Driving circuit and method capable of saving area and touch display driving chip

Abstract

The invention provides an area-saving driving circuit, an area-saving driving method and a touch display driving chip. The driving circuit comprises a common electrode driving circuit, the common electrode driving circuit outputs a common voltage used for driving a common electrode in a display driving period, and the common electrode driving circuit outputs a compensation voltage used for driving a compensation capacitor in a touch sensing period. And the compensation capacitor is used for compensating parasitic capacitance on the sensing path. The common electrode driving circuit is adopted to drive the compensation capacitor in the touch sensing time period, an additional driving circuit used for driving the compensation capacitor is omitted, and the complexity and the circuit area of a driving circuit on a touch display driving chip are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of driver chips, and in particular to an area-saving driver circuit, method and touch display driver chip. Background Art

[0002] Display panels are widely used in consumer electronics such as mobile phones, watches, and tablet computers. In order to reduce costs, touch display driver chips have developed rapidly, which integrate the common electrode drive circuit for display and the touch sensing circuit for touch control into the touch display driver chip, thereby realizing an integrated design of touch control and display.

[0003] Specifically, the common electrodes in the display panel are driven by the common electrode driving circuit during the display period, and the sensing electrodes in the display panel are driven by the touch sensing circuit during the touch sensing period. However, due to the parasitic capacitance of the display panel and the signal wiring in the chip, the sensing signal in the touch sensing circuit is easily saturated. Therefore, in the prior art, compensation capacitors are usually used to offset the additional sensing signals introduced by the parasitic capacitance, thereby requiring an additional driving circuit for driving the compensation capacitor to be added to the touch display driver chip, thereby increasing the complexity and circuit area of ​​the driving circuit on the touch display driver chip. Summary of the invention

[0004] An object of the present invention is to provide an area-saving driving circuit, method and touch display driving chip, so as to reduce the complexity and circuit area of ​​the driving circuit on the touch display driving chip.

[0005] In order to achieve the above objectives, the present invention is implemented by the following technical solutions:

[0006] A method for saving driving circuit area, the driving circuit includes a common electrode driving circuit, during a display driving period, the common electrode driving circuit outputs a common voltage for driving a common electrode, during a touch sensing period, the common electrode driving circuit outputs a compensation voltage for driving a compensation capacitor, and the compensation capacitor is used to compensate for the parasitic capacitance on the sensing path.

[0007] Optionally, the driving circuit includes a touch sensing circuit, a first end of the compensation capacitor is connected to a compensation node of the touch sensing circuit, and a second end of the compensation capacitor is connected to a voltage output end of the common electrode driving circuit.

[0008] Optionally, the first end of the compensation capacitor is also grounded through a first switch.

[0009] Optionally, during a touch sensing period, the first switch disconnects the ground connection of the compensation capacitor, and the common electrode driving circuit outputs a compensation voltage to drive the compensation capacitor, so that the compensation capacitor provides capacitance compensation for the sensing path; during a display driving period, the first switch turns on the ground connection of the compensation capacitor, so that the compensation capacitor is reused as a storage capacitor for maintaining the stability of the common voltage output by the common electrode driving circuit.

[0010] Optionally, the first end of the compensation capacitor is connected to the compensation node of the touch sensing circuit through a second switch. During the display driving period, the second switch disconnects the compensation capacitor from the compensation node of the touch sensing circuit to prevent the compensation capacitor from affecting the voltage of the compensation node.

[0011] Optionally, the voltage output end of the common electrode driving circuit is connected to a storage capacitor through a third switch. During the display driving period, the third switch turns on the connection between the common electrode driving circuit and the storage capacitor to maintain the common voltage stable. During the touch sensing period, the third switch disconnects the connection between the common electrode driving circuit and the storage capacitor to avoid charging and discharging the storage capacitor by the compensation voltage output by the common electrode driving circuit.

[0012] An area-saving driving circuit, comprising:

[0013] A multiplexer, used for selecting to output a common voltage to drive the common electrode during a display driving period, and for selecting to output a touch voltage to drive the sensing electrode during a touch sensing period;

[0014] A compensation capacitor, used to compensate for the parasitic capacitance on the sensing path;

[0015] The common electrode driving circuit is allowed by the multiplexer to output a common voltage to drive the common electrode during the display driving period, and outputs a compensation voltage for driving the compensation capacitor during the touch sensing period.

