CN213462414U - Constant current source generating circuit, display driving chip, LED lamp panel and LED display screen - Google Patents
Constant current source generating circuit, display driving chip, LED lamp panel and LED display screen Download PDFInfo
- Publication number
- CN213462414U CN213462414U CN202022429270.8U CN202022429270U CN213462414U CN 213462414 U CN213462414 U CN 213462414U CN 202022429270 U CN202022429270 U CN 202022429270U CN 213462414 U CN213462414 U CN 213462414U
- Authority
- CN
- China
- Prior art keywords
- current
- module
- output
- target
- switching element
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Control Of Indicators Other Than Cathode Ray Tubes (AREA)
Abstract
The embodiment of the utility model discloses constant current source production circuit, a show driver chip, a LED lamp plate and a LED display screen, constant current source production circuit includes: the current generation module is used for generating a reference current; the temperature detection module is connected with the current generation module and used for generating a target voltage difference representing the current circuit temperature based on the reference current and generating an output current regulation signal based on the target voltage difference; the current adjusting module is connected with the current generating module and the temperature detecting module and used for adjusting the reference current based on the current adjusting signal to obtain a target adjusting current; and the constant current output module is connected with the current regulating module and is used for regulating the target regulating current so as to output the target current. The embodiment of the utility model discloses constant current source generating circuit can prevent to show that driver chip leads to the life-span decline along with operating temperature constantly rises and causes the dangerous condition of burning out even, and the hardware is with low costs and nimble adjustable.
Description
Technical Field
The utility model relates to a show control technical field, especially relate to a constant current source generating circuit, a show driver chip, a LED lamp plate and a LED display screen.
Background
At present, in the application of an LED display driving chip, there often exists a situation that a channel current is large to cause a temperature of the display driving chip to rise quickly, and an excessively high temperature of the display driving chip causes performance degradation, a reduction in a working life, and even burning out to cause more serious consequences.
The conventional method for protecting the temperature of the display driving chip is to arrange a thermistor outside the display driving chip, and when the temperature of the display driving chip changes, the resistance value of the thermistor also changes, so that the power supply voltage of the display driving chip is adjusted to change the working state of the display driving chip to realize temperature adjustment.
Therefore, it is an urgent problem to provide a temperature protection scheme for a display driver chip with low hardware cost.
SUMMERY OF THE UTILITY MODEL
Therefore, in order to solve the defects and deficiencies of the prior art, the embodiment of the utility model discloses a constant current source generating circuit, a display driver chip, a LED lamp plate and a LED display screen.
On the one hand, the embodiment of the utility model discloses a constant current source produces circuit, include: the current generation module is used for generating a reference current; the temperature detection module is connected with the current generation module and used for generating a target voltage difference representing the current circuit temperature based on the reference current and generating an output current regulation signal based on the target voltage difference; the current adjusting module is connected with the current generating module and the temperature detecting module and used for adjusting the reference current based on the current adjusting signal to obtain a target adjusting current; and the constant current output module is connected with the current regulating module and is used for regulating the target regulating current so as to output the target current.
The temperature detection module is arranged in the constant current source generating circuit and connected with the current generating module and the current adjusting module, so that a target voltage difference representing the current circuit temperature is generated based on the reference current output by the current generating module, an output current adjusting signal is generated based on the target voltage difference and is sent to the current adjusting module, the reference current is adjusted by the current adjusting module based on the current adjusting signal, the dangerous condition that the service life of the display driving chip is reduced along with the continuous rising of the working temperature and even burnt is caused can be prevented, the condition that a controller and an analog-to-digital converter are arranged outside the display driving chip to reduce the target current is avoided, the hardware cost is low, and the hardware is flexible and adjustable.
In an embodiment of the present invention, the constant current source generating circuit further includes: the control module is connected with the temperature detection module, the current regulation module and the constant current output module; wherein, the temperature detection module includes: the temperature detection unit is connected with the current generation module and used for generating a first voltage and a second voltage based on the reference current; and the analog-to-digital conversion unit is connected with the temperature detection unit and the control module, and is used for obtaining the target voltage difference representing the current circuit temperature based on the first voltage and the second voltage, converting the target voltage difference into a target identification code and outputting the target identification code to the control module, so that the control module reads the current regulation signal from a preset current regulation table based on the target identification code and outputs the current regulation signal.
The control module is arranged in the constant current source generating circuit, the temperature detection unit and the analog-to-digital conversion unit are arranged in the temperature detection module, the analog-to-digital conversion unit is connected with the control module, a target voltage difference representing the current circuit temperature is obtained by the analog-to-digital conversion unit based on a first voltage and a second voltage output by the temperature detection unit, and the target voltage difference is converted into a target identification code and is output to the control module, so that the control module reads a current regulation signal from a preset current regulation table based on the target identification code, namely, the reduction amplitude of the target current output by the display driving chip can be regulated by the control module, the dangerous condition that the service life of the display driving chip is reduced along with the rise of the working temperature and even burnout is caused is avoided, the reduction amplitude of the target current is flexibly configurable, namely, the reduction gear of, the flexibility of the whole scheme is guaranteed, and meanwhile, the connection is simpler when the whole system is integrated.
