CN107947567B - Charge pump circuit, control method and display device - Google Patents
Charge pump circuit, control method and display device Download PDFInfo
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- CN107947567B CN107947567B CN201711096373.3A CN201711096373A CN107947567B CN 107947567 B CN107947567 B CN 107947567B CN 201711096373 A CN201711096373 A CN 201711096373A CN 107947567 B CN107947567 B CN 107947567B
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- 238000000034 method Methods 0.000 title claims abstract description 51
- 239000003990 capacitor Substances 0.000 claims abstract description 290
- 238000007599 discharging Methods 0.000 claims abstract description 31
- 239000010409 thin film Substances 0.000 claims description 12
- 238000010586 diagram Methods 0.000 description 26
- 239000004973 liquid crystal related substance Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of DC power input into DC power output
- H02M3/02—Conversion of DC power input into DC power output without intermediate conversion into AC
- H02M3/04—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters
- H02M3/06—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using resistors or capacitors, e.g. potential divider
- H02M3/07—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using resistors or capacitors, e.g. potential divider using capacitors charged and discharged alternately by semiconductor devices with control electrode, e.g. charge pumps
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
- G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
- G09G3/3611—Control of matrices with row and column drivers
- G09G3/3696—Generation of voltages supplied to electrode drivers
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/0083—Converters characterised by their input or output configuration
- H02M1/009—Converters characterised by their input or output configuration having two or more independently controlled outputs
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Physics & Mathematics (AREA)
- Computer Hardware Design (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Dc-Dc Converters (AREA)
Abstract
The application discloses charge pump circuit, control method and display device, charge pump circuit includes: an output end; at least one second group of capacitors including a first capacitor that outputs the first driving voltage or the second driving voltage by discharging, and a second capacitor that charges the first capacitor by discharging and outputs the first driving voltage or the second driving voltage; and the switch module is used for controlling output, controlling the second group of capacitors to charge and discharge and controlling the input of the multi-path input voltage so as to output a plurality of groups of first driving voltages and second driving voltages. When the first driving voltage or the second driving voltage is output, the two external capacitors are not connected in series, the equivalent capacitance value is not reduced, and the capacitive reactance is not increased. The first driving voltage and the second driving voltage have the same driving capability. The first driving voltage and the second driving voltage are output to the driving circuit, and the driving circuit outputs the image signal to the display panel to complete image display.
Description
Technical Field
The present invention relates to a circuit for supplying a driving voltage to a driving circuit of a liquid crystal display device, and more particularly, to a charge pump circuit, a control method, and a display device.
Background
Charge pump circuits eliminate magnetic fields and electromagnetic interference carried by inductors and transformers and have been frequently used as power supply circuits to provide voltage to loads.
Fig. 1 is a schematic diagram showing a charge pump circuit for inputting a driving voltage to a driving circuit of a liquid crystal display device in the related art. The charge pump circuit comprises a plurality of switches, an internal capacitor, a plurality of input voltages and two external capacitors, such as flying capacitors. The switches are used for outputting a plurality of groups of first driving voltages VGH and second driving voltages VGL through a first output end and a second output end by controlling the charging and discharging of the external capacitor and by controlling the input of the multipath input voltages. When the second driving voltage VGL is output, the external capacitor C2 is discharged; when the first driving voltage VGH is output, the two external capacitors C1 and C2 are serially connected to discharge, the equivalent capacitance value is increased and reduced to half of the original value in this state, the output first driving voltage VGH cannot provide large load current, the first driving voltage VGH is reduced, the driving capability of the first driving voltage is not matched with that of the second driving voltage, and the driving capability of the first driving voltage is reduced by half on the original basis. The problem of increased circuit area and high manufacturing cost is caused by replacing the capacitors with large capacitance or increasing the number of capacitors to increase the load current.
Therefore, there is a need to provide an improved technical solution to overcome the above technical problems in the prior art.
Disclosure of Invention
Accordingly, the present invention is directed to a charge pump circuit, a control method and a display device, which are capable of providing a consistent driving capability for a first driving voltage and a second driving voltage without replacing an original external capacitor, and outputting a plurality of sets of the first driving voltage and the second driving voltage for a driving circuit through a switch control so as to display an image on a display panel.