[0016] Optionally, the device further comprises: a touch sensing circuit, wherein during a touch sensing period, the touch sensing circuit is allowed by the multiplexer to output a touch voltage to drive the sensing electrode.

[0017] Optionally, the touch sensing circuit includes:

[0018] A second sub-driving module, used for outputting a sensing waveform and converting the sensed capacitance into a current signal;

[0019] The third sub-driving module is used to convert the current signal into a voltage signal.

[0020] Optionally, a compensation node is provided at the input end of the third sub-driving module, and the first end of the compensation capacitor is connected to the touch sensing circuit through the compensation node.

[0021] Optionally, the common electrode driving circuit includes a first sub-driving module, and the first sub-driving module outputs a common voltage in a display driving period or outputs a compensation voltage in a touch sensing period.

[0022] Optionally, the second end of the compensation capacitor is connected to a voltage output end of the common electrode driving circuit.

[0023] Optionally, the first end of the compensation capacitor is also connected to the ground through a first switch.

[0024] Optionally, the first end of the compensation capacitor is directly connected to the compensation node, or is connected to the compensation node via a second switch.

[0025] Optionally, the voltage output terminal of the common electrode driving circuit is connected to a storage capacitor through a third switch.

[0026] Optionally, the sensing electrode is reused as the common electrode.

[0027] A touch display driver chip comprises the area-saving driver circuit as described in any one of the above items.

[0028] Compared with the prior art, the present invention has the following advantages:

[0029] By multiplexing the common electrode driving circuit as a driving circuit for the compensation capacitor during the touch sensing period, the driving circuit does not need to be provided with an additional driving circuit for each compensation capacitor, thereby reducing the complexity and circuit area of ​​the driving circuit;

[0030] During the display driving period, the ground connection of the compensation capacitor is turned on through the first switch, so that the compensation capacitor can be reused as a storage capacitor for maintaining the stability of the common voltage output by the common electrode driving circuit, thereby enabling the common electrode driving circuit to provide a more stable voltage maintenance, thereby ensuring the stability and quality of the displayed image;

[0031] During the display driving period, the connection between the compensation capacitor and the compensation node of the touch sensing circuit is disconnected by the second switch, and during the touch sensing period, the connection between the compensation capacitor and the compensation node of the touch sensing circuit is turned on by the second switch, thereby preventing the compensation capacitor from affecting the voltage of the compensation node, thereby reducing the influence on the touch sensing circuit entering a preparatory state before sensing, so that the input and output of the touch sensing circuit can be reset to the corresponding common mode level before sensing starts, thereby improving touch sensing efficiency;

[0032] The voltage output terminal of the common electrode driving circuit is connected to a storage capacitor through a third switch. During the display driving period, the third switch turns on the connection between the common electrode driving circuit and the storage capacitor to maintain the stability of the common voltage. During the touch sensing period, the third switch disconnects the connection between the common electrode driving circuit and the storage capacitor to avoid the compensation voltage output by the common electrode driving circuit from generating additional power consumption in charging and discharging the storage capacitor. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for the description. Obviously, the drawings described below are an embodiment of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work:

[0034] Figure 1 It is a structural diagram of a driving circuit on an existing touch display driving chip;

[0035] Figure 2 A structural diagram of a first driving circuit on a touch display driving chip provided by an embodiment of the present invention;

[0036] Figure 3 A structural diagram of a second driving circuit on a touch display driving chip provided in one embodiment of the present invention;

[0037] Figure 4 A structural diagram of a third driving circuit on a touch display driving chip provided by an embodiment of the present invention;

[0038] Figure 5 This is a structural diagram of a fourth driving circuit on a touch display driving chip provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0039] The scheme proposed by the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the accompanying drawings are in a very simplified form and use non-precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the implementation method of the present invention. In order to make the purposes, features and advantages of the present invention more obvious and easy to understand, please refer to the accompanying drawings. It should be noted that the structures, proportions, sizes, etc. illustrated in the accompanying drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no technical substantive significance. Any structural modification, change in proportional relationship or adjustment of size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope of the technical content disclosed by the present invention.