In an embodiment of the present invention, the control module includes: a controller; the analog-to-digital conversion unit includes: the analog-to-digital converter is provided with a first input end, a second input end and an output end, wherein the output end is connected with the controller; the temperature detection unit includes: the first voltage output subunit is connected with the current generation module and the first input end of the analog-to-digital converter and is used for generating the first voltage based on the reference current and outputting the first voltage to the analog-to-digital converter; the second voltage output subunit is connected with the current generation module and the second input end of the analog-to-digital converter and is used for generating the second voltage based on the reference current and outputting the second voltage to the analog-to-digital converter; the analog-to-digital converter is used for obtaining the target voltage difference based on the first voltage and the second voltage, converting the target voltage difference into the target identification code and outputting the target identification code to the controller, so that the controller reads and outputs the current regulation signal from the preset current regulation table based on the target identification code.
The controller is arranged in the control module, the analog-to-digital converter is arranged in the analog-to-digital conversion unit, the first voltage output subunit and the second voltage output subunit are arranged in the temperature detection unit, the analog-to-digital converter obtains the target identification code based on the first voltage output by the first voltage output subunit and the second voltage output by the second voltage output subunit and sends the target identification code to the controller, the controller reads the current regulation signal from the preset current regulation table based on the target identification code, and the dangerous condition that the display driving chip is shortened in service life and even burnt down along with the rise of the working temperature is further avoided.
In an embodiment of the present invention, the first voltage output subunit includes: a first switch assembly connecting the current generating module and the first input terminal of the analog-to-digital converter; the second voltage output subunit includes: the resistor component is connected with the current generation module and the second input end of the analog-to-digital converter.
In an embodiment of the present invention, the first switch assembly includes: a first switch element, a third input terminal of which is connected to the current generation module and the first input terminal of the analog-to-digital converter, and a first control terminal of which and a second output terminal of which are connected to a ground terminal; each of the second switch assemblies includes: a second switching element, wherein a second control terminal of the second switching element and a third output terminal of the second switching element are connected to the ground terminal; the resistance assembly includes: a plurality of resistors connected in series, wherein the plurality of resistors connect a fourth input terminal of each of the second switching elements and the second input terminal of the analog-to-digital converter.
The first switch component is arranged in the first switch component, and the second switch component and the third switch component are arranged in each second switch component, so that the current circuit temperature is detected completely through a CMOS standard process, extra packaging or process cost is not needed, and the hardware cost is further reduced.
In an embodiment of the present invention, the current adjusting module includes: the first current adjusting unit is connected with the control module and the current generating module and used for receiving a first adjusting signal input by the control module to adjust the reference current to obtain a first adjusting current; and the second current regulating unit is connected with the control module, the first current regulating unit and the constant current output module and is used for regulating the first regulating current based on the current regulating signal to obtain the target regulating current and outputting the target regulating current to the constant current output module.
Through set up first current regulation unit and second current regulation unit in current regulation module, realize that the electric current enlargies on the one hand, guarantee target current's required precision, on the other hand can prevent to show that the driver chip leads to life-span decline or even causes the dangerous condition of burning out along with operating temperature constantly rises.
In an embodiment of the present invention, the second current adjusting unit includes: a third switching element; a plurality of fourth switching sub-units connected to the third switching element, wherein each of the fourth switching sub-units includes: a fourth switching element and a fifth switching element connected to the fourth switching element, wherein the fourth switching element is connected to the control module to control the connection or disconnection of the fifth switching element based on the current regulation signal; and the current output subunit is connected with the third switching element, the plurality of fourth switching subunits and the constant current output module.
On the other hand, the embodiment of the utility model discloses display driver chip, including above-mentioned arbitrary embodiment the constant current source produce the circuit.
In another aspect, an embodiment of the utility model discloses a LED lamp plate, include: a pixel array comprising a plurality of pixel points, each pixel point comprising a plurality of differently colored LEDs; and the display driving chip according to another aspect, wherein the constant current output module of the display driving chip is connected to the pixel array.
In another aspect, the embodiment of the utility model discloses a LED display screen, include: displaying a control card; and at least one LED lamp panel according to the above still another aspect, electrically connected to the display control card.