According to a first aspect of the present invention, a charge pump circuit is provided, which includes a first output terminal and a second output terminal, connected to a first group of capacitor filters, and configured to output a first driving voltage and a second driving voltage; at least one second set of capacitances, said second set of capacitances further comprising: a first capacitor that outputs the first driving voltage or the second driving voltage by discharging; a second capacitor that charges the first capacitor by discharging and outputs the first driving voltage or the second driving voltage; and a switch module, the switch module further comprising: a first set of switches for controlling the output of the first drive voltage and the second drive voltage; and the second group of switches are connected between the second group of capacitors and the multi-path input voltage or between the second group of capacitors and are used for controlling the second group of capacitors to be charged and discharged and controlling the input of the multi-path input voltage so as to output a plurality of groups of first driving voltages and second driving voltages.
Preferably, the first driving voltage is an on voltage of the thin film transistor, and the second driving voltage is an off voltage of the thin film transistor.
Preferably, the first set of capacitances and the second set of capacitances are external capacitances.
Preferably, the multiple input voltages include a first input voltage, a second input voltage, and a third input voltage, and the first input voltage, the second input voltage, and the third input voltage are respectively a positive voltage, a negative voltage, or a common mode voltage.
Preferably, the first set of switches comprises: the first switch is connected between the first output end and the first end of the first capacitor; and the second switch is connected between the second output end and the second end of the second capacitor.
Preferably, the second set of switches comprises: the third switch is connected between the first end of the first capacitor and the first end of the second capacitor; a fourth switch connected between the first input voltage and the first end of the first capacitor; a fifth switch, a sixth switch and a seventh switch, respectively connected between the first input voltage and the second end of the first capacitor, between the second input voltage and the second end of the first capacitor and between the third input voltage and the second end of the first capacitor; an eighth switch, a ninth switch, and a tenth switch respectively connected between the first input voltage and the first end of the second capacitor, between the second input voltage and the first end of the second capacitor, and between the third input voltage and the first end of the second capacitor; and an eleventh switch, a twelfth switch and a thirteenth switch respectively connected between the first input voltage and the second end of the second capacitor, between the second input voltage and the second end of the second capacitor and between the third input voltage and the second end of the second capacitor.
According to a second aspect of the present invention, there is provided a control method of the charge pump circuit, including the steps of:
a second capacitor is charged, and an input voltage is received to charge the second capacitor;
a second capacitor charges a first capacitor, connects the second capacitor with the first capacitor, and charges the first capacitor through discharging of the second capacitor; and
the first capacitor discharges and the second capacitor charges and discharges, and when the first capacitor discharges, the second capacitor charges and discharges.
Preferably, the control method further includes the steps of:
a second capacitor is charged, and an input voltage is received to charge the second capacitor;
a second capacitor charges a first capacitor, connects the second capacitor with the first capacitor, and charges the first capacitor through discharging of the second capacitor;
the method comprises the steps that a first capacitor discharges and a second capacitor charges, and when the first capacitor discharges, input voltage is received to charge the second capacitor; and
the second capacitor discharges and the first capacitor discharges.
Preferably, the first capacitor discharges to output the first driving voltage or the second driving voltage, and the second capacitor discharges to output the first driving voltage or the second driving voltage.
Preferably, the first driving voltage is an on voltage of the thin film transistor, and the second driving voltage is an off voltage of the thin film transistor.
Preferably, the input voltage comprises a positive voltage or a negative voltage or a common mode voltage.
According to a third aspect of the present invention, there is provided a display device, comprising the above-mentioned charge pump circuit, for generating a plurality of sets of first driving voltages and second driving voltages; a drive circuit that is driven by the first drive voltage and the second drive voltage; and a display panel on which an image is displayed according to the image signal output from the driving circuit.
Compared with the prior art, the charge pump circuit, the control method and the display device provided by the invention have the advantages that the input voltage and the switch for controlling the input voltage are added. The control method of the invention is as follows: when the first driving voltage or the second driving voltage is output, the two external capacitors are not connected in series. Therefore, the equivalent capacitance value is not reduced, and the capacitive reactance is not increased. The first and second driving voltages have the same driving capability without increasing the capacitance and the number of capacitors.
