CN114449699A

CN114449699A - Display driving chip and LED lamp panel

Info

Publication number: CN114449699A
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: 2022-05-06

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 the corresponding LED lamp strings; a detection output circuit connected to the plurality of voltage detection circuits; each voltage detection circuit is used for detecting a 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 based on the voltage comparison signal output by each voltage detection circuit and outputting the voltage detection signal. 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, an LED array, a power chip and a display driver chip are arranged inside an LED lamp panel, the display driver chip and the power chip are both connected to the LED array, wherein the power chip outputs voltage to the connected LED array, so that the LED array emits light under the drive control of the display driver chip to realize the display of images. However, in the practical application process, the situation that the LED lamp panel has a problem due to unreasonable output voltage of the power supply chip often exists, for example, the problem that the power consumption is increased and the display driving chip generates heat seriously due to too high output voltage of a certain channel in the LED array is caused by too high output voltage of the power supply chip, and if each LED needs a certain starting voltage for light emission, when the output voltage of the power supply chip is too low, some LEDs in the LED array cannot be normally lighted.

Therefore, it is an urgent problem to provide a scheme for implementing automatic detection of channel voltage.

Disclosure of Invention

Therefore, to overcome the defects and shortcomings of the prior art, embodiments of the present invention provide a display driver chip and an LED lamp panel.

In one aspect, a display driving chip provided in an embodiment of the present invention includes: the voltage detection circuits are used for connecting the corresponding LED lamp strings; a detection output circuit connected to the plurality of voltage detection circuits; each voltage detection circuit is used for detecting a 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 based on the voltage comparison signal output by each voltage detection circuit and outputting the voltage detection signal.

Through set up a plurality of voltage detection circuit that are used for connecting a plurality of LED lamp cluster and connect a plurality of voltage detection circuit's detection output circuit in showing driver chip, can realize automated inspection channel circuit, on the one hand can avoid appearing the channel voltage among the prior art too high, cause the consumption to rise, show driver chip serious phenomenon of generating heat, on the other hand can avoid the channel voltage to hang down, lead to the phenomenon that some LED can not normally light up, guarantee under the circumstances that shows driver chip normal work and LED normally lights up, reduce the channel voltage as far as possible, thereby furthest's reduction shows driver chip's consumption, the performance that shows driver chip has been improved.

In one embodiment of the present invention, the display driving chip further includes: a control circuit and a threshold selection circuit connected to the control circuit and the plurality of voltage detection circuits, wherein the threshold selection circuit is 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 a voltage comparison signal and outputting the voltage comparison signal to the detection output circuit.

The control circuit and the threshold selection circuit are arranged in the display driving chip, and the voltage comparison module is arranged in each voltage detection circuit, so that 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 comprises: the threshold selection circuit includes: a multiplexer, a voltage input terminal of the multiplexer receiving the input voltage thresholds, and a voltage selection input terminal of the multiplexer being connected to the control circuit to select the target voltage threshold from the voltage thresholds based on the voltage selection signal and output the selected voltage threshold through a selection output terminal of the multiplexer; the voltage comparison module includes: a first switching element and a comparator; the first input end of the first switch element is connected with the corresponding LED lamp string, and the first control end of the first switch element is connected with the control circuit; the positive input end of the comparator is connected with the first output end of the first switch element, the negative input end of the comparator is connected with the selection output end of the multiplexer, and the comparison output end of the comparator is connected with the detection output circuit, so that the voltage comparison signal obtained by comparing the measured voltage value with the target voltage threshold value is output to the detection output circuit through the comparison output end under the condition that the first switch element is switched on.

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 outputting.

The first port can be electrically connected with the internal circuit of the display driving chip by arranging the output control circuit between the detection output circuit and the first port.

In an 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 regulating circuit; a drive enhancement 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 adjusting circuit is used for adjusting the input current based on the current adjusting signal to obtain a target current to be output through the second port.

By arranging the current regulating circuit connected with the detection output circuit in the display driving chip and arranging the driving enhancement circuit between the first port and the detection output circuit, current regulation based on a processed voltage detection signal can be realized, and thus, automatic detection of channel voltage and automatic regulation of the 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; and a second control end of the second switching element is connected with the inverted output end of the phase inverter, a second output end of the second switching element is connected with a ground end, and a second input end of the second switching element is connected with the first port.