One or more of the above technical solutions may have the following advantages or beneficial effects: the temperature detection module is arranged in the constant current source generating circuit and connected with the current generating module and the current adjusting module, the target voltage difference for representing the current circuit temperature is generated based on the reference current output by the current generating module, the output current adjusting signal is generated based on the target voltage difference and is sent to the current adjusting module, the reference current is adjusted by the current adjusting module based on the current adjusting signal, the dangerous condition that the service life of the display driving chip is reduced along with the continuous rising of the working temperature and even burnt is caused can be prevented, the condition that a controller and an analog-to-digital converter are arranged outside the display driving chip to reduce the target current is avoided, the hardware cost is low, and the hardware is flexible and adjustable.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be 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 that other drawings can be obtained according to these drawings without creative efforts.
Fig. 1 is a schematic structural diagram of a constant current source generating circuit according to a first embodiment of the present invention.
Fig. 2 is another schematic structural diagram of the constant current source generating circuit disclosed in the first embodiment of the present invention.
Fig. 3 is a schematic structural diagram of a constant current source generating circuit according to a first embodiment of the present invention.
Fig. 4 is a schematic structural diagram of a temperature detection module 12 and a control module 15 in a constant current source generating circuit according to a first embodiment of the present invention.
Fig. 5 is a schematic diagram of a specific circuit structure of the temperature detection module 12 in the constant current source generating circuit according to the first embodiment of the present invention.
Fig. 6 is a schematic circuit diagram of the current adjusting module 13 in the constant current source generating circuit according to the first embodiment of the present invention.
Fig. 7 is a schematic diagram illustrating an example relationship between a temperature and a target voltage difference in a constant current source generating circuit according to a first embodiment of the present invention.
Fig. 8 is a schematic structural diagram of a display driver chip according to a second embodiment of the present invention.
Fig. 9 is a schematic structural view of the LED lamp panel disclosed in the third embodiment of the present invention.
Fig. 10 is a schematic structural diagram of an LED display screen according to a fourth embodiment of the present invention.
Description of the main element symbols:
10: a constant current source generating circuit; 11: a current generating module; 12: a temperature detection module; 121: a temperature detection unit; 1211: a first voltage output subunit; 12111: a first switch assembly; 1212: a second voltage output subunit; 12121: a second switch assembly; 12122: a resistance component; 122: an analog-to-digital conversion unit; 1221: an analog-to-digital converter; 13: a current regulation module; 131: a first current adjusting unit; 132: a second current adjusting unit; 1321: a current output subunit; 1322: a fifth switch subunit; 14: a constant current output module; 15: a control module; 151: a controller;
20: a display driving chip; 21: a constant current source generating circuit;
30: an LED lamp panel; 31: a display driving chip; 32: an array of pixels;
40: an LED display screen; 41: an LED lamp panel; 42: and displaying the control card.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.
[ first embodiment ] A method for manufacturing a semiconductor device
Referring to fig. 1, a first embodiment of the present invention discloses a constant current source generating circuit 10, as shown in fig. 1, the constant current source generating circuit 10 includes: the device comprises a current generation module 11, a temperature detection module 12, a current regulation module 13 and a constant current output module 14.
Specifically, the current generation module 11 is configured to generate a reference current. The temperature detection module 12 is connected to the current generation module 11, and configured to generate a target voltage difference representing a current circuit temperature based on the reference current, and generate an output current adjustment signal based on the target voltage difference. The current adjusting module 13 is connected to the current generating module 11 and the temperature detecting module 12, and is configured to adjust the reference current based on the current adjusting signal to obtain a target adjusting current. The constant current output module 14 is connected to the current regulating module 13, and is configured to regulate the target regulating current to output a target current.
The temperature detection module 12 is arranged in the constant current source generating circuit 10 and connected with the current generating module 11 and the current adjusting module 13, so that a target voltage difference representing the current circuit temperature is generated based on the reference current output by the current generating module 11, an output current adjusting signal is generated based on the target voltage difference and sent to the current adjusting module 13, the reference current is adjusted by the current adjusting module 13 based on the current adjusting signal, the dangerous condition that the service life of the display driving chip is reduced along with the continuous rising of the working temperature and even burnout is caused can be prevented, the condition that a controller and an analog-to-digital converter are arranged outside the display driving chip to reduce the target current is avoided, and the hardware cost is low, flexible and adjustable.
In other embodiments of the present invention, as shown in fig. 2, the constant current source generating circuit 10 further includes, for example: and the control module 15 is connected with the temperature detection module 12, the current regulation module 13 and the constant current output module 14.
Further, as shown in fig. 3, the temperature detection module 12 includes, for example: a temperature detection unit 121 and an analog-to-digital conversion unit 122. The temperature detecting unit 121 is connected to the current generating module 11, and is configured to generate a first voltage and a second voltage based on the reference current. The analog-to-digital conversion unit 122 is connected to the temperature detection unit 121 and the control module 15, and configured to obtain the target voltage difference representing the current circuit temperature based on the first voltage and the second voltage, convert the target voltage difference into a target identification code, and output the target identification code to the control module 15, so that the control module 15 reads and outputs the current adjustment signal from a preset current adjustment table based on the target identification code.