Drawings
The above and other objects, features and advantages of the present invention will become more apparent from the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:
FIG. 1 shows a schematic diagram of a prior art charge pump circuit; FIG. 2 shows a schematic diagram of the charge pump circuit of the present invention;
FIG. 3 is a flow chart of a control method of a charge pump circuit according to a first embodiment of the present invention;
FIG. 4a is a diagram illustrating a state where the charge pump circuit outputs the first set of driving voltages according to the first embodiment of the present invention; FIG. 4b shows a timing diagram of the embodiment of FIG. 4 a;
FIG. 5 is a diagram illustrating the state of the charge pump circuit outputting the second set of driving voltages according to the first embodiment of the present invention;
FIG. 6 is a diagram illustrating the state of the charge pump circuit outputting the third set of driving voltages according to the first embodiment of the present invention;
FIG. 7 is a diagram illustrating a state where the charge pump circuit outputs the fourth set of driving voltages according to the first embodiment of the present invention;
FIG. 8 is a flow chart of a charge pump circuit control method according to a second embodiment of the present invention;
FIG. 9a is a diagram illustrating a state where the charge pump circuit outputs the first set of driving voltages according to the second embodiment of the present invention; FIG. 9b shows a timing diagram of the embodiment of FIG. 9 a;
FIG. 10 is a diagram illustrating a state where the charge pump circuit outputs the second set of driving voltages according to the second embodiment of the present invention;
FIG. 11 is a diagram illustrating a state where the charge pump circuit outputs the third set of driving voltages according to the second embodiment of the present invention;
fig. 12 is a diagram showing a state where the charge pump circuit outputs the fourth set of driving voltages according to the second embodiment of the present invention;
fig. 13 shows a schematic diagram of a charge pump circuit according to a third embodiment of the present invention.
Detailed Description
The invention will be described in more detail below with reference to the accompanying drawings. Like elements in the various figures are denoted by like reference numerals. For purposes of clarity, the various features in the drawings are not necessarily drawn to scale. In addition, certain well known components may not be shown.
In the following description, numerous specific details of the invention, such as structure, materials, dimensions, processing techniques and techniques of the devices are described in order to provide a more thorough understanding of the invention. However, as will be understood by those skilled in the art, the present invention may be practiced without these specific details.
The present invention may be embodied in various forms, some of which will be described below. According to the present invention, the first capacitor C1 may output the first driving voltage VGH or the second driving voltage VGL from the first output terminal by discharging; the second capacitor C2 may output the first driving voltage VGH or the second driving voltage VGL from the second output terminal by discharging. In order to describe the embodiments of the present invention in detail, the first capacitor C1 outputs the first driving voltage VGH from the first output terminal by discharging, and the second capacitor C2 outputs the second driving voltage VGL from the second output terminal by discharging in the following embodiments, but the embodiments of the present invention are not limited to the following embodiments, and the first driving voltage VGH from the second output terminal can be discharged by the second capacitor C2, and the second driving voltage VGL from the first output terminal can be discharged by the first capacitor C1.
Fig. 2 shows a schematic diagram of the charge pump circuit of the present invention. As shown in fig. 2, the charge pump circuit includes a first output terminal, a second output terminal, a switch module, a second group of capacitors including a first capacitor C1 and a second capacitor C2, and a first group of capacitors including a third capacitor C3 and a fourth capacitor C4. The switch module comprises a first group of switches and a second group of switches, and acts on the second group of capacitors.
The first group of switches includes a first switch S1 and a second switch S2, for controlling the first output terminal and the second output terminal to output the first driving voltage VGH and the second driving voltage VGL. A first end of the first capacitor C1 is connected to a first output end through a first switch S1, filtered through a third capacitor C3 and grounded; the second terminal of the second capacitor C2 is connected to the second output terminal through the second switch S2, filtered by the fourth capacitor C4, and grounded.
And the second group of switches are used for controlling a group of second group of capacitors to carry out charging and discharging and outputting a plurality of groups of first driving voltages VGH and second driving voltages VGL by controlling the input of the multipath input voltages. The method comprises the following steps: a third switch S3 connected between the first terminal of the first capacitor C1 and the first terminal of the second capacitor C2; a fourth switch S4 connected between the first input voltage VSP and the first end of the first capacitor C1, a fifth switch S5, a sixth switch S6 and a seventh switch S7, wherein the first ends of the three switches are respectively connected to the first input voltage VSP, the second input voltage VN and the third input voltage VSN, the second ends of the three switches are connected to the second end of the first capacitor C1, and the fourth to seventh switches are used for controlling the charging and discharging of the first capacitor C1 and the input of multiple input voltages; an eighth switch S8, a ninth switch S9, and a tenth switch S10, wherein first ends of the three switches are respectively connected to the first input voltage VSP, the second input voltage VN, and the third input voltage VSN, second ends of the three switches are connected to a first end of a second capacitor C2, an eleventh switch S11, a twelfth switch S12, and a thirteenth switch S13, first ends of the three switches are respectively connected to the first input voltage VSP, the second input voltage VN, and the third input voltage VSN, second ends of the three switches are connected to a second end of a second capacitor C2, and the eighth to thirteenth switches are used for controlling charging and discharging of the second capacitor C2 and input of multiple input voltages.