In one embodiment of the present invention, the current regulating circuit includes: a current input module for receiving the input current; and the current adjusting module is connected with the current input module, the detection output circuit and the second port and used for adjusting the input current based on the current adjusting 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 enhancement 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 connected to the control circuit, the output control circuit, the current regulating 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 and outputting a current regulation signal to the current regulation circuit based on the processed voltage detection signal, so that the current regulation circuit regulates the input current based on the current regulation signal to obtain a target current; the control circuit inputs an automatic voltage regulating 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 regulating circuit to the fourth port for output; or the control circuit inputs a non-automatic voltage regulating 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.

By arranging the mode switching circuit in the display driving chip, the display driving chip not only supports the automatic voltage regulation mode but also supports the non-automatic voltage regulation mode, so that the display driving chip has great freedom in packaging type selection and customer application, and has stronger practicability.

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

On the other hand, the embodiment of the invention provides an LED lamp panel, which comprises: m X N LED lamp strings, wherein each LED lamp string comprises a first connecting end and a second connecting end; the power supply chip comprises a first voltage output end and a second voltage output end, wherein the first voltage output end is connected with the first connecting end of each LED lamp string; a first resistor connected between the first voltage output terminal and the second voltage output terminal; a second resistor connected between the second voltage output terminal and a ground terminal; each display driving chip is any one of the first four mentioned display driving chips, wherein each display driving chip is correspondingly connected with the second connecting ends of the N LED lamp strings, N is a positive integer larger than 1, and M is a positive integer not smaller 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 another aspect, an embodiment of the present invention provides an LED lamp panel, including: m X N LED lamp strings, wherein each LED lamp string comprises a first connecting end and a second connecting end; the power supply chip comprises a first voltage output end and a second voltage output end, wherein the first voltage output end is connected with the first connecting end of each LED lamp string; a first resistor connected between the first voltage output terminal and the second voltage output terminal; a second resistor connected between the second voltage output terminal and a ground terminal; the display driving chips are the display driving chips of the fifth item or the seventh item, wherein each display driving chip is correspondingly connected with the second connecting ends of the N LED lamp strings, N is a positive integer larger than 1, and M is a positive integer not smaller 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 port of a target display driving chip in the M display driving chips is connected with the second voltage output end.

In another aspect, an embodiment of the present invention provides an LED lamp panel, including: m X N LED lamp strings, wherein each LED lamp string comprises a first connecting end and a second connecting end; the power supply chip comprises a first voltage output end and a second voltage output end, wherein the first voltage output end is connected with the first connecting end of each LED lamp string; a first resistor connected between the first voltage output terminal and the second voltage output terminal; a second resistor connected between the second voltage output terminal and a ground terminal; the display driving chips are the display driving chips of the eighth item or the ninth item, wherein each display driving chip is correspondingly connected with the second connecting ends of the N LED lamp 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.

One or more of the above technical solutions may have the following advantages or beneficial effects: the display driving chip is internally provided with a plurality of voltage detection circuits for connecting a plurality of LED lamp strings and a detection output circuit for connecting the plurality of voltage detection circuits, so that the channel circuit can be automatically detected, on one hand, the phenomenon that the channel voltage is too high to cause power consumption increase and the display driving chip generates heat seriously in the prior related art can be avoided, on the other hand, the phenomenon that some LEDs cannot be normally lightened due to too low channel voltage can be avoided, and the channel voltage is reduced as far as possible under the condition that the display driving chip normally works and the LEDs are normally lightened, so that the power consumption of the display driving chip is reduced to the greatest extent, and the performance of the display driving chip is improved; the current regulation circuit connected with the detection output circuit and the drive enhancement circuit connected between the first port and the detection output circuit are arranged in the display drive chip, so that the current regulation can be realized based on the processed voltage detection signal, and the automatic detection of the channel voltage and the automatic regulation of the channel voltage are realized; by arranging the mode switching circuit in the display driving chip, the display driving chip not only supports the automatic voltage regulation mode but also supports the non-automatic voltage regulation mode, so that the display driving chip has great freedom in packaging type selection and customer application, and has stronger practicability.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

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

Fig. 2 is another schematic structural diagram of a display driver 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 driver chip shown in fig. 2.

Fig. 4 is a schematic structural diagram of a display driver chip according to a 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 driver chip shown in fig. 4.