By arranging the control module 15 in the constant current source generating circuit 10, arranging the temperature detecting unit 121 and the analog-to-digital converting unit 122 in the temperature detecting module 12, connecting the analog-to-digital converting unit 122 with the control module 15, obtaining a target voltage difference representing the current circuit temperature by the analog-to-digital converting unit 122 based on the first voltage and the second voltage output by the temperature detecting unit 121, and converting the target voltage difference into a target identification code to be output to the control module 15, so that the control module 15 reads a current adjusting signal from a preset current adjusting table based on the target identification code, that is, the reduction amplitude of the target current output by the display driving chip can be adjusted by the control module, thereby avoiding the dangerous situation that the display driving chip is reduced in service life and even burnt along with the rise of the working temperature, realizing that the reduction amplitude of the target current is flexibly configurable, that the reduction gear of the target current of the display, the flexibility of the whole scheme is guaranteed, and meanwhile, the connection is simpler when the whole system is integrated.
In other embodiments of the present invention, in conjunction with fig. 3 and 4, the control module 15 includes, for example: and a controller 151. The controller 151 is referred to as a programmable register, a field programmable gate array, or a processor with digital logic processing capability, for example.
Further, the analog-to-digital conversion unit 122 includes, for example: an analog-to-digital converter 1221 having a first input terminal, a second input terminal, and an output terminal, wherein the output terminal is connected to the controller 151.
Further, the temperature detection unit 121 includes, for example: a first voltage output subunit 1211 and a second voltage output subunit 1212. The first voltage output subunit 1211 is connected to the current generation module 11 and a first input terminal of the analog-to-digital converter 1221, and configured to generate the first voltage output to the analog-to-digital converter 1221 based on the reference current. The second voltage output subunit 1212 is connected to the current generation module 11 and the second input terminal of the analog-to-digital converter 1221, and is configured to generate the second voltage output to the analog-to-digital converter 1221 based on the reference current. The analog-to-digital converter 1221 is configured to obtain the target voltage difference based on the first voltage and the second voltage, convert the target voltage difference into the target identification code, and output the target identification code to the controller 151, so that the controller 151 reads and outputs the current adjustment signal from the preset current adjustment table based on the target identification code.
By arranging the controller 151 in the control module 15, arranging the analog-to-digital converter 1221 in the analog-to-digital conversion unit 122, arranging the first voltage output subunit 1211 and the second voltage output subunit 1212 in the temperature detection unit 121, so that the analog-to-digital converter 1221 obtains the target identification code based on the first voltage output by the first voltage output subunit 1211 and the second voltage output by the second voltage output subunit 1212 and sends the target identification code to the controller 151, and the controller 151 reads the current regulation signal from the preset current regulation table based on the target identification code, thereby further avoiding the dangerous situation that the display driving chip has a reduced life and even causes burnout as the working temperature rises.
It should be noted that the control module 15 includes, for example, one controller, and the one controller is connected to the analog-to-digital converter 1221, the current regulation module 13, and the constant current output module 14, but of course, the control module 15 may also include a plurality of controllers, and the plurality of controllers are respectively connected to the analog-to-digital converter 1221, the current regulation module 13, and the constant current output module 14.
In other embodiments of the present invention, as shown in fig. 5, the first voltage output subunit 1211 includes, for example: a first switch assembly 12111 connects the current generating module 11 and the first input of the analog-to-digital converter 1221. The second voltage output subunit 1212 includes, for example: at least one second switching element 12121 and a resistive element 12122 connected to the at least one second switching element, the resistive element 12122 being connected to the current generating module 11 and to said second input of the analog-to-digital converter 1221.
Specifically, as shown in fig. 5, the first switch assembly 12111 includes, for example: a third input terminal of the first switching element N1 and a third input terminal of the first switching element N1 are connected to the first input terminals of the current generation module 11 and the analog-to-digital converter 1221, and a first control terminal of the first switching element N1 and a second output terminal of the first switching element N1 are connected to the ground terminal. Each second switch assembly 12121 includes, for example: a second switching element N2, wherein a second control terminal of the second switching element N2 and a third output terminal of the second switching element N2 are connected to the ground terminal. The resistor assembly 12122 includes, for example: a plurality of resistors R connected in series, wherein the plurality of resistors R connect a fourth input terminal of each second switching element N2 and the second input terminal of the analog-to-digital converter 1221.
By providing the first switch element N1 in the first switch unit 12111 and the second switch element N2 in each second switch unit 12121, the current circuit temperature can be detected completely by CMOS standard process, no additional package or process cost is required, and hardware cost is further reduced.
The first switching element N1 and the second switching element N2 are, for example, MOS transistors, and the first switching element N1 and the second switching element N2 are not limited thereto, but may be other types of field effect transistors.