In the charge pump circuit of the invention, when the switch S3 is closed, the second capacitor C2 charges the first capacitor C1; when the switch S1 is closed, the switch S3 is opened, and the first capacitor C1 is controlled to discharge by part of the second group of switches and input voltage so as to output the first driving voltage VGH through the first output terminal; when the switch S2 is closed, the switch S3 is opened, and the second capacitor C2 is controlled to discharge by a part of the second group of switches and the input voltage is input to output the second driving voltage VGL through the second output terminal. When the charge pump circuit outputs the first driving voltage or the second driving voltage, the two external capacitors are not connected in series, the equivalent capacitance value is not reduced, the capacitance reactance is not increased, and the driving capacities of the first driving voltage and the second driving voltage are consistent under the condition that the capacitance value and the number of the capacitors are not increased.
In the present invention, the first driving voltage is an on voltage of the thin film transistor, and the second driving voltage is an off voltage of the thin film transistor. The first input voltage is a positive voltage, the second input voltage is a common-mode voltage of the first input voltage and the third input voltage, and the third input voltage is a negative voltage. The first group of capacitors and the second group of capacitors are external capacitors for storing more charge. But the implementation of the invention is not limited thereto.
Fig. 3 is a flow chart illustrating a control method of a charge pump circuit according to a first embodiment of the present invention. Fig. 3 shows a control method of the charge pump circuit, which includes the following steps:
step S01: a second capacitor is charged, and the second capacitor is charged by receiving the input voltage so as to enable the second capacitor to store the charges;
step S02: the second capacitor charges the first capacitor, connects the second capacitor with the first capacitor, and charges and stores charges by discharging the second capacitor; and
step S03: the first capacitor discharges and the second capacitor charges and discharges, and when the first capacitor discharges, the second capacitor charges and discharges. When the first capacitor discharges to output the first driving voltage or the second driving voltage, the second capacitor charges and discharges to output the second driving voltage or the first driving voltage.
The control method is a first embodiment of the charge pump circuit of the present invention, the first capacitor is charged by discharging the second capacitor, and the first driving voltage and the second driving voltage are respectively outputted by discharging one capacitor, so as to improve the driving capability of the first driving voltage and the second driving voltage. In this embodiment, the first capacitor discharges to output the first driving voltage, and the second capacitor discharges to output the second driving voltage. However, the present invention may also be implemented to output the second driving voltage by discharging through the first capacitor and output the first driving voltage by discharging through the second capacitor.
Fig. 4a is a schematic diagram illustrating a state where the charge pump circuit outputs the first set of driving voltages according to the first embodiment of the present invention, and fig. 4b is a schematic diagram illustrating a timing sequence of the embodiment of fig. 4 a. With reference to fig. 4a and 4b, a specific embodiment of the charge pump circuit outputting the first set of driving voltages according to the control method of fig. 3 is shown. As shown, in the first state, only the seventh switch S7, the eighth switch S8 and the thirteenth switch S13 are closed, so that the second capacitor C2 charges to store charge; in the second state, only the seventh switch S7, the third switch S3 and the eleventh switch S11 are closed, so that the first capacitor C1 is connected in series with the second capacitor C2, and the second capacitor C2 discharges to charge the first capacitor C1, so that the voltage across the first capacitor C1 is 2VSP-2 VSN; in the third state, only the first switch S1, the second switch S2, the sixth switch S6 and the tenth switch S10 are closed, the first driving voltage VGH having the voltage of 2VSP-2VSN + VN is discharged through the first capacitor C1, and the second driving voltage VGL having the voltage of 2VSN-VSP is discharged while being charged through the second capacitor C2.
The first driving voltage and the second driving voltage are controlled by the amount of the charge stored when the first capacitor and the second capacitor are charged and the input of the input voltage is controlled by part of the second group of switches. And closing or opening part of the second group of switches to output different groups of first driving voltage and second driving voltage. The following will continue to describe in detail the case where the charge pump circuit of the first embodiment of the present invention outputs a plurality of sets of driving voltages.
