CN115882720A - Voltage converter, RGB drive chip and display screen lamp pearl subassembly - Google Patents
Voltage converter, RGB drive chip and display screen lamp pearl subassembly Download PDFInfo
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Abstract
The embodiment of the invention discloses a voltage converter, which comprises a conversion control distribution processing module, a control output unit, an input voltage detection unit and a plurality of charge pump units, wherein the plurality of charge pump units are sequentially connected in series, then the output end of the last charge pump unit is connected with the control output unit, the input end of the first charge pump unit is connected with a voltage input end, the input ends of the plurality of charge pump units are all connected with the control output unit, the input voltage detection unit is connected with the voltage input end, the conversion control distribution processing module is respectively connected with the input voltage detection unit, the control output unit and the plurality of charge pump units so as to respectively control the work of the control output unit and the plurality of charge pump units according to the input voltage acquired by the input voltage detection unit, and the output end of the control output unit is the voltage output end of the voltage converter. The invention also discloses an RGB driving chip and a display screen lamp bead component.
Description
Technical Field
The invention relates to the technical field of LED display screens, in particular to a voltage converter, an RGB driving chip and a display screen lamp bead assembly.
Background
Most of LED outdoor display screens in the current market are supplied with power by 5V of total positive, the adopted lamp beads are three-in-one lamp beads of total positive RGB, namely, the LED red light lamp beads (R), the LED green light lamp beads (G) and the LED blue light lamp beads (B) are supplied with power by 5V, however, the power supply voltage actually required by the normal work of the LED is 2-3.5V, wherein, the power supply voltage of the LED red light (R) lamp beads is about 1.8-2.2V, the power supply voltage of the green light (G) lamp beads and the blue light (B) lamp beads is about 3.2-3.4V, the LED display screens supplied with power by 5V of total positive can have more useless power, the efficiency is low, and when the LED display screens have more useless power, the useless power is converted into heat, the heat productivity is large, the temperature in a constant current chip and the whole display screen box body is easily promoted, and the product reliability and the service life of the LED display screens are influenced.
Disclosure of Invention
The invention aims to solve the technical problem of providing a voltage converter, an RGB driving chip and a display screen lamp bead component so as to reduce useless power, improve the working efficiency of the lamp bead and reduce heat productivity.
In a first aspect, an embodiment of the present invention provides a voltage converter, including a conversion control distribution processing module, a control output unit, an input voltage detection unit, and a plurality of charge pump units, where the plurality of charge pump units are sequentially connected in series, an output terminal of the last charge pump unit is connected to the control output unit, an input terminal of the first charge pump unit is connected to a voltage input terminal, input terminals of the plurality of charge pump units are all connected to the control output unit, the input voltage detection unit is connected to the voltage input terminal, the conversion control distribution processing module is respectively connected to the input voltage detection unit, the control output unit, and the plurality of charge pump units, so as to respectively control operations of the control output unit and the plurality of charge pump units according to an input voltage acquired by the input voltage detection unit, and an output terminal of the control output unit is a voltage output terminal of the voltage converter.
The further technical scheme is as follows: the number of the charge pump units is three, the charge pump units are respectively a first charge pump unit, a second charge pump unit and a third charge pump unit, the input end of the first charge pump unit is connected with the voltage input end, the first charge pump unit, the second charge pump unit and the third charge pump unit are sequentially connected in series, the input ends of the first charge pump unit, the second charge pump unit and the third charge pump unit are all connected with the control output unit, and the output end of the third charge pump unit is connected with the control output unit.
The further technical scheme is as follows: the charge pump unit comprises a first NMOS tube, a second NMOS tube, a third NMOS tube, a fourth NMOS tube, a fifth NMOS tube, a sixth NMOS tube, a seventh NMOS tube, an eighth NMOS tube, a ninth NMOS tube, a tenth NMOS tube, an eleventh NMOS tube, a twelfth NMOS tube, a first capacitor and a second capacitor, wherein the drain electrodes of the first NMOS tube, the third NMOS tube, the seventh NMOS tube and the ninth NMOS tube are all connected with the input end, the source electrodes of the first NMOS tube and the third NMOS tube are respectively connected with two ends of the first capacitor, the drain electrodes of the second NMOS tube and the fourth NMOS tube are respectively connected with the source electrodes of the first NMOS tube and the third NMOS tube, the source electrodes of the seventh NMOS tube and the ninth NMOS tube are respectively connected with two ends of the second capacitor, the drain electrodes of the eighth NMOS tube and the tenth NMOS tube are respectively connected with the source electrodes of the seventh NMOS tube and the ninth NMOS tube, the source electrodes of the second NMOS transistor, the fourth NMOS transistor, the eighth NMOS transistor, and the tenth NMOS transistor are all connected to the drain electrode of the twelfth NMOS transistor, the source electrode of the twelfth NMOS transistor is connected to the output terminal, a ground capacitor is connected between the output terminal and the source electrode of the twelfth NMOS transistor, the drain electrode of the fifth NMOS transistor is connected to the source electrode of the third NMOS transistor and the drain electrode of the sixth NMOS transistor, respectively, the source electrode of the sixth NMOS transistor is connected to the drain electrode of the eighth NMOS transistor, the source electrodes of the fifth NMOS transistor and the eleventh NMOS transistor are both grounded, the drain electrode of the eleventh NMOS transistor is connected to the source electrode of the ninth NMOS transistor, and the first NMOS transistor, the second NMOS transistor, the third NMOS transistor, the fourth NMOS transistor, the fifth NMOS transistor, the sixth NMOS transistor, the seventh NMOS transistor, the eighth NMOS transistor, the ninth NMOS transistor, the tenth NMOS transistor, and the grids of the eleventh NMOS tube and the twelfth NMOS tube are connected with the conversion control distribution processing module.