Fig. 6 is a schematic structural view of a display driver 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 driver chip according to a second embodiment of the present invention.

FIG. 8 is a block diagram of a current regulator circuit in the display driver IC shown in FIG. 7.

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

Fig. 10 is a schematic structural diagram of a specific structure of an LED lamp panel in which a display driver chip is located according to a second embodiment of the present invention.

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

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

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

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

[ first embodiment ] A method for manufacturing a semiconductor device

As shown in fig. 1, a first embodiment of the present invention discloses a display driving chip 10, which includes: 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 voltage detection circuits 12 are used for connecting corresponding LED strings, and the detection output circuit 13 is connected to the voltage detection circuits 12. Each voltage detection circuit 12 is configured to detect a voltage value of the LED light string connected correspondingly to obtain a measured voltage value, compare the measured voltage value with a target voltage threshold value to obtain a voltage comparison signal, and output the voltage comparison signal to the detection output circuit 13, where the detection output circuit 13 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.

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

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

Further, each voltage detection circuit 12 includes, for example: a voltage comparison module 122. The threshold selection circuit 121 is connected to the control circuit 14 and each voltage detection circuit 12, and is 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 14 and output the selected target voltage threshold to each voltage detection circuit 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, and the other voltage detection circuits 12 have the same configuration as the configuration illustrated in fig. 2.

By arranging the control circuit 14 and the threshold selection circuit 121 in the display driving chip 10 and arranging the voltage comparison module 122 in each voltage detection circuit 12, the target voltage threshold can be adjusted according to actual requirements, and the 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 of the voltage comparison modules 122, for example, includes: a first switching element N1 and a comparator C1. It should be noted that fig. 3 illustrates one port to be tested 11, each voltage detection circuit 12 corresponds to one port to be tested 11, the port to be tested 11 is mainly used for electrically connecting the voltage detection circuit 12 with the corresponding LED light string,

wherein, multiplexer M1 includes: a plurality of voltage inputs receiving the input voltage thresholds, a voltage selection input connected to control circuit 14 (not shown in fig. 3) for selecting the target voltage threshold from the voltage thresholds based on the voltage selection signal, and a voltage selection output for outputting to each voltage detection circuit 12 via the selection output. The first switching element N1 includes: the circuit comprises a first input end, a first control end and a first output end, wherein the first input end is connected with the corresponding LED lamp string, namely, the first input end is connected with the corresponding LED lamp string through the port to be tested 11, and the first control end is connected with a control circuit 14 (not shown in fig. 3). The comparator C1 includes: a positive input terminal, a negative input terminal, and a comparison output terminal, wherein the positive input terminal is connected to the first output terminal, the negative input terminal is connected to the selection output terminal, and the comparison output terminal is connected to the detection output circuit 13, so that when the first switch element N1 is turned on, the measured voltage value is compared with the target voltage threshold value, and the voltage comparison signal is output to the detection output circuit 13 through the comparison output terminal. The first switch element N1 is, for example, an NMOS transistor, but the invention is not limited thereto, and the first switch element N1 may also be other types of field effect transistors. It should be noted that fig. 3 illustrates an example in which one voltage detection circuit 12 is connected to the threshold selection circuit 121, and the other voltage detection circuits 12 have the same configuration 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: an output control circuit 15 and a first port 16. The output control circuit 15 is connected between the detection output circuit 13 and the first port 16, and is configured to transmit 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 (a right end of the inverter F1 shown in fig. 5) and an inverting output terminal (a left end of the inverter F1 shown in fig. 5), where the inverting input terminal is connected to the detection output circuit 13 and is configured to perform an inverting process on 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 inverted output end, the second output end is connected with the grounding end, the second input end is connected with the first port 16 and used for processing the inverted voltage detection signal to obtain the voltage detection signal output 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 also be other types of field effect transistors. It should be noted that in other embodiments of the present invention, the output control circuit 15 may also have other structures, for example, including a plurality of inverters connected in series and a fet 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 main function of the esd protection circuit 152 is to implement electrostatic protection of the port. The electrostatic protection circuit 152 includes, for example: the electrostatic protection circuit comprises an electrostatic protection resistor Rj, an electrostatic protection switching element Nj and an electrostatic protection diode Lj, wherein one end of the electrostatic protection resistor Rj is connected with a second input end of the second switching element N2, the other end of the electrostatic protection resistor Rj is connected with the first port 16, a control end and an output end of the electrostatic protection switching 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 of the electrostatic protection diode Lj is connected with an input end of the electrostatic protection switching element Nj. The electrostatic protection switching element Nj is, for example, an NMOS transistor, but may be another type of field effect transistor.