Fig. 5 is a schematic diagram illustrating a state where the charge pump circuit outputs the second set of driving voltages according to the first embodiment of the present invention, that is, a specific embodiment where the charge pump circuit outputs the second set of driving voltages according to the control method of fig. 3. As shown, in the first state, only the seventh switch S7, the eighth switch S8 and the twelfth switch S12 are closed, so that the second capacitor C2 charges to store charge; in the second state, only the seventh switch S7, the third switch S3 and the eleventh switch S11 are closed, so that the first capacitor C1 is connected in series with the second capacitor C2, and the second capacitor C2 discharges to charge the first capacitor C1, so that the voltage across the first capacitor C1 is 2 VSP-VSN; in the third state, only the first switch S1, the second switch S2, the fifth switch S5 and the tenth switch S10 are closed, the first driving voltage VGH having the voltage VSP-VSN is discharged through the first capacitor C1, and the second driving voltage VGL having the voltage VSN-VSP is discharged through the second capacitor C2.
Fig. 6 is a schematic diagram illustrating a state where the charge pump circuit outputs the third set of driving voltages according to the first embodiment of the present invention, that is, a specific embodiment where the charge pump circuit outputs the third set of driving voltages according to the control method of fig. 3. As shown, in the first state, only the seventh switch S7, the eighth switch S8 and the thirteenth switch S13 are closed, so that the second capacitor C2 charges to store charge; in the second state, only the seventh switch S7, the third switch S3 and the eleventh switch S11 are closed, so that the first capacitor C1 is connected in series with the second capacitor C2, and the second capacitor C2 discharges to charge the first capacitor C1, so that the voltage across the first capacitor C1 is 2VSP-2 VSN; in the third state, only the first switch S1, the second switch S2, the fifth switch S5 and the ninth switch S9 are closed, the first driving voltage VGH having the voltage VSP-2VSN is discharged through the first capacitor C1, and the second driving voltage VGL having the voltage VSN-VSP is discharged through the second capacitor C2 while being charged.
Fig. 7 is a diagram illustrating a state where the charge pump circuit outputs the fourth set of driving voltages according to the first embodiment of the present invention, that is, a specific embodiment where the charge pump circuit outputs the fourth set of driving voltages according to the control method of fig. 3. As shown, in the first state, only the seventh switch S7, the eighth switch S8 and the thirteenth switch S13 are closed, so that the second capacitor C2 charges to store charge; in the second state, only the seventh switch S7, the third switch S3 and the eleventh switch S11 are closed, so that the first capacitor C1 is connected in series with the second capacitor C2, and the second capacitor C2 discharges to charge the first capacitor C1, so that the voltage across the first capacitor C1 is 2VSP-2 VSN; in the third state, only the first switch S1, the second switch S2, the fifth switch S5 and the tenth switch S10 are closed, the first driving voltage VGH having the voltage of 3VSP-2VSN is discharged through the first capacitor C1, and the second driving voltage VGL having the voltage of 2VSN-VSP is discharged through the second capacitor C2 while being charged.
Fig. 8 is a flowchart illustrating a charge pump circuit control method according to a second embodiment of the present invention. Fig. 8 shows another control method of the charge pump circuit of the present invention, which includes the following steps:
step S01: a second capacitor is charged, and the second capacitor is charged by receiving the input voltage so as to enable the second capacitor to store the charges;
step S02: the second capacitor charges the first capacitor, connects the second capacitor with the first capacitor, and charges and stores charges by discharging the second capacitor; and
step S31: the first capacitor is discharged and the second capacitor is charged, and when the first capacitor is discharged, the input voltage is received to charge the second capacitor to store charges; and
step S32: the second capacitor discharges and the first capacitor discharges, and the first driving voltage and the second driving voltage are output through the discharge of the first capacitor and the second capacitor.
The control method is a second embodiment of the charge pump circuit of the present invention, and the first capacitor is charged by discharging the second capacitor in four steps, and the first driving voltage and the second driving voltage are output by one capacitor, so that the driving capability of the first driving voltage and the second driving voltage is improved. In this embodiment, the first capacitor discharges to output the first driving voltage, and the second capacitor discharges to output the second driving voltage. However, the present invention may also be implemented to output the second driving voltage by discharging through the first capacitor and output the first driving voltage by discharging through the second capacitor.