The further technical scheme is as follows: the voltage converter further comprises an output voltage detection unit, and the output voltage detection unit is respectively connected with the output end of the control output unit and the conversion control distribution processing module so as to collect and transmit the output voltage of the control output unit to the conversion control distribution processing module.
In a second aspect, an embodiment of the present invention provides an RGB driver chip, including two voltage converters, an RGB data processing module, and three constant current driving modules, where output terminals of the three constant current driving modules are respectively connected to anodes of a red light bead, a green light bead, and a blue light bead, one of the voltage converters is connected to the red light bead through one of the constant current driving modules, the remaining two constant current driving modules are both connected to the other voltage converter and are respectively connected to the green light bead and the blue light bead, and the RGB data processing module is respectively connected to a signal input terminal, a signal output terminal, the three constant current driving modules, and the voltage input terminal.
In a third aspect, an embodiment of the present invention provides an RGB driver chip, which includes three voltage converters, an RGB data processing module, and three constant current driving modules, wherein output ends of the three constant current driving modules are respectively connected to anodes of red light beads, green light beads, and blue light beads, the voltage converters correspond to the constant current driving modules one by one and are electrically connected to each other, and the RGB data processing module is respectively connected to a signal input end, a signal output end, the three constant current driving modules, and the voltage input end.
The further technical scheme is as follows: the RGB driver chip further comprises a voltage converter respectively connected with the voltage input end and the RGB data processing module.
The further technical scheme is as follows: the constant current driving module comprises a constant current control unit and a PWM control unit, the constant current control unit comprises a constant current control transistor and an operational amplifier, the source electrode of the constant current control transistor is connected with the voltage output end of the voltage converter, the grid electrode of the constant current control transistor is connected with the output end of the operational amplifier, the non-inverting input end of the operational amplifier is connected with a reference standard voltage, the inverting input end of the operational amplifier is connected with the drain electrode of the constant current control transistor through a constant current resistor, the input end of the PWM control unit is electrically connected between the constant current resistor and the inverting input end of the operational amplifier, and the PWM control unit is connected with the RGB data processing module.
The further technical scheme is as follows: the PWM control unit comprises a PWM control transistor, the source electrode of the PWM control transistor is the input end of the PWM control unit, the source electrode of the PWM control transistor is electrically connected between the constant current resistor and the inverting input end of the operational amplifier, the grid electrode of the PWM control transistor is connected with the RGB data processing module, and the drain electrode of the PWM control transistor is the output end of the constant current driving module.
In a fourth aspect, the embodiment of the invention provides a display screen lamp bead assembly, which comprises an RGB lamp bead group and the RGB driving chip, wherein the RGB lamp bead group is electrically connected with the RGB driving chip, the RGB lamp bead group comprises a red light lamp bead, a green light lamp bead and a blue light lamp bead, the red light lamp bead, the green light lamp bead and the blue light lamp bead are connected in a common negative mode, and anodes of the red light lamp bead, the green light lamp bead and the blue light lamp bead are respectively connected with output ends of corresponding constant current driving modules.
The invention has the beneficial technical effects that: the voltage converter is provided with the conversion control distribution processing module, the control output unit, the input voltage detection unit and the plurality of charge pump units, so that the conversion control distribution processing module can control the working mode of each charge pump unit according to the input voltage collected by the input voltage detection unit, thereby converting the input voltage into the required output voltage, and outputting the corresponding output voltage by controlling the output unit, so that the output voltage can be close to the voltage required by the lamp beads, thereby reducing the useless power, improving the conversion efficiency, improving the working efficiency of the lamp beads, reducing the heat productivity, avoiding the problem of accelerated lamp bead aging caused by high temperature, prolonging the service life of the lamp beads, and connecting the output end of the voltage converter with the anode of the lamp beads, so that the subsequent lamp beads can be connected in a common cathode mode, preventing the display color deviation problem caused by unstable output voltage when the lamp beads are connected in a common anode mode, and realizing the automatic voltage regulation output of wide voltage input by voltage conversion through the charge pump units, simplifying the circuit structure, being convenient to realize miniaturization and having small volume. Meanwhile, the RGB driving chip and the display screen lamp bead component have the functions, the RGB driving chip is provided with a constant current driving module connected with the voltage converter to more accurately generate current required by the lamp bead to drive and control the lamp bead to work, and the RGB driving chip is also provided with an RGB data processing module to convert and acquire the corresponding PWM duty ratio according to data to be displayed and adjust and control the brightness of the lamp bead through the constant current driving module; the output end of the constant current driving module is connected with the anode of the lamp beads, and the lamp beads of the RGB lamp bead group are connected in a common cathode mode, so that the voltage drop on the constant current driving module can be effectively reduced.
