WO2022183451A1

WO2022183451A1 - Touch-control driving circuit, driving chip and touch-control display apparatus

Info

Publication number: WO2022183451A1
Application number: PCT/CN2021/079158
Authority: WO
Inventors: 孔晨阳
Original assignee: 深圳市汇顶科技股份有限公司
Priority date: 2021-03-04
Filing date: 2021-03-04
Publication date: 2022-09-09

Abstract

Provided in the present application are a touch-control driving circuit, a driving chip and a touch-control display apparatus. The touch-control driving circuit is used for outputting a driving signal to drive a driving electrode of a touch-control display apparatus. The touch-control driving circuit comprises a voltage generating circuit and a switching circuit, wherein the voltage generating circuit is electrically connected to the switching circuit. The voltage generating circuit comprises at least one energy storage capacitor, wherein the at least one energy storage capacitor is used for storing electric charges released by the driving electrode, and transferring the stored electric charges to the driving electrode. The switching circuit is used for controlling the voltage generating circuit to periodically output a power supply voltage, a first positive voltage, a second positive voltage, a third positive voltage and a zero voltage, wherein the first positive voltage, the second positive voltage and the third positive voltage are voltages provided by the at least one energy storage capacitor. The touch-control driving circuit has lower power consumption.

Description

Touch driving circuit, driving chip and touch display device

technical field

Embodiments of the present application relate to the technical field of electronic circuits, and in particular, to a touch driving circuit, a driving chip, and a touch display device.

Background technique

A capacitive touch display device includes a touch electrode array composed of driving electrodes TX and sensing electrodes RX in a criss-cross pattern. By driving the driving electrode TX and receiving the signal sensed by the sensing electrode RX, the capacitance change of the coupling capacitance between the driving electrode TX and the sensing electrode RX can be detected, and then the user's operation can be judged.

As shown in FIG. 1 , it is a schematic structural diagram of a conventional touch driving circuit. The touch drive circuit utilizes an inverter composed of a PMOS transistor 101 and an NMOS transistor 102 to provide a drive signal, so as to drive the drive electrode TX. The voltage V _DD is the power supply voltage, the capacitance _CL represents the equivalent capacitance of the driving electrode TX, and the resistance _RL represents the equivalent impedance (ie, the driving impedance) during coding. In one cycle T of the driving signal output by the touch driving circuit (hereinafter referred to as one cycle T), the average current value obtained by the capacitor _CL from the power supply is:

When the frequency of the driving signal is f (f=1/T), the driving power consumption of the touch driving circuit in one cycle T is:

As shown in FIG. 2 , it is a schematic diagram of the signal waveform of the driving signal output by the touch driving circuit shown in FIG. 1 in one cycle T. As shown in FIG. The shaded part represents the power consumption of the resistor _RL in one period T, that is, the driving power consumption of the touch driving circuit. The driving power consumption is mainly divided into two parts, one of which is the loss on the resistance _RL when the driving electrode TX is charged, and the other part is the loss on the resistance _RL when the driving electrode TX is discharged, both of which are

At present, OLED (Organic Light Emitting Display, organic light-emitting display) technology has many obvious advantages in display performance compared with traditional LCD (Liquid Crystal Display, liquid crystal display) technology, for example, OLED screen is thinner and lighter, and has a wide viewing angle , low temperature resistance, ecological environmental protection and other characteristics, so OLED screens have been widely used. However, compared with the LCD screen, the capacitance value of the load capacitance (equivalent capacitance C _L ) of the OLED screen is significantly larger, which in turn leads to an increase in the power consumption of the OLED screen, making it difficult to meet the needs of low-power touch detection.

SUMMARY OF THE INVENTION

In view of this, embodiments of the present application provide a touch driving circuit, a driving chip, and a touch display device, so as to reduce the driving power consumption of the touch driving circuit.

In a first aspect, an embodiment of the present application provides a touch drive circuit for outputting a drive signal to drive drive electrodes of a touch display device, including: a voltage generation circuit and a switch circuit; the voltage generation circuit and the switch circuit electrical connection;

The voltage generating circuit includes at least one energy storage capacitor; the at least one energy storage capacitor is used to store the charges released by the driving electrodes and transfer the stored charges to the driving electrodes;

the switch circuit is used for controlling the voltage generating circuit to periodically output the power supply voltage, the first positive voltage, the second positive voltage, the third positive voltage and the zero voltage;

The first positive voltage, the second positive voltage and the third positive voltage are the voltages provided by the at least one energy storage capacitor, and the power supply voltage is higher than the first positive voltage, the first The positive voltage is higher than the second positive voltage, the second positive voltage is higher than the third positive voltage, and the third positive voltage is higher than the zero voltage.

By adding at least one energy storage capacitor, and using the at least one energy storage capacitor to store the charges released when the driving electrodes are discharged, and transfer the stored charges back to the driving electrodes to charge the driving electrodes, it is equivalent to using the at least one energy storage capacitor to charge the driving electrodes. Capacitor recycles the charge released by the drive electrode, so no additional power consumption is caused during this charge transfer process, and multiple intermediate levels are introduced between the supply voltage and zero voltage, including the first positive voltage , the second positive voltage and the third positive voltage, thereby equivalently reducing the voltage variation across the driving electrodes when the driving electrodes are directly driven by the power supply voltage, thereby reducing the actual power consumption of the touch driving circuit.

Optionally, the voltage generating circuit further includes a power supply voltage generating circuit, a first energy storage capacitor and a second energy storage capacitor;

the power supply voltage generating circuit is used for generating the power supply voltage;

The switch circuit is further configured to control the driving electrodes to be connected to the power supply voltage generating circuit within a first period, the power supply voltage charging the driving electrodes so that the voltage across the driving electrodes is equal to the power supply voltage ; control the drive electrode to be connected to the first energy storage capacitor within the second period, and the first energy storage capacitor is used to store the charge released by the drive electrode, so that the voltage across the drive electrode is equal to the the first positive voltage; in the third period, the drive electrode is controlled to be connected in series with the first energy storage capacitor and the second energy storage capacitor, and the first energy storage capacitor and the second energy storage capacitor are inversely connected connected in series, the first energy storage capacitor and the second energy storage capacitor are used to store the charge released by the driving electrode, so that the voltage across the driving electrode is equal to the second positive voltage; within the fourth period controlling the driving electrode to be connected to the second energy storage capacitor, the second energy storage capacitor being used to store the charge released by the driving electrode, so that the voltage across the driving electrode is equal to the third positive voltage; and The driving electrode is controlled to be connected to the ground terminal GND in the fifth period, and the driving electrode discharges the ground terminal GND, so that the voltage across the driving electrode is equal to the zero voltage.

Optionally, the switch circuit is further configured to control the driving electrode to be connected to the second energy storage capacitor within a sixth time period, and the second energy storage capacitor is used to transfer the stored charge to the driving electrode , so that the voltage across the driving electrode is equal to the third positive voltage; in the seventh period, the driving electrode is controlled to be connected in series with the first energy storage capacitor and the second energy storage capacitor, and the first energy storage capacitor is connected in series. The energy storage capacitor is connected in reverse series with the second energy storage capacitor, and the first energy storage capacitor and the second energy storage capacitor are used to transfer the stored charge to the driving electrode, so that the two ends of the driving electrode are a voltage equal to the second positive voltage; and controlling the drive electrode to be connected to the first energy storage capacitor within an eighth period, the first energy storage capacitor being used to transfer the stored charge to the drive electrode, The voltage across the drive electrodes is made equal to the first positive voltage.

Optionally, the switch circuit further includes a first switch circuit, a second switch circuit, a third switch circuit, a fourth switch circuit, and a fifth switch circuit;

During the first period of time, the first switch circuit is turned on; during the second period of time, the second switch circuit is turned on; during the third period of time, the third switch circuit is turned on ; During the fourth period, the fourth switch circuit is turned on; during the fifth period, the fifth switch circuit is turned on; during the sixth period, the fourth switch circuit is turned on During the seventh period, the third switch circuit is conducting; during the eighth period, the second switch circuit is conducting;

When any one of the switch circuits is turned on, the other four switch circuits are all turned off.

Optionally, the first switch circuit further includes a first switch S ₁ ; the second switch circuit further includes a second switch S ₂ ; the third switch circuit further includes a third switch S ₃ and a fourth switch S ₄ ; the fourth switch circuit further includes a _fifth switch S5 and a sixth switch _S6 ; the fifth switch circuit further includes a _seventh switch S7;

The _first end of the first switch S1 is connected to the power supply voltage generating circuit, and the second end of the _first switch S1 is connected to the driving electrode;

The first end of the _second switch S2 is connected to the first end of the first energy storage capacitor, and the second end of the _second switch S2 is connected to the driving electrode;

The first end of the _third switch S3 is connected to the second end of the second energy storage capacitor, and the second end of the _third switch S3 is connected to the driving electrode;

The first end of the _fourth switch S4 is connected to the first end of the second energy storage capacitor, and the second end of the _fourth switch S4 is connected to the first end of the first energy storage capacitor;

The first terminal of the _fifth switch S5 is connected to the second terminal of the second energy storage capacitor, and the second terminal of the _fifth switch S5 is connected to the ground terminal GND;

The first end of the sixth switch _S6 is connected to the first end of the second energy storage capacitor, and the second end of the _sixth switch S6 is connected to the driving electrode;

The first terminal of the _seventh switch S7 is connected to the ground terminal GND, and the second terminal of the _seventh switch S7 is connected to the driving electrode;

The second terminal of the first energy storage capacitor is connected to the ground terminal GND.

Optionally, in the first period, only the first switch S ₁ is closed; in the second period, only the second switch S ₂ is closed; in the third period, only the The _third switch S3 and the _fourth switch S4 are closed; in the fourth period, only the _fifth switch S5 and the sixth switch _S6 are closed; in the fifth period, Only the seventh switch S ₇ is closed; in the sixth period, only the fifth switch S ₅ and the sixth switch S ₆ are closed; in the seventh period, only the third switch S ₃ and the fourth switch S ₄ are closed; in the eighth period, only the second switch S ₂ is closed.

