Common-mode voltage generation circuit, control method thereof, chip and electronic device

Abstract

The present disclosure relates to a common-mode voltage generation circuit, a control method thereof, a chip and an electronic device, the common-mode voltage generation circuit being configured to generate a common-mode voltage, comprising: a first operational amplifier, a positive input end of the first operational amplifier being configured to receive a reference voltage, and a negative input end of the first operational amplifier being configured to receive a feedback voltage through a feedback circuit, the feedback voltage being proportional to the common-mode voltage; a second operational amplifier, an input end of the second operational amplifier being connected to an output end of the first operational amplifier and a first end of a capacitance adjustment circuit, and an output end of the second operational amplifier being connected to one end of the feedback circuit, a second end of the capacitance adjustment circuit and a first end of an output control switch, the output end of the second operational amplifier being configured to output the common-mode voltage; a control end of the capacitance adjustment circuit being configured to receive a capacitance adjustment signal to change a capacitance of the capacitance adjustment circuit; and a second end of the output control switch being connected to a target display touch panel.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of integrated circuit technology, and in particular, to a common-mode voltage generation circuit, a control method thereof, a chip, and an electronic device. BACKGROUND

[0002] The liquid crystal cell of a liquid crystal display panel can be regarded as a liquid crystal capacitor composed of two parallel electrodes, one of which is a pixel electrode and the other of which is a common electrode.

[0003] Please refer to Figure 1a and Figure 1b for an example of a TDDI (Touch and Display Driver Integration) type display panel integrated with touch and display functions. As shown in the equivalent circuit of Figure 1a , the liquid crystal capacitor 11, the first switch 12, and the second switch 13 are provided, wherein the common-mode voltage VCOM is coupled to one end of the liquid crystal capacitor 11 through the first switch 12, and the other end of the liquid crystal capacitor 11 receives the source voltage VS to enable the liquid crystal cell to provide a display function. Figure 1b As shown in the equivalent circuit of , the liquid crystal capacitor 11, the first switch 12, and the second switch 13 are provided, wherein the excitation voltage VSTIM is coupled to one end of the liquid crystal capacitor 11 through the second switch 13, and the other end of the liquid crystal capacitor 11 is pressed by a finger to enable the liquid crystal cell to provide a touch sensing function.

[0004] Generally, the common-mode voltage VCOM is provided by an LDO (low dropout regulator). As shown in Figure 1c , the touch display driving chip 20 is configured to provide the common-mode voltage VCOM to the liquid crystal display panel 30 in a display phase, wherein the common-mode voltage generation circuit of the touch display driving chip 20 includes the LDO 21, the switch 22, and the external capacitor 40 coupled to the pin 23; and the equivalent load seen by the common-mode voltage generation circuit in the liquid crystal display panel 30 can be represented as a plurality of series resistors 31 and a plurality of grounded capacitors 32. When the touch display driving chip 20 operates in a touch mode, the switch 22 is turned off, and the LDO 21 obtains a low-frequency pole through its output resistor and the external capacitor 40 without generating oscillation. In this way, when the touch display driving chip 20 switches to the display mode, it can provide a stable common-mode voltage VCOM to the liquid crystal display panel 30 to avoid affecting the picture quality of the liquid crystal display panel 30.

[0005] However, this approach not only requires an additional pin in the touch display driving chip 20, but also requires an external capacitor 40, thereby increasing the cost of the overall driving circuit. SUMMARY

[0006] According to an aspect of the present disclosure, a common-mode voltage generation circuit for generating a common-mode voltage is provided, the circuit comprising:

[0007] a first operational amplifier, a positive input terminal of the first operational amplifier being configured to receive a reference voltage, and a negative input terminal of the first operational amplifier being configured to receive a feedback voltage through a feedback circuit, the feedback voltage being proportional to the common-mode voltage;

[0008] a second operational amplifier, an input terminal of the second operational amplifier being connected to an output terminal of the first operational amplifier and a first terminal of a capacitance adjustment circuit, and an output terminal of the second operational amplifier being connected to one end of the feedback circuit, a second terminal of the capacitance adjustment circuit, and a first terminal of an output control switch, the output terminal of the second operational amplifier being configured to output the common-mode voltage;

[0009] wherein a control terminal of the capacitance adjustment circuit is configured to receive a capacitance adjustment signal to change a capacitance of the capacitance adjustment circuit;

[0010] wherein a second terminal of the output control switch is connected to a target display touch panel.

[0011] In a possible implementation, the capacitance adjustment circuit comprises a capacitance adjustment switch and a capacitance, wherein:

[0012] a first terminal of the capacitance adjustment switch is connected to an input terminal of the second operational amplifier and an output terminal of the first operational amplifier, a second terminal of the capacitance adjustment switch is connected to a first terminal of the capacitance, and a second terminal of the capacitance is connected to an output terminal of the second operational amplifier.

[0013] a control terminal of the capacitance adjustment switch is configured to receive the capacitance adjustment signal.

[0014] In a possible implementation, the target display touch panel is a touch and display driver integrated (TDDI) display touch panel.

[0015] In a possible implementation, when the target display touch panel works in a touch detection period, the capacitance adjustment switch is turned on and the output control switch is turned off; or

[0016] In a possible implementation, when the target display touch panel works in a display period, the capacitance adjustment switch is turned off and the output control switch is turned on.

[0017] In a possible implementation, the feedback circuit comprises a voltage proportion adjustment module configured to adjust the common-mode voltage according to a preset proportion to generate the feedback voltage.

[0018] In a possible implementation, the target display touch panel includes any one of a liquid crystal display panel, an organic light-emitting diode display panel, a quantum dot light-emitting diode display panel, a mini light-emitting diode display panel, and a micro light-emitting diode display panel.

[0019] According to an aspect of the present disclosure, a control method of a common-mode voltage generation circuit is provided, which is applied to the common-mode voltage generation circuit, and the method comprises:

[0020] When the target display touch panel works in a touch detection period, a first capacitance adjustment signal is output to adjust a capacitance of the capacitance adjustment circuit to a first preset capacitance value, and the output control switch is turned off; or

[0021] When the target display touch panel works in a display period, a second capacitance adjustment signal is output to adjust the capacitance of the capacitance adjustment circuit to a second preset capacitance value, and the output control switch is turned on.

[0022] In a possible implementation, the capacitance adjustment circuit includes a capacitance adjustment switch and a capacitance, a first end of the capacitance adjustment switch is connected to an input end of the second operational amplifier and an output end of the first operational amplifier, a second end of the capacitance adjustment switch is connected to a first end of the capacitance, a second end of the capacitance is connected to an output end of the second operational amplifier, and a control end of the capacitance adjustment switch is configured to receive the capacitance adjustment signal, and the method further comprises:

[0023] When the target display touch panel works in a touch detection period, a first capacitance adjustment signal is output to control the capacitance adjustment switch to be turned on and the output control switch to be turned off, and the first preset capacitance value is a capacitance value of the capacitance; or

[0024] When the target display touch panel works in a display period, a second capacitance adjustment signal is output to control the capacitance adjustment switch to be turned off and the output control switch to be turned on, and the first preset capacitance value is 0.

[0025] According to an aspect of the present disclosure, a touch display driving chip is provided, and the touch display driving chip includes the common-mode voltage generation circuit.

[0026] According to an aspect of the present disclosure, a touch display panel is provided, and the touch display panel includes the touch display driving chip.

[0027] According to an aspect of the present disclosure, an electronic device is provided, and the electronic device includes the touch display panel.

[0028] In a possible implementation, the electronic device includes any one of a display, a smart phone, a smart watch, a smart bracelet, a tablet computer, a notebook computer, an all-in-one computer, an access control device, and an electronic door lock.

[0029] The common-mode voltage generation circuit of the embodiment of the present disclosure avoids the common-mode voltage generated by the common-mode voltage generation circuit from oscillating by setting the capacitor adjustment circuit between the output end and the input end of the second operational amplifier, changing the self-capacitance by the capacitor adjustment signal, so that the common-mode voltage remains stable, thereby reducing power consumption, improving the picture quality of the target display touch panel, and the embodiment of the present disclosure can not need to externally connect an external capacitor, thereby saving cost and saving external interface compared with the related art.

[0030] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, but not limiting the present disclosure. Other features and aspects of the present disclosure will become apparent from the following detailed description of exemplary embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0031] The accompanying drawings, which are incorporated into and form part of the specification, illustrate embodiments consistent with the present disclosure and, together with the specification, serve to explain the technical solutions of the present disclosure.

[0032] Figure 1a Equivalent circuit diagram for providing display function by liquid crystal cell is shown;

[0033] Figure 1b Equivalent circuit diagram for providing touch function by liquid crystal cell is shown.

[0034] Figure 1c Circuit diagram of common-mode voltage generation circuit of existing liquid crystal touch display driving chip is shown.

[0035] Figure 2 Schematic diagram of common-mode voltage generation circuit according to the embodiment of the present disclosure is shown.

[0036] Figure 3 Schematic diagram of common-mode voltage generation circuit according to the embodiment of the present disclosure is shown.

[0037] Figure 4 Flowchart of control method of common-mode voltage generation circuit according to the embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0038] Various exemplary embodiments, features and aspects of the present disclosure will be described in detail below with reference to the accompanying drawings. The same reference signs in the drawings represent functionally identical or similar elements. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

[0039] In the description of the disclosure, it needs to be understood that the terms "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the disclosure and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the disclosure.

[0040] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the disclosure, the meaning of "multiple" is two or more, unless otherwise explicitly specified and limited.

[0041] In the disclosure, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the disclosure can be understood according to the specific circumstances.

[0042] The term "exemplary" herein means "serving as an example, embodiment or illustration". Any embodiment described herein as "exemplary" is not necessarily to be construed as superior to or better than other embodiments.

[0043] The term "and / or" herein is only a description of the association relationship of the associated objects, which means that there can be three kinds of relationships, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone. In addition, the term "at least one" herein means any one of the plurality or any combination of at least two of the plurality, for example, including at least one of A, B and C can mean including any one or more elements selected from the set consisting of A, B and C.

[0044] In addition, in order to better illustrate the disclosure, a large number of specific details are given in the specific embodiments below. Those skilled in the art should understand that without certain specific details, the disclosure can also be implemented. In some examples, methods, means, elements and circuits well known to those skilled in the art are not described in detail, in order to highlight the main idea of the disclosure.

[0045] Referring to Figure 2 , Figure 2 A schematic diagram of a common-mode voltage generation circuit according to an embodiment of the present disclosure is shown.

[0046] The common-mode voltage generation circuit 110 is configured to generate a common-mode voltage V COM As shown in Figure 2 , the circuit comprises:

[0047] A first operational amplifier 111, a positive input terminal of the first operational amplifier 111 being configured to receive a reference voltage V REF , and a negative input terminal of the first operational amplifier 111 being configured to receive a feedback voltage through a feedback circuit 114, the feedback voltage being proportional to the common-mode voltage V COM ;

[0048] A second operational amplifier 112, an input terminal of the second operational amplifier 112 being connected to an output terminal of the first operational amplifier 111 and a first terminal of a capacitance adjustment circuit 113, and an output terminal of the second operational amplifier 112 being connected to one end of the feedback circuit 114, a second terminal of the capacitance adjustment circuit 113 and a first terminal of an output control switch 115, the output terminal of the second operational amplifier 112 being configured to output the common-mode voltage V COM ;

[0049] The capacitance adjustment circuit 113 is configured to receive a capacitance adjustment signal to change its own capacitance.

[0050] The second terminal of the output control switch 115 is connected to a target display touch panel 120.

[0051] The common-mode voltage generation circuit 110 according to the embodiment of the present disclosure, by arranging the capacitance adjustment circuit 113 between the output terminal and the input terminal of the second operational amplifier 112, changes its own capacitance through the capacitance adjustment signal, so as to avoid the common-mode voltage V COM generated by the common-mode voltage generation circuit 110 from oscillating, so that the common-mode voltage V COM remains stable, thereby reducing power consumption and improving the picture quality of the target display touch panel 120. Moreover, the embodiment of the present disclosure can not need to externally connect an external capacitance, thereby saving cost and external interface compared with the related art.

[0052] The embodiment of the present disclosure does not limit the specific implementation of the feedback circuit 114, and in one possible implementation, the feedback circuit 114 can comprise a voltage proportion adjustment module configured to adjust the common-mode voltage V COMThe voltage proportional adjustment module can be implemented by a hardware circuit, and the specific implementation manner is not limited in the embodiments of the present disclosure, and a person skilled in the art can implement by using related technologies, or can implement by using a mature module. For example, the voltage proportional adjustment module can be a voltage proportional regulator, a voltage amplifier, a voltage reduction circuit, etc. The proportion can be any value greater than 0. Of course, the proportion can be 1. In this case, the feedback circuit 114 can be a voltage transmission line, that is, the output end of the second operational amplifier 112 directly feeds back to the negative input end of the first operational amplifier 111 through the voltage transmission line.

[0053] The embodiments of the present disclosure do not limit the specific implementation manners of the first operational amplifier 111 and the second operational amplifier 112, and a person skilled in the art can implement by using an amplifier in related technologies. For example, the first operational amplifier 111 and the second operational amplifier 112 can both be transconductance amplifiers.

[0054] The embodiments of the present disclosure do not limit the specific implementation manners of the capacitance adjustment circuit 113, and a person skilled in the art can implement by using related technologies, as long as the adjustment of the capacitance size can be implemented. The embodiments of the present disclosure do not limit the range of the capacitance adjustment of the capacitance adjustment circuit 113, and a person skilled in the art can adjust according to actual conditions and needs.

[0055] Please refer to Figure 3 , Figure 3 A schematic diagram of the common-mode voltage generation circuit 110 according to the embodiments of the present disclosure is shown.

[0056] In a possible implementation manner, as shown in Figure 3 The capacitance adjustment circuit 113 includes a capacitance adjustment switch 113a and a capacitance 113b.

[0057] The first end of the capacitance adjustment switch 113a is connected to the input end of the second operational amplifier 112 and the output end of the first operational amplifier 111. The second end of the capacitance adjustment switch 113a is connected to the first end of the capacitance 113b. The second end of the capacitance 113b is connected to the output end of the second operational amplifier 112.

[0058] The control end of the capacitance adjustment switch 113a is used to receive the capacitance adjustment signal SW1.

[0059] The embodiments of the present disclosure can include the capacitance adjustment switch 113a and the capacitance by setting the capacitance adjustment circuit 113. By controlling the conduction state of the switch, the adjustment of the capacitance of the capacitance adjustment circuit 113 can be implemented.

[0060] For example, the target display touch panel 120 is a TDDI display touch panel. The TDDI display touch panel is a type of display touch panel that realizes control for display and touch detection on the same chip. The TDDI display touch panel can alternatively switch between a touch detection period and a display period, for example, detects in the interval between two frames of display, so as to realize display and touch detection.

[0061] For example, in a possible implementation, when the target display touch panel 120 works in the touch detection period, the capacitance adjustment switch 113a is turned on, and the output control switch 115 is turned off.

[0062] For example, in a possible implementation, when the target display touch panel 120 works in the display period, the capacitance adjustment switch 113a is turned off, and the output control switch 115 is turned on.

[0063] For example, when the capacitance adjustment switch 113a is turned on and the output control switch 115 is turned off, the output end of the first operational amplifier 111 sees the output resistance of the first operational amplifier 111 and the Miller equivalent capacitance generated by the second operational amplifier 112 and the capacitance adjustment circuit 113. The output resistance can be represented as R O1 The Miller equivalent capacitance can be represented as C M =(1+A2)C, where A2 represents the voltage gain of the second operational amplifier 112, and C represents the capacitance value of the capacitance 113b. In this way, the common-mode voltage generation circuit 110 can generate a low-frequency main pole 1 / (R O1 C M ), so as to effectively avoid oscillation of the common-mode voltage V COM . In this way, during the touch detection period, the main pole of the common-mode voltage generation circuit 110 is left-shifted by the capacitance adjustment circuit 113, so as to optimize the phase margin of the common-mode voltage generation circuit 110.

[0064] For example, when the target display touch panel 120 works in the display period, the capacitance adjustment switch 113a is turned off, and the output control switch 115 is turned on. The output end of the common-mode voltage generation circuit 110 is connected to the RC array of the target display touch panel 120. In this case, the output stage of the common-mode voltage generation circuit 110 is the main pole, and the input stage is the secondary pole. The main pole and the secondary pole are far apart, and the common-mode voltage generation circuit 110 also has a good phase margin.

[0065] The common-mode voltage generation circuit 110 of the embodiment of the present disclosure has a good phase margin, can avoid common-mode oscillation during touch detection and display, reduce power consumption, and improve the display effect and touch effect of the target display touch panel 120, no matter whether the target display touch panel 120 works in the touch detection period or the display period.

[0066] In one example, the common-mode voltage generation circuit 110 can further include a control module to control the capacitance of the capacitance adjustment circuit 113 and the conduction state of the output control switch 115 (such as through a switch control signal SW2). Specifically, the control module controls the conduction state of the capacitance adjustment switch 113a and the conduction state of the output control switch 115.

[0067] In one example, the control module can include a processing component, which can include, but is not limited to, a separate processor, or a combination of a processor and discrete components. The processor can include a controller having an execution instruction function in an electronic device, and the processor can be implemented in any appropriate manner, such as by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components. Inside the processor, the executable instructions can be executed by hardware circuits such as logic gates, switches, application specific integrated circuits (ASICs), programmable logic controllers, and embedded microcontrollers.

[0068] Of course, the common-mode voltage generation circuit 110 can also receive a control signal of a control module in a touch display driving chip. The touch display driving chip can be a TDDI touch display driving chip.

[0069] The embodiment of the present disclosure does not limit the specific type of the target display touch panel 120, as long as it can realize the touch and display functions. In one possible implementation, the light-emitting module includes any one or more of an LCD (Liquid Crystal Display) display panel, an LED (Light Emitting Diode) display panel, a Mini LED (Mini Light Emitting Diode) display panel, a Micro LED (Micro Light Emitting Diode) display panel, and an OLED (Organic Light-Emitting Diode) display panel.

[0070] Referring to Figure 4 , Figure 4 A flow chart of a control method of the common-mode voltage generation circuit 110 is shown.

[0071] The control method is applied to the common-mode voltage generation circuit 110, as Figure 4 shown, the method comprises:

[0072] Step S11, when the target display touch panel 120 works in a touch detection period, outputting a first capacitance adjustment signal to adjust the capacitance of the capacitance adjustment circuit 113 to a first preset capacitance value, and controlling the output control switch 115 to be turned off; or

[0073] Step S12, when the target display touch panel 120 works in a display period, outputting a second capacitance adjustment signal to adjust the capacitance of the capacitance adjustment circuit 113 to a second preset capacitance value, and controlling the output control switch 115 to be turned on.

[0074] The embodiment of the present disclosure sets the capacitance adjustment circuit 113 between the output end and the input end of the second operational amplifier 112, when the target display touch panel 120 works in a touch detection period, outputs a first capacitance adjustment signal to adjust the capacitance of the capacitance adjustment circuit 113 to a first preset capacitance value, and controls the output control switch 115 to be turned off, when the target display touch panel 120 works in a display period, outputs a second capacitance adjustment signal to adjust the capacitance of the capacitance adjustment circuit 113 to a second preset capacitance value, and controls the output control switch 115 to be turned on, changes its own capacitance through the capacitance adjustment signal SW1, so as to avoid the common-mode voltage V COM generated by the common-mode voltage generation circuit 110 from oscillating, so that the common-mode voltage V COM remains stable, reduces power consumption, improves the picture quality of the target display touch panel 120, and the embodiment of the present disclosure can not need to be externally connected with an external capacitance, saves cost and saves external interface compared with the related art.

[0075] For example, as Figure 2 shown, the circuit can comprise:

[0076] The first operational amplifier 111, the positive input end of the first operational amplifier 111 is used to receive a reference voltage V REF , the negative input end of the first operational amplifier 111 is used to receive a feedback voltage through a feedback circuit 114, and the feedback voltage is proportional to the common-mode voltage V COM ;

[0077] a second operational amplifier 112, an input end of the second operational amplifier 112 being connected to an output end of the first operational amplifier 111 and a first end of a capacitance adjustment circuit 113, an output end of the second operational amplifier 112 being connected to one end of the feedback circuit 114, a second end of the capacitance adjustment circuit 113 and a first end of an output control switch 115, the output end of the second operational amplifier 112 being used for outputting the common-mode voltage V COM ;

[0078] wherein a control end of the capacitance adjustment circuit 113 is used for receiving a capacitance adjustment signal SW1 to change a self capacitance thereof;

[0079] wherein a second end of the output control switch 115 is connected to the target display touch panel 120.

[0080] In a possible implementation, the capacitance adjustment circuit 113 can include a capacitance adjustment switch 113a and a capacitance, wherein

[0081] a first end of the capacitance adjustment switch 113a is connected to the input end of the second operational amplifier 112 and the output end of the first operational amplifier 111, a second end of the capacitance adjustment switch 113a is connected to a first end of the capacitance, and a second end of the capacitance is connected to the output end of the second operational amplifier 112.

[0082] a control end of the capacitance adjustment switch 113a is used for receiving the capacitance adjustment signal SW1.

[0083] In a possible implementation, when the target display touch panel 120 works in a touch detection period, the capacitance adjustment switch 113a is turned on, and the output control switch 115 is turned off; or

[0084] In a possible implementation, when the target display touch panel 120 works in a display period, the capacitance adjustment switch 113a is turned off, and the output control switch 115 is turned on.

[0085] In a possible implementation, the feedback circuit 114 includes a voltage proportion adjustment module, used for adjusting the common-mode voltage V COM in a preset proportion to generate the feedback voltage.

[0086] In a possible implementation, the target display touch panel 120 includes any one of a liquid crystal display panel, an organic light-emitting diode display panel, a quantum dot light-emitting diode display panel, a mini light-emitting diode display panel and a micro light-emitting diode display panel.

[0087] In a possible implementation, the method further includes:

[0088] When the target display touch panel 120 works in a touch detection period, a first capacitance adjustment signal is output to control the capacitance adjustment switch 113a to be turned on and the output control switch 115 to be turned off, and the first preset capacitance value is the capacitance value of the capacitor.

[0089] When the target display touch panel 120 works in a display period, a second capacitance adjustment signal is output to control the capacitance adjustment switch 113a to be turned off and the output control switch 115 to be turned on, and the first preset capacitance value is 0.

[0090] According to an aspect of the present disclosure, a touch display driving chip is provided, and the touch display driving chip comprises the common-mode voltage generation circuit 110.

[0091] According to an aspect of the present disclosure, a touch display panel is provided, and the touch display panel comprises the touch display driving chip.

[0092] According to an aspect of the present disclosure, an electronic device is provided, and the electronic device comprises the touch display panel.

[0093] In a possible implementation, the electronic device comprises any one of a display, a smart phone, a smart watch, a smart bracelet, a tablet computer, a notebook computer, an all-in-one computer, an access control device, and an electronic door lock.

[0094] In one example, the electronic device can also be a terminal, also known as a User Equipment (UE), a Mobile Station (MS), a Mobile Terminal (MT), etc., which is a device that provides voice and / or data connectivity to a user, such as a handheld device with a wireless connection, a car-mounted device, etc. Currently, some examples of terminals are: a mobile phone, a tablet computer, a notebook computer, a palm computer, a Mobile Internet device (MID), a wearable device, a Virtual Reality (VR) device, an Augmented Reality (AR) device, a wireless terminal in Industrial Control, a wireless terminal in Self driving, a wireless terminal in Remote medical Surgery, a wireless terminal in Smart Grid, a wireless terminal in Transportation Safety, a wireless terminal in Smart City, a wireless terminal in Smart Home, a wireless terminal in Internet of Vehicles, etc.

[0095] Having described various embodiments of the disclosure above, the descriptions are exemplary and not exhaustive, and are not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The choice of terms used herein is intended to best explain the principles of the embodiments, practical application, or improvement to the technology in the market, or to enable other ordinary skilled persons in the art to understand the embodiments disclosed herein.

Claims

1. A common mode voltage generation circuit, characterized by, The common-mode voltage generation circuit is used for generating a common-mode voltage, and the circuit comprises: a first operational amplifier, a positive input terminal of the first operational amplifier being used for receiving a reference voltage, and a negative input terminal of the first operational amplifier being used for receiving a feedback voltage through a feedback circuit, the feedback voltage being proportional to the common-mode voltage, the feedback circuit comprising a voltage proportion adjustment module, which is used for adjusting the common-mode voltage according to a preset proportion to generate the feedback voltage; a second operational amplifier, an input terminal of the second operational amplifier being connected to an output terminal of the first operational amplifier and a first terminal of a capacitance adjustment circuit, and an output terminal of the second operational amplifier being connected to one end of the feedback circuit, a second terminal of the capacitance adjustment circuit and a first terminal of an output control switch, the output terminal of the second operational amplifier being used for outputting the common-mode voltage; wherein a control terminal of the capacitance adjustment circuit is used for receiving a capacitance adjustment signal to change a capacitance of the capacitance adjustment circuit; wherein a second terminal of the output control switch is connected to a target display touch panel, the target display touch panel being a touch and display driver integrated (TDDI) display touch panel, when the target display touch panel works in a touch detection period, the capacitance adjustment switch is turned on, and the output control switch is turned off; or when the target display touch panel works in a display period, the capacitance adjustment switch is turned off, and the output control switch is turned on.

2. The common-mode voltage generation circuit according to claim 1, characterized by, The capacitance adjustment circuit comprises a capacitance adjustment switch and a capacitance, wherein a first terminal of the capacitance adjustment switch is connected to an input terminal of the second operational amplifier and an output terminal of the first operational amplifier, a second terminal of the capacitance adjustment switch is connected to a first terminal of the capacitance, and a second terminal of the capacitance is connected to an output terminal of the second operational amplifier, a control terminal of the capacitance adjustment switch is used for receiving the capacitance adjustment signal.

3. The common-mode voltage generation circuit according to claim 1, wherein The target display touch panel comprises any one of a liquid crystal display panel, an organic light emitting diode display panel, a quantum dot light emitting diode display panel, a mini light emitting diode display panel and a micro light emitting diode display panel.

4. A control method of a common mode voltage generation circuit, characterized by, The method is applied to the common-mode voltage generation circuit in any one of claims 1 to 3, and the method comprises: when the target display touch panel works in a touch detection period, outputting a first capacitance adjustment signal to adjust the capacitance of the capacitance adjustment circuit to a first preset capacitance value and control the output control switch to be turned off; or when the target display touch panel works in a display period, outputting a second capacitance adjustment signal to adjust the capacitance of the capacitance adjustment circuit to a second preset capacitance value and control the output control switch to be turned on.

5. The method of claim 4, wherein, The capacitance adjustment circuit comprises a capacitance adjustment switch and a capacitance, a first terminal of the capacitance adjustment switch is connected to an input terminal of the second operational amplifier and an output terminal of the first operational amplifier, a second terminal of the capacitance adjustment switch is connected to a first terminal of the capacitance, a second terminal of the capacitance is connected to an output terminal of the second operational amplifier, a control terminal of the capacitance adjustment switch is used for receiving the capacitance adjustment signal, and the method further comprises: When the target display touch panel works in a touch detection period, a first capacitance adjustment signal is output to control the capacitance adjustment switch to be turned on and the output control switch to be turned off, and the first preset capacitance value is a capacitance value of the capacitance; or When the target display touch panel works in a display period, a second capacitance adjustment signal is output to control the capacitance adjustment switch to be turned off and the output control switch to be turned on, and the first preset capacitance value is 0. 6.A touch display driving chip, characterized in that, The touch display driving chip comprises the common-mode voltage generation circuit according to any one of claims 1-3. 7.A touch display panel, characterized in that, The touch display panel comprises the touch display driving chip according to claim 6.

8. An electronic device, comprising: The electronic device comprises the touch display panel according to claim 7.

9. The electronic device of claim 8, wherein, The electronic device comprises any one of a display, a smart phone, a smart watch, a smart bracelet, a tablet computer, a notebook computer, an all-in-one computer, and an access control device.

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