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 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 block diagram of a voltage converter according to an embodiment of the present invention;
fig. 2 is a schematic circuit diagram of a charge pump unit according to an embodiment of the present invention;
FIG. 3 is a circuit diagram of a display screen lamp bead assembly according to an embodiment of the present invention;
fig. 4 is a circuit diagram of a display screen lamp bead assembly according to another 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 some, not all, embodiments of the present invention. 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.
It will be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
It is also to be understood that the terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the specification of the present invention and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.
It should be further understood that the term "and/or" as used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.
Referring to fig. 1, fig. 1 is a block diagram of a voltage converter according to an embodiment of the present invention, where the voltage converter 10 includes a conversion control distribution processing module 11, a control output unit 12, an input voltage detection unit 13, and a plurality of charge pump units 14, the plurality of charge pump units 14 are connected in series in sequence, an output terminal of the last charge pump unit 14 is connected to the control output unit 12, an input terminal of the first charge pump unit 14 is connected to a voltage input terminal VIN, input terminals of the plurality of charge pump units 14 are connected to the control output unit 12, the input voltage detection unit 13 is connected to the voltage input terminal VIN, the conversion control distribution processing module 11 is connected to the input voltage detection unit 13, the control output unit 12, and the plurality of charge pump units 14, respectively controls operations of the control output unit 12 and the plurality of charge pump units 14 according to an input voltage acquired by the input voltage detection unit 13, and an output terminal of the control output unit 12 is a voltage VOUT of the voltage converter 10.
The voltage input terminal VIN may be connected to a power supply VDD, so that the input terminals of the input voltage detection unit 13 and the first charge pump unit 14 are both connected to the power supply VDD. The input voltage acquired by the input voltage detection unit 13 is the voltage of the power supply VDD, the acquisition of the input voltage by the input voltage detection unit 13 can facilitate the subsequent conversion control distribution processing module 11 to control each charge pump unit 14 to work according to the acquired input voltage for voltage conversion, and finally the output voltage which is obtained by conversion and is close to the voltage required by the corresponding lamp bead is output by the control output unit 12. The conversion control distribution processing module 11 performs analysis and calculation according to the acquired input voltage, obtains a conversion coefficient of the charge pump unit 14 that needs to perform output conversion work, and controls the corresponding charge pump unit 14 to work, so as to obtain an optimal output combination of the required output voltage. The conversion coefficients of the charge pump unit 14 may be 0.33, 0.5, 0.66, 1.5, and 2.0. Different charge pump units 14 are connected in series, and the input end of each charge pump unit 14 is connected with the control output unit 12, so that the required output voltage can be obtained through multi-level connection and conversion coefficient conversion and output, the output voltage obtained through conversion is more accurate, more input voltages can be converted into the required output voltage, and the application range is wider. The voltage converter 10 is through setting up conversion control distribution processing module 11, control output unit 12, input voltage detecting element 13 and a plurality of charge pump unit 14, so that conversion control distribution processing module 11 can be according to the input voltage control each charge pump unit 14's that input voltage detecting element 13 gathered the operating mode, thereby convert input voltage into required output voltage, and through control output unit 12 output corresponding output voltage, make output voltage can be close with the required voltage of lamp pearl, in order to reduce the idle power, improve conversion efficiency, improve lamp pearl work efficiency, reduce calorific capacity, the problem of accelerated lamp pearl ageing that leads to because high temperature is avoided, prolong lamp pearl life, the output of voltage converter 10 links to each other with the positive pole of lamp pearl, so that the follow-up lamp pearl can connect in common negative, can prevent the unstable display color deviation problem that the output voltage leads to when the lamp pearl connects in common positive, and can realize the automatic pressure regulating output to wide voltage input through voltage conversion of charge pump unit 14, simplify the circuit structure, be convenient for realizing the miniaturization, small in size.