A specific implementation of the display driver chip disclosed in the embodiment of the present invention is illustrated in conjunction with fig. 3, fig. 5, and fig. 6.

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

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, wherein 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 ground. Each display driver chip 10 includes, for example: the N ports to be tested 11(out1-outN) are correspondingly connected to the second connection terminals 1022 of the N LED light 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 driver chip 10 is the same, the following description will be made by taking one of the display driver chips 10 as an example. As shown in fig. 3, the control circuit outputs a first enable signal EN1 to the first switch element N1, for example, when the first enable signal EN1 is "0", the first switch element N1 is in a non-conductive state, the display driving chip 10 does not perform voltage detection, and when the first enable signal EN1 is "1", the first switch element N1 is in a conductive state, the display driving chip 10 starts performing voltage detection. For example, if the first enable signal EN1 is "1", the display driving chip 10 performs voltage detection, and the multiplexer M1 is provided with 16 voltage input ends, for example, 16 voltage thresholds may be configured, but this embodiment is not limited thereto, the multiple voltage input ends of the multiplexer M1 may be set according to actual requirements, the control circuit inputs the voltage selection signal SEL to the multiplexer M1, and the multiplexer M1 selects a target voltage threshold from the 16 voltage thresholds input by the 16 voltage input ends based on the voltage selection signal SEL and outputs the target voltage threshold to the comparator C1 in each voltage detection circuit, where 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, and then compares the target voltage threshold with the measured voltage value to obtain a voltage comparison signal, and outputs the voltage comparison signal to the detection output circuit 13, where if the measured voltage value is that 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, and 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 value is 1V, and the comparator C1 compares the measured voltage value with the target voltage threshold value to obtain a voltage comparison signal "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 corresponding voltage comparison signal.

As shown in fig. 5, after the detection output circuit 13 receives the N voltage comparison signals, the N voltage comparison signals are subjected to and logic processing, that is, when only the N voltage comparison signals are all "1", it indicates that the measured voltage values of the corresponding N ports to be detected (OUT1-outN) 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 an existing display driver chip, and a specific circuit structure of the detection output circuit 13 is not described in detail herein. The detection output circuit 13 outputs a 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 the inverted voltage detection signal is sent to the second control terminal of the second switch element N2, and then the second switch element N2 processes the inverted voltage detection signal to obtain a voltage detection signal FB _ OUT represented by a high level, and the voltage detection signal FB _ OUT is output from the first port 16, wherein the input of the second control terminal of the second switch element N2 is a high level, the output of the second output terminal is a low level, otherwise, the input of the second control terminal of the second switch element N2 is a low level, and the output of the second output terminal is a high level.

As shown in fig. 6, since the first ports 16 of all the cascaded display driver chips 10 are "wired and" connected together outside the chip, a wired and is realized through the third resistor Rup, that is, only the first ports 16 of all the display driver chips 10 output high levels, that is, the voltages of the ports to be tested of all the display driver chips 10 are high at this time, which means that the first voltage VLED output by the power chip 101 is high, and a voltage reduction process is required to be performed, if the first port 16 of any one of the display driver chips 10 outputs low level, which means that the voltages of the ports to be tested inside one or more display driver chips 10 are low in the LED lamp panel 100 at this time, and the first voltage VLED output by the power chip 101 is low at this time, and a voltage boosting process is required to be performed, so that a user can manually adjust the first voltage VLED output by the power chip 101.

In summary, in the present embodiment, 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 are disposed in the display driving chip 10, so as to achieve automatic detection of the channel circuit, on one hand, a phenomenon that the channel voltage is too high to cause power consumption increase and the display driving chip generates heat seriously in the related art can be avoided, on the other hand, a phenomenon that some LEDs cannot be normally lit due to too low channel voltage can be avoided, and it is ensured that the channel voltage is reduced as much as possible under the condition that the display driving chip normally operates and the LEDs are normally lit, 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.