Optionally, when the voltages at both ends of the first energy storage capacitor and the second energy storage capacitor are established to a stable value, the amplitude of the first positive voltage is equal to the voltage across the first energy storage capacitor. value;

The magnitude of the second positive voltage is equal to the voltage value across the first energy storage capacitor minus the voltage value across the second energy storage capacitor;

The magnitude of the third positive voltage is equal to the voltage across the second energy storage capacitor.

Optionally, the drive electrodes further include positive-phase drive electrodes and negative-phase drive electrodes; the voltage generating circuit further includes a power supply voltage generating circuit and a third energy storage capacitor;

The switch circuit is further configured to simultaneously control the positive phase drive electrode to be connected to the power supply voltage generating circuit, the negative phase drive electrode to be connected to the ground terminal GND, and the power supply voltage to the positive phase The driving electrode is charged, and the negative-phase driving electrode discharges the ground terminal GND, so that the voltage across the positive driving electrode is equal to the power supply voltage, and the voltage across the negative-phase driving electrode is equal to the zero voltage; The positive-phase driving electrode, the third energy storage capacitor, and the negative-phase driving electrode are controlled to be connected in series within two time periods, and the positive-phase driving electrode and the third energy storage capacitor are connected in reverse series, and the positive-phase driving electrode is connected in reverse series with the third energy storage capacitor. The driving electrode charges the negative-phase driving electrode through the third storage capacitor, so that the voltage across the positive-phase driving electrode is equal to the first positive voltage, and the voltage across the negative-phase driving electrode is equal to the first positive voltage. Three positive voltages; control the positive phase drive electrode, the third energy storage capacitor, and the negative phase drive electrode in parallel in a third period, and the positive phase drive electrode is connected to the third energy storage capacitor and the The negative-phase driving electrodes are charged, so that the voltage across the positive-phase driving electrodes is equal to the voltage across the negative-phase driving electrodes and is equal to the second positive voltage; the positive-phase driving electrodes, all the The third energy storage capacitor and the negative phase driving electrode are connected in series, and the positive phase driving electrode is connected in positive series with the third energy storage capacitor, and the positive phase driving electrode is connected to the third energy storage capacitor through the third energy storage capacitor. charging the negative-phase drive electrodes so that the voltage across the positive-phase drive electrodes is equal to the third positive voltage, and the voltage across the negative-phase drive electrodes is equal to the first positive voltage; and simultaneously controlling the The positive-phase driving electrode is connected to the ground terminal GND, the negative-phase driving electrode is connected to the power supply voltage generating circuit, the positive-phase driving electrode discharges the ground terminal GND, and the power supply voltage discharges the power supply voltage to the power supply voltage generating circuit. The negative phase drive electrodes are charged such that the voltage across the positive phase drive electrodes is equal to the zero voltage and the voltage across the negative phase drive electrodes is equal to the supply voltage.

Optionally, the switch circuit is further configured to control the positive-phase driving electrode, the third energy storage capacitor, and the negative-phase driving electrode in series within a sixth period, and the positive-phase driving electrode is connected to the The third energy storage capacitor is connected in series in the positive direction, and the negative phase driving electrode charges the positive phase driving electrode through the third energy storage capacitor, so that the voltage across the negative phase driving electrode is equal to the fourth positive voltage, and the The voltage across the positive-phase driving electrodes is equal to the fifth positive voltage; the positive-phase driving electrodes, the third energy storage capacitors, and the negative-phase driving electrodes are controlled to be connected in parallel in the seventh period, and the negative-phase driving electrodes are connected to all charging the third energy storage capacitor and the positive-phase drive electrode so that the voltage across the positive-phase drive electrode is equal to the voltage across the negative-phase drive electrode and equal to the second positive voltage; and at the eighth time period Internally control the positive phase drive electrode, the third energy storage capacitor and the negative phase drive electrode in series, and the positive phase drive electrode and the third energy storage capacitor are connected in reverse series, the negative phase drive electrode The positive phase driving electrode is charged through the third energy storage capacitor, so that the voltage across the positive phase driving electrode is equal to the fourth positive voltage, and the voltage across the negative phase driving electrode is equal to the fifth positive voltage Voltage;

The fourth positive voltage is higher than the fifth positive voltage and lower than the power supply voltage.

Optionally, the switch circuit further includes a sixth switch circuit, a seventh switch circuit, an eighth switch circuit, a ninth switch circuit and a tenth switch circuit;

During the first period of time, the sixth switch circuit is turned on; during the second period of time, the seventh switch circuit is turned on; during the third period of time, the eighth switch circuit is turned on ; in the fourth period, the ninth switch circuit is turned on; in the fifth period, the tenth switch circuit is turned on; in the sixth period, the ninth switch circuit is turned on During the seventh time period, the eighth switch circuit is turned on; during the eighth time period, the seventh switch circuit is turned on.

Optionally, the sixth switch circuit further includes an eighth switch S ₈ and a ninth switch S ₉ ; the seventh switch circuit further includes a tenth switch S ₁₀ and an eleventh switch S ₁₁ ; the eighth switch The circuit further includes a twelfth switch S ₁₂ , a thirteenth switch S ₁₃ and a fourteenth switch S ₁₄ ; the ninth switch circuit further includes a fifteenth switch S ₁₅ and a sixteenth switch S ₁₆ ; the tenth switch The switch circuit further includes a seventeenth switch _S17 and an _eighteenth switch S18;

The first end of the _eighth switch S8 is connected to the power supply voltage generating circuit, and the second end of the _eighth switch S8 is connected to the positive-phase driving electrode;

The first terminal of the _ninth switch S9 is connected to the ground terminal GND, and the second terminal of the _ninth switch S9 is connected to the negative-phase driving electrode;

The first end of the _tenth switch S10 is connected to the first end of the third energy storage capacitor, and the second end of the _tenth switch S10 is connected to the positive-phase driving electrode;

The first end of the _eleventh switch S11 is connected to the second end of the third energy storage capacitor, and the second end of the _eleventh switch S11 is connected to the negative-phase driving electrode;

The first end of the _twelfth switch S12 is connected to the first end of the third energy storage capacitor, and the second end of the _twelfth switch S12 is connected to the positive-phase driving electrode;

The first end of the thirteenth switch _S13 is connected to the first end of the third energy storage capacitor, and the second end of the _thirteenth switch S13 is connected to the negative phase driving electrode;

The first terminal of the _fourteenth switch S14 is connected to the second terminal of the third energy storage capacitor, and the second terminal of the _fourteenth switch S14 is connected to the ground terminal GND;

The first end of the _fifteenth switch S15 is connected to the second end of the third energy storage capacitor, and the second end of the _fifteenth switch S15 is connected to the positive-phase driving electrode;

The first end of the _sixteenth switch S16 is connected to the first end of the third energy storage capacitor, and the second end of the _sixteenth switch S16 is connected to the negative-phase driving electrode;

The first terminal of the seventeenth switch _S17 is connected to the ground terminal GND, and the second terminal of the seventeenth switch _S17 is connected to the positive-phase driving electrode;

The first terminal of the _eighteenth switch S18 is connected to the power supply voltage generating circuit, and the second terminal of the _eighteenth switch S18 is connected to the negative-phase driving electrode.

Optionally, in the first period, only the eighth switch S ₈ and the ninth switch S ₉ are closed at the same time; in the second period, only the tenth switch S ₁₀ and the The eleventh switch S ₁₁ is closed; during the third period, only the twelfth switch S ₁₂ , the thirteenth switch S ₁₃ and the fourteenth switch S ₁₄ are closed; During the period, only the fifteenth switch S ₁₅ and the sixteenth switch S ₁₆ are closed; during the fifth period, only the seventeenth switch S ₁₇ and the eighteenth switch S ₁₈ are closed ; During the sixth period, only the fifteenth switch S ₁₅ and the sixteenth switch S ₁₆ are closed; during the seventh period, only the twelfth switch S ₁₂ and the sixteenth switch S 12 are closed. The thirteen switches S ₁₃ and the fourteenth switch S ₁₄ are closed; in the eighth period, only the tenth switch S ₁₀ and the eleventh switch S ₁₁ are closed.

Optionally, when the voltage across the third energy storage capacitor is established to a stable value, the amplitude of the first positive voltage minus the amplitude of the third positive voltage is equal to two of the third energy storage capacitor. terminal voltage value;

The magnitude of the second positive voltage is equal to the voltage across the third energy storage capacitor;

The magnitude of the fourth positive voltage minus the magnitude of the fifth positive voltage is equal to the voltage across the third energy storage capacitor.

Optionally, when the equivalent capacitance value of the positive phase drive electrode is equal to the equivalent capacitance value of the negative phase drive electrode, the fourth positive voltage is equal to the first positive voltage, and the fifth positive voltage equal to the third positive voltage.

In a second aspect, an embodiment of the present application provides a touch driving chip, including the touch driving circuit according to the first aspect or any optional manner of the first aspect.

In a third aspect, an embodiment of the present application provides a touch display device, including the touch driving chip as described in the second aspect.

It can be understood that the touch driving chip described in the second aspect and the touch display device described in the third aspect both apply the corresponding touch driving circuit provided above. Therefore, they can achieve For the beneficial effects, reference may be made to the beneficial effects of the corresponding touch driving circuits provided above, which will not be repeated here.

Description of drawings

One or more embodiments are exemplified by the pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Where the following description refers to the drawings, the same numerals in different drawings represent the same elements. Unless otherwise stated, the figures in the accompanying drawings do not constitute a scale limitation.

FIG. 1 is a schematic structural diagram of a conventional touch driving circuit;

FIG. 2 is a schematic diagram of a signal waveform of a driving signal output by the touch driving circuit shown in FIG. 1 in one cycle;

FIG. 3 is a schematic structural diagram of a touch driving circuit according to an embodiment of the present application;

FIG. 4 is a schematic structural diagram of another touch driving circuit provided by an embodiment of the present application;

FIG. 5 is a schematic diagram of the working principle of the touch driving circuit shown in FIG. 4;

FIG. 6 is a schematic diagram of a signal waveform of a driving signal output by the touch driving circuit shown in FIG. 4 in one cycle;

FIG. 7 is a schematic diagram of a circuit model of the touch driving circuit shown in FIG. 4;

FIG. 8 is a schematic structural diagram of another touch driving circuit provided by an embodiment of the present application;

FIG. 9 is a schematic diagram of the working principle of the touch driving circuit shown in FIG. 8;

FIG. 10 is a schematic diagram of a signal waveform of a driving signal output by the touch driving circuit shown in FIG. 8 in one cycle.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, but not all of the embodiments.