Specifically, in this embodiment, the number of the charge pump units 14 is three, and the number of the charge pump units is respectively a first charge pump unit 141, a second charge pump unit 142 and a third charge pump unit 143, an input end of the first charge pump unit 141 is connected to the voltage input end VIN, the first charge pump unit 141, the second charge pump unit 142 and the third charge pump unit 143 are sequentially connected in series, so that an output end of the first charge pump unit 141 is connected to an input end of the second charge pump unit 142, an output end of the second charge pump unit 142 is connected to an input end of the third charge pump unit 143, input ends of the first charge pump unit 141, the second charge pump unit 142 and the third charge pump unit 143 are all connected to the control output unit 12, and an output end of the third charge pump unit 143 is connected to the control output unit 12.
Specifically, the voltage converter 10 further includes an output voltage detection unit 15, and the output voltage detection unit 15 is respectively connected to the output end of the control output unit 12 and the conversion control distribution processing module 11, so as to collect and transmit the output voltage of the control output unit 12 to the conversion control distribution processing module 11. The conversion control distribution processing module 11 obtains the output voltage to perform analysis and calculation, obtains the conversion coefficient of the charge pump unit 14 that needs to perform output conversion work, and controls the corresponding charge pump unit 14 to obtain the optimal output combination of the required output voltage.
The required output voltage of the lamp bead refers to the output voltage output by the voltage converter 10 required by the lamp bead, the corresponding numerical value of the required output voltage of the lamp bead can be the sum of the power supply voltage of the lamp bead and the minimum voltage drop (0.3V) of constant current control, the required output voltage of the red light lamp bead can be 2.3V, and the required output voltages of the green light lamp bead and the blue light lamp bead can be 3.5V. When the input voltage is 5V, the input voltage detection unit 13 transmits the acquired input voltage to the conversion control distribution processing module 11 for analysis and calculation, and for the output voltage 2.3V required by the red light bead, the corresponding optimal mode of the voltage converter 10 is as follows: the conversion control distribution processing module 11 controls the conversion coefficient of the first charge pump unit 141 to be 0.5 and controls the second charge pump unit 142 and the third charge pump unit 143 to be turned off, that is, the first charge pump unit 141 is in a 0.5X step-down mode, at this time, an output voltage of 2.5V is obtained, the light conversion efficiency reaches 80%, and the light conversion efficiency is obtained by calculating a percentage of a ratio of the power supply voltage of the lamp bead to the obtained actual output voltage of the voltage converter 10. For the output voltage 3.5V required by the green light lamp bead and the blue light lamp bead, the optimal mode of the corresponding voltage converter 10 is as follows: the conversion control distribution processing module 11 controls the conversion coefficient of the first charge pump unit 141 to be 0.5 and controls the conversion coefficient of the second charge pump unit 142 to be 1.5 and controls the third charge pump unit 143 to be turned off, that is, the first charge pump unit 141 is in a 0.5X buck mode and the second charge pump unit 142 is in a 1.5X boost mode, and at this time, an output voltage of 3.75V is obtained, and the light conversion efficiency reaches 85.33%.
And when the input voltage is 10V, the input voltage detection unit 13 transmits the acquired input voltage to the conversion control distribution processing module 11 for analysis and calculation, and for the output voltage 2.3V required by the red light bead, the optimal mode of the corresponding voltage converter 10 is as follows: the conversion control distribution processing module 11 controls the conversion coefficients of the first charge pump unit 141 and the second charge pump unit 142 to be 0.5 and controls the third charge pump unit 143 to be turned off, that is, the first charge pump unit 141 and the second charge pump unit 142 are in a 0.5X step-down mode, at this time, an output voltage of 2.5V is obtained, and the light conversion efficiency reaches 80%. For the output voltage 3.5V required by the green light lamp bead and the blue light lamp bead, the optimal mode of the corresponding voltage converter 10 is as follows: the conversion control distribution processing module 11 controls the conversion coefficients of the first charge pump unit 141 and the second charge pump unit 142 to be 0.5 and controls the conversion coefficient of the third charge pump unit 143 to be 1.5, that is, the first charge pump unit 141 and the second charge pump unit 142 are in a 0.5X buck mode and the third charge pump unit 143 is in a 1.5X boost mode, at this time, an output voltage of 3.75V is obtained, and the light conversion efficiency reaches 85.33%.