[ 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 voltage detection circuits 22 are used for connecting corresponding LED strings, and the detection output circuit 23 is connected to the voltage detection circuits 22. The control circuit 24 is connected to each voltage detection circuit 22. The threshold 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 the LED string connected correspondingly to obtain a measured voltage value, compare the measured voltage value with a target voltage threshold value to obtain a voltage comparison signal, and output the voltage comparison signal to the 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 the output control circuit 25.

In the present embodiment, the aforementioned port to be tested 21, the voltage detection circuit 22, the detection output circuit 23, the control circuit 24, the threshold selection circuit 221, the output control circuit 25, and the first port 26 can all refer to the related descriptions of the port to be tested 11, the voltage detection circuit 12, the detection output circuit 13, the control circuit 14, the threshold selection circuit 121, the output control circuit 15, and the first port 16 in the display driving chip 10 disclosed in the first embodiment, and the description of the present embodiment is omitted here for brevity.

The display driver chip 20 disclosed in this embodiment is different from the display driver chip 10 disclosed in the foregoing first embodiment in that the display driver chip 20 disclosed in this embodiment further includes, for example: a current regulating circuit 27, a second port 28 and a drive enhancing circuit 29, wherein the current regulating circuit 27 is connected with the detection output circuit 23, the second port 28 is connected with the current regulating 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 driving enhancement circuit 29, and output a current adjustment signal to the current adjustment circuit 27 based on the processed voltage detection signal. The current adjusting circuit 27 is used for adjusting the input current based on the current adjusting signal to obtain a target current output via the second port 28.

The mentioned driving enhancement 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 enhancement circuit 29, that is, the detection output circuit 23 is directly connected to the first port 26 through a wire.

As described above, 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 driver chip 20, it is possible to perform current adjustment based on the processed voltage detection signal, thereby realizing automatic detection of the channel voltage and automatic adjustment of the channel voltage.

The processed voltage detection signal can be understood as the result of the external wired-and of the display driving chip mentioned in the first embodiment.

In other embodiments of the present invention, as shown in fig. 8, the current regulating 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 and output the target current to the second port 28.

Specifically, as shown in fig. 9, the current adjusting module 272 includes: a plurality of first current adjusting switch elements D1 and a plurality of second current adjusting switch elements D2 correspondingly connected to the plurality of first current adjusting switch elements D1, wherein a control terminal of each first current adjusting switch element D1 is connected to the detection output circuit 23, an output terminal of each first current adjusting switch element D1 is connected to an input terminal of a corresponding second current adjusting switch element D2, an input terminal of each first current adjusting switch element D1 is connected to the second port 28, a control terminal of the second current adjusting switch element D2 is connected to the current input module 271, and an output terminal of the second current adjusting switch element D2 is grounded.

The current input module 271 includes, for example, a third current regulation switch element D3, a fourth current regulation switch element D4, and a fifth current regulation switch element D5, wherein an input terminal and a control terminal of the fifth current regulation switch element D5 are connected to the control terminal of the second current regulation switch element D2 and an external current source, an output terminal of the fifth current regulation switch element D5 is grounded, an input terminal of the third current regulation switch element D3 is connected to the external current source, an output terminal of the third current regulation switch element D3 is connected to the input terminal of the fourth current regulation switch element D4, a control terminal of the fourth current regulation switch element D4 is connected to the control terminal of the fifth current regulation switch element D5, and an output terminal of the fourth current regulation switch element D4 is grounded. The first current regulation switch element D1, the second current regulation switch element D2, the third current regulation switch element D3, the fourth current regulation switch element D4 and the fifth current regulation switch element D5 are NMOS transistors, for example, although this embodiment is not limited thereto, other types of field effect transistors may be used, and the specific number of the first current regulation switch element D1, the second current regulation switch element D2, the third current regulation switch element D3, the fourth current regulation switch element D4 and the fifth current regulation switch element D5 is not limited in this embodiment. Fig. 9 illustrates an example of a voltage detection circuit 22, but the invention is not limited thereto, and it should be noted that the voltage detection circuit 22 is connected to the corresponding LED light string through the port to be tested 21, for example.

A specific embodiment of the display driving chip disclosed in this embodiment is illustrated in conjunction with fig. 9 and 10.

