the current regulation module is connected with the current input module, the detection output circuit and the second port and is used for regulating the input current based on the current regulation signal and outputting the target current to the second port.

In one embodiment of the present invention, the display driving chip further includes: a third port; a fourth port; an output control circuit connected between the detection output circuit and the third port; a drive enhancing circuit connected between the third port and the detection output circuit; the current regulating circuit is connected with the detection output circuit; a mode switching circuit connecting the control circuit, the output control circuit, the current adjusting circuit, and the fourth port; the detection output circuit is further used for receiving a processed voltage detection signal input by the third port through the drive increasing circuit, outputting a current adjustment signal to the current adjustment circuit based on the processed voltage detection signal, and adjusting an input current by the current adjustment circuit based on the current adjustment signal to obtain a target current; the control circuit inputs an automatic voltage regulation signal to the mode switching circuit, so that the mode switching circuit transmits the voltage detection signal output by the detection output circuit to the third port for output, and transmits the target current output by the current regulation circuit to the fourth port for output; or the control circuit inputs a non-automatic voltage regulation signal to the mode switching circuit so that the voltage detection signal output by the detection output circuit is transmitted to the fourth port for output by the mode switching circuit.

By arranging the mode switching circuit in the display driving chip, the display driving chip can support the automatic voltage regulation mode and the non-automatic voltage regulation mode, so that the display driving chip has great freedom in the aspects of packaging type selection and client application of the display driving chip and has stronger practicability.

In one embodiment of the present invention, the mode switching circuit includes: the first selection control end of the first selector is connected with the control circuit, the first selection input end of the first selector is used for receiving a high-level signal, and the second selection input end and the first selection output end of the first selector are connected with the output control circuit; the second selection control end of the second selector is connected with the control circuit, the third selection input end of the second selector is used for receiving the high-level signal, and the fourth selection input end of the second selector is connected with the output control circuit; a third input end of the third switching element is connected with the fourth port, and a third control end of the third switching element is connected with the second selection output end of the second selector; the third selection control end of the third selector is connected with the control circuit, the fifth selection input end of the third selector is used for receiving a low-level signal, the sixth selection input end of the third selector is connected with the current regulating circuit, and the third selection output end of the third selector is connected with the third output end of the third switching element.

In another aspect, an embodiment of the present invention provides an LED lamp panel, including: m×n LED light strings, each of the LED light strings including a first connection end and a second connection end; the power chip comprises a first voltage output end and a second voltage output end, wherein the first voltage output end is connected with the first connection end of each LED lamp string; the first resistor is connected between the first voltage output end and the second voltage output end; the second resistor is connected between the second voltage output end and the grounding end; m display driving chips, wherein each display driving chip is any one of the four display driving chips mentioned above, each display driving chip is correspondingly connected with the second connecting ends of N LED light strings, N is a positive integer greater than 1, and M is a positive integer not less than 1; and one end of the third resistor is connected with the grounding end, and the other end of the third resistor is connected with the first port of each display driving chip.

In still another aspect, an embodiment of the present invention provides an LED lamp panel, including: m×n LED light strings, each of the LED light strings including a first connection end and a second connection end; the power chip comprises a first voltage output end and a second voltage output end, wherein the first voltage output end is connected with the first connection end of each LED lamp string; the first resistor is connected between the first voltage output end and the second voltage output end; the second resistor is connected between the second voltage output end and the grounding end; m display driving chips, wherein each display driving chip is a display driving chip of the fifth or seventh item, each display driving chip is correspondingly connected with the second connecting ends of N LED light strings, N is a positive integer greater than 1, and M is a positive integer not less than 1; one end of the third resistor is connected with the grounding end, and the other end of the third resistor is connected with the first port of each display driving chip; and the second ports of the target display driving chips in the M display driving chips are connected with the second voltage output end.

In still another aspect, an embodiment of the present invention provides an LED lamp panel, including: m×n LED light strings, each of the LED light strings including a first connection end and a second connection end; the power chip comprises a first voltage output end and a second voltage output end, wherein the first voltage output end is connected with the first connection end of each LED lamp string; the first resistor is connected between the first voltage output end and the second voltage output end; the second resistor is connected between the second voltage output end and the grounding end; the display driving chips are respectively the display driving chips of the eighth or ninth item, wherein each display driving chip is correspondingly connected with the second connecting ends of the N LED light strings; one end of the third resistor is connected with the grounding end; the other end of the third resistor is connected with the third port of each display driving chip, and the fourth port of a target display driving chip in the M display driving chips is connected with the second voltage output end; or the other end of the third resistor is connected with the fourth port of each display driving chip.

The above technical solution may have the following advantages or benefits: by arranging a plurality of voltage detection circuits for connecting a plurality of LED lamp strings and a detection output circuit for connecting a plurality of voltage detection circuits in a display driving chip, an automatic detection channel circuit can be realized, on one hand, the phenomenon that the power consumption is increased due to overhigh channel voltage in the prior art and the display driving chip heats seriously can be avoided, on the other hand, the phenomenon that certain LEDs cannot be normally lightened due to overhigh channel voltage can be avoided, the channel voltage is reduced as much as possible under the conditions that the display driving chip works normally and the LEDs are normally lightened, so that the power consumption of the display driving chip is reduced to the maximum extent, and the performance of the display driving chip is improved; by arranging the current adjusting circuit connected with the detection output circuit and the drive enhancing circuit connected between the first port and the detection output circuit in the display driving chip, current adjustment based on the processed voltage detection signal can be realized, and thus automatic detection of channel voltage and automatic adjustment of channel voltage are realized; by arranging the mode switching circuit in the display driving chip, the display driving chip can support the automatic voltage regulation mode and the non-automatic voltage regulation mode, so that the display driving chip has great freedom in the aspects of packaging type selection and client application of the display driving chip and has stronger practicability.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of a display driving chip according to a first embodiment of the present invention.

Fig. 2 is a schematic diagram of another structure of a display driving chip according to a first embodiment of the present invention.

Fig. 3 is a schematic diagram of a specific circuit structure of a voltage detection circuit in the display driving chip shown in fig. 2.