With reference to fig. 2, specifically, the charge pump unit 14 includes a first NMOS transistor S1, a second NMOS transistor S2, a third NMOS transistor S3, a fourth NMOS transistor S4, a fifth NMOS transistor S5, a sixth NMOS transistor S6, a seventh NMOS transistor S7, an eighth NMOS transistor S8, a ninth NMOS transistor S9, a tenth NMOS transistor S10, an eleventh NMOS transistor S11, a twelfth NMOS transistor S12, a first capacitor CF1, and a second capacitor CF2, drain electrodes of the first NMOS transistor S1, the third NMOS transistor S3, the seventh NMOS transistor S7, and the ninth NMOS transistor S9 are all connected to an input terminal Vin, source electrodes of the first NMOS transistor S1 and the third NMOS transistor S3 are respectively connected to two ends of the first capacitor CF1, drain electrodes of the second NMOS transistor S2 and the fourth NMOS transistor S4 are respectively connected to drain electrodes of the first NMOS transistor S1 and the third NMOS transistor S3, so that the drain electrodes of the second NMOS transistor S2 and the fourth NMOS transistor CF 4 are respectively connected to the second end of the first capacitor S1, the source electrodes of the seventh NMOS transistor S7 and the ninth NMOS transistor S9 are respectively connected to two ends of the second capacitor CF2, the drain electrodes of the eighth NMOS transistor S8 and the tenth NMOS transistor S10 are respectively connected to the source electrodes of the seventh NMOS transistor S7 and the ninth NMOS transistor S9, so that the drain electrodes of the eighth NMOS transistor S8 and the tenth NMOS transistor S10 are respectively connected to two ends of the second capacitor CF2, the source electrodes of the second NMOS transistor S2, the fourth NMOS transistor S4, the eighth NMOS transistor S8 and the tenth NMOS transistor S10 are all connected to the drain electrode of the twelfth NMOS transistor S12, the source electrode of the twelfth NMOS transistor S12 is connected to the output terminal Vout, a ground capacitor CO is connected between the output terminal Vout and the source electrode of the twelfth NMOS transistor S12, the drain electrode of the fifth NMOS transistor S5 is respectively connected to the drain electrode of the third NMOS transistor S3 and the drain electrode of the sixth NMOS transistor S6, and the drain electrode of the sixth NMOS transistor S6 is connected to the drain electrode of the eighth NMOS transistor S8, the source electrodes of the fifth NMOS transistor S5 and the eleventh NMOS transistor S11 are both grounded, the drain electrode of the eleventh NMOS transistor S11 is connected to the source electrode of the ninth NMOS transistor S9, and the gates of the first NMOS transistor S1, the second NMOS transistor S2, the third NMOS transistor S3, the fourth NMOS transistor S4, the fifth NMOS transistor S5, the sixth NMOS transistor S6, the seventh NMOS transistor S7, the eighth NMOS transistor S8, the ninth NMOS transistor S9, the tenth NMOS transistor S10, the eleventh NMOS transistor S11, and the twelfth NMOS transistor S12 are all connected to the conversion control distribution processing module 11, so that the on/off of each NMOS transistor can be controlled by the conversion control distribution processing module 11, and the charge transfer of each capacitor can be adjusted to adjust the output voltage of the charge pump unit 14.
Referring to fig. 3, fig. 3 is a circuit diagram of a display screen lamp bead assembly according to an embodiment of the present invention, where the display screen lamp bead assembly includes an RGB lamp bead group 31 and an RGB driver chip 20, the RGB lamp bead group 31 is electrically connected to the RGB driver chip 20, the RGB lamp bead group 31 includes a red lamp bead LED-R, a green lamp bead LED-G, and a blue lamp bead LED-B, the red lamp bead LED-R, the green lamp bead LED-G, and the blue lamp bead LED-B are connected to a common cathode, and anodes of the red lamp bead LED-R, the green lamp bead LED-G, and the blue lamp bead LED-B are respectively connected to an output end of a corresponding constant current driver module 22. As shown in fig. 3, the RGB driver chip 20 includes three voltage converters 10, one RGB data processing module 21, and three constant current driving modules 22, output terminals of the three constant current driving modules 22 are respectively connected to anodes of the red light bead LED-R, the green light bead LED-G, and the blue light bead LED-B, the voltage converters 10 are in one-to-one correspondence with the constant current driving modules 22 and are electrically connected to each other, and the RGB data processing module 21 is respectively connected to the signal input terminal DI, the signal output terminal DO, the three constant current driving modules 22, and the voltage input terminal VIN.
And cathodes of the red light bead LED-R, the green light bead LED-G and the blue light bead LED-B are all grounded. The number of the voltage converters 10 is three, so that the voltage converters can convert the lamp beads corresponding to different colors to output corresponding output voltages, and the lamp beads corresponding to different colors can be better controlled. The RGB driving chip 20 controls the corresponding lamp beads to operate according to the output voltages required by the lamp beads by setting different voltage converters 10 and constant current driving modules 22 connected to the corresponding voltage converters 10, the voltage converters 10 control the distribution processing module 11, the control output unit 12, the input voltage detection unit 13 and the plurality of charge pump units 14 by setting the conversion control, so that the conversion control, distribution processing module 11 can control the operating modes of the charge pump units 14 according to the input voltages collected by the input voltage detection unit 13, thereby converting the input voltages into the required output voltages, and outputting the corresponding output voltages by controlling the output unit 12, so that the output voltages can be close to the voltages required by the lamp beads, thereby reducing the idle power, improving the conversion efficiency, improving the operating efficiency of the lamp beads, reducing the heat generation, avoiding the problem of accelerated lamp bead aging caused by high temperature, prolonging the service life of the lamp beads, connecting the output ends of the voltage converters 10 with the anodes of the corresponding lamp beads through the constant current driving modules 22, so that the lamps are connected in a common cathode, effectively preventing the problem of unstable display color deviation caused by the output voltages when the lamp beads are connected in a common anode, and realizing the voltage conversion of the voltage pump units 14, and simplifying the small-size of the voltage conversion circuit, thereby facilitating the automatic voltage conversion. Moreover, the RGB driver chip 20 controls the lamp bead to work by setting the constant current driver module 22 connected to the voltage converter 10 to more accurately generate the current required for the lamp bead to work, and the RGB driver chip 20 further controls the lamp bead to work by setting the RGB data processing module 21 to obtain the corresponding PWM duty ratio according to the data conversion to be displayed and adjusting the brightness of the lamp bead by the constant current driver module 22. Meanwhile, the display screen lamp bead assembly 30 also has the above functions, the output end of the constant current driving module 22 is connected with the anode of the lamp bead, and the lamp beads of the RGB lamp bead group 31 are connected in a common cathode mode, so that the voltage drop on the constant current driving module 22 can be effectively reduced.