In other embodiments of the present invention, as shown in fig. 6, the current adjusting module 13 includes, for example: a first current adjusting unit 131 and a second current adjusting unit 132. The first current adjusting unit 131 is connected to the control module 15 and the current generating module 11, and is configured to receive a first adjusting signal input by the control module 11 to adjust the reference current to obtain a first adjusting current. The second current adjusting unit 132 is connected to the control module 15, the first current adjusting unit 131 and the constant current output module 14, and is configured to adjust the first adjusting current based on the current adjusting signal to obtain the target adjusting current, and output the target adjusting current to the constant current output module 14.
Through setting up first current regulation unit 131 and second current regulation unit 132 in current regulation module 13, realize the current amplification on the one hand, guarantee the required precision of target current, on the other hand can prevent to show that the driver chip leads to the life-span decline and even causes the dangerous condition of burning out along with operating temperature constantly rises.
Specifically, as shown in fig. 6, the second current adjusting unit 132 includes, for example: a third switching element N4, a plurality of fourth switching sub-units 1322, and a current output sub-unit 1321.
Wherein, a plurality of fourth switch subunits 1322 are connected to the third switching element N4, wherein each fourth switch subunit 1322 includes: a fourth switching element N5 and a fifth switching element N6 connected to the fourth switching element N5, wherein the fourth switching element N5 is connected to the control module 15 to control the connection or disconnection of the connected fifth switching element N6 based on the current adjustment signal. The current output subunit 1321 is connected to the third switching element N4, the plurality of fourth switching subunits 1322, and the constant current output module 14.
The current output subunit 1321 is a structure of a conventional constant current source generating circuit, for example, the current output subunit 1321 includes, for example, a second operational amplifier OP2, a thirteenth switching element N13, a third operational amplifier OP3, and a fourteenth switching element N14. A positive input end and a negative input end of the second operational amplifier OP2 are respectively connected to the first current adjusting unit 131 and the fourth switching element N5, an output end of the second operational amplifier OP2 is connected to a control end of the thirteenth switching element N13, an output end of the thirteenth switching element N13 is connected to each fourth switching element N5, an input end of the thirteenth switching element N13 is connected to a positive input end of the third operational amplifier OP3, an output end of the third operational amplifier is connected to a control end of the fourteenth switching element N14, and an output end of the fourteenth switching element N14 is connected to an input end of the thirteenth switching element N13.
The first current adjusting unit 131 is also a structure of a conventional constant current source generating circuit, for example, the first current adjusting unit 131 includes: a first operational amplifier OP1, a seventh switching element N7, an eighth switching element N8, a plurality of ninth switching elements N9, a plurality of tenth switching elements N10, a plurality of eleventh switching elements N11 and a plurality of twelfth switching elements N12, wherein one end of each twelfth switching element N12 is connected with an eleventh switching element N11, the other end of each twelfth switching element N12 is connected with the current generation module 11, the control end of each eleventh switching element N11 is connected with and connected to the control end of the seventh switching element N7 and the positive input end of the first operational amplifier OP1, the output end of the seventh switching element N7 is connected with the negative input end of the first operational amplifier OP1, the output end of the first operational amplifier OP1 is connected with the control end of the eighth switching element N8, the input end of the eighth switching element N8 is connected with the output end of the seventh switching element N7, the positive input end of the eighth switching element N585 is connected with the second output end of the ninth switching element N57324, each of the ninth switching elements N9 is connected to one tenth switching element N10, and a control terminal of each of the tenth switching elements N10 is connected to a control terminal of the third switching element N4.
It is worth mentioning that each switching element N12, each switching element N9 and each fourth switching element N5 is for example connected to the control module 15, the control module 15 for example outputs the control signals S (0) -S (M-1) and T (0) -T (N-1) as the aforementioned first regulating signal, and the control module 15 for example outputs the control signals G (0) -G (K-1) as the aforementioned current regulating signal. The eleventh switching element N11, the seventh switching element N7, and the eighth switching element N8 are, for example, PMOS transistors, the tenth switching element 10 is, for example, an NMOS transistor, and the twelfth switching element N12 and the ninth switching element N9 are, for example, PMOS transistors, but the present embodiment is not limited thereto, and the aforementioned switching elements may also be other field effect transistors.
It should be noted that the present embodiment does not limit the specific number of the aforementioned resistors R, the fifth switching elements N6, the fourth switching elements N5, the eleventh switching elements N11, the twelfth switching elements N12, the ninth switching elements N9 and the tenth switching elements N10, which may be set according to the actual circuit requirement, wherein the resistance values of the resistors R may be the same or different.
The operation of the constant current source generating circuit disclosed in the present embodiment will be briefly described with reference to fig. 5, 6, and 7.