Fig. 9a is a schematic diagram illustrating a state where the charge pump circuit outputs the first set of driving voltages according to the second embodiment of the present invention, and fig. 9b is a schematic diagram illustrating a timing sequence of the embodiment of fig. 9 a. With reference to fig. 9a and 9b, a specific embodiment of the charge pump circuit outputting the first set of driving voltages according to the control method of fig. 8 is shown. As shown, in the first state, only the seventh switch S7, the eighth switch S8 and the thirteenth switch S13 are closed, so that the second capacitor C2 charges to store charge; in the second state, only the seventh switch S7, the third switch S3 and the eleventh switch S11 are closed, so that the first capacitor C1 is connected in series with the second capacitor C2, and the second capacitor C2 discharges to charge the first capacitor C1, so that the voltage across the first capacitor C1 is 2VSP-2 VSN; a third state in which only the first switch S1, the sixth switch S6, the eighth switch S8, and the thirteenth switch S13 are closed, the first driving voltage VGH having the voltage of 2VSP-2VSN + VN is discharged through the first capacitor C1 while the second capacitor C2 is charged to store charges; in the fourth state, only the first switch S1, the sixth switch S6, the second switch S2, and the tenth switch S10 are closed, the second driving voltage VGL having the output voltage of 2VSN-VSP is discharged through the second capacitor C2, and the first capacitor C1 is discharged and the first driving voltage VGH is output.
The first driving voltage and the second driving voltage are controlled by the amount of the charge stored when the first capacitor and the second capacitor are charged and the input of the input voltage is controlled by part of the second group of switches. And closing or opening part of the second group of switches to output different groups of first driving voltage and second driving voltage. The following will continue to describe in detail the case where the charge pump circuit of the second embodiment of the present invention outputs a plurality of sets of driving voltages.
Fig. 10 is a schematic diagram illustrating a state where the charge pump circuit outputs the second group of driving voltages according to the second embodiment of the present invention, that is, a specific embodiment where the charge pump circuit outputs the second group of driving voltages according to the control method of fig. 8 is shown. As shown, in the first state, only the seventh switch S7, the eighth switch S8 and the twelfth switch S12 are closed, so that the second capacitor C2 charges to store charge; in the second state, only the seventh switch S7, the third switch S3 and the eleventh switch S11 are closed, so that the first capacitor C1 is connected in series with the second capacitor C2, and the second capacitor C2 discharges to charge the first capacitor C1, so that the voltage across the first capacitor C1 is 2 VSP-VSN; in a third state, only the first switch S1, the fifth switch S5, the eighth switch S8, and the twelfth switch S12 are closed, the first driving voltage VGH having the voltage of 3VSP-VSN is discharged through the first capacitor C1, and the second capacitor C2 is charged with the stored charge; in the fourth state, only the first switch S1, the sixth switch S6, the second switch S2, and the tenth switch S10 are closed, the second driving voltage VGL having the VSN-VSP output voltage is discharged through the second capacitor C2, and the first capacitor C1 is discharged and the first driving voltage VGH is output.
Fig. 11 is a schematic diagram illustrating a state where the charge pump circuit outputs the third group of driving voltages according to the second embodiment of the present invention, that is, a specific embodiment where the charge pump circuit outputs the third group of driving voltages according to the control method of fig. 8 is shown. As shown, in the first state, only the seventh switch S7, the eighth switch S8 and the thirteenth switch S13 are closed, so that the second capacitor C2 charges to store charge; in the second state, only the seventh switch S7, the third switch S3 and the eleventh switch S11 are closed, so that the first capacitor C1 is connected in series with the second capacitor C2, and the second capacitor C2 discharges to charge the first capacitor C1, so that the voltage across the first capacitor C1 is 2VSP-2 VSN; in a third state, only the first switch S1, the fifth switch S5, the eighth switch S8, and the thirteenth switch S13 are closed, the first driving voltage VGH having the voltage of 3VSP-2VSN is discharged through the first capacitor C1, and the second capacitor C2 is charged with the stored charge; in the fourth state, only the first switch S1, the fifth switch S5, the second switch S2, and the ninth switch S9 are closed, the second driving voltage VGL having the VSN-VSP voltage is discharged through the second capacitor C2, and the first capacitor C1 is discharged and the first driving voltage VGH is output.
Fig. 12 is a schematic diagram illustrating a state where the charge pump circuit outputs the fourth set of driving voltages according to the second embodiment of the present invention, that is, a specific embodiment where the charge pump circuit outputs the fourth set of driving voltages according to the control method of fig. 8 is shown. As shown, in the first state, only the seventh switch S7, the eighth switch S8 and the thirteenth switch S13 are closed, so that the second capacitor C2 charges to store charge; in the second state, only the seventh switch S7, the third switch S3 and the eleventh switch S11 are closed, so that the first capacitor C1 is connected in series with the second capacitor C2, and the second capacitor C2 discharges to charge the first capacitor C1, so that the voltage across the first capacitor C1 is 2VSP-2 VSN; in a third state, only the first switch S1, the fifth switch S5, the eighth switch S8, and the thirteenth switch S13 are closed, the first driving voltage VGH having the voltage of 3VSP-2VSN is discharged through the first capacitor C1, and the second capacitor C2 is charged with the stored charge; in the fourth state, only the first switch S1, the fifth switch S5, the second switch S2, and the tenth switch S10 are closed, the second driving voltage VGL having the output voltage of 2VSN-VSP is discharged through the second capacitor C2, and the first capacitor C1 is discharged and the first driving voltage VGH is output.
Fig. 13 shows a schematic circuit diagram of a charge pump according to a third embodiment of the present invention. A third embodiment is a charge pump circuit obtained by cascading two sets of second capacitors of the charge pump circuit of the present invention, and the charge pump circuit includes a first output terminal, a second output terminal, a switch module, two sets of second capacitors, and a first capacitor. One group of second group of capacitors comprises a first capacitor C1 and a second capacitor C2, the other group of second group of external capacitors comprises a fifth capacitor C5 and a sixth capacitor C6, the first group of capacitors comprises a third capacitor C3 and a fourth capacitor C4, and the switch module comprises a first group of switches and two groups of second group of switches which are respectively applied to one group of second group of capacitors.
The working principle of the charge pump circuit in the third embodiment is consistent with the working principle of the charge pump circuit in the present invention, and the charge pump circuit can output a plurality of sets of first driving voltages and second driving voltages according to the control method shown in fig. 3 and the control method shown in fig. 8, and the specific working state is consistent with the principle that the charge pump circuit outputs a plurality of sets of first driving voltages and second driving voltages according to the control method shown in fig. 3 and the control method shown in fig. 8, and therefore, the detailed description is omitted here.
According to the charge pump circuit, the control method and the display device provided by the invention, when the first driving voltage or the second driving voltage is output, the two external capacitors are not connected in series, the equivalent capacitance value is not reduced, the capacitance reactance is not increased, and the driving capacities of the first driving voltage and the second driving voltage are consistent under the condition that the capacitance value and the number of the capacitors are not increased. The charge pump circuit outputs the first driving voltage and the second driving voltage to the driving circuit, and the driving circuit outputs the image signal to the display panel to complete image display.
It is noted that, herein, relational terms such as one and the other, first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
While embodiments in accordance with the invention have been described above, these embodiments are not intended to be exhaustive or to limit the invention to the precise embodiments described. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated.
Claims (14)
1. A charge pump circuit, comprising:
the first output end and the second output end are connected with the first group of capacitor filters and used for outputting a first driving voltage and a second driving voltage;
at least one second set of capacitances, said second set of capacitances further comprising: a first capacitor that outputs the first driving voltage or the second driving voltage by discharging; a second capacitor that charges the first capacitor by discharging and outputs the first driving voltage or the second driving voltage; and
a switch module, the switch module further comprising:
a first set of switches for controlling the output of the first drive voltage and the second drive voltage, the first set of switches comprising:
the first switch is connected between the first output end and the first end of the first capacitor;
the second switch is connected between the second output end and the second end of the second capacitor; and
and the second group of switches are connected between the second group of capacitors and the multi-path input voltage or between the second group of capacitors and are used for controlling the second group of capacitors to be charged and discharged and controlling the input of the multi-path input voltage so as to output a plurality of groups of first driving voltages and second driving voltages.
2. The charge pump circuit of claim 1, wherein the first driving voltage is an on voltage of the thin film transistor and the second driving voltage is an off voltage of the thin film transistor.
3. The charge pump circuit of claim 1, wherein the first set of capacitors and the second set of capacitors are external capacitors.
4. The charge pump circuit of claim 1, wherein the plurality of input voltages comprises a first input voltage, a second input voltage, and a third input voltage, and wherein the first input voltage, the second input voltage, and the third input voltage are respectively a positive voltage or a negative voltage or a common mode voltage.
5. The charge pump circuit of claim 4, wherein the second set of switches comprises:
the third switch is connected between the first end of the first capacitor and the first end of the second capacitor;
a fourth switch connected between the first input voltage and the first end of the first capacitor;
a fifth switch, a sixth switch and a seventh switch, respectively connected between the first input voltage and the second end of the first capacitor, between the second input voltage and the second end of the first capacitor and between the third input voltage and the second end of the first capacitor;
an eighth switch, a ninth switch, and a tenth switch respectively connected between the first input voltage and the first end of the second capacitor, between the second input voltage and the first end of the second capacitor, and between the third input voltage and the first end of the second capacitor; and
an eleventh switch, a twelfth switch, and a thirteenth switch, respectively connected between the first input voltage and the second end of the second capacitor, between the second input voltage and the second end of the second capacitor, and between the third input voltage and the second end of the second capacitor.
6. A control method for the charge pump circuit according to any one of claims 1 to 5, characterized in that the control method comprises the steps of:
a second capacitor is charged, and an input voltage is received to charge the second capacitor;
a second capacitor charges a first capacitor, connects the second capacitor with the first capacitor, and charges the first capacitor through discharging of the second capacitor; and
the first capacitor discharges and the second capacitor charges and discharges, and when the first capacitor discharges, the second capacitor charges and discharges.
7. The control method according to claim 6, wherein the first driving voltage or the second driving voltage is output by discharging the first capacitor, and the first driving voltage or the second driving voltage is output by discharging the second capacitor.
8. The control method according to claim 6, wherein the first driving voltage is an on voltage of the thin film transistor, and the second driving voltage is an off voltage of the thin film transistor.
9. The control method of claim 6, wherein the input voltage comprises a positive voltage or a negative voltage or a common mode voltage.
10. A control method for the charge pump circuit according to any one of claims 1 to 5, characterized in that the control method further comprises the steps of:
a second capacitor is charged, and an input voltage is received to charge the second capacitor;
a second capacitor charges a first capacitor, connects the second capacitor with the first capacitor, and charges the first capacitor through discharging of the second capacitor;
the method comprises the steps that a first capacitor discharges and a second capacitor charges, and when the first capacitor discharges, input voltage is received to charge the second capacitor; and
the second capacitor discharges and the first capacitor discharges.
11. The control method according to claim 10, wherein the first driving voltage or the second driving voltage is output by discharging the first capacitor, and the first driving voltage or the second driving voltage is output by discharging the second capacitor.
12. The method according to claim 10, wherein the first driving voltage is an on voltage of the thin film transistor, and the second driving voltage is an off voltage of the thin film transistor.
13. The control method of claim 10, wherein the input voltage comprises a positive voltage or a negative voltage or a common mode voltage.
14. A display device, comprising:
the charge pump circuit of any of claims 1-5, configured to generate a plurality of sets of first drive voltages and second drive voltages;
a drive circuit that is driven by the first drive voltage and the second drive voltage; and
and a display panel on which an image is displayed according to the image signal output from the driving circuit.
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| CN201711096373.3A CN107947567B (en) | 2017-11-09 | 2017-11-09 | Charge pump circuit, control method and display device |
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| CN201711096373.3A CN107947567B (en) | 2017-11-09 | 2017-11-09 | Charge pump circuit, control method and display device |
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| CN107947567B true CN107947567B (en) | 2020-04-07 |
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| CN111508444B (en) * | 2019-01-31 | 2022-12-30 | 格科微电子（上海）有限公司 | Chip control method for improving driving capability of charge pump |
| US11659297B2 (en) * | 2020-10-27 | 2023-05-23 | Shenzhen GOODIX Technology Co., Ltd. | Image sensor with charge pump cell quantity control |
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| JP2002262547A (en) * | 2001-03-01 | 2002-09-13 | Sharp Corp | Power circuit for display and display mounting the same |
| CN1576984A (en) * | 2003-07-15 | 2005-02-09 | 松下电器产业株式会社 | Power supply |
| CN101278225A (en) * | 2005-12-08 | 2008-10-01 | 罗姆股份有限公司 | Charge pump circuit, LCD driver IC, and electronic device |
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