Specifically, in this embodiment, the RGB driving chip 20 further includes a voltage converter 10 connected to the voltage input terminal VIN and the RGB data processing module 21, respectively. The operating efficiency of the RGB data processing module 21 is improved by providing the voltage converter 10 connected to the RGB data processing module 21 to more precisely control according to the voltage required by the RGB data processing module 21.
Specifically, the constant current driving module 22 includes a constant current control unit 221 and a PWM control unit 222, the constant current control unit 221 includes a constant current control transistor and an operational amplifier, a source of the constant current control transistor is connected to a voltage output end of the voltage converter 10, a gate of the constant current control transistor is connected to an output end of the operational amplifier, a non-inverting input end of the operational amplifier is connected to a reference standard voltage Vref, an inverting input end of the operational amplifier is connected to a drain of the constant current control transistor through a constant current resistor, an input end of the PWM control unit 222 is electrically connected between the constant current resistor and the inverting input end of the operational amplifier, and the PWM control unit 222 is connected to the RGB data processing module 21. The constant current control unit 221 is arranged to more accurately generate rated current required by the lamp beads to drive and control the lamp beads, and the PWM control unit 222 connected with the RGB data processing module 21 is arranged to generate PWM duty ratios of the lamp beads calculated by the RGB data module 21 according to data to be displayed according to the driving of the RGB data module 21 and output the PWM duty ratios to the corresponding lamp beads to control the brightness of the lamp beads.
Specifically, the PWM control unit 222 includes a PWM control transistor, a source of the PWM control transistor is an input terminal of the PWM control unit 222, the source of the PWM control transistor is electrically connected between the constant current resistor and an inverting input terminal of the operational amplifier, a gate of the PWM control transistor is connected to the RGB data processing module 21, and a drain of the PWM control transistor is an output terminal of the constant current driving module 22 to be connected to an anode of a corresponding lamp bead.
The constant current control transistor and the PWM control transistor can be PMOS tubes. A constant current control transistor, an operational amplifier and a constant current resistor of a constant current control unit 221 of the constant current driving module 22 connected with the red light lamp bead LED-R are respectively marked as QR, AR and R1; a constant current control transistor, an operational amplifier and a constant current resistor of a constant current control unit 221 of the constant current driving module 22 connected with the green light bead LED-G are respectively marked as QG, AG and R2; and a constant current control transistor, an operational amplifier and a constant current resistor of a constant current control unit 221 of the constant current driving module 22 connected with the blue light lamp bead LED-B are respectively marked as QB, AB and R3. A PWM control transistor of a PWM control unit 222 of the constant current driving module 22 connected with the red light bead LED-R is marked as PR; a PWM control transistor of a PWM control unit 222 of the constant current driving module 22 connected with the green light bead LED-G is marked as PG; and the PWM control transistor of the PWM control unit 222 of the constant current driving module 22 connected with the blue light bead LED-B is recorded as PB.
Referring to fig. 4, fig. 4 is a circuit diagram of a display screen lamp bead assembly according to another embodiment of the present invention, where the display screen lamp bead assembly includes an RGB lamp bead group 31 and an RGB driving chip 20, the RGB lamp bead group 31 is electrically connected to the RGB driving chip 20, the RGB lamp bead group 31 includes a red lamp bead LED-R, a green lamp bead LED-G, and a blue lamp bead LED-B, the red lamp bead LED-R, the green lamp bead LED-G, and the blue lamp bead LED-B are connected to a common cathode, and anodes of the red lamp bead LED-R, the green lamp bead LED-G, and the blue lamp bead LED-B are respectively connected to an output end of a corresponding constant current driving module 22. As shown in fig. 4, in this embodiment, the RGB driving chip 31 includes two voltage converters 10, one RGB data processing module 21, and three constant current driving modules 22, output terminals of the three constant current driving modules 22 are respectively connected to anodes of a red light bead LED-R, a green light bead LED-G, and a blue light bead LED-B, one of the voltage converters 10 is connected to the red light bead LED-R through one of the constant current driving modules 22, the remaining two constant current driving modules 22 are both connected to the other voltage converter 10 and are respectively connected to the green light bead LED-G and the blue light bead LED-B, and the RGB data processing module 21 is respectively connected to a signal input terminal DI, a signal output terminal DO, the three constant current driving modules 22, and the voltage input terminal VIN. The rest of the structure and the function are similar to those of the previous embodiment, and are not described again.