Fig. 4 is a schematic diagram of another structure of a display driving chip according to the first embodiment of the present invention.

Fig. 5 is a schematic diagram of a specific circuit structure of the output control circuit in the display driving chip shown in fig. 4.

Fig. 6 is a schematic structural diagram of a display driving chip applied to an LED lamp panel according to a first embodiment of the present invention.

Fig. 7 is a schematic structural diagram of a display driving chip according to a second embodiment of the present invention.

Fig. 8 is a schematic diagram of a module of the current adjusting circuit in the display driving chip shown in fig. 7.

Fig. 9 is a schematic circuit diagram of a specific circuit structure of the display driving chip shown in fig. 7.

Fig. 10 is a schematic diagram of a specific structure of an LED lamp panel with a display driving chip according to a second embodiment of the present invention.

Fig. 11 is a schematic structural diagram of a display driving chip according to a third embodiment of the present invention.

Fig. 12 is a schematic diagram of a specific circuit structure of the display driving chip shown in fig. 11.

Fig. 13 is a schematic diagram of a specific structure of a display driving chip according to a third embodiment of the present invention applied to an LED lamp panel.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

[ First embodiment ]

As shown in fig. 1, a first embodiment of the present invention discloses a display driving chip 10, which includes, for example: a plurality of voltage detection circuits 12 and a detection output circuit 13. Fig. 1 illustrates two voltage detection circuits 12, but the invention is not limited thereto.

The plurality of voltage detection circuits 12 are used for connecting a plurality of corresponding LED light strings, and the detection output circuit 13 is connected with the plurality of voltage detection circuits 12. Each voltage detection circuit 12 is configured to detect a voltage value of a corresponding connected LED string to obtain a measured voltage value, and compare the measured voltage value with a target voltage threshold to obtain a voltage comparison signal, and output the voltage comparison signal to a detection output circuit 13, where the detection output circuit 13 is configured to generate a voltage detection signal output based on the voltage comparison signal output by each voltage detection circuit.

Above through setting up the detection output circuit 13 that is used for connecting a plurality of voltage detection circuits 12 of a plurality of LED lamp cluster and connects a plurality of voltage detection circuits 12 in display driver chip 10, can realize automatic detection channel circuit, on the one hand can avoid appearing the channel voltage in the prior art too high, cause the consumption to rise, the serious phenomenon of display driver chip generates heat, on the other hand can avoid the channel voltage too low, lead to some LED not normally to light the phenomenon, ensure that the channel voltage is reduced as far as under the circumstances that display driver chip normally works and LED normally lights, thereby furthest's reduction display driver chip's consumption, display driver chip's performance has been improved.

In other embodiments of the present invention, as shown in fig. 2, the display driving chip 10 further includes, for example: a control circuit 14 and a threshold selection circuit 121. The control circuit 14 includes, for example: at least one controller, for example a programmable register, or a microprocessor such as an MCU or the like.

Further, each voltage detection circuit 12 includes, for example: the voltage comparison module 122. Wherein the threshold selection circuit 121 is connected to the control circuit 14 and each of the voltage detection circuits 12, and is configured to receive a plurality of input voltage thresholds, select the target voltage threshold from the plurality of voltage thresholds based on a voltage selection signal input from the control circuit 14, and output the target voltage threshold to each of the voltage detection circuits 12. The voltage comparison module 122 in each voltage detection circuit 12 is connected to the control circuit 14, the corresponding LED string, the threshold selection circuit 121, and the detection output circuit 13, and is configured to compare the measured voltage value with the target voltage threshold to obtain the voltage comparison signal and output the voltage comparison signal to the detection output circuit 13. It should be noted that fig. 2 illustrates one voltage detection circuit 12 as an example, and the other voltage detection circuits 12 have the same structure as that illustrated in fig. 2.

By providing the control circuit 14 and the threshold selection circuit 121 in the display driving chip 10 and providing the voltage comparison module 122 in each voltage detection circuit 12, it is realized that the target voltage threshold can be adjusted according to actual requirements, and flexibility of voltage detection is improved.

In other embodiments of the present invention, as shown in fig. 2 and 3, the threshold selection circuit 121 includes, for example: the multiplexers M1, each voltage comparison module 122, for example, includes: a first switching element N1 and a comparator C1. It should be noted that, fig. 3 illustrates one to-be-tested port 11, each voltage detection circuit 12 corresponds to one to-be-tested port 11, the to-be-tested port 11 is mainly used for establishing electrical connection between the voltage detection circuit 12 and the corresponding LED light string,

Wherein the multiplexer M1 comprises: a plurality of voltage inputs that receive the plurality of voltage thresholds input, a voltage selection input that is connected to the control circuit 14 (not shown in fig. 3) to select the target voltage threshold from the plurality of voltage thresholds based on the voltage selection signal, and a voltage selection output through which the target voltage threshold is output to each of the voltage detection circuits 12. The first switching element N1 includes: the first input end, the first control end and the first output end, wherein the first input end is connected with the corresponding LED lamp string, namely, the corresponding LED lamp string is connected with the port 11 to be tested, and the first control end is connected with the control circuit 14 (not shown in fig. 3). The comparator C1 includes: the positive input end is connected with the first output end, the negative input end is connected with the selection output end, the comparison output end is connected with the detection output circuit 13, and the voltage comparison signal obtained by comparing the measured voltage value with the target voltage threshold value under the condition that the first switching element N1 is conducted is output to the detection output circuit 13 through the comparison output end. The first switching element N1 is, for example, an NMOS transistor, but the invention is not limited thereto, and the first switching element N1 may be any other type of field effect transistor. It should be noted that, in fig. 3, one voltage detection circuit 12 is connected to the threshold selection circuit 121 as an example, and the other voltage detection circuits 12 have the same structure as that illustrated in fig. 3 and are connected to the same threshold selection circuit 121.

In other embodiments of the present invention, as shown in fig. 4, the display driving chip 10 further includes, for example: an output control circuit 15 and a first port 16. Wherein, the output control circuit 15 is connected between the detection output circuit 13 and the first port 16, and is used for transmitting the voltage detection signal output by the detection output circuit 13 to the first port 16 for output.