As shown in fig. 10, the display driver chip 20 disclosed in the foregoing of the embodiment of the present invention is, for example, disposed in an LED lamp panel 200, and the LED lamp panel 200 includes: the LED lamp comprises a power supply chip 201, M X N LED lamp 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 ground. Each display driving chip 20 includes: the N ports to be tested 21(out1-outN) are correspondingly connected to the second connection terminals 2022 of the N LED light 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 the target display driver chip of the M display driver chips 20, e.g., the leftmost display driver chip in fig. 10, is connected to the second voltage output terminal O2.

For the process of each display driving chip 20 outputting its own voltage detection signal FB _ OUT from the first port 26, reference may be made to the description of the first embodiment, and no further description is provided herein.

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 the display driving chip disclosed in this embodiment adds an automatic voltage adjustment function on the basis of the display driving chip disclosed in the first embodiment, that is, the first output voltage VLED can be automatically adjusted after the voltage detection is completed, and the principle is as follows:

each display driving 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 the display driving chips 20 together through a third resistor Rup line, when the voltage detection signals FB _ OUT output by all the display driving chips are at a high level, the line and result is at a high level, when the voltage detection signal FB _ OUT of one display driving chip is at a low level, the voltage detection signals output by the first ports 26 of all the display driving chips are at a low level, the line and result is at a low level, that is, the voltage detection signals output by each display driving chip 20 are processed inside the LED lamp panel 200, that is, the aforementioned line and process are performed to obtain the processed voltage detection signals, wherein when the voltage detection signals output by each display driving chip 20 are at a high level, the processed voltage detection signals are at a high level, when there is a low level of the voltage detection signal output from the display driving chip 20, the processed voltage detection signal is at a low level.

The detection output circuit 23 of the display driver chip 20 is connected to the first port 26 through a buffer H1 in the driving enhancement circuit 29, so that the processed voltage detection signal can be read from the first port 26, wherein the buffer 29 is used for enhancing the driving capability. The detection output circuit 23 may then output a current regulation signal to the current regulation circuit based on the processed voltage detection signal FB _ OUT _ R, i.e., the detection output circuit 23 determines whether to step up or step down the processed voltage detection signal FB _ OUT _ R. For example, if the voltage detection signal FB _ OUT output by one display driver chip 20 of the N display driver chips 20 is at a low level, and the voltage detection signals FB _ OUT output by the other display driver chips 20 are at a high level, the result of the external wired-and of the display driver chips 20 is at a low level, so that the processed voltage detection signal FB _ OUT _ R is at a low level, and after the output detection circuit 23 receives the processed voltage detection signal FB _ OUT _ R at the low level, the output detection circuit outputs a current adjustment signal to the current adjustment circuit 27 for current adjustment, so as to increase VLED.

Specifically, the current input block 271 and the current adjusting block 272 constitute a current mirror circuit, wherein the current input block 271 receives an input current I0 from an external current source, the first current adjusting switch element D1 in the current adjusting block 272 is connected to the detection output circuit 23, when the current adjusting signal inputted from the detection output circuit 23 is "1", the corresponding first current adjusting switch element D1 is in a conducting state, and when the current adjusting signal is "0", the corresponding first current adjusting switch element D1 is in a non-conducting state, and the current adjusting signal is changed to complete the adjustment of the input current so as 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, at this time, the target current output from the target display driver chip can be equivalent to a pull-down resistor R, and the voltage regulation formula is: VLED ═ Vref (1+ R1/(R2| | | R)), where Vref is the reference voltage inside the power chip 202. The detection output circuit 23 of the target display driver chip continuously calculates 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, and VLED is the lowest.

In summary, in the present embodiment, the current adjusting circuit 27 connected to the detection output circuit 23 and the driving enhancement circuit 29 connected between the first port 26 and the detection output circuit 23 are disposed in the display driving chip 20, so that current adjustment based on the processed voltage detection signal can be realized, and automatic detection of the channel voltage and automatic adjustment of the channel voltage can be realized.

[ 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.

Wherein, a plurality of voltage detection circuit 32 are used for connecting a plurality of LED lamp plates that correspond, detect output circuit 33 and connect a plurality of voltage detection circuit 32. The control circuit 34 is connected to each voltage detection circuit 32. The threshold 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 regulation circuit 37 is connected to the detection output circuit 33, the fourth port 38 is connected to the current regulation circuit 37, and the drive enhancement circuit 39 is connected between the third port 36 and the detection output circuit 33.