In summary, the voltage converter of the present invention is provided with the conversion control distribution processing module, the control output unit, the input voltage detection unit and the plurality of charge pump units, so that the conversion control distribution processing module can control the operating mode of each charge pump unit according to the input voltage collected by the input voltage detection unit, thereby converting the input voltage into the required output voltage, and output the corresponding output voltage by controlling the output unit, so that the output voltage can be close to the voltage required by the lamp bead, thereby reducing the idle power, improving the conversion efficiency, improving the working efficiency of the lamp bead, reducing the heat generation amount, avoiding the problem of accelerated lamp bead aging caused by high temperature, prolonging the service life of the lamp bead, and connecting the output end of the voltage converter with the anode of the lamp bead, so that the subsequent lamp beads can be connected in a common cathode mode, thereby preventing the problem of display color deviation caused by unstable output voltage when the lamp beads are connected in a common anode mode, and realizing automatic voltage regulation output for wide voltage input through voltage conversion by the charge pump units, simplifying the circuit structure, which is convenient for realizing miniaturization and has a small volume. Meanwhile, the RGB driving chip and the display screen lamp bead assembly have the functions, the RGB driving chip can more accurately generate current driving required by the lamp bead to control the lamp bead to work by arranging the constant current driving module connected with the voltage converter, and the RGB driving chip can also obtain the corresponding PWM duty ratio according to the data conversion to be displayed by arranging the RGB data processing module and adjust and control the brightness of the lamp bead through the constant current driving module; the output end of the constant current driving module is connected with the anode of the lamp beads, and the lamp beads of the RGB lamp bead group are connected in a cathode mode, so that the voltage drop on the constant current driving module can be effectively reduced.
While the invention has been described with reference to specific embodiments, the invention is not limited thereto, and various equivalent modifications and substitutions can be easily made by those skilled in the art within the technical scope of the invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (10)
1. A voltage converter is characterized by comprising a conversion control distribution processing module, a control output unit, an input voltage detection unit and a plurality of charge pump units, wherein the charge pump units are sequentially connected in series, the output end of the last charge pump unit is connected with the control output unit, the input end of the first charge pump unit is connected with a voltage input end, the input ends of the charge pump units are connected with the control output unit, the input voltage detection unit is connected with the voltage input end, the conversion control distribution processing module is respectively connected with the input voltage detection unit, the control output unit and the charge pump units so as to respectively control the work of the control output unit and the charge pump units according to input voltage acquired by the input voltage detection unit, and the output end of the control output unit is the voltage output end of the voltage converter.
2. The voltage converter according to claim 1, wherein the number of the charge pump units is three, and the number of the charge pump units is a first charge pump unit, a second charge pump unit and a third charge pump unit, an input terminal of the first charge pump unit is connected to the voltage input terminal, the first charge pump unit, the second charge pump unit and the third charge pump unit are sequentially connected in series, input terminals of the first charge pump unit, the second charge pump unit and the third charge pump unit are all connected to the control output unit, and an output terminal of the third charge pump unit is connected to the control output unit.
3. The voltage converter according to claim 1, wherein the charge pump unit comprises a first NMOS transistor, a second NMOS transistor, a third NMOS transistor, a fourth NMOS transistor, a fifth NMOS transistor, a sixth NMOS transistor, a seventh NMOS transistor, an eighth NMOS transistor, a ninth NMOS transistor, a tenth NMOS transistor, an eleventh NMOS transistor, a twelfth NMOS transistor, a first capacitor and a second capacitor, wherein drain electrodes of the first NMOS transistor, the third NMOS transistor, the seventh NMOS transistor and the ninth NMOS transistor are connected to an input terminal, source electrodes of the first NMOS transistor and the third NMOS transistor are respectively connected to two terminals of the first capacitor, drain electrodes of the second NMOS transistor and the fourth NMOS transistor are respectively connected to source electrodes of the first NMOS transistor and the third NMOS transistor, source electrodes of the seventh NMOS transistor and the ninth NMOS transistor are respectively connected to two terminals of the second capacitor, the drain electrodes of the eighth NMOS transistor and the tenth NMOS transistor are respectively connected to the source electrodes of the seventh NMOS transistor and the ninth NMOS transistor, the source electrodes of the second NMOS transistor, the fourth NMOS transistor, the eighth NMOS transistor and the tenth NMOS transistor are all connected to the drain electrode of the twelfth NMOS transistor, the source electrode of the twelfth NMOS transistor is connected to the output terminal, a grounding capacitor is connected between the output terminal and the source electrode of the twelfth NMOS transistor, the drain electrode of the fifth NMOS transistor is respectively connected to the source electrode of the third NMOS transistor and the drain electrode of the sixth NMOS transistor, the source electrode of the sixth NMOS transistor is connected to the drain electrode of the eighth NMOS transistor, the source electrodes of the fifth NMOS transistor and the eleventh NMOS transistor are all grounded, the drain electrode of the eleventh NMOS transistor is connected to the source electrode of the ninth NMOS transistor, and the first NMOS transistor, the second NMOS transistor, the third NMOS transistor, the fourth NMOS transistor, the fifth NMOS transistor, the sixth NMOS transistor, the seventh NMOS transistor, and the seventh NMOS transistor are all connected to the drain electrode of the sixth NMOS transistor, and the grids of the eighth NMOS transistor, the ninth NMOS transistor, the tenth NMOS transistor, the eleventh NMOS transistor and the twelfth NMOS transistor are all connected with the conversion control distribution processing module.