Specifically, as shown in fig. 5, the output control circuit 15 includes, for example: an inverter F1 and a second switching element N2, wherein the inverter F1 includes, for example: an inverting input terminal (right end of the inverter F1 shown in fig. 5) and an inverting output terminal (left end of the inverter F1 shown in fig. 5), wherein the inverting input terminal is connected with the detection output circuit 13, and is configured to invert the voltage detection signal output by the detection output circuit 13 to obtain the inverted voltage detection signal. The second switching element N2 includes: the second control end is connected with the reversed phase output end, the second output end is connected with the grounding end, the second input end is connected with the first port 16, and the second control end is used for processing the reversed phase voltage detection signal to obtain the voltage detection signal and outputting the voltage detection signal to the first port 16. The second switching element N2 is, for example, an NMOS transistor, but the embodiment is not limited thereto, and the second switching element N2 may be any other type of field effect transistor. It should be noted that, in other embodiments of the present invention, the output control circuit 15 may have other structures, for example, a plurality of inverters connected in series and a field effect transistor connected to the plurality of inverters, where the number of the plurality of inverters is singular.

In the embodiment of the present invention, the output control circuit 15 includes, for example: the electrostatic protection circuit 152 has a main function of implementing electrostatic protection of the port. The electrostatic protection circuit 152 includes, for example: the electrostatic protection resistor Rj, the electrostatic protection switch element Nj and the electrostatic protection diode Lj, wherein one end of the electrostatic protection resistor Rj is connected with the second input end of the second switch element N2, the other end is connected with the first port 16, the control end and the output end of the electrostatic protection switch element Nj are grounded, the input end is connected with the first port 16, one end of the electrostatic protection diode Lj is grounded, and the other end is connected with the input end of the electrostatic protection switch element Nj. The electrostatic protection switching element Nj is, for example, an NMOS transistor, and of course, the electrostatic protection switching element Nj may be another type of field effect transistor.

A specific implementation of the display driving chip disclosed in the embodiment of the present invention is illustrated in the following with reference to fig. 3, 5 and 6.

As shown in fig. 6, in the embodiment of the present invention, the display driving chip 10 disclosed above is disposed in an LED lamp panel 100, and the LED lamp panel 100 includes: the LED driving circuit comprises a power chip 101, M.N LED lamp strings 102, a first resistor R1, a second resistor R2, M display driving chips 10 and a third resistor Rup. The LED string 102 includes, for example, S LEDs connected in series with each other, S being a positive integer not less than 1.

Wherein each LED string 102 includes a first connection end 1021 and a second connection end 1022. The power chip 101 includes a first voltage output terminal O1 and a second voltage output terminal O2, where the first voltage output terminal O1 is connected to the first connection terminal 1021 of each LED string 102. The first resistor R1 is connected between the first voltage output terminal O1 and the second voltage output terminal O2. The second resistor R2 is connected between the second voltage output terminal O2 and the ground terminal. Each display driving chip 10 includes, for example: n ports under test 11 (out 1-outN) are correspondingly connected to the second connection ends 1022 of the N LED strings 102, where N is a positive integer greater than 1 and M is a positive integer not less than 1. One end of the third resistor Rup is connected to the ground terminal, and the other end is connected to the first port 16 of each display driving chip 10.

Since the structure of each display driving chip 10 is identical, a detailed description of the operation will be given below taking one of the display driving chips 10 as an example. Each display driver chip 10 is provided with a voltage detection circuit 12 connected to each to-be-detected port 11, the voltage detection circuit 12 completes the voltage detection of the corresponding LED string 102 in the display driver chip 10, as shown in fig. 3, the control circuit outputs, for example, a first enable signal EN1 to a first switching element N1, wherein when the first enable signal EN1 is "0", the first switching element N1 is in a non-conductive state, the display driver chip 10 does not perform the voltage detection, and when the first enable signal EN1 is "1", the first switching element N1 is in a conductive state, and the display driver chip 10 starts to perform the voltage detection. For example, the first enable signal EN1 is "1", the display driver chip 10 performs voltage detection, the multiplexer M1 is provided with 16 voltage input terminals, and then 16 voltage threshold values can be configured, but the embodiment is not limited thereto, the multiplexer input terminals of the multiplexer M1 can be configured according to actual requirements, the control circuit inputs the voltage selection signal SEL to the multiplexer M1, so that the multiplexer M1 selects the target voltage threshold value from the 16 voltage threshold values input from the 16 voltage input terminals based on the voltage selection signal SEL, and outputs the target voltage threshold value to the comparator C1 in each voltage detection circuit, wherein the voltage selection signal SEL is composed of 4 bits, for example. The comparator C1 in each voltage detection circuit receives the same target voltage threshold, compares the target voltage threshold with the measured voltage value to obtain a voltage comparison signal, outputs the voltage comparison signal to the detection output circuit 13, and if the measured voltage value, that is, the voltage at the port to be detected is higher than the target voltage threshold, it represents that the voltage at the port to be detected is higher, otherwise, it represents that the voltage at the port to be detected is lower. For example, the measured voltage value is 2V, the target voltage threshold is 1V, and the comparator C1 compares the measured voltage value with the target voltage threshold to obtain a voltage comparison signal of "1", which indicates that the voltage at the corresponding port to be measured is higher. Each voltage detection circuit 12 in the display driving chip 10 performs the voltage detection process disclosed above to obtain a respective corresponding voltage comparison signal.

As shown in fig. 5, after the detection output circuit 13 receives N voltage comparison signals, and logic processing is performed on the N voltage comparison signals, that is, when only N voltage comparison signals are all "1", it means that the measured voltage values of the corresponding N ports (OUT 1-outN) to be detected are all higher than the target voltage threshold, at this time, the detection output circuit 13 outputs a voltage detection signal fb_out represented by a high level, where the detection output circuit 13 is a circuit in the existing display driving chip, and the specific circuit structure of the detection output circuit 13 is not described in detail herein. The detection output circuit 13 outputs the voltage detection signal fb_out, which is inverted by the inverter F1 to obtain an inverted voltage detection signal represented by a low level, and sends the inverted voltage detection signal to the second control end of the second switching element N2, then the second switching element N2 processes the inverted voltage detection signal to obtain a voltage detection signal fb_out represented by a high level, and outputs the voltage detection signal fb_out from the first port 16, where the second control end of the second switching element N2 inputs the high level, and the second output end outputs the low level, and otherwise the second control end of the second switching element N2 inputs the low level, and the second output end outputs the high level.