[0040] First, the working principle of a driving circuit for touch sensing and display in the prior art is introduced. Figure 1 This is a schematic diagram of a driving circuit in an existing touch display driver chip. The common electrode in the touch display driver chip is divided into many small blocks as sensing electrodes. The specific position of the touch point can be determined by detecting the change in the capacitance of each sensing electrode. Figure 1 Only one sensing electrode SX is shown <k>, in the display driving period, it is multiplexed as a common electrode, and is driven by the common voltage output by the common electrode driving circuit 100 selected by the multiplexer MUX. In the touch sensing period, the sensing electrode is driven by the touch voltage output by the touch sensing circuit 200 selected by the multiplexer MUX. The operational amplifier OP1 in the touch sensing circuit 200 is used to generate a touch signal V according to the sensing signal V SX Output touch voltage, and convert the detected capacitance into current signal Isense and send it to operational amplifier OP2, which converts the input current into voltage and compares it with reference voltage V ref After comparison, two differential voltage signals VOP are obtained. <k>and VON <k>Isense reflects the size of all capacitances on the sensing path, of which only the touch capacitance C T It is an effective signal for detection and judgment, while parasitic capacitance such as Csp from the panel and C from the signal wiring inside the chip SC The induction caused by the touch signal Vsx is not only irrelevant to the touch, but also saturates the operational amplifier OP2 signal. Therefore, a compensation capacitor Ccomp is introduced at the input end of the operational amplifier OP2 to generate a reverse current Icomp to offset the induction caused by the parasitic capacitance. At the same time, a corresponding additional driving circuit 300 is added. The operational amplifier OP3 in the additional driving circuit 300 outputs a compensation voltage according to a compensation waveform Vcomp opposite to the sensing signal Vsx to drive the compensation capacitor Ccomp, and the compensation waveform Vcomp also requires an additional reference circuit to generate. Since each touch sensing circuit 200 requires a compensation capacitor Ccomp for compensation, that is, each touch sensing circuit 200 needs to be provided with an additional driving circuit 300, which results in high complexity of the existing driving circuit and increased occupied area.

[0041] In view of the above-mentioned defects, the present invention is based on the time-sharing operation characteristics of the touch display driver chip. By reusing the common electrode driver circuit 100 to drive the common electrode and the compensation capacitor Ccomp in a time-sharing manner, the additional driver circuit 300 for driving the compensation capacitor Ccomp is omitted, thereby reducing the complexity and circuit area of ​​the driver circuit on the touch display driver chip.

[0042] Based on the above invention ideas, the present invention provides a method for saving the driving circuit area. Figure 2 As shown, the driving circuit includes a common electrode driving circuit 100. In the display driving period, the common electrode driving circuit 100 outputs a common voltage for driving the common electrode. In the touch sensing period, the common electrode driving circuit 100 outputs a compensation voltage for driving the compensation capacitor Ccomp. The compensation capacitor Ccomp is used to compensate for the parasitic capacitance on the sensing path. By multiplexing the common electrode driving circuit 100 as a driving circuit for the compensation capacitor Ccomp in the touch sensing period, the driving circuit does not need to set an additional driving circuit 300 for each compensation capacitor Ccomp, thereby reducing the complexity and circuit area of ​​the driving circuit. Specifically, the driving circuit includes a touch sensing circuit 200. In the touch sensing period, the touch sensing circuit 200 outputs a touch voltage for driving the sensing electrode. The first end of the compensation capacitor Ccomp is connected to the compensation node A of the touch sensing circuit 200, and the second end of the compensation capacitor Ccomp is connected to the voltage output end of the common electrode driving circuit 100.

[0043] Further, if Figure 3 As shown, the first end of the compensation capacitor Ccomp is also grounded through the first switch S1. Specifically, during the touch sensing period, the first switch S1 disconnects the ground connection of the compensation capacitor Ccomp, and the common electrode driving circuit 100 outputs a compensation voltage to drive the compensation capacitor Ccomp, so that the compensation capacitor Ccomp provides capacitance compensation for the sensing path. By disconnecting the first switch S1, it is possible to avoid the compensation capacitor Ccomp being grounded and causing the charge to be released through the ground line, so that the compensation capacitor is at the ground potential (0V) and cannot provide the compensation voltage to the touch sensing circuit 200. During the display driving period, since the compensation capacitor Ccomp is in an idle state, in this embodiment, by connecting the first switch S1 to the ground connection of the compensation capacitor Ccomp, the compensation capacitor Ccomp can be reused as a storage capacitor to maintain the stability of the common voltage output by the common electrode driving circuit 100, so that the common electrode driving circuit 100 can provide a more stable voltage maintenance, thereby ensuring the stability and quality of the displayed image.

[0044] Going further, Figure 4 As shown, the first end of the compensation capacitor Ccomp can also be connected to the compensation node A of the touch sensing circuit 200 through the second switch S2. During the display driving period, the second switch S2 disconnects the compensation capacitor Ccomp from the compensation node A of the touch sensing circuit 200. During the touch sensing period, the second switch S2 connects the compensation capacitor Ccomp to the compensation node A of the touch sensing circuit 200. This can prevent the compensation capacitor Ccomp from affecting the voltage of the compensation node A, thereby reducing the impact on the touch sensing circuit 200 entering the preparation state before sensing, so that the input and output of the touch sensing circuit 200 can be reset to the corresponding common mode level before sensing starts, thereby improving touch sensing efficiency.

[0045] In other implementations, such as Figure 5 As shown, the voltage output terminal of the common electrode driving circuit 100 can also be connected to a storage capacitor Cvcom through a third switch S3. During the display driving period, the third switch S3 turns on the connection between the common electrode driving circuit 100 and the storage capacitor Cvcom to maintain the stability of the common voltage; during the touch sensing period, the third switch S3 disconnects the connection between the common electrode driving circuit 100 and the storage capacitor Cvcom to avoid the compensation voltage output by the common electrode driving circuit 100 generating additional power consumption for charging and discharging the storage capacitor Cvcom. The storage capacitor Cvcom can be set inside the touch display driver chip or outside the touch display driver chip, and the present invention is not limited to this.

[0046] Based on the above method for saving the area of ​​the driving circuit, the present invention also provides an area-saving driving circuit, such as Figure 2 As shown, the driving circuit includes: a multiplexer MUX, which is used to select and output a common voltage to drive a common electrode (in this embodiment, a sensing electrode SX) during a display driving period. <k>In the display driving period, it is reused as a common electrode), and in the touch sensing period, it selects to output a touch voltage to drive the sensing electrode SX <k>; compensation capacitor Ccomp, used to compensate for parasitic capacitance on the sensing path; common electrode driving circuit 100, in the display driving period, the common electrode driving circuit 100 is allowed by the multiplexer to output a common voltage to drive the common electrode, and in the touch sensing period, the common electrode driving circuit 100 outputs a compensation voltage for driving the compensation capacitor Ccomp. In this embodiment, by multiplexing the common electrode driving circuit 100 as a driving circuit for the compensation capacitor Ccomp in the touch sensing period, the driving circuit does not need to set an additional driving circuit 300 for each compensation capacitor Ccomp, thereby reducing the complexity and circuit area of ​​the driving circuit.

[0047] Specifically, the common electrode driving circuit 100 includes a first sub-driving module 101 . The first sub-driving module 101 outputs a common voltage in a display driving period or outputs a compensation voltage in a touch sensing period. Figure 2 The first sub-driver module 101 shown is an operational amplifier. In other embodiments, the first sub-driver module 101 may also be other structures, as long as it can output a common voltage in the display driving period or output a compensation voltage in the touch sensing period. The common voltage is usually a fixed level to drive the common electrode to be in a voltage stable state. The compensation voltage is a voltage waveform opposite to the sensing signal Vsx. Both the fixed level and the compensation voltage can be achieved by setting the input voltage VCOM_REF of the first sub-driver module 101. The high and low levels of the compensation voltage can be selected according to the requirements of the compensation current and the circuit performance, etc., and this embodiment does not limit this.

[0048] The driving circuit further includes: a touch sensing circuit 200. During a touch sensing period, the touch sensing circuit 200 is allowed by the multiplexer MUX to output a touch voltage to drive the sensing electrode SX. <k>, and during the display driving period, the touch sensing circuit 200 is in a non-operating state. Specifically, the touch sensing circuit 200 includes a second sub-driving module 201 and a third sub-driving module 202 connected in circuit, and the second sub-driving module 201 is connected to the sensing electrode SX through the multiplexer MUX. <k>The third sub-driving module 202 is connected to the output end of the second sub-driving module 201, and is used to convert the current signal into a voltage signal, thereby realizing the measurement of the induced capacitance. Figure 2 The second sub-driving module 201 and the third sub-driving module 202 are both operational amplifiers. In other embodiments, the second sub-driving module 201 and the third sub-driving module 202 may also be other structures as long as they can achieve corresponding functions.

[0049] Specifically, the input end of the third sub-driving module 202 is provided with a compensation node A, and the first end of the compensation capacitor Ccomp is directly connected to the compensation node A, so that the compensation capacitor Ccomp is connected to the touch sensing circuit 200, and then a compensation voltage can be provided to offset the parasitic capacitance on the sensing path. The second end of the compensation capacitor Ccomp is connected to the voltage output end of the common electrode driving circuit 100, so that the common electrode driving circuit 100 can output a compensation voltage during the touch sensing period to drive the compensation capacitor Ccomp to provide capacitance compensation for the sensing path.

[0050] In another embodiment, if Figure 3 As shown, the first end of the compensation capacitor Ccomp is also connected to the ground through the first switch S1. By controlling the opening and closing of the first switch S1, the compensation capacitor Ccomp is used to compensate for the parasitic capacitance on the sensing path and as a storage capacitor to maintain the stability of the common voltage. Specifically, during the touch sensing period, the first switch S1 is opened, and the common electrode driving circuit 100 outputs a compensation voltage to drive the compensation capacitor Ccomp to provide capacitance compensation for the sensing path, so as to avoid the compensation capacitor Ccomp being grounded and causing the charge to be released through the ground line, so that the compensation capacitor Ccomp is at the ground potential (0V) and cannot provide the compensation voltage to the touch sensing circuit 200; during the display driving period, the first switch S1 is closed, so that the compensation capacitor Ccomp is connected to the ground, and at this time, the compensation capacitor Ccomp is reused as a storage capacitor to maintain the stability of the common voltage output by the common electrode driving circuit 100, so that the common electrode driving circuit 100 can provide a more stable voltage maintenance, thereby ensuring the stability and quality of the displayed image.

[0051] In yet another embodiment, Figure 4 As shown, the first end of the compensation capacitor Ccomp can also be connected to the compensation node A through a second switch S2. The second switch S2 is located between the connection point B between the first switch S1 and the first end of the compensation capacitor Ccomp and the compensation node A. In the touch sensing period, the second switch S2 is turned on. In the display driving period, the second switch S2 is controlled to be turned off to avoid the compensation capacitor Ccomp being grounded and pulling down the voltage of the compensation node A (that is, the voltage of the compensation node A is 0V), thereby affecting the touch sensing circuit 200 to enter the pre-sensing state, so that the input and output of the touch sensing circuit 200 can be reset to the corresponding common mode level before the start of sensing. When the input and output are reset to the common mode level, the signal baseline used for sensing signal comparison can be stabilized at the common mode level, and the subsequent signal processing unit can more accurately quantify and process the change amount between the sensing signal and the signal baseline, reduce the error caused by the fluctuation of the signal baseline, improve the processing accuracy of the sensing signal, and improve the touch sensing efficiency.

[0052] like Figure 5 As shown, in Figure 2 On the basis of the embodiment shown, the voltage output terminal of the common electrode driving circuit 100 can also be connected to a storage capacitor Cvcom through a third switch S3. In the display driving period, the third switch S3 conducts the connection between the common electrode driving circuit 100 and the storage capacitor Cvcom to maintain the stability of the common voltage; in the touch sensing period, the third switch S3 disconnects the common electrode driving circuit 100 from the storage capacitor Cvcom to avoid the compensation voltage output by the common electrode driving circuit 100 to charge and discharge the storage capacitor Cvcom and generate additional power consumption.

[0053] An embodiment of the present invention further discloses an area-saving touch display driver chip, wherein the touch display driver chip comprises the area-saving driver circuit described in any one of the above embodiments.

[0054] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0055] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.< / k> < / k> < / k> < / k> < / k> < / k> < / k>

Claims

1. A method for saving driving circuit area, characterized in that: The driving circuit includes a common electrode driving circuit. During a display driving period, the common electrode driving circuit outputs a common voltage for driving a common electrode. During a touch sensing period, the common electrode driving circuit outputs a compensation voltage for driving a compensation capacitor. The compensation capacitor is used to compensate for parasitic capacitance on a sensing path.

2. The method for saving driving circuit area according to claim 1, characterized in that: The driving circuit includes a touch sensing circuit, a first end of the compensation capacitor is connected to a compensation node of the touch sensing circuit, and a second end of the compensation capacitor is connected to a voltage output end of the common electrode driving circuit.

3. The method for saving driving circuit area as claimed in claim 2, characterized in that: The first end of the compensation capacitor is also grounded through the first switch.

4. The method for saving driving circuit area as claimed in claim 3, characterized in that: During a touch sensing period, the first switch disconnects the ground connection of the compensation capacitor, and the common electrode driving circuit outputs a compensation voltage to drive the compensation capacitor, so that the compensation capacitor provides capacitance compensation for the sensing path; During the display driving period, the first switch turns on the ground connection of the compensation capacitor, so that the compensation capacitor is reused as a storage capacitor for maintaining the stability of the common voltage output by the common electrode driving circuit.

5. The method for saving driving circuit area according to any one of claims 2 to 4, characterized in that: The first end of the compensation capacitor is connected to the compensation node of the touch sensing circuit through a second switch. During the display driving period, the second switch disconnects the compensation capacitor from the compensation node of the touch sensing circuit to prevent the compensation capacitor from affecting the voltage of the compensation node.

6. The method for saving driving circuit area as claimed in claim 2, characterized in that: The voltage output terminal of the common electrode driving circuit is connected to a storage capacitor through a third switch. During the display driving period, the third switch conducts the connection between the common electrode driving circuit and the storage capacitor to maintain the common voltage stable. During the touch sensing period, the third switch disconnects the common electrode driving circuit from the storage capacitor to prevent the storage capacitor from being charged or discharged by the compensation voltage output by the common electrode driving circuit.

7. An area-saving driving circuit, characterized in that: include: A multiplexer, used for selecting to output a common voltage to drive the common electrode during a display driving period, and for selecting to output a touch voltage to drive the sensing electrode during a touch sensing period; A compensation capacitor, used to compensate for the parasitic capacitance on the sensing path; The common electrode driving circuit is allowed by the multiplexer to output a common voltage to drive the common electrode during the display driving period, and outputs a compensation voltage for driving the compensation capacitor during the touch sensing period.

8. The area-saving driving circuit according to claim 1, characterized in that: Also includes: A touch sensing circuit is allowed by the multiplexer to output a touch voltage to drive a sensing electrode during a touch sensing period.

9. The area-saving driving circuit according to claim 8, characterized in that: The touch sensing circuit comprises: A second sub-driving module, used for outputting a sensing waveform and converting the sensed capacitance into a current signal; The third sub-driving module is used to convert the current signal into a voltage signal.

10. The area-saving driving circuit according to claim 9, characterized in that: A compensation node is provided at the input end of the third sub-driving module, and the first end of the compensation capacitor is connected to the touch sensing circuit through the compensation node.

11. The area-saving driving circuit according to any one of claims 7 to 10, characterized in that: The common electrode driving circuit includes a first sub-driving module, which outputs a common voltage in a display driving period or a compensation voltage in a touch sensing period.

12. The area-saving driving circuit according to claim 11, characterized in that: The second end of the compensation capacitor is connected to the voltage output end of the common electrode driving circuit.

13. The area-saving driving circuit according to claim 10, characterized in that: The first end of the compensation capacitor is also connected to the ground through a first switch.

14. The area-saving driving circuit according to claim 13, characterized in that: The first end of the compensation capacitor is directly connected to the compensation node, or is connected to the compensation node through a second switch.

15. The area-saving driving circuit according to claim 12, characterized in that: The voltage output terminal of the common electrode driving circuit is connected to a storage capacitor through a third switch.

16. The area-saving driving circuit according to claim 7, characterized in that: The sensing electrode is reused as the common electrode. 17 . A touch display driver chip, comprising the area-saving driver circuit according to any one of claims 7 to 16 .

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