For a specific description 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 regulation circuit 37 and the driving enhancement circuit 39 included in the display driving chip 30 disclosed in this embodiment, reference may be made to the foregoing embodiments, and details are not repeated herein for brevity.

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

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

When the display driver chip 30 operates in the auto voltage regulation mode, the control circuit 34 inputs the auto voltage regulation signal to the mode switching circuit 40, so that the mode switching circuit 40 outputs the voltage detection signal to the third port 36 for output, and outputs the target current output by the current regulation circuit 37 from the fourth port 38.

When the display driver chip 30 operates in the non-auto voltage regulation mode, the control circuit 34 inputs the non-auto voltage regulation signal to the mode switching circuit 40, so that the mode switching circuit 40 transmits the voltage detection signal to the output terminal 38.

The scheme shown in fig. 12 is compatible with the two embodiments, and since different chip packages and power chip types have different requirements for voltage detection, the structure shown in fig. 12 can realize switching between the auto-regulated voltage mode and the non-auto-regulated voltage mode, and certainly when the display driver chip 30 adopts different modes, the circuit architecture outside the display driver chip 30 needs to be changed accordingly. It should be noted that fig. 12 only illustrates one voltage detection circuit 32, but the invention is not limited thereto, and it should be noted that each voltage detection circuit 32 is connected to the corresponding LED string through the port 31 to be tested, for example.

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

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 AUTO voltage regulation signal, the current operation mode of the display driver chip 30 is an AUTO voltage regulation mode, and then the third port 36 and the fourth port 38 in the display driver chip 30 have the same functions as the first port 26 and the second port 28 in 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-AUTO voltage regulation signal, and the current operating mode of the display driver chip 30 is a non-AUTO voltage regulation mode, that is, only voltage detection is performed, and the output voltage VLED of the power supply chip is regulated externally or manually, and at this time, 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 connected to the control circuit 34, a first selection input terminal for receiving a high level signal, for example "1", a second selection input terminal connected to the inverter F1, and a first selection output terminal connected to the second control terminal of the second switching element N2. The second selector B2 includes: a second selection control terminal connected to the control circuit 34, a third selection input terminal for receiving the high level signal, for example "1", a fourth selection input terminal connected to a second inverter F2, and a second selection output terminal. The third switching element N3 includes: a third input terminal connected to the fourth port 38, a third output terminal connected to the second selection output terminal of the second selector B2, and a third control terminal. 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, for example, "0", a sixth selection input terminal connected to the current regulating circuit 37, and a third selection output terminal connected to the third output terminal of the third switching element N3.

When the display driver chip 30 operates in the auto voltage regulation mode, the first selector B1 outputs the inverted voltage detection signal FB _ DET outputted from the inverter F1 to the second switch 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, the third switching element N3 outputs the target current to the fourth port 38, thereby achieving the automatic voltage detection and automatic voltage regulation functions similar to those disclosed in the foregoing second embodiment, in which 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-auto voltage adjusting 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, e.g., "0", to the third switching element N3, 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 for processing, and outputs the voltage detection signal FB _ OUT to the fourth port 38, thus, the automatic voltage detection and manual voltage adjustment functions similar to those disclosed in the first embodiment described above are achieved, and the fourth port 38 has the same function 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, that is, 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 this embodiment is, for example, disposed in the LED lamp panel, for example, as shown in fig. 13, the LED lamp panel 300 further includes: the LED lamp comprises M X N LED lamp strings, a power supply chip 301, a first resistor R1, a second resistor R2 and a third resistor Rup. Each LED string for example includes a first connection end and a second connection end, the power chip 301 for example includes a first voltage output end O1 and a second voltage output end O2, wherein the first voltage output end O1 is connected to the first connection end of each LED string, the first resistor R1 is connected between the first voltage output end O1 and the second voltage output end O2, the second resistor R2 is connected between the second voltage output end O2 and a ground end, and each display driving chip 30 includes: the N ports (out0-outN) to be tested are correspondingly connected with the N second connecting ends of the LED lamp strings, and one end of a third resistor Rup is connected with the grounding end. When the display driver chips 30 operate in the auto voltage regulation mode, the other end of the third resistor Rup is connected to the third port 36 of each display driver chip 30, and the fourth port 38 of a target display driver chip, for example, the leftmost display driver chip in fig. 13, in the M display driver chips 30 is connected to the second voltage output terminal O2. Or when the display driving chips 30 operate in the non-automatic voltage regulation mode, the other end of the third resistor Rup is connected to the fourth port 38 of each display driving chip 30.