As shown in fig. 6, since the first ports 16 of all cascaded display driving chips 10 are wired together off-chip, the wired-together is implemented by the third resistor Rup, that is, only the first ports 16 of all display driving chips 10 output high voltage, that is, the voltage of the to-be-tested ports of all display driving chips 10 is higher at this time, the first voltage VLED output by the power chip 101 is higher, and a step-down process is required, if the first port 16 of any one of the display driving chips 10 outputs low voltage, it means that at this time, the voltage of the to-be-tested port in one or several display driving chips 10 in the LED lamp panel 100 is lower, and at this time, the first voltage VLED output by the power chip 101 is lower, and a step-up process is required, so that the user can manually adjust the first voltage VLED output by the power chip 101.

In summary, in this embodiment, by providing the plurality of voltage detection circuits 12 for connecting the plurality of LED strings and the detection output circuit 13 for connecting the plurality of voltage detection circuits in the display driver chip 10, an automatic detection channel circuit can be realized, on one hand, the phenomenon that the channel voltage is too high to cause the increase of power consumption in the related art, and the display driver chip generates heat seriously can be avoided, on the other hand, the phenomenon that some LEDs cannot be normally turned on due to the too low channel voltage can be avoided, and the channel voltage is reduced as much as possible under the conditions that the display driver chip works normally and the LEDs are normally turned on, thereby reducing the power consumption of the display driver chip to the maximum extent and improving the performance of the display driver chip.

[ Second embodiment ]

As shown in fig. 7, a second embodiment of the present invention discloses a display driving chip, for example, including: a plurality of voltage detection circuits 22, a detection output circuit 23, a control circuit 24, an output control circuit 25, and a first port 26. Fig. 7 illustrates two voltage detection circuits 22, but the invention is not limited thereto.

The plurality of voltage detection circuits 22 are used for connecting a plurality of corresponding LED lamp strings, and the detection output circuit 23 is connected with the plurality of voltage detection circuits 22. The control circuit 24 is connected to each of the voltage detection circuits 22. The threshold value selection circuit 221 connects the control circuit 24 and the plurality of voltage detection circuits 22. The output control circuit 25 is connected between the detection output circuit 23 and the first port 26. Each voltage detection circuit 22 is configured to detect a voltage value of a corresponding connected LED lamp string to obtain a measured voltage value, and compare the measured voltage value with a target voltage threshold to obtain a voltage comparison signal, and output the voltage comparison signal to a detection output circuit 23, where the detection output circuit 23 is configured to generate a voltage detection signal based on the voltage comparison signal output by each voltage detection circuit, and output the voltage detection signal to the first port 26 via an output control circuit 25.

The above-mentioned to-be-measured port 21, voltage detection circuit 22, detection output circuit 23, control circuit 24, threshold selection circuit 221, output control circuit 25 and first port 26 in the present embodiment can be referred to the to-be-measured port 11, voltage detection circuit 12, detection output circuit 13, control circuit 14, threshold selection circuit 121, output control circuit 15 and first port 16 in the display driving chip 10 disclosed in the first embodiment, and the description thereof is omitted herein.

The display driving chip 20 disclosed in the present embodiment is different from the display driving chip 10 disclosed in the foregoing first embodiment in that the display driving chip 20 disclosed in the present embodiment further includes, for example: a current adjusting circuit 27, a second port 28 and a drive enhancing circuit 29, wherein the current adjusting circuit 27 is connected to the detection output circuit 23, the second port 28 is connected to the current adjusting circuit 27, and the drive enhancing circuit 29 is connected between the first port 26 and the detection output circuit 23.

The detection output circuit 23 is further configured to receive the processed voltage detection signal input from the first port 26 through the drive enhancing circuit 29, and output a current adjustment signal to the current adjustment circuit 27 based on the processed voltage detection signal. The current regulation circuit 27 is configured to regulate the input current based on the current regulation signal to obtain the target current output via the second port 28.

The mentioned driving enhancing circuit 29 includes, for example, a buffer, which can enhance the processed voltage detection signal so as to facilitate the processing of the detection output circuit 23, and of course, in other embodiments of the present invention, the display driving chip 20 may not be provided with the driving enhancing circuit 29, that is, the detection output circuit 23 is directly connected to the first port 26 through a wire.

By providing the current adjusting circuit 27 connected to the detection output circuit 23 and the drive enhancing circuit 29 connected between the first port 26 and the detection output circuit 23 in the display driving chip 20 as described above, current adjustment based on the processed voltage detection signal can be realized, thereby realizing automatic detection of the channel voltage and automatic adjustment of the channel voltage.

The above-mentioned post-processing voltage detection signal can be understood as the result of the external line and the external line of the display driving chip according to the first embodiment.

In other embodiments of the present invention, as shown in fig. 8, the current adjusting circuit 27 includes, for example: a current input module 271 and a current regulation module 272. The current input module 271 is configured to receive the input current. The current adjusting module 272 is connected to the current input module 271, the detection output circuit 23 and the second port 28, and is configured to adjust the input current based on the current adjusting signal to output the target current to the second port 28.

Specifically, as shown in fig. 9, the current adjustment module 272 includes: the circuit comprises a plurality of first current regulation switching elements D1 and a plurality of second current regulation switching elements D2 correspondingly connected with the plurality of first current regulation switching elements D1, wherein the control end of each first current regulation switching element D1 is connected with a detection output circuit 23, the output end of each first current regulation switching element D1 is connected with the input end of the corresponding second current regulation switching element D2, the input end of each first current regulation switching element D1 is connected with a second port 28, the control end of each second current regulation switching element D2 is connected with a current input module 271, and the output end of each second current regulation switching element D2 is grounded.