4. The voltage converter according to claim 1, further comprising an output voltage detection unit, wherein the output voltage detection unit is respectively connected to the output end of the control output unit and the conversion control distribution processing module, so as to collect and transmit the output voltage of the control output unit to the conversion control distribution processing module.
5. An RGB driver chip comprising two voltage converters according to any one of claims 1 to 4, an RGB data processing module, and three constant current driving modules, wherein the output terminals of the three constant current driving modules are respectively connected to the anodes of the red light bead, the green light bead, and the blue light bead, one of the voltage converters is connected to the red light bead through one of the constant current driving modules, the remaining two constant current driving modules are connected to the other voltage converter and are respectively connected to the green light bead and the blue light bead, and the RGB data processing module is respectively connected to a signal input terminal, a signal output terminal, the three constant current driving modules, and the voltage input terminal.
6. An RGB driver chip, comprising three voltage converters of any one of claims 1 to 4, an RGB data processing module and three constant current driving modules, wherein the output terminals of the three constant current driving modules are respectively connected with the anodes of the red light bulbs, the green light bulbs and the blue light bulbs, the voltage converters are in one-to-one correspondence with the constant current driving modules and are electrically connected with each other, and the RGB data processing module is respectively connected with a signal input terminal, a signal output terminal, the three constant current driving modules and the voltage input terminal.
7. The RGB driving chip of claim 5 or 6, further comprising a voltage converter respectively connected to the voltage input terminal and the RGB data processing module.
8. The RGB driver chip according to claim 5 or 6, wherein the constant current driver module includes a constant current control unit and a PWM control unit, the constant current control unit includes a constant current control transistor and an operational amplifier, a source of the constant current control transistor is connected to a voltage output terminal of the voltage converter, a gate of the constant current control transistor is connected to an output terminal of the operational amplifier, a non-inverting input terminal of the operational amplifier is connected to a reference standard voltage, an inverting input terminal of the operational amplifier is connected to a drain of the constant current control transistor through a constant current resistor, an input terminal of the PWM control unit is electrically connected between the constant current resistor and the inverting input terminal of the operational amplifier, and the PWM control unit is connected to the RGB data processing module.
9. The RGB driver chip of claim 8, wherein the PWM control unit includes a PWM control transistor, a source of the PWM control transistor is an input terminal of the PWM control unit, a source of the PWM control transistor is electrically connected between the constant current resistor and an inverting input terminal of the operational amplifier, a gate of the PWM control transistor is connected to the RGB data processing module, and a drain of the PWM control transistor is an output terminal of the constant current driver module.
10. A display screen lamp bead component is characterized by comprising an RGB lamp bead group and the RGB driver chip of any one of claims 5 to 9, wherein the RGB lamp bead group is electrically connected with the RGB driver chip and comprises red light lamp beads, green light lamp beads and blue light lamp beads, the red light lamp beads, the green light lamp beads and the blue light lamp beads are connected in a common negative mode, and anodes of the red light lamp beads, the green light lamp beads and the blue light lamp beads are respectively connected with output ends of corresponding constant current driver modules.
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| CN202211502247.4A CN115882720A (en) | 2022-11-28 | 2022-11-28 | Voltage converter, RGB drive chip and display screen lamp pearl subassembly |
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| CN202211502247.4A CN115882720A (en) | 2022-11-28 | 2022-11-28 | Voltage converter, RGB drive chip and display screen lamp pearl subassembly |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN118137830A (en) * | 2024-05-08 | 2024-06-04 | 成都光电传感技术研究所有限公司 | Zero-voltage starting power supply conversion system, method and starting device |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN118137830A (en) * | 2024-05-08 | 2024-06-04 | 成都光电传感技术研究所有限公司 | Zero-voltage starting power supply conversion system, method and starting device |
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