In short, based on the foregoing first embodiment and second embodiment, the display driver chip 30 disclosed in this embodiment is actually applied to an LED lamp panel, and the working mode of the display driver chip 30 may be determined first, and then the peripheral circuit of the display driver chip 30 is set based on the determined working mode, so as to obtain an LED lamp panel similar to that in fig. 6 or fig. 10.

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

In summary, by setting the mode switching circuit in the display driver chip, the display driver chip supports both the automatic voltage regulation mode and the non-automatic voltage regulation mode, so that the display driver chip has great freedom in packaging type selection and client application, and is more practical.

In addition, it should be understood that the foregoing embodiments are merely exemplary illustrations of the present invention, and technical solutions of the embodiments can be arbitrarily combined and used without conflict between technical features and structures, and without departing from the purpose of the present invention.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present 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 solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. A display driver chip, comprising:

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

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

each voltage detection circuit is used for detecting a 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 based on the voltage comparison signal output by each voltage detection circuit and outputting the voltage detection signal.

2. The display driver chip of claim 1, further comprising: a control circuit and a threshold selection circuit connected with the control circuit and the voltage detection circuits, wherein the threshold selection circuit is used for receiving a plurality of input voltage thresholds and selecting the target voltage threshold from the voltage thresholds to output to each voltage detection circuit based on a voltage selection signal input by the control circuit;

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 a 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, a voltage input terminal of the multiplexer receiving the input voltage thresholds, and a voltage selection input terminal of the multiplexer being connected to the control circuit to select the target voltage threshold from the voltage thresholds based on the voltage selection signal and output the selected voltage threshold through a selection output terminal of the multiplexer;

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

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 outputting.

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 regulating circuit;

a drive enhancement 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 adjusting circuit is used for adjusting the input current based on the current adjusting signal to obtain a 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 comprises:

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

and a second control end of the second switching element is connected with the inverted output end of the phase inverter, a second output end of the second switching element is connected with a ground end, and a 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 regulation circuit comprises:

a current input module for receiving the input current;

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

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

a third port;

a fourth port;

an output control circuit connected between the detection output circuit and the third port;

a drive enhancement 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 connected to the control circuit, the output control circuit, the current regulating 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 and outputting a current regulation signal to the current regulation circuit based on the processed voltage detection signal, so that the current regulation circuit regulates the input current based on the current regulation signal to obtain a target current;

the control circuit inputs an automatic voltage regulating 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 regulating circuit to the fourth port for output; or

The control circuit inputs a non-automatic voltage regulating 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.

9. The display driver chip of claim 8, wherein the mode switching circuit comprises:

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

a second selector, a second selection control end of which is connected to the control circuit, a third selection input end of which is used for receiving the high-level signal, and a fourth selection input end of which is connected to the output control circuit;

a third switching element, a third input terminal of which is connected to the fourth port, and a third control terminal of which is connected to the second selection output terminal of the second selector;

a third selector, a third selection control terminal of the third selector is connected to the control circuit, a fifth selection input terminal of the third selector is used for receiving a low level signal, a sixth selection input terminal of the third selector is connected to the current regulation circuit, and a third selection output terminal of the third selector is connected to a third output terminal of the third switching element.

10. The utility model provides a LED lamp plate, its characterized in that includes:

m X N LED lamp strings, wherein each LED lamp string comprises a first connecting end and a second connecting end;

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

a first resistor connected between the first voltage output terminal and the second voltage output terminal;

a second resistor connected between the second voltage output terminal and a ground terminal;

m display driving chips, each display driving chip being as claimed in any one of claims 1 to 4, wherein each display driving chip is correspondingly connected to the second connection terminals of the N LED lamp 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. The utility model provides a LED lamp plate, its characterized in that includes:

m display driving chips, each display driving chip being the display driving chip of claim 5 or 7, wherein each display driving chip is correspondingly connected to the second connection terminals of N LED lamp 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 port of a target display driving chip in the M display driving chips is connected with the second voltage output end.

12. The utility model provides a LED lamp plate, its characterized in that includes:

m display driver chips, each of which is the display driver chip of claim 8 or 9, wherein each of the display driver chips is correspondingly connected to the second connection terminals 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.