The current input module 271 includes, for example, a third current regulation switching element D3, a fourth current regulation switching element D4, and a fifth current regulation switching element D5, where an input end and a control end of the fifth current regulation switching element D5 are connected to a control end of the second current regulation switching element D2 and an external current source, an output end of the fifth current regulation switching element D5 is grounded, an input end of the third current regulation switching element D3 is connected to the external current source, an output end of the third current regulation switching element D3 is connected to an input end of the fourth current regulation switching element D4, a control end of the fourth current regulation switching element D4 is connected to a control end of the fifth current regulation switching element D5, and an output end of the fourth current regulation switching element D4 is grounded. The first current adjusting switch element D1, the second current adjusting switch element D2, the third current adjusting switch element D3, the fourth current adjusting switch element D4, and the fifth current adjusting switch element D5 are, for example, NMOS transistors, which is not limited to this, but may be other types of field effect transistors, and the specific number of the first current adjusting switch element D1, the second current adjusting switch element D2, the third current adjusting switch element D3, the fourth current adjusting switch element D4, and the fifth current adjusting switch element D5 is not limited to this. In fig. 9, a voltage detection circuit 22 is taken as an example, but the invention is not limited thereto, and it is worth mentioning that the voltage detection circuit 22 is connected with a corresponding LED string through the to-be-detected port 21, for example.

A specific implementation of the display driving chip disclosed in this embodiment is illustrated in the following with reference to fig. 9 and 10.

As shown in fig. 10, in the embodiment of the present invention, the display driving chip 20 disclosed above is disposed in an LED lamp panel 200, and the LED lamp panel 200 includes, for example: the power chip 201, m×n LED strings 202, a first resistor R1, a second resistor R2, M display driving chips 20, and a third resistor Rup.

Each LED light string 202 includes a first connection end 2021 and a second connection end 2022. The power chip 201 includes a first voltage output terminal O1 and a second voltage output terminal O2, wherein the first voltage output terminal O1 is connected to the first connection terminal 2021 of each LED string 202. The first resistor R1 is connected between the first voltage output terminal O1 and the second voltage output terminal O2. The second resistor R2 is connected between the second voltage output terminal O2 and the ground terminal. Each display driving chip 20 includes: n ports 21 (out 1-outN) to be tested are correspondingly connected to the second connection ends 2022 of N LED strings 202, where N is a positive integer greater than 1 and M is a positive integer not less than 1. One end of the third resistor Rup is connected to the ground terminal, and the other end is connected to the first port 26 of each display driving chip 20. Wherein the second port 28 of a target display driver chip of the M display driver chips 20, for example, the leftmost display driver chip in fig. 10, is connected to the second voltage output terminal O2.

The process of outputting the voltage detection signal fb_out of each display driving chip 20 from the first port 26 will be referred to the description of the first embodiment, and will not be repeated here.

The display driving chip disclosed in the first embodiment needs a user to manually adjust the first voltage VLED after outputting the voltage detection signal, and adds a voltage automatic adjusting function on the basis of the display driving chip disclosed in the first embodiment, namely, the display driving chip can automatically adjust the first output voltage VLED after finishing voltage detection, and the principle is as follows:

Each display driver chip 20 outputs a voltage detection signal fb_out from the first port 26, the LED lamp panel 200 connects the first ports 26 of all display driver chips 20 together through the third resistor Rup line, when the voltage detection signal fb_out output by all display driver chips is at a high level, the line and result are at a high level, when the voltage detection signal fb_out output by one display driver chip is at a low level, the voltage detection signal output by the first port 26 of all display driver chips is changed to a low level, the line and result are at a low level, that is, the voltage detection signal output by each display driver chip 20 is processed inside the LED lamp panel 200, that is, the aforementioned line and processing result are performed to obtain a processed voltage detection signal, wherein when the voltage detection signal output by each display driver chip 20 is at a high level, the processed voltage detection signal is at a high level, and when the voltage detection signal output by one display driver chip 20 is at a low level, the processed voltage detection signal is at a low level.

The detection output circuit 23 of the display driving chip 20 is connected to the first port 26 through the buffer H1 in the driving enhancing circuit 29, i.e. the processed voltage detection signal can be read from the first port 26, wherein the buffer 29 functions to enhance the driving capability. The detection output circuit 23 may then output a current adjustment signal to the current adjustment circuit based on the processed voltage detection signal fb_out_r, i.e., the detection output circuit 23 determines whether to boost or buck the processed voltage detection signal fb_out_r. For example, when the voltage detection signal fb_out output by one display driver chip 20 is low and the voltage detection signals fb_out output by the other display driver chips 20 are high, the result of the external line summation of the display driver chips 20 is low, so that the processed voltage detection signal fb_out_r is low, and the output detection circuit 23 receives the processed voltage detection signal fb_out_r with low, and then outputs a current adjustment signal to the current adjustment circuit 27 for current adjustment, thereby increasing VLED.

Specifically, the current input module 271 and the current adjustment module 272 constitute a current mirror circuit in which the current input module 271 receives an input current I0 from an external current source, a first current adjustment switching element D1 in the current adjustment module 272 is connected to the detection output circuit 23, the corresponding first current adjustment switching element D1 is in a conductive state when a current adjustment signal input by the detection output circuit 23 is "1", and the corresponding first current adjustment switching element D1 is in a non-conductive state when the current adjustment signal is "0", and adjustment of the input current is completed by changing the current adjustment signal to output the target current I1 to the second port 28.

Wherein, any one of the M display driver chips 20 is selected as a target display driver chip, and the second port 28 thereof is connected to the second voltage output terminal O2, and at this time, the target current output from the target display driver chip can be equivalently referred to as a pull-down resistor R, and the voltage regulation formula is as follows: vled=vref (1+r1/(r2||r)), where Vref is a reference voltage inside the power chip 202. The detection output circuit 23 of the target display driving chip will calculate the output current adjustment signal according to the processed voltage detection signal fb_out_r until VLED reaches an ideal value, that is, the voltage values of all the ports to be tested are higher than the target voltage threshold value, and VLED is the lowest.