The constant current source generating circuit 10 is disposed in the LED display driving chip, wherein the current generating module 11 in the constant current source generating circuit 10 is, for example, a current type Bandgap, i.e., a current reference circuit, which can generate a temperature-independent reference current, and the reference current enters the temperature detecting module 12 and the current adjusting module 13.
The control module 15 outputs, for example, a fixed control signal S (0) -S (M-1), a fixed control signal T (0) -T (N-1), and a fixed current regulation signal G (0) -G (K-1) to amplify the reference current entering the current regulation module 13 to obtain a required current, and then the constant current output module 14 drives an external load to output a constant target current, at this time, the constant current source generation circuit 10 can normally and stably operate, but due to the limitations of the operating environment and the packaging capability, in some cases, the heat of the constant current source generation circuit 10 cannot be dissipated in time, and the heat accumulation causes the operating temperature of the display driving chip to continuously rise. When the temperature rises to a certain degree, the display driving chip must be protected in a specific manner to protect the life of the chip and prevent accidents. In this embodiment, temperature protection is achieved by providing a temperature detection module.
The control module 15, for example, the controller 151, stores a preset current adjustment table, which can be set by a user according to actual needs, and the preset current adjustment table is provided with a plurality of gears, for example, three gears are taken as follows, the first gear is 100 degrees, the second gear is 120 degrees, and the third gear is 140 degrees. When the temperature detection module 12 detects that the current circuit temperature is 100 degrees, the first gear is triggered, and the control module 15, for example, the controller 151, receives the corresponding first digital code, but does not perform any processing. When the second gear is triggered when the current circuit temperature is detected to be 120 degrees, the controller 151 receives the corresponding second digital code, and at this time, the controller 151 changes the previously output current adjustment signals G (0) -G (K-1) based on the second digital code to reduce the target current output by the display driving chip, for example, to reduce 5% of the target current, thereby reducing power consumption. If the current circuit temperature of the display driver chip starts to decrease until the current circuit temperature decreases to 100 ℃, the current reduction of 5% is cancelled, normal operation is resumed, if the current circuit temperature of the display driver chip does not increase any more or does not reach the third gear, the current state is maintained, that is, the current reduction of 5% is maintained, if the temperature of the display driver chip continues to increase to 140 °, the controller 151 receives the corresponding third digital code and directly closes the display driver chip, and burnout is prevented.
Specifically, as shown in fig. 5, the same reference current flows through the first switch module 12111 and the resistor module 12122, wherein the first switch module 12111 is provided with one first switch element N1, the second switch module 12121 is provided with a plurality of second switch elements N2, for example, and each of the first switch element N1 and the second switch element N2 is a device that changes with the temperature change output voltage, so that the first voltage VA and the second voltage VB can be generated at the input terminal of the analog-to-digital converter ADC based on the first switch element N1 and the second switch element N2, respectively, so as to generate a target voltage difference Vin ═ VA-VB proportional to the temperature, i.e., the target voltage difference represents the current circuit temperature, see fig. 7, whereby the current circuit temperature is reflected on the input voltage of the ADC, and then the target voltage difference is converted into a target identification code, i.e., a digital code, which is fed into the controller 151, the controller 151 stores a preset current adjustment table, for example, as shown in table 1 below.
TABLE 1
| Temperature of | Vin＝VA-VB | Digital code | Current regulation signal |
| 100 | 800mV | XX001 | Holding |
| 120 | 1000mV | XX010 | The current is reduced by 5% |
| 140 | 1200mV | XX100 | Shutdown |
After receiving the input digital code, the controller 11 reads a corresponding current adjustment signal from table 1 based on the digital code and outputs the current adjustment signal to the current adjustment circuit 13, thereby adjusting the target current output from the display driving chip. It can be understood that the current adjusting signal is outputted to the plurality of fourth switching elements N5 of the current adjusting circuit 13 in a binary form, for example, the fourth switching element N5 is a PMOS transistor, when the current adjusting signal outputted from the controller 151 is "0", the corresponding fourth switching element N5 is in a closed state, so that the fifth switching element N6 connected to the fourth switching element N5 is turned on, and when the current adjusting signal outputted from the controller 151 is "1", the corresponding fourth switching element N5 is in an open state, so that the fifth switching element N6 connected to the fourth switching element N5 is turned off.
It should be noted that, in the embodiment, the foregoing table 1 is only for better understanding of the embodiment, and the parameters included therein may be adjusted according to actual needs, and in addition, the actually output current adjustment signal may also be flexibly configured according to application scenarios, for example, the current adjustment signal corresponding to a temperature of 120 ° may be changed to reduce 10% output current or 20% output current, and the like.