The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to limit the application. As used in this application and the appended claims, the singular forms "a," "the," and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. It will also be understood that the term "and/or" as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

In addition, terms such as "first" and "second" are only used to distinguish similar objects, and should not be construed as indicating or implying relative importance, or implying the number of indicated technical features. Thus, a feature defined as "first", "second", etc., may expressly or implicitly include one or more of that feature.

Embodiments of the present application provide a touch driving circuit, a driving chip and a touch display device. The touch driving circuit can be applied to a capacitive touch display device to drive the driving electrodes of the touch display device. The touch display apparatus may further include a display device, and examples of the display device include a liquid crystal (LCD) display, an organic light emitting (OLED) display, a plasma (PDP) display, and a cathode ray (CRT) display.

As shown in FIG. 3 , a schematic structural diagram of a touch driving circuit provided by an embodiment of the present application; wherein, the resistance R _tx represents the driving impedance, including the equivalent impedance of the driving electrodes and the touch driving circuit, and the capacitance _CL represents the driving Equivalent capacitance of the electrodes. The touch drive circuit 20 includes a voltage generation circuit 201 and a switch circuit 202, and the voltage generation circuit 201 is electrically connected to the switch circuit 202; the voltage generation circuit 201 includes at least one energy storage capacitor (not shown in the figure), the at least one energy storage capacitor The capacitor can store the charges released by the driving electrodes and transfer the stored charges to the driving electrodes; the switching circuit 202 can control the voltage generating circuit 201 to periodically output the power supply voltage, the first positive voltage, the second positive voltage, the third positive voltage and the Zero voltage; wherein, the first positive voltage, the second positive voltage and the third positive voltage are the voltages provided by the at least one energy storage capacitor, and their amplitudes satisfy the following relationship: power supply voltage>first positive voltage>second positive voltage Voltage > third positive voltage > zero voltage.

By adding at least one energy storage capacitor, the charge released when the driving electrode is discharged can be recycled, and no additional power consumption is generated during the charge transfer process between the at least one energy storage capacitor and the driving electrode, and Multiple intermediate levels are introduced between the power supply voltage and zero voltage, which effectively reduces the voltage variation across the drive electrodes when the drive electrodes are directly charged by the power supply voltage, effectively reducing the drive of the touch drive circuit. power consumption.

Based on the touch driving circuit shown in FIG. 3 , the voltage generating circuit may further include a power supply voltage generating circuit, a first energy storage capacitor and a second energy storage capacitor. The power supply voltage generating circuit can generate the above-mentioned power supply voltage. The switch circuit can further control the driving electrodes to be connected to the power supply voltage generating circuit within the first period, and the power supply voltage can charge the driving electrodes, so that the voltage across the driving electrodes is equal to the power supply voltage; during the second period, the driving electrodes are controlled to be connected to the first energy storage The first energy storage capacitor can store the charge released by the driving electrode, so that the voltage across the driving electrode is equal to the above-mentioned first positive voltage; in the third period of time, the driving electrode is controlled to be connected in series with the first energy storage capacitor and the second energy storage capacitor, And the first energy storage capacitor and the second energy storage capacitor are connected in reverse series, and the first energy storage capacitor and the second energy storage capacitor can store the charge released by the driving electrode, so that the voltage at both ends of the driving electrode is equal to the above-mentioned second positive voltage; The driving electrodes are controlled to be connected to the second energy storage capacitors within four periods of time, and the second energy storage capacitors can store the charges released by the driving electrodes, so that the voltage across the driving electrodes is equal to the above-mentioned third positive voltage; and the connection of the driving electrodes is controlled within the fifth period of time To the ground terminal GND, the driving electrode discharges to the ground terminal GND, so that the voltage across the driving electrode is equal to zero voltage.

In the above process, the voltage across the driving electrodes first drops from the power supply voltage to the first positive voltage, then from the first positive voltage to the second positive voltage, and then from the second positive voltage to the third positive voltage, and then from the first positive voltage to the third positive voltage. The three positive voltages drop to zero voltage, that is, the driving electrodes are always in the discharge state during this process. By setting two energy storage capacitors to store the charges released by the driving electrodes during the discharge process, three intermediate levels are introduced between the power supply voltage and zero voltage, thereby reducing the loss on the resistance _RL when the driving electrodes are discharged, and then The driving power consumption of the touch driving circuit is reduced.

Based on the content disclosed in the above embodiments, in this embodiment, the switch circuit can further control the driving electrode to be connected to the second energy storage capacitor within the sixth period, and the second energy storage capacitor can transfer the stored charge to the driving electrode, so that the driving electrode can be driven The voltage at both ends of the electrode is equal to the above-mentioned third positive voltage; in the seventh period, the driving electrode is controlled to be connected in series with the first energy storage capacitor and the second energy storage capacitor, and the first energy storage capacitor and the second energy storage capacitor are connected in reverse series, and the first energy storage capacitor and the second energy storage capacitor are connected in reverse series. An energy storage capacitor and a second energy storage capacitor can transfer the stored charge to the driving electrode, so that the voltage across the driving electrode is equal to the above-mentioned second positive voltage; and the driving electrode is controlled to be connected to the first energy storage capacitor in the eighth time period, The first energy storage capacitor can transfer the stored charge to the driving electrode, so that the voltage across the driving electrode is equal to the above-mentioned first positive voltage.

In the above process, the voltage across the driving electrodes first rises from zero voltage to the third positive voltage, then rises from the third positive voltage to the second positive voltage, and then rises from the second positive voltage to the first positive voltage, That is, the driving electrodes are always in a charged state during this process.

Combining the above-mentioned discharge stage and charging stage of the driving electrodes can constitute one working cycle of the touch driving circuit, which corresponds to one cycle of the driving signal output by the touch driving circuit. The two energy storage capacitors can store the charge released by the drive electrode during the discharge process, and then transfer the stored charge back to the drive electrode to charge the drive electrode without additional power consumption during the charge transfer process. And three intermediate levels are introduced between the power supply voltage and the zero voltage, so that the signal amplitude of the driving signal in one cycle is sequentially equal to the power supply voltage, the first positive voltage, the second positive voltage, the third positive voltage, and the zero voltage. , the third positive voltage, the second positive voltage, and the first positive voltage can not only reduce the loss on the resistance _RL when the driving electrode is charged, but also reduce the loss on the resistance _RL when the driving electrode is discharged, thereby effectively reducing The drive power consumption of the touch drive circuit.

Based on the contents disclosed in the foregoing embodiments, in this embodiment, the switch circuit may further include a first switch circuit, a second switch circuit, a third switch circuit, a fourth switch circuit, and a fifth switch circuit. In order to make the signal amplitude of the driving signal in one cycle equal to the power supply voltage, the first positive voltage, the second positive voltage, the third positive voltage, the zero voltage, the third positive voltage, the second positive voltage, and the first positive voltage , can control: in the first time period, the first switch circuit is turned on; in the second time period, the second switch circuit is turned on; in the third time period, the third switch circuit is turned on; in the fourth time period, the first switch circuit is turned on The four switch circuit is turned on; in the fifth period, the fifth switch circuit is turned on; in the sixth period, the fourth switch circuit is turned on; in the seventh period, the third switch circuit is turned on; in the eighth period , the second switch circuit is turned on, and when any one of the above switch circuits is turned on, the other four switch circuits are turned off.

Specifically, each switch circuit can be controlled by a control circuit, so that each switch circuit can be periodically cyclically turned on according to the above-mentioned turn-on sequence, and then the driving signal is controlled to have the above-mentioned stepped signal waveform. The control circuit may be integrated with the touch driving circuit on the same chip, or may be independent of the touch driving circuit, that is, the control circuit and the touch driving circuit may be integrated in different chips, which are not limited in the embodiments of the present application.

Based on the contents disclosed in the above embodiments, the embodiments of the present application provide a schematic structural diagram of another touch drive circuit, as shown in FIG. 4 ; wherein, the resistance R _tx represents the drive impedance (including the Effective impedance), the capacitance _CL represents the equivalent capacitance of the driving electrode. Specifically, in the switch circuit, the first switch circuit further includes a first switch S ₁ ; the second switch circuit further includes a second switch S ₂ ; the third switch circuit further includes a third switch S ₃ and a fourth switch S ₄ ; The four-switch circuit further includes a fifth switch S ₅ and a sixth switch S ₆ ; the fifth switch circuit further includes a seventh switch S ₇ . Specifically, the connection relationship of each element in the touch driving circuit 30 is as follows: the first end of the _first switch S1 is connected to the power supply voltage generating circuit to connect to the power supply voltage V _DD , and the second end of the _first switch S1 is connected to to the drive electrode; the first end of the _second switch S2 is connected to the first end of the first energy storage capacitor C _S1 , the second end of the _second switch S2 is connected to the drive electrode; the third end of the _third switch S3 One end is connected to the second end of the second energy storage capacitor C _S2 , the second end of the third switch S ₃ is connected to the driving electrode; the first end of the fourth switch S ₄ is connected to the second end of the second energy storage capacitor C _S2 The first end, the second end of the _fourth switch S4 is connected to the first end of the first energy storage capacitor C _S1 ; the first end of the _fifth switch S5 is connected to the second end of the second energy storage capacitor C _S2 , The second end of the _fifth switch S5 is connected to the ground GND; the first end of the sixth switch _S6 is connected to the first end of the second energy storage capacitor C _S2 , and the second end of the _sixth switch S6 is connected to the driving electrode; the first terminal of the _seventh switch S7 is connected to the ground terminal GND, the second terminal of the _seventh switch S7 is connected to the driving electrode; the second terminal of the first energy storage capacitor C _S1 is connected to the ground terminal GND.