In summary, the present embodiment can implement current adjustment based on the processed voltage detection signal by providing the current adjustment circuit 27 connected to the detection output circuit 23 and the drive enhancing circuit 29 connected between the first port 26 and the detection output circuit 23 in the display driving chip 20, thereby implementing automatic detection of the channel voltage and automatic adjustment of the channel voltage.

[ Third embodiment ]

As shown in fig. 11, a third embodiment of the present invention discloses a display driving chip, for example, including: a plurality of voltage detection circuits 32, a detection output circuit 33, a control circuit 34, a threshold selection circuit 321, an output control circuit 35, a third port 36, a current regulation circuit 37, a fourth port 38, and a drive enhancement circuit 39. Fig. 11 illustrates two voltage detection circuits 32, but the invention is not limited thereto.

The voltage detection circuits 32 are used for connecting a plurality of corresponding LED lamp panels, and the detection output circuit 33 is connected with the voltage detection circuits 32. The control circuit 34 is connected to each of the voltage detection circuits 32. The threshold value selection circuit 321 connects the control circuit 34 and each voltage detection circuit 32. The output control circuit 35 is connected between the detection output circuit 33 and the first port 36. The current adjusting circuit 37 is connected to the detection output circuit 33, the fourth port 38 is connected to the current adjusting circuit 37, and the drive enhancing circuit 39 is connected between the third port 36 and the detection output circuit 33.

The specific circuit descriptions of the voltage detection circuit 32, the detection output circuit 33, the control circuit 34, the threshold selection circuit 321, the output control circuit 35, the current adjustment circuit 37 and the drive enhancement circuit 39 included in the display driving chip 30 in this embodiment can refer to the foregoing embodiments, and are not repeated herein for brevity.

The display driving chip 30 disclosed in this embodiment is different from the display driving chip disclosed in the foregoing embodiment in that the display driving chip 30 disclosed in this embodiment can support two voltage adjustment functions, namely, an automatic voltage adjustment function as disclosed in the foregoing second embodiment and a non-automatic voltage adjustment function as disclosed in the foregoing first embodiment, and specifically, the display driving chip 30 disclosed in this embodiment further includes, for example: a mode switching circuit 40 connected to the control circuit 34, the output control circuit 35, the current adjusting circuit 37, and the fourth port 38.

Wherein each voltage detection circuit 32 is configured to detect a voltage value of a corresponding connected LED lamp panel to obtain a measured voltage value, and compare the measured voltage value with a target voltage threshold to obtain a voltage comparison signal, and output the voltage comparison signal to the detection output circuit 33, the detection output circuit 33 is configured to generate a voltage detection signal output based on the voltage comparison signal output by each voltage detection circuit 32, and the detection output circuit 33 is further configured to receive the processed voltage detection signal input by the third port 36 through the drive adding circuit 39, and output a current adjustment signal to the current adjustment circuit 37 based on the processed voltage detection signal, so that the input current is adjusted by the current adjustment circuit 37 based on the current adjustment signal to obtain the target current.

Wherein, when the display driving chip 30 operates in the automatic voltage adjustment mode, the control circuit 34 inputs an automatic voltage adjustment signal to the mode switching circuit 40 to output a voltage detection signal to the third port 36 by the mode switching circuit 40 and to output the target current output from the current adjustment circuit 37 from the fourth port 38.

When the display driving chip 30 operates in the non-automatic voltage regulation mode, the control circuit 34 inputs a non-automatic voltage regulation signal to the mode switching circuit 40 to transmit the voltage detection signal to the output from the fourth port 38 by the mode switching circuit 40.

The scheme shown in fig. 12 is compatible with the two embodiments, and since the requirements of different chip packages and power chip models for voltage detection are different, the switching between the automatic voltage regulation mode and the non-automatic voltage regulation mode can be realized through the structure shown in fig. 12, and the circuit architecture outside the display driving chip 30 will change when the display driving chip 30 adopts different modes. It should be noted that fig. 12 only illustrates one voltage detection circuit 32 as an example, and the invention is not limited thereto, and it should be noted that each voltage detection circuit 32 is connected to a corresponding LED string through the to-be-detected port 31, for example.

Further, as shown in fig. 12, the mode switching circuit 40 includes, for example: the first selector B1, the second selector B2, the third selector B3, and the third switching element N3. The first selector B1, the second selector B2, and the third selector B3 are, for example, two-out selectors, which can select one of the two input signals to be output based on the mode selection signal input by the control circuit 34.

The control circuit 34 outputs, for example, a mode selection signal rg_fb_auto to the first selector B1, the second selector B2 and the third selector B3, wherein when the mode selection signal rg_fb_auto is "1", the corresponding mode selection signal is an automatic voltage adjustment signal, and the current operation mode of the display driver chip 30 is the automatic voltage adjustment mode, and then the third port 36 and the fourth port 38 of the display driver chip 30 have the same functions as the first port 26 and the second port 28 of the second embodiment, so that the voltage detection process described in the foregoing second embodiment can be implemented. When the mode selection signal rg_fb_auto is "0", the corresponding mode selection signal is a non-automatic voltage regulation signal, and the current operation mode of the display driver chip 30 is the non-automatic voltage regulation mode, that is, only the voltage detection is performed, and the output voltage VLED of the power supply chip is externally or manually regulated, and the fourth port 38 of the display driver chip 30 has the same function as the first port 16 of the first embodiment, so that the voltage detection process described in the foregoing first embodiment can be implemented.

Specifically, the first selector B1 includes: a first selection control terminal, a first selection input terminal, a second selection input terminal and a first selection output terminal, wherein the first selection control terminal is connected with the control circuit 34, the first selection input terminal is used for receiving a high-level signal such as "1", the second selection input terminal is connected with the inverter F1, and the first selection output terminal is connected with the second control terminal of the second switching element N2. The second selector B2 includes: a second selection control terminal, a third selection input terminal, a fourth selection input terminal and a second selection output terminal, wherein the second selection control terminal is connected with the control circuit 34, the third selection input terminal is used for receiving the high level signal, such as '1', and the fourth selection input terminal is connected with a second inverter F2. The third switching element N3 includes: a third input terminal, a third output terminal and a third control terminal, wherein the third input terminal is connected to the fourth port 38, and the third control terminal is connected to the second selection output terminal of the second selector B2. The third selector B3 includes: a third selection control terminal connected to the control circuit 34, a fifth selection input terminal for receiving a low level signal such as "0", a sixth selection input terminal connected to the current adjusting circuit 37, and a third selection output terminal connected to the third output terminal of the third switching element N3.