In summary, the constant current source generating circuit 10 disclosed in this embodiment is provided with the temperature detecting module 12, and is connected to the current generating module 11 and the current adjusting module 13, so as to generate a target voltage difference representing a current circuit temperature based on the reference current output by the current generating module 11, and generate an output current adjusting signal to the current adjusting module 13 based on the target voltage difference, so that the current adjusting module 13 adjusts the reference current based on the current adjusting signal, which can prevent the display driver chip from being damaged due to life reduction and even burning-out caused by continuous rise of the operating temperature, and avoid the situation that a controller and an analog-to-digital converter are provided outside the display driver chip to reduce the target current, and the hardware cost is low and is flexible and adjustable.
[ second embodiment ]
As shown in fig. 8, a display drive chip 20 is shown which includes a constant current source generating circuit 21. The constant current source generating circuit 21 is, for example, the constant current source generating circuit 10 disclosed in the first embodiment, and is not described herein again.
[ third embodiment ]
As shown in fig. 9, an LED lamp panel 30 is shown, which includes: a pixel array 32 comprising a plurality of pixel points and each of the pixel points comprising a plurality of differently colored LEDs; the display driving chip 31 is, for example, the display driving chip 20 disclosed in the second embodiment, and details are not repeated herein, the constant current output module of the display driving chip 31 is electrically connected to the pixel array 32, and the current output by the constant current source generating circuit of the display driving chip 31 is input to the pixel array 32 to control lighting of the LEDs in the pixel array 32.
[ fourth example ] A
As shown in fig. 10, there is shown an LED display screen 40 comprising: a display control card 42 and an LED lamp panel 41. The display control card 42 is electrically connected to the LED lamp panel 41. The display control card 42 adopts a hardware structure similar to a receiving card, a scanning card or a module controller, which is mature in the LED display control technology Field, for example, that is, a Programmable logic device such as an FPGA (Field Programmable Gate Array) device is used as an image processor. LED lamp plate 41 is above-mentioned third embodiment LED lamp plate 30, the embodiment of the utility model discloses no longer describe here.
In addition, it can be understood that the foregoing embodiments are only exemplary illustrations of the present invention, and the technical solutions of the embodiments can be arbitrarily combined and collocated for use on the premise that the technical features are not conflicted, the structure is not contradictory, and the purpose of the present invention is not violated.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention in its corresponding aspects.
Claims (10)
1. A constant current source generating circuit, comprising:
the current generation module is used for generating a reference current;
the temperature detection module is connected with the current generation module and used for generating a target voltage difference representing the current circuit temperature based on the reference current and generating an output current regulation signal based on the target voltage difference;
the current adjusting module is connected with the current generating module and the temperature detecting module and used for adjusting the reference current based on the current adjusting signal to obtain a target adjusting current; and
and the constant current output module is connected with the current regulating module and is used for regulating the target regulating current so as to output the target current.
2. The constant current source generation circuit according to claim 1, further comprising:
the control module is connected with the temperature detection module, the current regulation module and the constant current output module;
wherein, the temperature detection module includes:
the temperature detection unit is connected with the current generation module and used for generating a first voltage and a second voltage based on the reference current;
and the analog-to-digital conversion unit is connected with the temperature detection unit and the control module, and is used for obtaining the target voltage difference representing the current circuit temperature based on the first voltage and the second voltage, converting the target voltage difference into a target identification code and outputting the target identification code to the control module, so that the control module reads the current regulation signal from a preset current regulation table based on the target identification code and outputs the current regulation signal.
3. The constant current source generating circuit according to claim 2,
the control module includes: a controller;
the analog-to-digital conversion unit includes: the analog-to-digital converter is provided with a first input end, a second input end and an output end, wherein the output end is connected with the controller;
the temperature detection unit includes:
the first voltage output subunit is connected with the current generation module and the first input end of the analog-to-digital converter and is used for generating the first voltage based on the reference current and outputting the first voltage to the analog-to-digital converter;
the second voltage output subunit is connected with the current generation module and the second input end of the analog-to-digital converter and is used for generating the second voltage based on the reference current and outputting the second voltage to the analog-to-digital converter;
the analog-to-digital converter is used for obtaining the target voltage difference based on the first voltage and the second voltage, converting the target voltage difference into the target identification code and outputting the target identification code to the controller, so that the controller reads and outputs the current regulation signal from the preset current regulation table based on the target identification code.
4. The constant current source generating circuit according to claim 3,
the first voltage output subunit includes: a first switch assembly connecting the current generating module and the first input terminal of the analog-to-digital converter;
the second voltage output subunit includes: the resistor component is connected with the current generation module and the second input end of the analog-to-digital converter.
5. The constant current source generating circuit according to claim 4,
the first switch assembly includes: a first switch element, a third input terminal of which is connected to the current generation module and the first input terminal of the analog-to-digital converter, and a first control terminal of which and a second output terminal of which are connected to a ground terminal;
each of the second switch assemblies includes: a second switching element, wherein a second control terminal of the second switching element and a third output terminal of the second switching element are connected to the ground terminal;
the resistance assembly includes: a plurality of resistors connected in series, wherein the plurality of resistors connect a fourth input terminal of each of the second switching elements and the second input terminal of the analog-to-digital converter.