FIG. 5 is a schematic diagram of the working principle of the touch driving circuit shown in FIG. 4 , wherein the voltage across the first energy storage capacitor C _S1 is denoted as V _C1 , and the voltage across the second energy storage capacitor C _S2 is denoted as V _C2 . It can be seen that in the period _t1 , only the first switch circuit is turned on, that is, only the _first switch S1 is closed, and the power supply voltage V _DD charges the capacitor _CL until the voltage across the capacitor _CL is equal to the power supply voltage V _DD .

During the period of _t2 , only the second switch circuit is turned on, that is, only the _second switch S2 is closed, the capacitor _CL discharges the first energy storage capacitor C _S1 , and the first energy storage capacitor C _S1 stores the charge released by the capacitor _CL , until the voltage across the capacitor _CL is equal to the first positive voltage.

During the period of _t3 , only the third switch circuit is turned on, that is, the _third switch S3 and the _fourth switch S4 are closed at the same time, and the series connection of the capacitor _CL to the first energy storage capacitor C _S1 and the second energy storage capacitor C _S2 The capacitor is discharged, and the first energy storage capacitor C _S1 and the second energy storage capacitor C _S2 store the charge released by the capacitor _CL until the voltage across the capacitor _CL is equal to the second positive voltage.

During the period of t4, only the _fourth switch circuit is turned on, that is, the _fifth switch S5 and the sixth switch _S6 are closed at the same time, and the capacitor _CL discharges the second energy storage capacitor _CS2 until the voltage across the capacitor _CL is equal to third positive voltage.

During the period of t5, only the _fifth switch circuit is turned on, that is, only the _seventh switch S7 is closed, and the capacitor _CL is discharged to the ground until the voltage across the capacitor _CL is equal to zero voltage.

During the period of t6, only the fourth switch circuit is turned on, that is, the _fifth switch S5 and the _sixth switch _S6 are closed at the same time, and the second energy storage capacitor _CS2 charges the capacitor _CL until the voltage across the capacitor _CL is equal to third positive voltage.

During the period of t7, only the third switch circuit is turned _on , that is, the _third switch S3 and the _fourth switch S4 are closed at the same time, and the series capacitance of the first energy storage capacitor C _S1 and the second energy storage capacitor C _S2 is connected to the capacitance C _L charges until the voltage across capacitor _CL equals the second positive voltage.

During the period of _t8 , only the second switch circuit is turned on, that is, only the _second switch _S2 is closed, and the first energy storage capacitor CS1 charges the capacitor _CL until the voltage across the capacitor _CL is equal to the first positive voltage.

The touch drive circuit provided by the embodiment of the present application can operate cyclically according to the above-mentioned eight time periods as one cycle, and the voltage V _C1 across the first energy storage capacitor C _S1 and the voltage V _C2 across the second energy storage capacitor C _S2 are in this During the working process of the cycle, it will gradually establish to a stable value, and when the voltages at both ends of the first energy storage capacitor C _S1 and the second energy storage capacitor C _S2 are established to a stable value, the amplitude of the first positive voltage is equal to the first energy storage capacitor. The voltage value V _C1 across the energy storage capacitor C _S1 and the magnitude of the second positive voltage is equal to the voltage value V _C1 across the first energy storage capacitor C _S1 minus the voltage value V _C2 across the second energy storage capacitor C _S2 , which is equal to V _C1 -V _C2 , the magnitude of the third positive voltage is equal to the voltage value V _C2 across the second energy storage capacitor _CS2 .

It should be noted that when the capacitance values of the first energy storage capacitor C _S1 and the second energy storage capacitor C _S2 are far greater than the capacitance value of the capacitor _CL , the first energy storage capacitor C _S1 and the second energy storage capacitor C _S2 store After the charge released by the capacitor _CL or the charge is transferred to the capacitor _CL , the voltage values across the first energy storage capacitor C _S1 and the second energy storage capacitor C _S2 hardly change. Specifically, when the capacitance values of the first energy storage capacitor C _S1 and the second energy storage capacitor C _S2 are greater than 50 to 100 times the capacitance value of the capacitor _CL , it can be determined that the first energy storage capacitor C _S1 and the second energy storage capacitor C S2 The capacitance value of the capacitor _CS2 is much larger than the capacitance value of the capacitor _CL .

In the following, based on the law of charge conservation, the charge transfer between the first energy storage capacitor C _S1 , the second energy storage capacitor C _S2 , and the capacitor _CL in the above-mentioned eight time periods is analyzed to calculate the first energy storage capacitor C _S1 The specific values of the first positive voltage, the second positive voltage and the third positive voltage when the voltages across the second energy storage capacitor CS2 and the second energy storage capacitor C _S2 are established to a stable value. The capacitance values of the first energy storage capacitor C _S1 , the second energy storage capacitor C _S2 , and the capacitor CL are set as follows: C _S1 =C _S2 =C _S >> _{C L} _.

During the period _t1 , the final value of the voltage across the capacitor _CL is equal to the power supply voltage V _DD .

In the period of _t2 , the initial value of the voltage across the capacitor _CL is V _DD , the final value is recorded as V _x1 , the initial value of the voltage across the first energy storage capacitor C _S1 is V _C1 , and the final value is also V _x1 , According to the law of conservation of charge, the above voltage value and capacitance value satisfy the following relationship:

C _L *(V _DD -V _x1 )=C _S1 *(V _x1 -V _C1 ). (Equation 1)

According to formula 1, we can get:

V _x1 = (C _S1 *V _C1 +C _L *V _DD )/(C _S1 +C _L ). (Equation 2)

Since the capacitance values of the first energy storage capacitor C _S1 , the second energy storage capacitor C _S2 , and the capacitor _CL satisfy: C _S1 =C _S2 =C _S >>C _L , according to formula 2, it can be obtained:

V _x1 ≈(1-C _L /C _S )*V _C1 +C _L /C _S *V _DD . (Equation 3)

In the period of _t3 , the initial value of the voltage across the capacitor _CL is V _x1 , and the final value is V _x2 ; the initial value of the voltage across the first energy storage capacitor C _S1 is V _x1 , and the final value is V _x3 ; the second value is V x1 ; The initial value of the voltage across the energy storage capacitor _{CS2 is V C2} _, and the final value is V _x3 -V _x2 ; according to the law of conservation of charge, the above voltage value and capacitance value satisfy the following relationship:

C _S1 *(V _x3 -V _x1 )=C _L *(V _x1 -V _x2 ); (Equation 4)

C _S2 *(V _x2 -V _x3 )+C _S2 *V _C2 =C _L *(V _x1 -V _x2 ). (Equation 5)

According to Equation 4 and Equation 5, we can get:

V _x2 ≈(1-C _L /C _S )*V _C1 -(1-2*C _L /C _S )*V _C2 +C _L /C _S *V _DD ; (Equation 6)

V _x1 ≈(1-C _L /C _S )*V _C1 +C _L /C _S *V _C2 +C _L /C _S *V _DD . (Equation 7)

During the period of _{t4, the initial value of the voltage across the capacitor CL is V x3 -V x2 , and the final value is V x4} _; _the _initial _value of the voltage across the second energy storage capacitor C _S2 is V _x2 , and the final value is also V _x4 ; According to the law of conservation of charge, the above voltage value and capacitance value satisfy the following relationship:

C _L *(V _x2 -V _x4 )=C _S2 *[V _x4 -(V _x3 -V _x2 )]. (Equation 8)

According to Equation 8, it can be obtained:

V _x4 ≈(1-3*C _L /C _S )*V _C2 +C _L /C _S *V _C1 . (Equation 9)

_At the end of the t5 period, the capacitor _CL is discharged to the ground until the voltage at both ends is equal to zero voltage, so in the t6 period, the initial value of the voltage across the capacitor _CL is 0, and the final value is V _x5 _. The second energy storage capacitor The initial value of the voltage across C _S2 is V _x4 , and the final value is also V _x5 ; according to the law of conservation of charge, the above voltage value and capacitance value satisfy the following relationship:

C _L *V _x5 =C _S2 *(V _x4 -V _x5 ). (Equation 10)

According to formula 10, we can get:

V _x5 ≈C _L /C _S *V _C1 +(1-4*C _L /C _S )*V _C2 . (Equation 11)

_In the period of t7, the initial value of the voltage across the capacitor _CL is V _x5 , and the final value is V _x6 ; the initial value of the voltage across the first energy storage capacitor C _S1 is V _x3 , and the final value is V _x7 ; The initial value of the voltage across the energy storage capacitor _CS2 is V _x5 , and the final value is V _x7 -V _x6 ; according to the law of conservation of charge, the above voltage value and capacitance value satisfy the following relationship:

C _L *(V _x6 -V _x5 )=C _S1 *(V _x3 -V _x7 )=C _S2 *[(V _x7 -V _x6 )-V _x5 ]. (Equation 12)

According to formula 12, it can be obtained:

V _x6 ≈(1-4*C _L /C _S )*V _C1 -(1-4*C _L /C _S )*V _C2 +C _L /C _S *V _DD ; (Equation 13)

V _x7 ≈(1-2*C _L /C _S )*V _C1 +3*C _L /C _S *V _C2 +C _L /C _S *V _DD . (Equation 14)

In the period of _{t8, the initial value of the voltage at both ends of the capacitor CL is Vx6} _, _and the final value is _Vx8 ; the initial value of the voltage at both ends of the first energy storage capacitor C _S1 is _Vx7 , and the final value is also _Vx8 ; according to According to the law of conservation of charge, the above voltage value and capacitance value satisfy the following relationship:

C _S1 *(V _x7 -V _x8 )=C _L *(V _x8 -V _x6 ). (Equation 15)

According to Equation 15, it can be obtained:

V _x8 ≈(1-2*C _L /C _S )*V _C1 +2*C _L /C _S *V _C2 +C _L /C _S *V _DD . (Equation 16)

When the voltage V _C1 across the first energy storage capacitor C _S1 and the voltage V _C2 across the second energy storage capacitor C _S2 reach a stable state, the following relationship is satisfied:

V _x7 -V _x6 =V _C2 ; (Equation 17)

V _x8 = V _C1 . (Equation 18)

According to Equation 17 and Equation 18, it can be calculated:

Therefore, after the voltages across the first energy storage capacitor C _S1 and the second energy storage capacitor C _S2 are established and stabilized, the first positive voltage, the second positive voltage, and the third positive voltage are respectively equal to 3/4V _DD , 1/2V _DD , 1/4V _DD .

As shown in FIG. 6 , it is a schematic diagram of the signal waveform of the driving signal output by the touch driving circuit shown in FIG. 4 in one cycle; the waveform of the driving signal is based on the first energy storage capacitor C _S1 and the second energy storage capacitor C The situation where the voltage across _S2 has settled to a stable value. It can be seen that the waveform of the driving signal is stepped, and one cycle of the driving signal can be divided into eight periods, and these eight periods correspond to four different signal amplitudes, which are the power supply voltage VDD, A positive voltage of 3/4V _DD , a second positive voltage of 1/2V _DD , and a third positive voltage of 1/4V _DD . Since in the whole cycle, there is only one period of time when the driving electrodes are directly charged by the power supply voltage, and the voltage across the driving electrodes rises from 3/4V _DD to V _DD in this period, the power consumption ΔQ is:

ΔQ=C _L *(V _DD -3/4*V _DD )=1/4*C _L *V _DD . (Equation 19)

Therefore, the driving power consumption of the touch driving circuit in one cycle T is:

P=V _DD *ΔQ/T=1/4*C _L *V _DD ² *f. (Equation 20)

By adding two energy storage capacitors, the touch driving circuit provided by the embodiment of the present application introduces three intermediate levels between the power supply voltage and zero voltage, which is equivalent to reducing the power supply voltage when driving the driving electrodes directly. The amount of voltage change across the driving electrodes, so compared with the traditional touch driving circuit shown in The power consumption is significantly reduced, only 25% of the traditional touch drive circuit.

Next, the driving power consumption of the touch driving circuit is calculated from another angle, as shown in FIG. 6 , where the eight shaded parts represent the losses on the driving impedance _RL in one cycle T. In order to facilitate the calculation of the loss on the driving impedance _RL in one period T, the schematic diagram of the circuit model shown in FIG. 7 can be used, and the circuit model can represent the touch driving in any period t _i (i=1, 2...8) A condition in which a circuit charges or discharges a drive electrode.

The current when the touch drive circuit charges or discharges the drive electrodes is:

because

So according to Equation 21 we can get:

According to Equation 22, the energy consumed by the driving impedance _RL in a period of time can be obtained as:

Therefore, the loss on the driving impedance _RL in one cycle T is 1/4*C _L *V _DD ² *f, where f=1/T, which represents the frequency of the driving signal.

After the switch circuit is turned on, the voltage across the capacitor _CL often changes in a non-ideal state, that is, the voltage across the capacitor _CL will not change to the target stable value at the moment when the switch circuit is turned on. Therefore, in order to ensure the implementation of the present application The drive power consumption and the amplitude of the output drive signal of the touch drive circuit provided in the example can reach the preset target value, and the first switch circuit, the second switch circuit, the third switch circuit, the fourth switch circuit, the The conduction time of the five-switch circuit is greater than or equal to the time for the voltage across the driving electrodes to establish to a stable value within a corresponding period of time.

On the other hand, in the application of mutual capacitance detection, the orthogonal coding method can also be used, that is, at the same time, some of the driving electrodes are driven with a positive-phase driving waveform, which is called a positive-phase driving electrode, while another part of the driving electrodes is driven by a negative-phase driving waveform. The driving waveform of the phase is driven, which is called the negative phase driving electrode. In response to this coding method, the embodiment of the present application also provides a touch driving circuit, which can drive the positive-phase driving electrodes and the negative-phase driving electrodes at the same time, so as to better adapt to touch detection using the orthogonal coding method application.

Based on the touch driving circuit shown in FIG. 3 , the voltage generating circuit may further include a power supply voltage generating circuit and a third energy storage capacitor. The power supply voltage generating circuit can generate the above-mentioned power supply voltage. The switch circuit can further control the positive phase drive electrode to be connected to the power supply voltage generating circuit, the negative phase drive electrode to be connected to the ground terminal GND, the power supply voltage to charge the positive phase drive electrode, and the negative phase drive electrode to discharge to the ground terminal GND during the first period , so that the voltage at both ends of the positive-phase driving electrode is equal to the above-mentioned power supply voltage, and the voltage at both ends of the negative-phase driving electrode is equal to zero voltage; in the second period, the positive-phase driving electrode, the third energy storage capacitor, and the negative-phase driving electrode are controlled in series, and the positive-phase driving electrode is connected in series. The driving electrode is connected in reverse series with the third energy storage capacitor, and the positive phase driving electrode charges the negative phase driving electrode through the third energy storage capacitor, so that the voltage at both ends of the positive phase driving electrode is equal to the above-mentioned first positive voltage, and the voltage at both ends of the negative phase driving electrode is equal to the above-mentioned first positive voltage. The voltage is equal to the above-mentioned third positive voltage; in the third period of time, the positive phase driving electrode, the third energy storage capacitor and the negative phase driving electrode are controlled in parallel, and the positive phase driving electrode charges the third energy storage capacitor and the negative phase driving electrode, so that the positive phase driving electrode is charged. The voltage across the phase drive electrodes is equal to the voltage across the negative phase drive electrodes, and is equal to the above-mentioned second positive voltage; the positive phase drive electrodes, the third energy storage capacitor, and the negative phase drive electrodes are controlled in series in the fourth period, and the positive phase drive electrodes are connected in series. The electrode is connected in positive series with the third energy storage capacitor, and the positive phase driving electrode charges the negative phase driving electrode through the third energy storage capacitor, so that the voltage across the positive phase driving electrode is equal to the above-mentioned third positive voltage, and the voltage across the negative phase driving electrode equal to the above-mentioned first positive voltage; and simultaneously control the positive phase drive electrode to be connected to the ground terminal GND in the fifth period, the negative phase drive electrode to be connected to the power supply voltage generating circuit, the positive phase drive electrode to discharge to the ground terminal GND, and the power supply voltage to the negative The phase drive electrodes are charged such that the voltage across the positive phase drive electrodes is equal to zero voltage and the voltage across the negative phase drive electrodes is equal to the supply voltage.

In the above process, the voltage across the positive phase driving electrodes first drops from the power supply voltage to the first positive voltage, while the voltage across the negative phase driving electrodes rises from zero voltage to the third positive voltage; the voltage across the positive phase driving electrodes is again From the first positive voltage to the second positive voltage, the voltage across the negative-phase drive electrodes increases from the third positive voltage to the second positive voltage; the voltage across the positive-phase drive electrodes drops from the second positive voltage to the third positive voltage, while the voltage across the negative phase drive electrode rises from the second positive voltage to the first positive voltage; then the voltage across the positive phase drive electrode drops from the third positive voltage to zero voltage, while the voltage across the negative phase drive electrode From the first positive voltage to the power supply voltage, that is, during this process, the positive-phase driving electrodes are in a discharge state, and the negative-phase driving electrodes are in a charging state. By setting a third energy storage capacitor and using a switch circuit to switch the series-parallel state between the third energy storage capacitor, the positive phase drive electrode and the negative phase drive electrode, three energy storage capacitors are introduced between the power supply voltage and the zero voltage. middle level, thereby reducing the loss on the resistor _RL when the positive-phase driving electrode is discharged, and the loss on the resistor _RL when charging the negative-phase driving electrode, thereby reducing the driving power consumption of the touch driving circuit.

Based on the content disclosed in the above embodiments, in this embodiment, the switch circuit can further control the positive phase driving electrode, the third energy storage capacitor, and the negative phase driving electrode to be connected in series in the sixth time period, and the positive phase driving electrode and the third energy storage electrode are connected in series. The capacitors are connected in series in the positive direction, and the negative-phase driving electrode charges the positive-phase driving electrode through the third energy storage capacitor, so that the voltage across the negative-phase driving electrode is equal to the fourth positive voltage, and the voltage across the positive-phase driving electrode is equal to the fifth positive voltage; In the seventh period, the positive phase drive electrode, the third energy storage capacitor and the negative phase drive electrode are controlled in parallel, and the negative phase drive electrode charges the third energy storage capacitor and the positive phase drive electrode, so that the voltage across the positive phase drive electrode is equal to the negative phase drive electrode The voltage at both ends of the electrode is equal to the above-mentioned second positive voltage; and in the eighth time period, the positive phase driving electrode, the third energy storage capacitor and the negative phase driving electrode are controlled in series, and the positive phase driving electrode and the third energy storage capacitor are connected in reverse series , the negative phase drive electrode charges the positive phase drive electrode through the third energy storage capacitor, so that the voltage across the positive phase drive electrode is equal to the fourth positive voltage, and the voltage across the negative phase drive electrode is equal to the fifth positive voltage. Wherein, the magnitudes of the fourth positive voltage and the fifth positive voltage satisfy: power supply voltage>fourth positive voltage>fifth positive voltage>zero voltage.

In the above process, the voltage across the positive-phase driving electrodes first increases from zero voltage to the fifth positive voltage, while the voltage across the negative-phase driving electrodes decreases from the power supply voltage to the fourth positive voltage; the voltage across the positive-phase driving electrodes is again From the fifth positive voltage to the second positive voltage, while the voltage across the negative-phase drive electrodes drops from the fourth positive voltage to the second positive voltage; and then the voltage across the positive-phase drive electrodes rises from the second positive voltage to the first Four positive voltages, while the voltage across the negative-phase driving electrodes drops from the second positive voltage to the fifth positive voltage, that is, during this process, the positive-phase driving electrodes are in a charged state, and the negative-phase driving electrodes are in a discharging state. Combining this process with the previous process, one working cycle of the touch driving circuit can be formed, which corresponds to one cycle of the driving signal output by the touch driving circuit. The third energy storage capacitor can recycle the charges released by the positive-phase driving electrodes and the negative-phase driving electrodes during the discharge process, so as to realize the charging of the positive-phase driving electrodes and the negative-phase driving electrodes. Additional power consumption, and the switching circuit introduces five intermediate levels between the power supply voltage and zero voltage by switching the series-parallel state between the third energy storage capacitor, the positive-phase driving electrode, and the negative-phase driving electrode. The driving signal has a stepped signal waveform, and at the same time, it can be well adapted to the driving mode of quadrature coding.

Based on the contents disclosed in the foregoing embodiments, in this embodiment, the switch circuit may further include: a sixth switch circuit, a seventh switch circuit, an eighth switch circuit, a ninth switch circuit, and a tenth switch circuit. In order to make the driving signal have the above-mentioned stepped signal waveform, it can be controlled: in the above-mentioned first period of time, the sixth switch circuit is turned on; in the above-mentioned second period of time, the seventh switch circuit is turned on; in the above-mentioned third period of time, The eighth switch circuit is turned on; in the fourth time period, the ninth switch circuit is turned on; in the fifth time period, the tenth switch circuit is turned on; in the sixth time period, the ninth switch circuit is turned on; During the seventh period, the eighth switch circuit is turned on; during the eighth period, the seventh switch circuit is turned on; when any one of the switch circuits is turned on, the other four switch circuits are turned off.

Specifically, a control circuit can be used to control the switch circuit, so that the switch circuit can be periodically cyclically turned on according to the above turn-on sequence, thereby controlling the drive signal output by the touch drive circuit to have the above-mentioned stepped signal waveform. The control circuit may be integrated with the touch driving circuit on the same chip, or may be independent of the touch driving circuit, that is, the control circuit and the touch driving circuit may be integrated in different chips, which are not limited in the embodiments of the present application.

Based on the contents disclosed in the above embodiments, the embodiments of the present application provide a schematic structural diagram of another touch driving circuit, as shown in FIG. 8 , to adapt to the touch detection scene using the orthogonal coding method; wherein, the resistance R _{tx ,p} and resistance R _tx,n represent the positive-phase driving impedance and negative-phase driving impedance, respectively, and the capacitance _CL,p and capacitance _CL,n represent the equivalent capacitance of the positive-phase driving electrode and the negative-phase driving electrode, respectively. In the switch circuit, the sixth switch circuit further includes an eighth switch _S8 and a ninth switch _S9 ; the seventh switch circuit further includes a tenth switch _S10 and an eleventh switch _S11 ; the eighth switch circuit further includes a twelfth switch switch S ₁₂ , thirteenth switch S ₁₃ and fourteenth switch S ₁₄ ; the ninth switch circuit further includes a fifteenth switch S ₁₅ and a sixteenth switch S ₁₆ ; the tenth switch circuit further includes a seventeenth switch S ₁₇ and the eighteenth switch S ₁₈ . Specifically, the connection relationship of each element in the touch driving circuit 40 is as follows: the first end of the _eighth switch S8 is connected to the power supply voltage generating circuit, which is connected to the power supply voltage V _DD , and the second end of the _eighth switch S8 is connected to the power supply voltage V DD . the positive phase drive electrode; the first end of the _ninth switch S9 is connected to the ground GND, the second end of the _ninth switch S9 is connected to the negative phase drive electrode; the first end of the _tenth switch S10 is connected to the The first end of the three energy storage capacitors C _S3 , the second end of the _tenth switch S10 is connected to the positive phase driving electrode; the first end of the _eleventh switch S11 is connected to the second end of the third energy storage capacitor C _S3 terminal, the second terminal of the _eleventh switch S11 is connected to the negative phase drive electrode; the first terminal of the _twelfth switch S12 is connected to the first terminal of the twelfth switch _S12 and the first terminal of the twelfth switch S12 is connected to the twelfth switch _S12 The second end of the thirteenth switch S13 is connected to the positive phase drive electrode; the first end of the thirteenth switch _S13 is connected to the first end of the third energy storage capacitor C _S3 , and the second end of the _thirteenth switch S13 is connected to the negative Phase drive electrode; the first end of the _fourteenth switch S14 is connected to the second end of the third energy storage capacitor C _S3 , the second end of the _fourteenth switch S14 is connected to the ground GND; the _fifteenth switch S15 The first end of the switch S15 is connected to the second end of the third energy storage capacitor C _S3 , the second end of the _fifteenth switch S15 is the positive phase drive electrode; the first end of the _sixteenth switch S16 is connected to the third energy storage capacitor The first end of the capacitor C _S3 and the second end of the sixteenth switch S ₁₆ are connected to the negative phase drive electrode; the first end of the seventeenth switch S ₁₇ is connected to the ground GND, and the first end of the seventeenth switch S ₁₇ The two terminals are connected to the positive phase driving electrode; the first terminal of the _eighteenth switch S18 is connected to the power supply voltage generating circuit, and the second terminal of the _eighteenth switch S18 is connected to the negative phase driving electrode.

FIG. 9 is a schematic diagram of the working principle of the touch drive circuit shown in FIG. 8 ; in order to clearly show the touch drive circuit between the third energy storage capacitor C _S3 , the positive phase drive electrode, and the negative phase drive electrode during the working process In the figure, the resistance R _tx,p and the resistance R _tx,n are omitted. The voltage across the third energy storage capacitor C _S3 is denoted as V _C3 , the voltage across the capacitor C _L,p is denoted as V _p , the capacitance The voltage across C _L,n is denoted as V _n , and the capacitance value between the capacitance C _L,p and the capacitance C _L,n satisfies: C _L,p /C _L,n =k(k>0).

During the period of _t1 , only the sixth switch circuit is turned on, that is, only the eighth switch _S8 and the ninth switch _S9 are closed at the same time, and the power supply voltage V _DD charges the capacitor CL, _p until the capacitors _CL,p are both closed. The voltage _Vp at the terminals is equal to the supply voltage V _DD , and the capacitors _CL,n are discharged to ground until the voltage Vn across the capacitors _CL,n _is equal to zero.

During the period of _t2 , only the seventh switch circuit is turned on, that is, only the tenth switch _S10 and the eleventh switch _S11 are closed at the same time, and the capacitor _CL,p is connected to the capacitor _CL,n through the third energy storage capacitor _CS3 . Charging is performed until the voltage V _p across the capacitor _CL, p is equal to the first positive voltage, and the voltage _Vn across the capacitor _CL _,n _is equal to the third positive voltage; The ratio of the variation ΔV _p of the voltage across the capacitor _CL,p is equal to k (ΔV _n /ΔV _p =k).

During the period of _t3 , only the eighth switch circuit is turned on, that is, only the twelfth switch S ₁₂ , the thirteenth switch S ₁₃ and the fourteenth switch S ₁₄ are closed at the same time, the capacitor C _L,p and the third energy storage capacitor C _S3 and capacitor C _L,n are connected in parallel, and the capacitor C _L,p charges the third energy storage capacitor C _S3 and the capacitor C _L,n until the voltages across the capacitor C _L,p and the capacitor C _L,n are equal, and equal to the second positive voltage.

During the period of t4, only the ninth switch circuit is turned _on , that is, only the _fifteenth switch S15 and the _sixteenth switch S16 are closed at the same time, and the capacitors C _L,p pass through the third energy storage capacitor C _S3 to the capacitor C _{L, n} is charged until the voltage Vn across the capacitor _CL, _n is equal to the first positive voltage, and the voltage Vp across the capacitor _CL,p _is equal to the third positive voltage; the change in the voltage across the capacitor _CL,n _is ΔVn The ratio of the change ΔV _p to the voltage across the capacitor _CL,p is equal to k (ΔV _n /ΔV _p =k).

During the period of t5, only the tenth switch circuit is turned _on , that is, only the seventeenth switch _S17 and the _eighteenth switch S18 are closed at the same time, and the power supply voltage V _DD charges the capacitor _{CL, n} until the capacitor _CL, The voltage V _n across _n is equal to the supply voltage V _DD , and the capacitors _CL,p are discharged to ground until the voltage Vp across the capacitors _CL,p _is equal to zero.

During the period of t6, only the ninth switch circuit is turned _on , that is, only the _fifteenth switch S15 and the _sixteenth switch S16 are closed at the same time, and the capacitor C _L,n is connected to the capacitor C L through the third energy storage capacitor C _S3 _{, p} is charged until the voltage V _n across the capacitor C _L,n is equal to the fourth positive voltage, and the voltage V _p across the capacitor C _L,p is equal to the fifth positive voltage; the change in the voltage across the capacitor C _L,n ΔV _n The ratio of the change ΔV _p to the voltage across the capacitor _CL,p is equal to k (ΔV _n /ΔV _p =k).

During the period of t7, only the eighth switch circuit is turned _on , that is, only the twelfth switch S ₁₂ , the thirteenth switch S ₁₃ and the fourteenth switch S ₁₄ are closed at the same time, the capacitor _CL,n and the third energy storage capacitor C _S3 and capacitor C _L,p are connected in parallel, and the capacitor C _L,n charges the third energy storage capacitor C _S3 and the capacitor C _L,p until the voltages across the capacitor C _L,p and the capacitor C _L,n are equal, and equal to the second positive voltage.

During the period of _t8 , only the seventh switch circuit is turned on, that is, only the tenth switch _S10 and the eleventh switch _S11 are closed at the same time, and the capacitor C _L,n is connected to the capacitor C _L,p through the third energy storage capacitor C _S3 Charging is performed until the voltage V _p across the capacitor _CL, p is equal to the fourth positive voltage, and the voltage _Vn across the capacitor _CL _,n _is equal to the fifth positive voltage; The ratio of the variation ΔV _p of the voltage across the capacitor _CL,p is equal to k (ΔV _n /ΔV _p =k).

Therefore, the touch driving circuit provided by the embodiment of the present application can cyclically work according to the above-mentioned eight time periods as one cycle. The voltage V _C3 across the third energy storage capacitor C _S3 will gradually build up to a stable value during this cycle of operation, and when the voltage across the third energy storage capacitor C _S3 is established to a stable value, the first positive voltage The amplitude minus the third positive voltage is equal to the voltage value V _C3 at both ends of the third energy storage capacitor C _S3 ; the amplitude of the second positive voltage is equal to the voltage value V _C3 at both ends of the third energy storage capacitor C _S3 ; the fourth The magnitude of the positive voltage minus the magnitude of the fifth positive voltage is equal to the voltage value V _C3 across the third energy storage capacitor _CS3 .

In addition, according to the law of conservation of charge, it can be obtained that when the capacitance value of the third energy storage capacitor C _S3 is much larger than the capacitance values of the capacitors CL _,p and CL _,n , when the voltage across the third energy storage capacitor C _S3 is established When stable, the second voltage value is approximately equal to V _DD /2. Specifically, when the capacitance value of the third energy storage capacitor C _S3 is greater than 50 to 100 times the capacitance values of the capacitors _CL,p and CL _,n , it can be determined that the capacitance value of the third energy storage capacitor C _S3 is much larger than Capacitance value of capacitor C _L,p and capacitor C _L,n .

Therefore, in the above-mentioned t ₄ period, the initial value of the voltage across the capacitor _CL,p is V _DD /2, the final value is recorded as V _y1 , the initial value of the voltage across the capacitor CL _,n is V _DD /2, The final value is recorded as V _y2 ; according to the law of conservation of charge, the above voltage value and capacitance value satisfy the following relationship:

_CL,p *(V _DD /2-V _y1 )= _CL,n *(V _y2 -V _DD /2); (Equation 24)

V _y2 -V _y1 =V _DD /2; (Equation 25)

C _L,p /C _L,n =k,C _L,p +C _L,n =C _L . (Equation 26)

According to Equation 24 to Equation 26, it can be obtained:

In a period T, it is equivalent to only supply the charge directly from the power supply during the period t ₁ and t ₅ , wherein the amount of charge ΔQ ₁ obtained by the capacitor _CL,p from the power source during the period t ₁ is:

In the same way, the amount of charge ΔQ ₂ obtained by the capacitor _CL,n from the power supply in the period of t ₅ is:

According to Equation 29 and Equation 30, the average current drawn from the power supply in one cycle T is:

where f is the frequency of the drive signal, and f=1/T.

According to formula 32, it can be obtained that the driving power consumption of the touch driving circuit increases with the increase of the k value, and the maximum value is 1/2*C _L *V _DD ² *f; specifically, when k=1, The drive power consumption of the touch drive circuit is 1/4*C _L *V _DD ² *f.

The touch driving circuit provided by the embodiments of the present application can only add an external capacitor (third energy storage capacitor), so as to effectively reduce the driving power consumption of the touch driving circuit, thereby saving the area and cost of the touch detection PCB, and can It is well suited for touch detection application scenarios where orthogonal coding is used and the number of positive and negative code channels is symmetrical.

When the voltage across the third energy storage capacitor C _S3 is established and stabilized, the waveforms of the driving signals corresponding to the positive-phase driving electrodes and the negative-phase driving electrodes under ideal conditions are shown in Figure 10, and the influence of driving impedance is ignored in the figure; , the capacitance value between the capacitance C _L,p and the capacitance C _L,n satisfies: C _L,p /C _L,n =k, 0<k<1. It can be seen that the driving voltages on the positive-phase driving electrodes and the negative-phase driving electrodes change synchronously in opposite trends, and the waveforms of the driving signals are all stepped; the magnitude relationship of each driving voltage in the figure satisfies: power supply voltage>fourth positive voltage> The first positive voltage>the second positive voltage>the fifth positive voltage>the third positive voltage>zero voltage, wherein the difference between the first positive voltage and the third positive voltage is equal to the difference between the fourth positive voltage and the fifth positive voltage and equal to the second positive voltage.

In addition, when k=1, C _S3 >> C _L , and the voltage across the third energy storage capacitor C _S3 is established and stable, the magnitude relationship of each driving voltage satisfies: the first positive voltage and the fourth positive voltage are approximately equal to 3/ 4V _DD , the third positive voltage and the fifth positive voltage are approximately equal to 1/4V _DD , and the difference between the first positive voltage or the fourth positive voltage and the second positive voltage is equal to the second positive voltage and the third positive voltage or The difference between the fifth positive voltages; when k>1, and the voltage across the third energy storage capacitor C _S3 is stable, the magnitude relationship of each driving voltage satisfies: power supply voltage>first positive voltage>fourth positive voltage >second positive voltage>third positive voltage>fifth positive voltage>zero voltage, wherein the difference between the first positive voltage and the third positive voltage is equal to the difference between the fourth positive voltage and the fifth positive voltage, and equal to the second positive voltage.

It should be noted that Fig. 10 is a schematic diagram of an ideal coding signal waveform. However, after the switching circuit is turned on, the voltages across the capacitors _CL,p and CL _,n often change in a non-ideal state, that is, The voltage across the capacitor _CL,p and the capacitor _CL,n will not change to the target stable value at the moment when the switch circuit is turned on. Therefore, in order to ensure the driving power consumption and output driving of the touch driving circuit provided by the embodiment of the present application The amplitude of the signal can reach the preset target value, and the conduction time of the sixth switch circuit, the seventh switch circuit, the eighth switch circuit, the ninth switch circuit and the tenth switch circuit can be set to be greater than or equal to the positive phase drive electrode, The time for the voltage across the negative phase drive electrode to build up to a stable value within the corresponding period.

An embodiment of the present application provides a touch driving chip, and the touch driving chip includes the touch driving circuit provided in the above-mentioned embodiment. It should be noted that the touch driving chip may also include other circuits, such as a control circuit, which can be used for The control switch circuit is periodically turned on in a preset manner.

Embodiments of the present application provide a touch display device, where the touch display device includes the touch drive chip provided by the above embodiments.

The touch display device may include display devices, such as liquid crystal displays, organic light emitting displays, plasma displays, and cathode ray displays.

It should be understood that the specific implementations in the embodiments of the present application are only for helping those skilled in the art to better understand the embodiments of the present application, rather than limiting the scope of the embodiments of the present application. Those skilled in the art can Various improvements and deformations are made on the above, and these improvements or deformations all fall within the protection scope of the present application.

Claims

A touch driving circuit for outputting driving signals to drive driving electrodes of a touch display device, characterized in that it comprises: a voltage generating circuit and a switching circuit; the voltage generating circuit is electrically connected with the switching circuit;

The voltage generating circuit includes at least one energy storage capacitor; the at least one energy storage capacitor is used to store the charges released by the driving electrodes and transfer the stored charges to the driving electrodes;

the switch circuit is used for controlling the voltage generating circuit to periodically output the power supply voltage, the first positive voltage, the second positive voltage, the third positive voltage and the zero voltage;

The first positive voltage, the second positive voltage and the third positive voltage are the voltages provided by the at least one energy storage capacitor, and the power supply voltage is higher than the first positive voltage, the first The positive voltage is higher than the second positive voltage, the second positive voltage is higher than the third positive voltage, and the third positive voltage is higher than the zero voltage.
The touch driving circuit according to claim 1, wherein the voltage generating circuit further comprises a power supply voltage generating circuit, a first energy storage capacitor and a second energy storage capacitor;

the power supply voltage generating circuit is used for generating the power supply voltage;

The switch circuit is further configured to control the driving electrodes to be connected to the power supply voltage generating circuit within a first period, the power supply voltage charging the driving electrodes so that the voltage across the driving electrodes is equal to the power supply voltage ; control the drive electrode to be connected to the first energy storage capacitor within the second period, and the first energy storage capacitor is used to store the charge released by the drive electrode, so that the voltage across the drive electrode is equal to the the first positive voltage; in the third period, the drive electrode is controlled to be connected in series with the first energy storage capacitor and the second energy storage capacitor, and the first energy storage capacitor and the second energy storage capacitor are inversely connected connected in series, the first energy storage capacitor and the second energy storage capacitor are used to store the charge released by the driving electrode, so that the voltage across the driving electrode is equal to the second positive voltage; within the fourth period controlling the driving electrode to be connected to the second energy storage capacitor, the second energy storage capacitor being used to store the charge released by the driving electrode, so that the voltage across the driving electrode is equal to the third positive voltage; and The driving electrode is controlled to be connected to the ground terminal GND in the fifth period, and the driving electrode discharges the ground terminal GND, so that the voltage across the driving electrode is equal to the zero voltage.
The touch drive circuit according to claim 2, wherein the switch circuit is further configured to control the drive electrode to be connected to the second energy storage capacitor within a sixth time period, and the second energy storage capacitor for transferring the stored charge to the driving electrode, so that the voltage across the driving electrode is equal to the third positive voltage; controlling the driving electrode and the first energy storage capacitor, the The second energy storage capacitors are connected in series, and the first energy storage capacitors are connected in reverse series with the second energy storage capacitors, and the first energy storage capacitors and the second energy storage capacitors are used to transfer the stored charges to the driving electrode, so that the voltage across the driving electrode is equal to the second positive voltage; and controlling the driving electrode to be connected to the first energy storage capacitor within the eighth time period, the first energy storage capacitor using In order to transfer the stored charge to the drive electrode, the voltage across the drive electrode is equal to the first positive voltage.
The touch drive circuit according to claim 3, wherein the switch circuit further comprises a first switch circuit, a second switch circuit, a third switch circuit, a fourth switch circuit and a fifth switch circuit;

During the first period of time, the first switch circuit is turned on; during the second period of time, the second switch circuit is turned on; during the third period of time, the third switch circuit is turned on ; During the fourth period, the fourth switch circuit is turned on; during the fifth period, the fifth switch circuit is turned on; during the sixth period, the fourth switch circuit is turned on During the seventh period, the third switch circuit is conducting; during the eighth period, the second switch circuit is conducting;

When any one of the switch circuits is turned on, the other four switch circuits are all turned off.
The touch driving circuit according to claim 4, wherein the first switch circuit further comprises a first switch S 1 ; the second switch circuit further comprises a second switch S 2 ; the third switch circuit further includes a third switch S3 and a fourth switch S4; the fourth switch circuit further includes a fifth switch S5 and a sixth switch S6 ; the fifth switch circuit further includes a seventh switch S7;

The first end of the first switch S1 is connected to the power supply voltage generating circuit, and the second end of the first switch S1 is connected to the driving electrode;

The first end of the second switch S2 is connected to the first end of the first energy storage capacitor, and the second end of the second switch S2 is connected to the driving electrode;

The first end of the third switch S3 is connected to the second end of the second energy storage capacitor, and the second end of the third switch S3 is connected to the driving electrode;

The first end of the fourth switch S4 is connected to the first end of the second energy storage capacitor, and the second end of the fourth switch S4 is connected to the first end of the first energy storage capacitor;

The first terminal of the fifth switch S5 is connected to the second terminal of the second energy storage capacitor, and the second terminal of the fifth switch S5 is connected to the ground terminal GND;

The first end of the sixth switch S6 is connected to the first end of the second energy storage capacitor, and the second end of the sixth switch S6 is connected to the driving electrode;

The first terminal of the seventh switch S7 is connected to the ground terminal GND, and the second terminal of the seventh switch S7 is connected to the driving electrode;

The second terminal of the first energy storage capacitor is connected to the ground terminal GND.
The touch driving circuit according to claim 5, wherein in the first period, only the first switch S 1 is closed; in the second period, only the second switch S 2 closed; in the third period, only the third switch S 3 and the fourth switch S 4 are closed; in the fourth period, only the fifth switch S 5 and the sixth switch S 6 is closed; in the fifth period, only the seventh switch S 7 is closed; in the sixth period, only the fifth switch S 5 and the sixth switch S 6 are closed; During the seventh period, only the third switch S 3 and the fourth switch S 4 are closed; during the eighth period, only the second switch S 2 is closed.
The touch driving circuit according to any one of claims 3 to 6, wherein when the voltages at both ends of the first energy storage capacitor and the second energy storage capacitor are established to a stable value, the first energy storage capacitor The magnitude of a positive voltage is equal to the voltage across the first energy storage capacitor;

The amplitude of the second positive voltage is equal to the voltage value at both ends of the first energy storage capacitor minus the voltage value at both ends of the second energy storage capacitor;

The magnitude of the third positive voltage is equal to the voltage across the second energy storage capacitor.
The touch driving circuit according to claim 1, wherein the driving electrodes further comprise positive-phase driving electrodes and negative-phase driving electrodes; the voltage generating circuit further comprises a power supply voltage generating circuit and a third energy storage capacitor;

the power supply voltage generating circuit is used for generating the power supply voltage;

The switch circuit is further configured to simultaneously control the positive phase drive electrode to be connected to the power supply voltage generating circuit, the negative phase drive electrode to be connected to the ground terminal GND, and the power supply voltage to the positive phase The driving electrode is charged, and the negative-phase driving electrode discharges the ground terminal GND, so that the voltage across the positive driving electrode is equal to the power supply voltage, and the voltage across the negative-phase driving electrode is equal to the zero voltage; The positive-phase driving electrode, the third energy storage capacitor, and the negative-phase driving electrode are controlled to be connected in series within two time periods, and the positive-phase driving electrode and the third energy storage capacitor are connected in reverse series, and the positive-phase driving electrode is connected in reverse series with the third energy storage capacitor. The driving electrode charges the negative-phase driving electrode through the third storage capacitor, so that the voltage across the positive-phase driving electrode is equal to the first positive voltage, and the voltage across the negative-phase driving electrode is equal to the first positive voltage. Three positive voltages; control the positive phase drive electrode, the third energy storage capacitor, and the negative phase drive electrode in parallel in a third period, and the positive phase drive electrode is connected to the third energy storage capacitor and the The negative-phase driving electrodes are charged, so that the voltage across the positive-phase driving electrodes is equal to the voltage across the negative-phase driving electrodes and is equal to the second positive voltage; the positive-phase driving electrodes, all the The third energy storage capacitor and the negative phase driving electrode are connected in series, and the positive phase driving electrode is connected in positive series with the third energy storage capacitor, and the positive phase driving electrode is connected to the third energy storage capacitor through the third energy storage capacitor. charging the negative-phase drive electrodes so that the voltage across the positive-phase drive electrodes is equal to the third positive voltage, and the voltage across the negative-phase drive electrodes is equal to the first positive voltage; and simultaneously controlling the The positive-phase driving electrode is connected to the ground terminal GND, the negative-phase driving electrode is connected to the power supply voltage generating circuit, the positive-phase driving electrode discharges the ground terminal GND, and the power supply voltage discharges the power supply voltage to the power supply voltage generating circuit. The negative phase drive electrodes are charged such that the voltage across the positive phase drive electrodes is equal to the zero voltage and the voltage across the negative phase drive electrodes is equal to the supply voltage.
The touch driving circuit according to claim 8, wherein the switch circuit is further configured to control the positive phase driving electrode, the third energy storage capacitor, and the negative phase driving electrode in a sixth time period connected in series, and the positive phase driving electrode is connected in positive series with the third energy storage capacitor, and the negative phase driving electrode charges the positive phase driving electrode through the third energy storage capacitor, so that the negative phase driving The voltage across the electrodes is equal to the fourth positive voltage, and the voltage across the positive-phase drive electrodes is equal to the fifth positive voltage; the positive-phase drive electrodes, the third energy storage capacitor, and the negative-phase are controlled within a seventh period of time The drive electrodes are connected in parallel, and the negative phase drive electrode charges the third energy storage capacitor and the positive phase drive electrode, so that the voltage across the positive phase drive electrode is equal to the voltage across the negative phase drive electrode and equal to the second positive voltage; and controlling the positive-phase drive electrode, the third storage capacitor, and the negative-phase drive electrode to be connected in series within an eighth period, and the positive-phase drive electrode and the third storage capacitor are connected in series. The energy capacitors are connected in reverse series, and the negative phase drive electrode charges the positive phase drive electrode through the third energy storage capacitor, so that the voltage across the positive phase drive electrode is equal to the fourth positive voltage, and the negative phase drive electrode is charged. The voltage across the phase drive electrodes is equal to the fifth positive voltage;

The fourth positive voltage is higher than the fifth positive voltage and lower than the power supply voltage.
The touch driving circuit according to claim 9, wherein the switch circuit further comprises a sixth switch circuit, a seventh switch circuit, an eighth switch circuit, a ninth switch circuit and a tenth switch circuit;

During the first period of time, the sixth switch circuit is turned on; during the second period of time, the seventh switch circuit is turned on; during the third period of time, the eighth switch circuit is turned on ; in the fourth period, the ninth switch circuit is turned on; in the fifth period, the tenth switch circuit is turned on; in the sixth period, the ninth switch circuit is turned on During the seventh time period, the eighth switch circuit is turned on; during the eighth time period, the seventh switch circuit is turned on.

When any one of the switch circuits is turned on, the other four switch circuits are all turned off.
The touch driving circuit according to claim 10, wherein the sixth switch circuit further comprises an eighth switch S8 and a ninth switch S9 ; the seventh switch circuit further comprises a tenth switch S10 and a ninth switch S9; the eleventh switch S 11 ; the eighth switch circuit further includes a twelfth switch S 12 , a thirteenth switch S 13 and a fourteenth switch S 14 ; the ninth switch circuit further includes a fifteenth switch S 15 and a sixteenth switch S 16 ; the tenth switch circuit further includes a seventeenth switch S 17 and an eighteenth switch S 18 ;

The first end of the eighth switch S8 is connected to the power supply voltage generating circuit, and the second end of the eighth switch S8 is connected to the positive-phase driving electrode;

The first terminal of the ninth switch S9 is connected to the ground terminal GND, and the second terminal of the ninth switch S9 is connected to the negative-phase driving electrode;

The first end of the tenth switch S10 is connected to the first end of the third energy storage capacitor, and the second end of the tenth switch S10 is connected to the positive-phase driving electrode;

The first end of the eleventh switch S11 is connected to the second end of the third energy storage capacitor, and the second end of the eleventh switch S11 is connected to the negative-phase driving electrode;

The first end of the twelfth switch S12 is connected to the first end of the third energy storage capacitor, and the second end of the twelfth switch S12 is connected to the positive-phase driving electrode;

The first end of the thirteenth switch S13 is connected to the first end of the third energy storage capacitor, and the second end of the thirteenth switch S13 is connected to the negative phase driving electrode;

The first terminal of the fourteenth switch S14 is connected to the second terminal of the third energy storage capacitor, and the second terminal of the fourteenth switch S14 is connected to the ground terminal GND;

The first end of the fifteenth switch S15 is connected to the second end of the third energy storage capacitor, and the second end of the fifteenth switch S15 is connected to the positive-phase driving electrode;

The first end of the sixteenth switch S16 is connected to the first end of the third energy storage capacitor, and the second end of the sixteenth switch S16 is connected to the negative-phase driving electrode;

The first terminal of the seventeenth switch S17 is connected to the ground terminal GND, and the second terminal of the seventeenth switch S17 is connected to the positive-phase driving electrode;

The first terminal of the eighteenth switch S18 is connected to the power supply voltage generating circuit, and the second terminal of the eighteenth switch S18 is connected to the negative-phase driving electrode.
The touch driving circuit according to claim 11, wherein in the first period, only the eighth switch S 8 and the ninth switch S 9 are closed at the same time; in the second period , only the tenth switch S 10 and the eleventh switch S 11 are closed; in the third period, only the twelfth switch S 12 , the thirteenth switch S 13 and the The fourteenth switch S 14 is closed; in the fourth period, only the fifteenth switch S 15 and the sixteenth switch S 16 are closed; in the fifth period, only the seventeenth switch S17 and the eighteenth switch S18 are closed; in the sixth period, only the fifteenth switch S15 and the sixteenth switch S16 are closed; in the seventh period, only The twelfth switch S 12 , the thirteenth switch S 13 and the fourteenth switch S 14 are closed; in the eighth period, only the tenth switch S 10 and the eleventh switch S 10 are closed. Switch S11 is closed.
The touch driving circuit according to any one of claims 9 to 12, wherein when the voltage across the third energy storage capacitor is established to a stable value, the amplitude of the first positive voltage minus the The amplitude of the third positive voltage is equal to the voltage value across the third energy storage capacitor;

The magnitude of the second positive voltage is equal to the voltage across the third energy storage capacitor;

The magnitude of the fourth positive voltage minus the magnitude of the fifth positive voltage is equal to the voltage across the third energy storage capacitor.
The touch driving circuit according to claim 13, wherein when the equivalent capacitance value of the positive phase driving electrodes is equal to the equivalent capacitance value of the negative phase driving electrodes, the fourth positive voltage is equal to the the first positive voltage, the fifth positive voltage is equal to the third positive voltage.
A touch driving chip, comprising the touch driving circuit according to any one of claims 1 to 14.
A touch display device, comprising the touch driving chip of claim 15 .