When the display driving chip 30 operates in the automatic voltage regulation mode, the first selector B1 outputs the inverted voltage detection signal fb_det output from the inverter F1 to the second switching element N2 for processing and outputs the voltage detection signal fb_out to the third port 36, the second selector B2 outputs the high level signal "1" to the third control terminal of the third switching element N3, and the third selector B3 outputs the target current I1 to the third switching element N3, and the third switching element N3 outputs the target current to the fourth port 38, thereby realizing the automatic voltage detection and automatic voltage regulation functions similar to those disclosed in the foregoing second embodiment, and the third port 36 and the fourth port 38 have the same functions as the first port 26 and the second port 28 in the second embodiment.

In addition, when the display driving chip 30 operates in the non-automatic voltage regulation mode, the first selector B1 outputs the high level signal "1" to the second switching element N2, so that the first port 36 does not output the voltage detection signal fb_out, the third selector B3 outputs the low level signal, for example, "0", to the third switching element N3, and the second selector B2 outputs the inverted voltage detection signal fb_det obtained by processing the voltage detection signal fb_out by the second inverter F2 to the third switching element N3 and outputs the voltage detection signal fb_out to the fourth port 38, thereby realizing the voltage automatic detection and manual voltage regulation functions similar to those disclosed in the first embodiment, and the fourth port 38 has the same functions as the first port 16 in the first embodiment. It should be noted that the aforementioned second inverter F2 may also be the same inverter as the inverter F1, i.e. the fourth selection input terminal of the second selector B2 may be directly connected to the inverting output terminal of the inverter F1.

It should be noted that, the display driving chip 30 disclosed in the present embodiment is disposed in an LED lamp panel, for example, as shown in fig. 13, the LED lamp panel 300 further includes: m×n LED strings, a power chip 301, a first resistor R1, a second resistor R2, and a third resistor Rup. Wherein each LED string comprises, for example, a first connection terminal and a second connection terminal, the power chip 301 comprises, for example, a first voltage output terminal O1 and a second voltage output terminal O2, wherein the first voltage output terminal O1 is connected to the first connection terminal of each LED string, a first resistor R1 is connected between the first voltage output terminal O1 and the second voltage output terminal O2, and a second resistor R2 is connected between the second voltage output terminal O2 and a ground terminal, and each display driving chip 30 comprises: and N ports (out 0-outN) to be tested are correspondingly connected with the second connecting ends of the N LED lamp strings, and one end of a third resistor Rup is connected with the grounding end. Wherein, when the display driving chips 30 operate in the automatic voltage regulation mode, the other end of the third resistor Rup is connected to the third port 36 of each of the display driving chips 30, and the fourth port 38 of a target display driving chip of the M display driving chips 30, for example, the leftmost display driving chip of fig. 13, is connected to the second voltage output terminal O2. Or when the display driving chips 30 are operated in the non-automatic voltage regulation mode, the other end of the third resistor Rup is connected to the fourth port 38 of each of the display driving chips 30.

In short, based on the foregoing first embodiment and second embodiment, the display driving chip 30 disclosed in the present embodiment is actually applied to the LED lamp panel, the operation mode of the display driving chip 30 may be determined first, and then the peripheral circuit of the display driving chip 30 is set based on the determined operation mode, thereby obtaining the LED lamp panel similar to fig. 6 or 10.

Of course, in other embodiments of the present invention, the compatibility of the two operation modes of the display driving chip may be implemented on the same LED lamp panel, as shown in fig. 13, where a 0 ohm resistor is soldered on the PCB circuit board of the LED lamp panel 300 to implement the compatibility of the two operation modes in the display driving chip, that is, when each display driving chip 30 works in the automatic voltage regulation mode, the 0 ohm resistor between the fourth port 38 and the second voltage output terminal O2 is soldered, and the 0 ohm resistor between the third port 36 and the third resistor Rup of each display driving chip 30 is soldered, and the other 0 ohm resistors are not soldered; when each display driver chip 30 is operated in the non-automatic voltage regulation mode, the 0 ohm resistor between the fourth port 38 of each display driver chip 30 and the third resistor Rup is soldered, and the other 0 ohm resistors are not soldered.

In summary, by setting the mode switching circuit in the display driving chip, the display driving chip can support the automatic voltage regulation mode and the non-automatic voltage regulation mode, so that the display driving chip has great freedom in the aspects of packaging selection and client application, and has stronger practicability.

In addition, it should be understood that the foregoing embodiments are merely exemplary illustrations of the present invention, and the technical solutions of the embodiments may be arbitrarily combined and matched without conflict in technical features, contradiction in structure, and departure from the purpose of the present invention.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A display driving chip, comprising:

the voltage detection circuits are used for connecting a plurality of corresponding LED lamp strings;

a detection output circuit connected to the plurality of voltage detection circuits;

Each voltage detection circuit is used for detecting the voltage value of the corresponding connected LED lamp string to obtain a measured voltage value, comparing the measured voltage value with a target voltage threshold to obtain a voltage comparison signal and outputting the voltage comparison signal to the detection output circuit, and the detection output circuit is used for generating a voltage detection signal output based on the voltage comparison signal output by each voltage detection circuit;

the display driving chip further includes:

A control circuit;

A third port;

A fourth port;

a mode switching circuit connected to the control circuit, the detection output circuit, and the fourth port;

The control circuit inputs an automatic voltage regulation signal to the mode switching circuit so that the mode switching circuit transmits the voltage detection signal output by the detection output circuit to the third port for output; or alternatively

The control circuit inputs a non-automatic voltage regulation signal to the mode switching circuit so that the mode switching circuit transmits the voltage detection signal output by the detection output circuit to the fourth port for output;

wherein the mode switching circuit includes:

the first selection control end of the first selector is connected with the control circuit, and the first selection input end of the first selector is used for receiving a high-level signal;

the second selection control end of the second selector is connected with the control circuit, and the third selection input end of the second selector is used for receiving the high-level signal;

A third input end of the third switching element is connected with the fourth port, and a third control end of the third switching element is connected with a second selection output end of the second selector;

And a third selector, wherein a third selection control end of the third selector is connected with the control circuit, a fifth selection input end of the third selector is used for receiving a low-level signal, and a third selection output end of the third selector is connected with a third output end of the third switching element.

2. The display driver chip of claim 1, further comprising: a threshold selection circuit connecting the control circuit and the plurality of voltage detection circuits, the threshold selection circuit being configured to receive a plurality of input voltage thresholds, and select the target voltage threshold from the plurality of voltage thresholds based on a voltage selection signal input by the control circuit and output the target voltage threshold to each of the voltage detection circuits;

Each of the voltage detection circuits includes: and the voltage comparison module is connected with the control circuit, the corresponding LED lamp string, the threshold selection circuit and the detection output circuit and is used for comparing the measured voltage value with the target voltage threshold to obtain the voltage comparison signal and outputting the voltage comparison signal to the detection output circuit.

3. The display driver chip of claim 2, wherein the threshold selection circuit comprises: a multiplexer, wherein a multiplexing voltage input end of the multiplexer receives the input voltage thresholds, and a voltage selection input end of the multiplexer is connected with the control circuit so as to select the target voltage threshold from the voltage thresholds based on the voltage selection signal and output the target voltage threshold through a selection output end of the multiplexer;

The voltage comparison module includes: a first switching element and a comparator; the first input end of the first switching element is connected with the corresponding LED lamp string, and the first control end of the first switching element is connected with the control circuit; the positive input end of the comparator is connected with the first output end of the first switching element, the negative input end of the comparator is connected with the selection output end of the multiplexer, the comparison output end of the comparator is connected with the detection output circuit, and the voltage comparison signal is obtained by comparing the measured voltage value with the target voltage threshold value under the condition that the first switching element is conducted and is output to the detection output circuit through the comparison output end.

4. The display driver chip of claim 2, further comprising:

A first port;

And the output control circuit is connected between the detection output circuit and the first port and is used for transmitting the voltage detection signal output by the detection output circuit to the first port for output.

5. The display driver chip of claim 4, further comprising:

The current regulating circuit is connected with the detection output circuit;

A second port connected to the current regulation circuit;

A drive enhancing circuit connected between the first port and the detection output circuit;

The detection output circuit is further used for receiving a processed voltage detection signal input by the first port through the drive enhancement circuit and outputting a current regulation signal to the current regulation circuit based on the processed voltage detection signal;

the current regulation circuit is used for regulating input current based on the current regulation signal so as to obtain target current to be output through the second port.

6. The display driver chip according to claim 4 or 5, wherein the output control circuit includes:

The inverting input end of the inverter is connected with the detection output circuit;

The second control end of the second switching element is connected with the inverting output end of the inverter, the second output end of the second switching element is connected with the grounding end, and the second input end of the second switching element is connected with the first port.

7. The display driver chip of claim 5, wherein the current adjustment circuit comprises:

a current input module for receiving the input current;

and the current regulation module is connected with the current input module, the detection output circuit and the second port and is used for regulating the input current based on the current regulation signal and outputting the target current to the second port.

8. The display driver chip of claim 2, further comprising:

An output control circuit connected between the detection output circuit and the third port and connected to the mode switching circuit;

a drive enhancing circuit connected between the third port and the detection output circuit;

A current adjusting circuit connected to the detection output circuit and the mode switching circuit;

The detection output circuit is further used for receiving a processed voltage detection signal input by the third port through the drive increasing circuit, outputting a current adjustment signal to the current adjustment circuit based on the processed voltage detection signal, and adjusting an input current by the current adjustment circuit based on the current adjustment signal to obtain a target current;

When the control circuit inputs the automatic voltage regulation signal to the mode switching circuit, the mode switching circuit transmits the target current output by the current regulation circuit to the fourth port for output.

9. The display driver chip of claim 8, wherein the second select input and the first select output of the first selector are connected to the output control circuit; a fourth selection input end of the second selector is connected with the output control circuit; a sixth selection input of the third selector is connected to the current regulating circuit.

10. An LED lamp panel, comprising:

m×n LED light strings, each of the LED light strings including a first connection end and a second connection end;

the power chip comprises a first voltage output end and a second voltage output end, wherein the first voltage output end is connected with the first connection end of each LED lamp string;

The first resistor is connected between the first voltage output end and the second voltage output end;

The second resistor is connected between the second voltage output end and the grounding end;

M display driver chips, each of which is a display driver chip according to any one of claims 1 to 3, wherein each of the display driver chips is correspondingly connected to the second connection ends of N LED light strings, where N is a positive integer greater than 1, and M is a positive integer not less than 1;

and one end of the third resistor is connected with the grounding end, and the other end of the third resistor is connected with the first port of each display driving chip.

11. An LED lamp panel, comprising:

M display driving chips, each of which is a display driving chip according to claim 5 or 7, wherein each display driving chip is correspondingly connected to the second connection ends of N LED light strings, where N is a positive integer greater than 1, and M is a positive integer not less than 1;

one end of the third resistor is connected with the grounding end, and the other end of the third resistor is connected with the first port of each display driving chip;

And the second ports of the target display driving chips in the M display driving chips are connected with the second voltage output end.

12. An LED lamp panel, comprising:

M display driving chips, each of which is a display driving chip according to claim 8 or 9, wherein each display driving chip is correspondingly connected with the second connection ends of N LED light strings;

One end of the third resistor is connected with the grounding end;

the other end of the third resistor is connected with the third port of each display driving chip, and the fourth port of a target display driving chip in the M display driving chips is connected with the second voltage output end; or alternatively

The other end of the third resistor is connected with the fourth port of each display driving chip.