6. The constant current source generation circuit according to claim 2, wherein the current adjustment module includes:
the first current adjusting unit is connected with the control module and the current generating module and used for receiving a first adjusting signal input by the control module to adjust the reference current to obtain a first adjusting current;
and the second current regulating unit is connected with the control module, the first current regulating unit and the constant current output circuit and is used for regulating the first regulating current based on the current regulating signal to obtain the target regulating current and outputting the target regulating current to the constant current output module.
7. The constant current source generation circuit according to claim 6, wherein the second current adjustment unit includes:
a third switching element;
a plurality of fourth switching sub-units connected to the third switching element, wherein each of the fourth switching sub-units includes: a fourth switching element and a fifth switching element connected to the fourth switching element, wherein the fourth switching element is connected to the control module to control the connection or disconnection of the fifth switching element based on the current regulation signal; and
and the current output subunit is connected with the third switching element, the plurality of fourth switching subunits and the constant current output module.
8. A display driver chip, comprising:
the constant current source generating circuit of any one of claims 1 to 7.
9. The utility model provides a LED lamp plate, its characterized in that includes:
a pixel array comprising a plurality of pixel points and each of the pixel points comprising a plurality of differently colored LEDs; and
the display driving chip of claim 8, wherein the constant current output module of the display driving chip is connected to the pixel array.
10. An LED display screen, comprising:
displaying a control card; and
the LED light panel of claim 9, electrically connected to the display control card.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202022429270.8U CN213462414U (en) | 2020-10-27 | 2020-10-27 | Constant current source generating circuit, display driving chip, LED lamp panel and LED display screen |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202022429270.8U CN213462414U (en) | 2020-10-27 | 2020-10-27 | Constant current source generating circuit, display driving chip, LED lamp panel and LED display screen |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN213462414U true CN213462414U (en) | 2021-06-15 |
Family
ID=76296046
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202022429270.8U Active CN213462414U (en) | 2020-10-27 | 2020-10-27 | Constant current source generating circuit, display driving chip, LED lamp panel and LED display screen |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN213462414U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115542229A (en) * | 2022-11-25 | 2022-12-30 | 中国兵器装备集团自动化研究所有限公司 | Constant current source calibration system under complex temperature environment |
-
2020
- 2020-10-27 CN CN202022429270.8U patent/CN213462414U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115542229A (en) * | 2022-11-25 | 2022-12-30 | 中国兵器装备集团自动化研究所有限公司 | Constant current source calibration system under complex temperature environment |
| CN115542229B (en) * | 2022-11-25 | 2023-03-24 | 中国兵器装备集团自动化研究所有限公司 | Constant current source calibration system under complex temperature environment |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7923978B2 (en) | Regulator circuit having over-current protection | |
| JP6894287B2 (en) | Dual input power management methods and systems | |
| US8466718B2 (en) | Semiconductor device | |
| US8766679B1 (en) | Power on reset (POR) circuit | |
| US20160231758A1 (en) | Circuit for regulating startup and operation voltage of an electronic device | |
| JP2023553251A (en) | Power supply circuit, drive chip and display device | |
| US7382160B2 (en) | Differential output circuit with reduced differential output variation | |
| CN213462414U (en) | Constant current source generating circuit, display driving chip, LED lamp panel and LED display screen | |
| JP2008117254A (en) | Power supply voltage circuit | |
| CN110007707A (en) | Low pressure difference linear voltage regulator and system | |
| US11150677B2 (en) | Series regulator | |
| US20140300999A1 (en) | Excess power protection circuit | |
| US20160342167A1 (en) | Integrated circuit, dynamic voltage scaling regulator and dynamic voltage scaling method | |
| US9214853B2 (en) | Two-wire transmitter starter circuit and two-wire transmitter including the same | |
| US10317981B2 (en) | Data processing device and data processing system | |
| TWI534583B (en) | Low-dropout voltage regulator | |
| CN108319325A (en) | Radiating circuit and adjuster control circuit including radiating circuit | |
| CN108879605B (en) | Over-temperature protection circuit | |
| KR101413350B1 (en) | Circuit for compensation temperature of light source in an optical communication system | |
| JP2011013877A (en) | Semiconductor device | |
| CN101504557B (en) | Constant current element construction in tandem connection, and circuit employing the same | |
| KR20070006514A (en) | Current limit circuit of low drop out regulator | |
| EP3030050B1 (en) | Offset voltage eliminating circuit structure for protection mechanism of dimmer | |
| US20230376062A1 (en) | Linear regulator and voltage regulation method | |
| CN113966034B (en) | LED system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |