Driving circuit, touch driving device and electronic equipment

Abstract

Embodiments of the present application provide a driving circuit, a touch driving device and an electronic device. The driving circuit is applied to a touch screen including a driving electrode. The driving circuit includes a first node, a second node, a ground node, a switch circuit and an energy storage capacitor. The first node is configured to provide a first positive voltage. The second node is configured to provide a first negative voltage. The energy storage capacitor includes a first end and a second end. The switch circuit is configured to control the first end of the energy storage capacitor to selectively access the ground node or the driving electrode, and control the second end of the energy storage capacitor to selectively access the ground node or the driving electrode. In one time period, the first end of the energy storage capacitor receives charges released by the driving electrode. In another time period, the second end of the energy storage capacitor charges the driving electrode by using the stored charges. The driving circuit has a lower driving power consumption.

Description

Technical Field

[0001] This application relates to the field of touch technology, and more specifically, to driving circuits, touch driving devices, and electronic devices. Background Technology

[0002] Touchscreens are widely used in various electronic devices. A touchscreen consists of driving electrodes and sensing electrodes. By driving the driving electrodes and receiving signals sensed by the sensing electrodes, the change in capacitance of the sensing capacitor can be determined, thereby identifying the user's operation. When driving the driving electrodes, they receive charge from the power supply, charging them to the target voltage. This charging process consumes energy from the power supply and generates power consumption. The power consumption of the driving electrodes is a major power consumption issue for touchscreens. Reducing the power consumption of the driving electrodes is a pressing problem that needs to be solved. Summary of the Invention

[0003] In view of this, embodiments of this application provide a driving circuit, a touch driving device, and an electronic device to reduce driving power consumption.

[0004] In a first aspect, embodiments of this application provide a driving circuit applied to a touchscreen including driving electrodes. The driving circuit includes: a first node for providing a first positive voltage; a second node for providing a first negative voltage; a ground node; an energy storage capacitor including a first terminal and a second terminal; and a switching circuit for controlling the first terminal of the energy storage capacitor to selectively connect to either the ground node or the driving electrode, and controlling the second terminal of the energy storage capacitor to selectively connect to either the ground node or the driving electrode.

[0005] Optionally, the switching circuit is configured to control the driving electrode to connect to the first node during a first time period, wherein the first node charges the driving electrode, such that the voltage of the driving electrode is equal to the first positive voltage; control the driving electrode to connect to the first terminal of the energy storage capacitor during a second time period, wherein the energy storage capacitor stores the charge released by the driving electrode, such that the voltage of the driving electrode is equal to the second positive voltage; control the driving electrode to connect to the ground node during a third time period, such that the voltage of the driving electrode is equal to zero voltage; control the driving electrode to connect to the second terminal of the energy storage capacitor during a fourth time period, wherein the energy storage capacitor transfers charge to the driving electrode, such that the voltage of the driving electrode is equal to the second negative voltage; and control the driving electrode to connect to the second node during a fifth time period, wherein the second node charges the driving electrode, such that the voltage of the driving electrode is equal to the first negative voltage. Wherein, the second positive voltage is lower than the first positive voltage and higher than the zero voltage; the second negative voltage is higher than the first negative voltage and lower than the zero voltage.

[0006] Optionally, during the second time period, the switching circuit controls the second terminal of the energy storage capacitor to be connected to the ground node; during the fourth time period, the switching circuit controls the first terminal of the energy storage capacitor to be connected to the ground node.

[0007] Optionally, the switching circuit is further configured to: control the driving electrode to connect to the second terminal of the energy storage capacitor during a sixth time period, the energy storage capacitor storing the charge released by the driving electrode, such that the voltage of the driving electrode is equal to a third negative voltage; control the driving electrode to connect to the ground node during a seventh time period, such that the voltage of the driving electrode is equal to zero voltage; and control the driving electrode to connect to the first terminal of the energy storage capacitor during an eighth time period, such that the energy storage capacitor transfers charge to the driving electrode, such that the voltage of the driving electrode is equal to a third positive voltage. Specifically, during the sixth time period, the switching circuit controls the first terminal of the energy storage capacitor to connect to the ground node; and during the eighth time period, the switching circuit controls the second terminal of the energy storage capacitor to connect to the ground node.

[0008] Optionally, the switching circuit includes: an output node configured to connect to the driving electrode; a first switch disposed between the first node and the output node; a second switch disposed between the second node and the output node; a third switch disposed between the ground node and the output node; a fourth switch disposed between the ground node and a second terminal of the energy storage capacitor; a fifth switch disposed between the ground node and a first terminal of the energy storage capacitor; a sixth switch disposed between the ground node and a second terminal of the energy storage capacitor; and a seventh switch disposed between the ground node and a first terminal of the energy storage capacitor.

[0009] Optionally, during the first time period, the first switch and the fourth switch are on, and the second switch, the third switch, the fifth switch, the sixth switch, and the seventh switch are off; during the second time period, the fourth switch and the seventh switch are on, and the first switch, the second switch, the third switch, the fifth switch, and the sixth switch are off; during the third time period, the third switch and the fifth switch are on, and the first switch, the second switch, the fourth switch, the sixth switch, and the seventh switch are off; during the fourth time period, the fifth switch and the sixth switch are on, and the first switch, the second switch, the third switch, the fourth switch, and the seventh switch are off. During the fifth time period, the second switch and the fifth switch are on, and the first switch, the third switch, the fourth switch, the sixth switch, and the seventh switch are off; during the sixth time period, the fifth switch and the sixth switch are on, and the first switch, the second switch, the third switch, the fourth switch, and the seventh switch are off; during the seventh time period, the third switch and the fourth switch are on, and the first switch, the second switch, the fifth switch, the sixth switch, and the seventh switch are off; during the eighth time period, the fourth switch and the seventh switch are on, and the first switch, the second switch, the third switch, the fifth switch, and the sixth switch are off.

[0010] Optionally, during the second time period, the switching circuit controls the second terminal of the energy storage capacitor to be connected to the ground node; during the fourth time period, the switching circuit controls the first terminal of the energy storage capacitor to be connected to the second node.

[0011] Optionally, the switching circuit is further configured to: control the driving electrode to connect to the second terminal of the energy storage capacitor during a sixth time period, the energy storage capacitor storing the charge released by the driving electrode, such that the voltage of the driving electrode is equal to a third negative voltage; control the driving electrode to connect to the ground node during a seventh time period, such that the voltage of the driving electrode is equal to zero voltage; and control the driving electrode to connect to the first terminal of the energy storage capacitor during an eighth time period, such that the energy storage capacitor transfers charge to the driving electrode, such that the voltage of the driving electrode is equal to a third positive voltage. Specifically, during the sixth time period, the switching circuit controls the first terminal of the energy storage capacitor to connect to the ground node; and during the eighth time period, the switching circuit controls the second terminal of the energy storage capacitor to connect to the first node.

[0012] Optionally, the switching circuit includes: an output node configured to connect to the driving electrode; a first switch disposed between the first node and the output node; a second switch disposed between the second node and the output node; a third switch disposed between the ground node and the output node; a fourth switch disposed between the ground node and a second terminal of the energy storage capacitor; a fifth switch disposed between the ground node and a first terminal of the energy storage capacitor; a sixth switch disposed between the ground node and a second terminal of the energy storage capacitor; a seventh switch disposed between the ground node and a first terminal of the energy storage capacitor; an eighth switch disposed between the second terminal of the energy storage capacitor and the first node; and a ninth switch disposed between the first terminal of the energy storage capacitor and the second node.

[0013] Optionally, during the first time period, the first switch and the fourth switch are on, and the second switch, the third switch, the fifth switch, the sixth switch, the seventh switch, the eighth switch, and the ninth switch are off; during the second time period, the fourth switch and the seventh switch are on, and the first switch, the second switch, the third switch, the fifth switch, the sixth switch, the eighth switch, and the ninth switch are off; during the third time period, the third switch and the ninth switch are on, and the first switch, the second switch, the fourth switch, the fifth switch, the sixth switch, the seventh switch, and the eighth switch are off; during the fourth time period, the sixth switch and the ninth switch are on, and the first switch, the second switch, the third switch, the fourth switch, the fifth switch, the seventh switch, and the eighth switch are off. During the fifth time period, the second switch and the fifth switch are on, and the first switch, the third switch, the fourth switch, the sixth switch, the seventh switch, the eighth switch, and the ninth switch are off; during the sixth time period, the fifth switch and the sixth switch are on, and the first switch, the second switch, the third switch, the fourth switch, the seventh switch, the eighth switch, and the ninth switch are off; during the seventh time period, the third switch and the eighth switch are on, and the first switch, the second switch, the third switch, the fourth switch, the fifth switch, the sixth switch, the seventh switch, and the ninth switch are off; during the eighth time period, the seventh switch and the eighth switch are on, and the first switch, the second switch, the third switch, the fourth switch, the fifth switch, the sixth switch, and the ninth switch are off.

[0014] Optionally, the capacitance value of the energy storage capacitor is greater than the capacitance value of the equivalent capacitance of the driving electrode to ground.

[0015] Secondly, embodiments of this application provide a touch driving device, including the driving circuit provided in the first aspect or any optional method of the first aspect.

[0016] Optionally, the switching circuit of the driving circuit is formed on the die, wherein the energy storage capacitor and the die are encapsulated together, or the energy storage capacitor is disposed outside the package of the die.

[0017] Thirdly, embodiments of this application provide a touch driving device, including a touch screen and a touch chip provided by the second aspect or an optional approach of the second aspect.

[0018] During one period, the energy storage capacitor stores the charge released by the driving electrode; during another period, the energy storage capacitor stores the charge supplied to the driving electrode, thus charging the driving electrode. Therefore, the above-described driving circuit reduces power consumption and lowers driving power consumption. It is understood that the above-described touch driving device and electronic device both utilize the above-described driving circuit; therefore, the beneficial effects they achieve can be referenced from the beneficial effects of the driving circuit, and will not be repeated here. Attached Figure Description

[0019] One or more embodiments are illustrated by way of example with corresponding images in the accompanying drawings, which are not intended to limit the embodiments. When the following description refers to the accompanying drawings, the same numbers in different drawings represent the same elements. Unless otherwise stated, the figures in the drawings are not intended to be scaled.

[0020] Figure 1 A schematic block diagram of an electronic device provided in an embodiment of this application.

[0021] Figure 2 This is a schematic diagram of a touch driving device provided in an embodiment of this application.

[0022] Figure 3 This is a schematic diagram of a driving circuit for a related technology.

[0023] Figure 4 for Figure 3 The diagram shows the waveform of the drive signal provided by the drive circuit.

[0024] Figure 5 This is a schematic diagram of another driving circuit in the related technology.

[0025] Figure 6 for Figure 5 The diagram shows the waveform of the drive signal provided by the drive circuit.

[0026] Figure 7 This is a schematic block diagram of the driving circuit provided in the embodiments of this application.

[0027] Figure 8 This is a circuit diagram of a driving circuit provided in an embodiment of this application.

[0028] Figure 9 for Figure 8 The diagram shows the waveform of the drive signal provided by the drive circuit.

[0029] Figures 10A to 10I for Figure 8 The diagram shows the principle of the driving process of the driving circuit.

[0030] Figure 11 for Figure 8 The timing diagram of the driving circuit is shown.

[0031] Figure 12 yes Figure 8 The diagram shows a waveform of a driving signal provided by the driving circuit.

[0032] Figure 13 yes Figure 8 The diagram shows a waveform of another driving signal provided by the driving circuit.

[0033] Figure 14 A circuit diagram of another driving circuit provided in an embodiment of this application.

[0034] Figure 15 for Figure 12 The timing diagram of the driving circuit is shown.

[0035] Figure 16 This is a schematic diagram of the packaging of a touch driving device provided in an embodiment of this application.

[0036] Figure 17 for Figure 16 The diagram shows a schematic block diagram of a touch-driving device.

[0037] Figure 18 This is a schematic diagram of the packaging of another touch driving device provided in an embodiment of this application. Detailed Implementation

[0038] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this application, but not all embodiments.

[0039] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” as used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0040] Furthermore, terms such as "first" and "second" are used only to distinguish similar objects and should not be construed as indicating or implying relative importance, or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature.

[0041] This application provides a driving circuit, a touch driving device, and an electronic device. The driving circuit can be applied to a touch screen including driving electrodes. The driving circuit drives the driving electrodes to achieve touch detection functionality. The driving circuit includes a switching circuit and an energy storage capacitor. The switching circuit controls the first terminal of the energy storage capacitor to be connected to either a ground node or a driving electrode, and controls the second terminal of the energy storage capacitor to be connected to either a ground node or a driving electrode. During one time period, the first terminal of the energy storage capacitor is connected to the driving electrode and stores the charge released by the driving electrode. During another time period, the second terminal of the energy storage capacitor is connected to the driving electrode, and the charge stored in the energy storage capacitor is transferred to the driving electrode to charge it. Therefore, the time spent charging the driving electrode using a power supply is reduced, power consumption is reduced, the driving power consumption of the driving electrode is lowered, and thus the power consumption of the touch screen is reduced.

[0042] Figure 1 This is a block diagram of an exemplary electronic device. Figure 1 As shown, the electronic device includes a touchscreen 20 and a touch driver 10. By way of example and not limitation, the electronic device can be a terminal device, mobile phone, tablet computer, laptop computer, desktop computer, gaming device, in-vehicle electronic device, or wearable smart device, etc., as well as other electronic devices such as electronic databases, automobiles, and automated teller machines (ATMs). The wearable smart device includes fully functional, large-sized devices that can achieve complete or partial functionality without relying on a smartphone, such as smartwatches or smart glasses, as well as devices focused on a specific type of application function that require use with other devices such as smartphones, such as various smart bracelets and smart jewelry for vital sign monitoring.

[0043] Electronic devices may also include displays. Displays include, but are not limited to, liquid crystal (LCD) displays, organic light-emitting diode (OLED) displays, plasma display panels (PDP) displays, and cathode ray tube (CRT) displays.

[0044] The touch screen 20 includes first electrodes 211-21 extending along a first direction. m and the second electrode 221-22 extending along the second direction n The first direction is, for example, the longitudinal direction, and the second direction is, for example, the transverse direction. First electrode 211-21m Having a self-capacitance Cd to ground, the second electrode 221-22 n It has a self-capacitance Cs to ground. First electrode 211-21 m Second electrode 221-22 n There is a mutual capacitance Cm between them. Figure 1 With the first electrode 21 m Self-capacitance Cd, second electrode 22 n Self-capacitance Cs, first electrode 21 m-1 The mutual capacitance Cm between the second electrode 222 is used as an example. When a conductor, such as a human hand, touches the touchscreen, the values ​​of its self-capacitance and mutual capacitance change. The touchscreen 20 can use self-capacitance detection and mutual capacitance detection to achieve touch detection.

[0045] During self-capacitance detection, the touch chip 10 directs the signal to the first electrode 21. i (1≤i≤m) provides the drive signal and detects the first electrode 21. i The change in self-capacitance Cd (i.e., detection capacitance), first electrode 21 i It serves as both a driving electrode and a detection electrode. Furthermore, the touch chip 10 connects to the second electrode 22. j (1≤j≤n) provides the drive signal and detects the second electrode 22. j The change in self-capacitance Cs (i.e., detection capacitance), second electrode 22 j It serves as both a driving electrode and a detection electrode. According to the first electrode 21... i The self-capacitance Cd and the second electrode 22 j The change in self-capacitance Cs is used to identify the user's touch operation.

[0046] During mutual capacitance detection, the first electrode 21 i Second electrode 22 j The first electrode 21 serves as both the driving electrode and the detection electrode. i Second electrode 22 j The mutual capacitance Cm is used as the detection capacitance. The touch chip 10 directs the first electrode 211-21... m Provide drive signals from the second electrode 221-22 n It receives a detection signal to detect changes in mutual capacitance Cm. It then identifies the user's touch operation based on changes in mutual capacitance C1.

[0047] Therefore, during self-capacitance detection, the first electrode 21 i Second electrode 22 j Both are both driving electrodes and detection electrodes; during mutual capacitance detection, the first electrode 21 i The second electrode 22 is the driving electrode. jThis is the detection electrode. The following explanation uses mutual capacitance detection as an example.

[0048] Figure 2 This is a schematic block diagram of a touch driving device according to an embodiment of this application. The touch chip 10 includes a driving circuit 100 and a detection circuit 200. The driving circuit 100 provides a driving signal to the driving electrode TX through pin O1. The detection circuit 200 receives a detection signal from the detection electrode RX through pin O2, amplifies the detection signal, and converts the amplified signal into a digital signal. The driving electrode TX is, for example, the first electrode 211-21. m The detection electrode RX is, for example, the second electrode 221-22. n .

[0049] The detection circuit 200 is, for example, a trans-impedance amplifier-based circuit. The detection circuit 200 includes an operational amplifier 201 and an analog-to-digital converter 202. The non-inverting input of the operational amplifier 201 is connected to a common-mode voltage Vcm, and the inverting input is connected to a detection electrode. A feedback capacitor Cf is provided between the inverting input and the output. The signal gain of the detection circuit 200 is Cm / Cf. When a finger touches the touchscreen 20, the mutual capacitance Cm decreases, and the output of the operational amplifier 201 drops.

[0050] The process by which the driving circuit 100 provides a driving signal to the driving electrode TX of the touch screen 200 is also known as coding. Providing the driving signal to the driving electrode TX includes charging and discharging the driving electrode TX to bring it to a target voltage. The detection circuit 20 can detect the change in capacitance value of the mutual capacitance Cm at different coordinates of the touch screen 200. During the driving process, the driving circuit 100 causes the voltage of the driving electrode to successively reach a first positive voltage VCC and a first negative voltage VSS. The driving process consumes energy (charge) from the power source (e.g., a battery) and generates power consumption in the driving circuit 100 and the driving electrode. The amount of charge required to bring the driving electrode TX to the first positive voltage VCC or the first negative voltage VSS depends on the size of the equivalent capacitance Cd (also called the load capacitance) of the driving electrode TX to ground. Figure 1 and Figure 2 The driving circuit 100 can drive the first electrodes 211-21 one by one. m Or group-drive the first electrode 211-21 m The first electrode in each group is driven simultaneously, or the first electrodes 211-21 are driven simultaneously. m .

[0051] Touchscreen 200 is typically used in conjunction with a display screen. Touchscreen 200 is located above the display screen. The display screen is, for example, an OLED display. The cathode layer of the OLED display is grounded. The equivalent capacitance Cd of the driving electrode TX to ground is the capacitance between the driving electrode TX and the cathode layer of the OLED display. As displays evolve from rigid screens to flexible screens and then to foldable screens, the thin film encapsulation (TFE) layer of the display becomes thinner, the distance between the driving electrode TX and the cathode layer of the OLED display becomes smaller, and the capacitance between the driving electrode TX and the cathode layer of the OLED display becomes larger. This results in a larger amount of charge required to bring the driving electrode TX to the first positive voltage VCC or the first negative voltage VSS, and a larger power consumption required to drive the driving electrode TX.

[0052] Figure 3 This is a schematic diagram of a driving circuit based on related technologies. Figure 4 yes Figure 3 The diagram shows the waveform of the drive signal provided by the drive circuit. This drive circuit includes switches K01 and K02. Switch K01 is located between the terminal providing the first positive voltage VCC and the drive electrode TX. Switch K02 is located between the terminal providing the first negative voltage VSS and the drive electrode TX. Capacitor Cd is the equivalent capacitance of the drive electrode TX to ground. Figure 3 and Figure 4 As shown, at time t01, switch K01 is on and switch K02 is off, and the drive circuit 100 charges the drive electrode TX to the first positive voltage VCC through switch K01; at time t02, switch K01 is off and switch K02 is on, and the drive circuit 100 charges the drive electrode TX to the first negative voltage VSS through switch K02. Figure 3 The driving circuit requires the power supply to provide charge and consume power energy during the process of driving the electrode TX from the first negative voltage VSS to the first positive voltage VCC and from the first positive voltage VCC to the first negative voltage VSS.

[0053] Figure 5 This is a schematic diagram of another driving circuit in the related technology. Figure 6 yes Figure 5 The diagram shows the waveform of the drive signal provided by the drive circuit. This drive circuit includes switches K01, K02, and K03. Switch K01 is located between the terminal providing the first positive voltage VCC and the drive electrode TX. Switch K02 is located between the terminal providing the first negative voltage VSS and the drive electrode TX. Switch K03 is located between the ground node GND and the drive electrode TX. Figure 5 and Figure 6As shown, at time t03, switch K03 is turned on, and switches K01 and K02 are turned off. The driving electrode TX is connected to the ground node GND, and the negative charge on the driving electrode TX is released to the ground node GND. The driving electrode TX rises from the first negative voltage VSS to 0V. At time t04, switch K01 is turned on, and switches K02 and K03 are turned off. The first positive voltage VCC provides positive charge to the driving electrode TX, and the driving electrode TX is charged from 0V to the first positive voltage VCC. At time t05, switch K03 is turned on, and switches K01 and K02 are turned off. The positive charge on the driving electrode TX is released to the ground node GND through switch K03, and the voltage of the driving electrode TX drops to 0V. At time t06, switch K02 is turned on, and switches K01 and K03 are turned off. The first negative voltage VSS provides negative charge to the driving electrode TX, and the voltage of the driving electrode TX drops to the first negative voltage VSS. Figure 5 In the driving circuit, during the process of the driving electrode TX changing from the first positive voltage VCC to 0V and during the process of the driving electrode TX changing from the first negative voltage VSS to 0V, the charge on the driving electrode TX is discharged to ground, without consuming power. However, Figure 5 The fundamental component of the driving signal of the driving circuit shown is lower than... Figure 3 The fundamental component of the driving signal of the driving circuit shown will cause the demodulated signal to decrease.

[0054] This application provides a driving circuit for a touch screen to reduce power consumption during the driving process. Figure 7 This is a schematic diagram of a driving circuit provided in an embodiment of this application. For example... Figure 7As shown, the driving circuit 100 includes: a first node T1, a second node T2, a ground node GND, a switching circuit 110, and an energy storage capacitor Ce. The first node T1 provides a first positive voltage VCC. The second node T2 provides a first negative voltage VSS. The energy storage capacitor Ce includes a first terminal N1 and a second terminal N2. The switching circuit 110 has an output node OUT, which is configured to connect to the driving electrode TX. The switching circuit 110 controls the connection or disconnection of the driving electrode and the energy storage capacitor Ce. The switching circuit 110 controls the first terminal N1 of the energy storage capacitor Ce to be connected to either the ground node GND or the driving electrode, and the switching circuit 110 controls the second terminal N2 of the energy storage capacitor Ce to be connected to either the ground node GND or the driving electrode. Specifically, the switching circuit 110 controls the drive electrode to connect to the first terminal of the energy storage capacitor Ce, and controls the second terminal of the energy storage capacitor Ce to connect to the ground node GND; the switching circuit 110 controls the drive electrode to connect to the second terminal of the energy storage capacitor Ce, and controls the first terminal of the energy storage capacitor Ce to connect to either the ground node GND or the second node T2; the energy storage capacitor Ce is greater than the equivalent capacitance Cd of the drive electrode TX to ground. For example, the capacitance value of the energy storage capacitor Ce is greater than or equal to 50 times the capacitance value of the equivalent capacitance Cd of the drive electrode TX to ground. Through this connection method of the drive circuit, the energy storage capacitor recovers and releases the charge of the drive electrode, reducing power consumption during the drive process.

[0055] The timing sequence of the driving circuit in this application can include five time periods: a first time period, a second time period, a third time period, a fourth time period, and a fifth time period. During the first time period, the switching circuit 110 controls the driving electrode TX to connect to the first node T1, and the first node T1 charges the driving electrode TX, making the voltage of the driving electrode TX equal to the first positive voltage VCC. During the second time period, the switching circuit 110 controls the driving electrode TX to connect to the first terminal N1 of the energy storage capacitor Ce, and the energy storage capacitor Ce stores the charge released by the driving electrode TX, making the voltage of the driving electrode TX equal to the second positive voltage. During the third time period, the switching circuit 110 controls the driving electrode TX to connect to the ground node GND, making the voltage of the driving electrode TX equal to zero voltage. During the fourth time period, the switching circuit 110 controls the driving electrode TX to connect to the second terminal N2 of the energy storage capacitor Ce, and the energy storage capacitor Ce transfers charge to the driving electrode TX, making the voltage of the driving electrode TX equal to the second negative voltage. During the fifth time period, the switching circuit 110 controls the driving electrode TX to connect to the second node T2, and the second node T2 charges the driving electrode TX, making the voltage of the driving electrode TX equal to the first negative voltage VSS. The second positive voltage is lower than the first positive voltage VCC and higher than zero voltage; the second negative voltage is higher than the first negative voltage VSS and lower than zero voltage.

[0056] In the second time period, the energy storage capacitor Ce stores the charge released when the driving electrode TX discharges. In the fourth time period, the energy storage capacitor Ce transfers the stored charge to the driving electrode TX. That is, in the fourth stage, the driving circuit uses the charge stored in the energy storage capacitor Ce to charge the driving electrode TX. The driving circuit provided in this application saves power supply charge, reduces power consumption, and increases the operating time of electronic devices.

[0057] Furthermore, based on the above five time periods, the timing of the driving circuit of this application may also include a sixth stage, a seventh stage, and an eighth stage. During the sixth time period, the switching circuit 110 controls the driving electrode TX to connect to the second terminal N2 of the energy storage capacitor Ce. The energy storage capacitor Ce stores the charge released by the driving electrode TX, making the voltage of the driving electrode TX equal to the third negative voltage. During the seventh time period, the switching circuit 110 controls the driving electrode TX to connect to the ground node GND, making the voltage of the driving electrode TX equal to zero voltage. During the eighth time period, the switching circuit 110 controls the driving electrode TX to connect to the first terminal N1 of the energy storage capacitor Ce. The energy storage capacitor Ce transfers charge to the driving electrode TX, making the voltage of the driving electrode TX equal to the third positive voltage.

[0058] In the sixth time period, the energy storage capacitor Ce stores the charge released when the driving electrode TX discharges. In the eighth time period, the energy storage capacitor Ce transfers the stored charge to the driving electrode TX. That is, the charging process of the driving electrode TX in the eighth stage uses the charge stored in the energy storage capacitor Ce, which saves power supply charge, reduces power consumption, and increases the operating time of electronic devices.

[0059] Figure 8 This is a schematic diagram of a driving circuit provided in an embodiment of this application. For example... Figure 8 As shown, the driving circuit 100 includes: a first node T1, a second node T2, a ground node GND, a switching circuit, and an energy storage capacitor Ce. The switching circuit includes: an output node OUT, a first switch K1, a second switch K2, a third switch K3, a fourth switch K4, a fifth switch K5, a sixth switch K6, and a seventh switch K7. The energy storage capacitor Ce is a discrete capacitor, such as a ceramic capacitor.

[0060] The first node T1 is used to provide a first positive voltage VCC. The first node T1 is connected, for example, to a first voltage generation circuit that generates the first positive voltage VCC. This first voltage generation circuit is connected to a power supply and generates the first positive voltage VCC based on the power supply voltage. The first voltage generation circuit is, for example, a DC-DC circuit or a low dropout regulator. The second node T2 is used to provide a first negative voltage VSS. The second node T2 is connected, for example, to a second voltage generation circuit that generates the first negative voltage VSS. The second voltage generation circuit is connected to either a power supply or the first voltage generation circuit and generates the first negative voltage VSS based on the power supply voltage or the first positive voltage VCC. The second voltage generation circuit is, for example, a negative charge pump. The absolute value of the first negative voltage VSS is, for example, equal to the absolute value of the first positive voltage VCC. The output node OUT is connected to the drive electrode TX and is used to output a drive signal, i.e., to charge and discharge the drive electrode TX.

[0061] The first switch K1 is connected at one end to the first node T1 and at the other end to the output node OUT. The first switch K1 is used to charge the drive electrode TX to the first positive voltage VCC. The second switch K2 is connected at one end to the second node T2 and at the other end to the output node OUT. The second switch K2 is used to charge the drive electrode TX to the first negative voltage VSS. The third switch K3 is connected at one end to the ground node GND and at the other end to the output node OUT. The third switch K3 is used to discharge the drive electrode TX to 0V.

[0062] The energy storage capacitor Ce includes a first terminal N1 and a second terminal N2. One end of the fourth switch K4 is connected to the ground node GND, and the other end is connected to the second terminal N2 of the energy storage capacitor Ce. When the fourth switch K4 is on, the second terminal N2 of the energy storage capacitor Ce is set to 0V. One end of the fifth switch K5 is connected to the ground node GND, and the other end is connected to the first terminal N1 of the energy storage capacitor Ce. When the fifth switch K5 is on, the first terminal N1 of the energy storage capacitor Ce is set to 0V. One end of the sixth switch K6 is connected to the second terminal N2 of the energy storage capacitor Ce, and the other end is connected to the output node OUT. One end of the seventh switch K7 is connected to the first terminal N1 of the energy storage capacitor Ce, and the other end is connected to the output node OUT.

[0063] The energy storage capacitor Ce stores the charge released by the driving electrode TX during one time period and releases the charge to the driving electrode TX during another time period. The sixth switch K6 and the seventh switch K7 are the charge transfer paths between the energy storage capacitor Ce and the driving electrode TX.

[0064] The first switch K1, the second switch K2, the third switch K3, the fourth switch K4, the fifth switch K5, the sixth switch K6, and the seventh switch K7 each include one or more transistors. For example, the first switch K1 to the seventh switch K7 can be implemented by a PMOS or an NMOS, or the first switch K1 to the seventh switch K7 can be implemented by a combination of PMOS and NMOS. This application does not limit the way the first switch K1 to the seventh switch K7 are implemented.

[0065] The first switch K1, the second switch K2, the third switch K3, the fourth switch K4, the fifth switch K5, the sixth switch K6, and the seventh switch K7 are turned on and off under the control of the corresponding control signals.

[0066] Figure 9 yes Figure 8 The diagram shows the waveform of the drive signal provided by the drive circuit. Specifically, Figure 9 It is the waveform after the drive signal has stabilized. For example... Figure 9 As shown, one cycle T of the driving process of the driving circuit 100 to the driving electrode TX includes 8 time periods. The switching circuit controls the first terminal of the energy storage capacitor to connect to either the ground node or the driving electrode at different time periods, and also controls the second terminal of the energy storage capacitor to connect to either the ground node or the driving electrode at different time periods. For example, in the sixth time period of a cycle T, the switching circuit controls the first terminal of the energy storage capacitor to connect to the ground node; in the second time period of a cycle T, the switching circuit controls the first terminal of the energy storage capacitor to connect to the driving electrode; in the eighth time period of a cycle T, the switching circuit controls the second terminal of the energy storage capacitor to connect to the ground node; and in the fourth time period of a cycle T, the switching circuit controls the second terminal of the energy storage capacitor to connect to the driving electrode. Figures 10A to 10I for Figure 8 The diagram shows the driving principle of the driving circuit. Figure 11 yes Figure 8 The timing diagram of the drive circuit is shown. When the signal corresponding to the switch is high, it indicates that the switch is on; when the signal corresponding to the switch is low, it indicates that the switch is off. The following section will discuss this in conjunction with... Figures 8 to 11 Describe the driving process of the driving circuit 100 to the driving electrode TX.

[0067] First period The first switch K1 and the fourth switch K4 are on, while the second switch K2, the third switch K3, the fifth switch K5, the sixth switch K6, and the seventh switch K7 are off. For example... Figure 10A As shown, the first node T1 provides positive charge to the driving electrode TX through the first switch K1, charging the driving electrode TX to the first positive voltage VCC. The second terminal N2 of the energy storage capacitor Ce is grounded. The first terminal N1 of the energy storage capacitor Ce is in the first time period. It has a voltage V0. First period At the end, the voltage at the drive electrode TX is the first positive voltage VCC. During the first time period... The driving electrode TX obtains a positive charge from the first node T1, so the driving process consumes the power supply's energy.

[0068] Second period The seventh switch K7 and the fourth switch K4 are on, while the first switch K1, the second switch K2, the third switch K3, the fifth switch K5, and the sixth switch K6 are off. For example... Figure 10B As shown, the fourth switch K4 is turned on, and the second terminal N2 of the energy storage capacitor Ce is grounded. The seventh switch K7 is turned on, connecting the first terminal N1 of the energy storage capacitor Ce to the driving electrode TX. The voltage VCC of the driving electrode TX is higher than the voltage V0 of the first terminal N1 of the energy storage capacitor Ce, and the positive charge of the driving electrode TX is transferred to the first terminal N1 of the energy storage capacitor Ce via the seventh switch K7. The voltage of the driving electrode TX drops to the second positive voltage V1, and the voltage of the first terminal N1 of the energy storage capacitor Ce rises to the second positive voltage V1. That is, VCC > V1 > V0. Second time period This is the charge storage period for the energy storage capacitor Ce. According to the principle of charge conservation, VCC*Cd + V0*Ce = V1*Cd + V1*Ce (Formula 1). Since the first switch K1 and the second switch K2 are open, the drive circuit 100 operates during the second time period. It does not consume power.

[0069] In the third period The third switch K3 and the fifth switch K5 are on, while the first switch K1, the second switch K2, the fourth switch K4, the sixth switch K6, and the seventh switch K7 are off. For example... Figure 10C As shown, the remaining positive charge on the driving electrode TX is released to ground through the third switch K3, and the voltage of the driving electrode TX becomes 0. The fourth switch K4 is open, and the fifth switch K5 is open. The voltage at the first terminal N1 of the energy storage capacitor Ce becomes 0, the voltage difference between the first terminal N1 and the second terminal N2 of the energy storage capacitor Ce remains unchanged, and the voltage at the second terminal N2 becomes a negative voltage -V1. The driving circuit 100 operates in the third time period... It does not consume power.

[0070] In the fourth period When the fifth switch K5 and the sixth switch K6 are on, the first switch K1, the second switch K2, the third switch K3, the fourth switch K4, and the seventh switch K7 are off. With the fifth switch K5 on, the voltage at the first terminal N1 of the energy storage capacitor Ce remains zero. With the sixth switch K6 on, the second terminal N2 of the energy storage capacitor Ce is connected to the driving electrode TX. The voltage at the driving electrode TX (zero voltage) is higher than the voltage at the second terminal N2 of the energy storage capacitor Ce (negative voltage -V1). The negative charge at the second terminal N2 of the energy storage capacitor Ce is transferred to the driving electrode TX via the sixth switch K6 until the second terminal N2 of the energy storage capacitor Ce and the driving electrode TX have the same voltage. Figure 10D As shown, the voltage of the driving electrode TX decreases to the second negative voltage -V2, and the voltage at the second terminal N2 of the energy storage capacitor Ce also becomes the second negative voltage -V2, where -V1 < -V2. According to the law of conservation of charge, V1*Ce = V2*Cd + V2*Ce (Equation 2). That is, in the fourth time period... This is the period when the energy storage capacitor Ce releases its charge. The drive circuit 100 operates in the fourth period. It does not consume power.

[0071] In the fifth period The second switch K2 and the fifth switch K5 are on, while the first switch K1, the third switch K3, the fourth switch K4, the sixth switch K6, and the seventh switch K7 are off. For example... Figure 10E As shown, the voltage at the second terminal N2 of the energy storage capacitor Ce remains at the second negative voltage -V2. The driving electrode TX is connected to the second node T2, and the negative charge at the second node T2 is transferred to the driving electrode TX, causing the voltage at the driving electrode TX to become the first negative voltage VSS. The driving circuit 100 operates in the fifth time period. It consumes the power source's energy.

[0072] In the sixth period When the fifth switch K5 and the sixth switch K6 are on, the first switch K1, the second switch K2, the third switch K3, the fourth switch K4, and the seventh switch K7 are off. When the fifth switch K5 is on, the voltage at the first terminal N1 of the energy storage capacitor Ce remains 0. When the sixth switch K6 is on, the second terminal N2 of the energy storage capacitor Ce is connected to the driving electrode TX. Figure 10F As shown, the negative charge of the driving electrode TX is transferred to the second terminal N2 of the energy storage capacitor Ce via the sixth switch K6. The voltage of the driving electrode TX rises from the first negative voltage VSS to the third negative voltage -V3, and the voltage at the second terminal N2 of the energy storage capacitor Ce decreases from the second negative voltage -V2 to the third negative voltage -V3. According to the law of conservation of charge, |VSS|*Cd+V2*Ce=V3*(Cd+Ce) (Equation 3). Sixth time period This is the charge storage period for the energy storage capacitor Ce. Because the first switch K1 and the second switch K2 are open, the drive circuit 100 operates in the sixth period. It does not consume power.

[0073] In the seventh period The third switch K3 and the fourth switch K4 are on, while the first switch K1, the second switch K2, the fifth switch K5, the sixth switch K6, and the seventh switch K7 are off. For example... Figure 10G As shown, the third switch K3 is turned on, and the negative charge of the driving electrode TX is released to the ground node through the third switch K3, causing the voltage of the driving electrode TX to change from the third negative voltage -V3 to 0. The fourth switch K4 is turned on, and the fifth switch K5 is turned off. The voltage at the second terminal N2 of the energy storage capacitor Ce is 0, and the voltage at the first terminal N1 becomes the positive voltage V3. Since the first switch K1 and the second switch K2 are turned off, the driving circuit 100 operates in the seventh time period. It does not consume power.

[0074] In the eighth period The fourth switch K4 and the seventh switch K7 are on, while the first switch K1, the second switch K2, the third switch K3, the fifth switch K5, and the sixth switch K6 are off. For example... Figure 10H As shown, the seventh switch K7 is turned on, connecting the driving electrode TX and the first terminal N1 of the energy storage capacitor Ce. The positive charge on the first terminal N1 of the energy storage capacitor Ce is transferred to the driving electrode TX, and the voltage of the driving electrode TX and the voltage of the first terminal N1 of the energy storage capacitor Ce become the third positive voltage V4. (Sixth time period) This is the period during which the energy storage capacitor Ce releases its charge. According to the law of charge conservation, V3*Ce=V4*(Ce+Cd) (Formula 4). Since the first switch K1 and the second switch K2 are open, the drive circuit 100 operates in the eighth period. It does not consume power.

[0075] The drive circuit 100 periodically cycles through the first time period described above. Up to the eighth period In the first period of the next driving cycle T The first switch K1 and the fourth switch K4 are on, while the second switch K2, the third switch K3, the fifth switch K5, the sixth switch K6, and the seventh switch K7 are off. For example... Figure 10I As shown, the first node T1 charges the driving electrode TX from the third positive voltage V4 to the first positive voltage VCC through the first switch K1, and the voltage of the first terminal N1 of the energy storage capacitor Ce remains at the third positive voltage V4.

[0076] Before the driving circuit 100 starts driving the driving electrode TX, the charge on the first terminal N1 and the second terminal N2 of the energy storage capacitor Ce is 0, and the voltage difference is 0. After the first few cycles of the driving process, the charge on the energy storage capacitor Ce tends to stabilize, and the driving signal 100 is in a steady state. Figure 11 As shown, in the eighth period of the nth driving cycle After this, it is the first period of the (n+1)th driving cycle. The fourth switch K4 and the fifth switch K5 in the first time period The state and in the eighth period The states are the same, therefore the first end N1 in the first time period The voltage V0 is equal to the third positive voltage V4.

[0077] In summary, the first terminal N1 of the energy storage capacitor Ce is in the second time period. The positive charge released by the storage driving electrode TX causes the voltage of the driving electrode TX to decrease from the first positive voltage VCC to the second positive voltage V2; the second terminal N2 of the energy storage capacitor Ce is in the fourth time period. A negative charge is transferred to the driving electrode TX, causing the voltage of the driving electrode TX to change from zero voltage to a second negative voltage -V2; the second terminal N2 of the energy storage capacitor Ce is in the sixth time period. The negative charge released by the storage driving electrode TX causes the voltage of the driving electrode TX to change from the first negative voltage VSS to the third negative voltage -V3; the first terminal N1 of the energy storage capacitor Ce is in the eighth time period. Positive charge is transferred to the driving electrode TX, causing the voltage of the driving electrode TX to change from zero voltage to a third positive voltage V4. The power supply operates only during the first period. and the fifth period It provides charge, thus reducing power consumption.

[0078] for Figure 5 The driving circuit shown requires power from the power source for both the voltage at the driving electrode TX to rise from zero to the first positive voltage VCC and to rise from zero to the first negative voltage VSS. Figure 8 The driving circuit shown only requires a power source to supply charge during the processes of the voltage at the driving electrode TX changing from the third positive voltage V4 to the first positive voltage VCC and from the second negative voltage -V2 to the first negative voltage VSS. Therefore, Figure 8 Compared to the driving circuit shown Figure 5 The driving circuit shown reduces power consumption.

[0079] Figure 8 The schematic driving circuit 100 includes one energy storage capacitor Ce. The driving circuit 100 may also include multiple energy storage capacitors Ce connected in parallel.

[0080] As described above, during the eight time periods of the driving cycle T, the driving electrode TX is sequentially connected to the first node T1, the energy storage capacitor Ce, the ground node GND, the second node T2, the energy storage capacitor Ce, the ground node GND, and the energy storage capacitor Ce again. At any given moment in the driving cycle T, the driving electrode TX is connected to only one of the energy storage capacitor Ce, the first node T1, the second node T2, and the ground node GND. Therefore, in each time period from the first to the eighth stage, only one of the first switch K1, the second switch K2, the third switch K3, the sixth switch K6, and the seventh switch K7 is in the on state to avoid incorrect charge transfer paths. Since the switching between the on and off states of the switches takes time, the switching from the on state to the off state of the next time period begins after the switch in the previous time period has switched from the on state to the off state. For example, in the first stage... Phase Two If the switching of the first switch K1 from the on state to the off state and the switching of the seventh switch K7 from the off state to the on state occur simultaneously, a conduction path may appear from the first node T1 to the first terminal N1 of the energy storage capacitor Ce. The first node T1 charges the energy storage capacitor Ce, causing the voltage of the first terminal N1 of the energy storage capacitor Ce to deviate from the target value, resulting in the circuit failing to work properly.

[0081] like Figure 11 As shown, one of the fourth switch K4 and the fifth switch K5 is in the ON state, and the other is in the OFF state. The fourth switch K4 and the fifth switch K5 are controlled, for example, by a non-overlapping signal. When the fourth switch K4 switches between the ON and OFF states, the sixth switch K6 is in the OFF state, thereby preventing the drive electrode TX from being connected to the ground node through the sixth switch K6 and the fourth switch K4. Similarly, when the fifth switch K5 is between the ON and OFF states, the seventh switch K7 is in the OFF state.

[0082] According to formulas (1) to (4), in each charge transfer process of the energy storage capacitor Ce and the driving electrode TX (second time period) Fourth period Sixth period and the eighth period The voltage change of the energy storage capacitor Ce depends on the difference between the capacitance of the energy storage capacitor Ce and the capacitance of the driving electrode TX to ground equivalent capacitance Cd. For example, according to formula (1), the greater the difference between the capacitance of the energy storage capacitor Ce and the capacitance of the driving electrode TX to ground equivalent capacitance Cd, the greater the voltage change of the first terminal N1 of the energy storage capacitor Ce in the first time period. The voltage V0 and in the second period The closer the voltage (second positive voltage V1) is to the voltage of the energy storage capacitor Ce, the smaller the voltage change. The equivalent capacitance Cd of the driving electrode TX to ground is usually constant. Therefore, the larger the capacitance of the energy storage capacitor Ce, the smaller the voltage change of the energy storage capacitor Ce, and the smaller the electromagnetic interference (EMI) caused by this voltage change. This results in less electromagnetic interference affecting the driving circuit and other circuits of the touch driving device.

[0083] The amplitudes of the first positive voltage VCC and the first negative voltage VSS are equal, i.e., VSS = -VCC. According to formulas (1) to (4), the amplitude of the second positive voltage V1 is the same as the amplitude of the third negative voltage -V3, and the amplitude of the second negative voltage -V2 is the same as the amplitude of the third positive voltage V4. Further, we can obtain:

[0084]

[0085]

[0086] When the capacitance of the energy storage capacitor Ce is much greater than the capacitance of the equivalent capacitance to ground Cd of the driving electrode TX, according to the above formula, the amplitudes of the second positive voltage V1 and the third positive voltage V4 are approximately equal to VCC / 2. That is, the second positive voltage V1, the second negative voltage -V2, the third negative voltage -V3, and the third positive voltage V4 are VCC / 2, -VCC / 2, -VCC / 2, and VCC / 2, respectively. The larger the ratio of the capacitance of the energy storage capacitor Ce to the capacitance of the equivalent capacitance to ground Cd of the driving electrode TX, the closer the second positive voltage V1 and the third positive voltage V4 are to VCC / 2, and the closer the second negative voltage -V2 and the third negative voltage -V3 are to -VCC / 2. The voltage on the driving electrode TX can be considered as a five-order stepped waveform. In some embodiments, the capacitance of the energy storage capacitor Ce is greater than 50 times the capacitance of the equivalent capacitance to ground Cd of the driving electrode TX.

[0087] The duty cycle of the drive signal (i.e., the voltage on the drive electrode TX) provided by the drive circuit 100 refers to the ratio of the time the magnitude of the drive signal is close to zero voltage to the drive period T. The duty cycle of the drive signal can be adjusted by the on-time of the third switch K3. Figure 5 The driving circuit shown and Figure 8 Experimental comparisons were conducted on the driving circuit. The capacitance of the energy storage capacitor Cd was set to be 9 times the equivalent capacitance to ground of the driving electrode TX. The frequency of the driving signal was 100kHz, i.e., the period T of the driving signal was 10 microseconds. Figure 5 The power consumption of the driving circuit shown is 2.23mW, and the signal amplitude (peak-to-peak voltage of the driving electrode TX) is 56.63mV. Figure 12 yes Figure 8The diagram shows the waveform of the drive signal with a 10% duty cycle provided by the drive circuit. Figure 13 yes Figure 8 The diagram shows the waveform of the drive signal with a 25% duty cycle provided by the drive circuit. When a drive signal with a 25% duty cycle is provided, Figure 8 The power consumption of the driving circuit shown is 0.742mW, the signal amplitude is 36.2mV, and the power consumption is... Figure 5 The drive circuit shown represents 33%. When a drive signal with a 10% duty cycle is provided, Figure 8 The power consumption of the driving circuit shown is 0.917mW, the signal amplitude is 52.52mV, and the power consumption is... Figure 5 The driving circuit shown accounts for 41%. Experimental results indicate... Figure 8 The power consumption of the driving circuit shown is reduced.

[0088] Figure 14 This is a circuit diagram of another driving circuit provided in an embodiment of this application. For example... Figure 14 As shown, the driving circuit 100 includes: a first node T1, a second node T2, a ground node GND, a switching circuit, and an energy storage capacitor Ce. The switching circuit includes: an output node OUT, a first switch K1, a second switch K2, a third switch K3, a fourth switch K4, a fifth switch K5, a sixth switch K6, a seventh switch K7, an eighth switch K8, and a ninth switch K9. The energy storage capacitor Ce is a discrete capacitor, such as a ceramic capacitor.

[0089] Compared to Figure 8 The driving circuit shown, Figure 14 The driving circuit shown also includes an eighth switch K8 and a ninth switch K9. The ninth switch K9 is located between the first terminal N1 of the energy storage capacitor Ce and the second node T2. The eighth switch K8 is located between the second terminal N2 of the energy storage capacitor Ce and the first node T1. The eighth switch K8 is, for example, a PMOS transistor, and the ninth switch K9 is, for example, an NMOS transistor.

[0090] Figure 15 for Figure 14 The timing diagram of the driving circuit is shown. When the signal corresponding to the switch is high, it indicates that the switch is on; when the signal corresponding to the switch is low, it indicates that the switch is off. One cycle T of the driving process of the driving circuit 100 for the driving electrode TX includes 8 time periods.

[0091] First period First switch K1 and fourth switch K4 are on, while the other switches are off. When first switch K1 is on, the first node T1 charges the driving electrode TX to the first positive voltage VCC through first switch K1. When fourth switch K4 is on, the second terminal N2 of the energy storage capacitor Ce is grounded, and its voltage is zero; the first terminal N1 has a voltage V0. During the first time period... The drive circuit 100 consumes power from the power supply.

[0092] Second period The fourth switch K4 and the seventh switch K7 are turned on, while the other switches are turned off. The second terminal N2 of the energy storage capacitor Ce is grounded. The seventh switch K7 is turned on, connecting the first terminal N1 of the energy storage capacitor Ce to the driving electrode TX. The voltage VCC of the driving electrode TX is higher than the voltage V0 of the first terminal N1 of the energy storage capacitor Ce, and the positive charge of the driving electrode TX is transferred to the first terminal N1 of the energy storage capacitor Ce via the seventh switch K7. The voltage of the driving electrode TX drops to the second positive voltage V1, and the voltage of the first terminal N1 of the energy storage capacitor Ce rises to the second positive voltage V1. That is, VCC > V1 > V0. Second time period. This is the charge storage period for the energy storage capacitor Ce. According to the principle of charge conservation, VCC*Cd+V0*Ce=V1*Cd+V1*Ce (Equation 5). With the first switch K1 and the second switch K2 open, the drive circuit 100 operates in the second time period. It does not consume power.

[0093] In the third period The third switch K3 and the ninth switch K9 are turned on, while the other switches are turned off. The ninth switch K9 is turned on, and the fourth switch K4 is turned off. The voltage at the first terminal N1 of the energy storage capacitor Ce changes from the second positive voltage V1 to the first negative voltage VSS, and the voltage at the second terminal N2 becomes a negative voltage -V1-|VSS|. The third switch K3 is turned on, releasing the positive charge of the driving electrode TX to the ground node, and the voltage at the driving electrode TX drops to zero. The first switch K1 and the second switch K2 are turned off, and the driving circuit 100 operates in the third time period. It does not consume power.

[0094] In the fourth period Switches K6 and K9 are turned on, while the other switches are turned off. With switch K9 on, the voltage at terminal N1 of the energy storage capacitor Ce remains at the first negative voltage VSS. With switch K6 on, terminal N2 of the energy storage capacitor Ce is connected to the driving electrode TX. The negative charge at terminal N2 of the energy storage capacitor Ce is transferred to the driving electrode TX via switch K6, charging the driving electrode TX until terminal N2 of the energy storage capacitor Ce and the driving electrode TX have the same voltage. The voltage at the driving electrode TX decreases from zero to the second negative voltage -V2, and the voltage at terminal N2 of the energy storage capacitor Ce increases from -V1 - |VSS| to the second negative voltage -V2, i.e., -V1 - |VSS| < -V2 < 0. According to the principle of charge conservation, V2*Cd = (|VSS| - V2)*Ce + V1*Ce (Equation 6). Fourth time period This refers to the charge release period of the energy storage capacitor Ce.

[0095] In the fifth period The second switch K2 and the fifth switch K5 are turned on, while the other switches are turned off. With the second switch K2 on, the driving electrode TX connects to the second node T2. The negative charge on the second node T2 is transferred to the driving electrode TX, and the voltage on the driving electrode TX decreases from the second negative voltage -V2 to the first negative voltage VSS. During the fifth time period, the driving circuit 100... It consumes the power supply's energy. When the fifth switch K5 is turned on, the voltage at the first terminal N1 of the energy storage capacitor Ce changes from the first negative voltage VSS to zero voltage, and the voltage at the second terminal N2 of the energy storage capacitor Ce changes from the second negative voltage -V2 to a positive voltage |VSS|-V2.

[0096] In the sixth period The sixth switch K6 and the fifth switch K5 are turned on, while the other switches are turned off. With the fifth switch K5 on, the first terminal N1 of the energy storage capacitor Ce remains at zero voltage. With the sixth switch K6 on, the second terminal N2 of the energy storage capacitor Ce is connected to the driving electrode TX. The negative charge of the driving electrode TX is transferred to the second terminal N2 of the energy storage capacitor Ce via the sixth switch K6. The voltage of the driving electrode TX rises from the first negative voltage VSS to the third negative voltage -V3. The voltage at the second terminal N2 of the energy storage capacitor Ce changes from |VSS|-V2 to the third negative voltage -V3. According to the principle of charge conservation, |VSS|*Cd=V3*Cd+V3*Ce+(|VSS|-V2)*Ce (Equation 7). Sixth time period. This represents the charge storage period of the energy storage capacitor Ce.

[0097] In the seventh period The third switch K3 and the eighth switch K8 are turned on, while the other switches are turned off. When the third switch K3 is turned on, the negative charge on the driving electrode TX is released to the ground node. The voltage of the driving electrode TX changes from the third negative voltage -V3 to zero voltage. When the eighth switch K8 is turned on, the voltage at the second terminal N2 of the energy storage capacitor Ce changes from the third negative voltage -V3 to the first positive voltage VCC, and the voltage at the first terminal N1 changes from zero voltage to VCC+V3.

[0098] In the eighth period The seventh switch K7 and the eighth switch K8 are turned on, while the other switches are turned off. With the eighth switch K8 on, the voltage at the second terminal N2 of the energy storage capacitor Ce remains at the first positive voltage VCC. With the seventh switch K7 on, the first terminal N1 of the energy storage capacitor Ce is connected to the driving electrode TX, and the positive charge at the first terminal N1 of the energy storage capacitor Ce is transferred to the driving electrode TX through the seventh switch K7. The voltage at the driving electrode TX rises from zero to the third positive voltage V4. The voltage at the first terminal N1 of the energy storage capacitor Ce decreases from VCC+V3 to the third positive voltage V4. (Eighth time period) This represents the charge release period of the energy storage capacitor Ce. According to the principle of charge conservation, V3*Ce=(VCC-V4)*Ce+V4*Cd (Equation 8).

[0099] Before the driving circuit 100 starts driving the driving electrode TX, the charge on the first terminal N1 and the second terminal N2 of the energy storage capacitor Ce is 0, and the voltage difference is 0. After the first few cycles of the driving process, the charge on the energy storage capacitor Ce tends to stabilize, and the driving signal 100 is in a steady state. Figure 15 As shown, the eighth time period of the nth driving cycle The next period is the first phase of the (n+1)th driving cycle. In the eighth period The eighth switch K8 is turned on during the first time period. The fourth switch K4 is turned on, therefore the first terminal N1 is active in the first time period. The voltage is compared to the eighth period. The voltage drop is VCC, that is, V0 equals V4-VCC. Therefore, according to formula (5), we can obtain VCC*Cd+(V4-Vcc)*Ce=V1*Cd+V1*Ce (formula 9).

[0100] like Figure 15 As shown, at any time during the driving cycle, one of the fourth switch K4, the fifth switch K5, the eighth switch K8, and the ninth switch K9 is in the on state, while the other three are in the off state.

[0101] In summary, the first terminal N1 of the energy storage capacitor Ce is in the second time period. The positive charge released by the storage driving electrode TX causes the voltage of the driving electrode TX to decrease from the first positive voltage VCC to the second positive voltage V2; the second terminal N2 of the energy storage capacitor Ce is in the fourth time period. A negative charge is transferred to the driving electrode TX, causing the voltage of the driving electrode TX to decrease from zero to a second negative voltage -V2; the second terminal N2 of the energy storage capacitor Ce is in the sixth time period. The negative charge released by the storage driving electrode TX causes the voltage of the driving electrode TX to rise from the first negative voltage VSS to the third negative voltage -V3; the first terminal N1 of the energy storage capacitor Ce is in the eighth time period. A positive charge is transferred to the driving electrode TX, causing the voltage of the driving electrode TX to rise from zero to a third positive voltage V4.

[0102] The amplitudes of the first positive voltage VCC and the first negative voltage VSS are equal, i.e., VSS = -VCC. According to formulas (5) to (9), the amplitude of the first positive voltage V1 is equal to the amplitude of the third negative voltage -V3, and the amplitude of the second negative voltage -V2 is equal to the amplitude of the fourth positive voltage V4. Further, according to formulas (6) to (9), when the capacitance of the energy storage capacitor Ce is much greater than the capacitance of the driving electrode TX to ground equivalent capacitance Cd, the first positive voltage V1 is slightly higher than zero voltage, the third negative voltage -V3 is slightly lower than zero voltage, the second negative voltage -V2 is slightly higher than -VCC, and the third positive voltage V4 is slightly lower than VCC. The larger the ratio of the capacitance of the energy storage capacitor Ce to the capacitance of the driving electrode TX to ground equivalent capacitance Cd, the closer the first positive voltage V1 and the third negative voltage -V3 are to zero voltage, the closer the second negative voltage -V2 is to -VCC, and the closer the third positive voltage V4 is to VCC. The voltage on the driving electrode TX is as follows Figure 15 As shown, the voltage on the driving electrode TX can be considered as a third-order stepped waveform. In some embodiments, the capacitance of the energy storage capacitor Ce is greater than 5 times the capacitance of the driving electrode TX to ground equivalent capacitance Cd.

[0103] Because the energy storage capacitor Ce has a large capacitance, the switching circuit is fabricated on the die. The energy storage capacitor Ce is located outside the die.

[0104] In some embodiments, the bare die containing the switching circuit is packaged separately. Figure 16 This is a schematic diagram of the packaging of a touch driving device provided in an embodiment of this application. Figure 17 for Figure 16 A schematic block diagram of the touch driving device is shown. Figure 16 and 17 As shown, the bare die 400 containing the switching circuit is packaged within the housing 300. The bare die 400 may employ a ball grid array (BGA) package, for example. The packaged bare die 400 has pins O1-O4. Both the packaged bare die 400 and the energy storage capacitor Ce are mounted on a printed circuit board (PCB). The packaged bare die 400 and the energy storage capacitor Ce are connected via the PCB layout. The output node OUT of the drive circuit 100 is connected to the drive electrode TX via pin O1. For example, the output node OUT is connected to pin O1 via a gold wire, and pin O1 is connected to the drive electrode TX via the PCB layout. The detection circuit 200 is also formed on this bare die 400, and the detection circuit 200 is connected to the detection electrode RX via pin O2. The first terminal N1 of the energy storage capacitor Ce is connected to pin O3 via the PCB layout, and the second terminal N2 is connected to pin O4 via the PCB layout. Figure 17 The driving circuit in Figure 8 The driving circuit shown is an example.

[0105] In other embodiments, the energy storage capacitor Ce and the bare core 400 containing the switching circuit are packaged together, that is, the energy storage capacitor Ce and the bare core 400 containing the switching circuit are encapsulated together. Figure 18 This is a schematic diagram of another touch driver device package provided in an embodiment of this application. The bare die 400 containing the switching circuit and the energy storage capacitor Ce are both packaged within the housing 300. The bare die 400 containing the switching circuit and the energy storage capacitor Ce are, for example, packaged using a ball grid array (BGA). The first terminal N1 and the second terminal N2 of the energy storage capacitor Ce are connected to the switching circuit via gold wires. By encapsulating the bare die 400 containing the switching circuit and the energy storage capacitor Ce, the number of pins in the touch driver chip can be reduced.

[0106] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A driving circuit applied to a touch screen, the touch screen including driving electrodes, characterized in that, The driving circuit includes: The first node is used to provide a first positive voltage; The second node is used to provide the first negative voltage; Ground node; An energy storage capacitor, the energy storage capacitor including a first terminal and a second terminal; and A switching circuit is used to control the first terminal of the energy storage capacitor to be connected to the ground node or the driving electrode, and to control the second terminal of the energy storage capacitor to be connected to the ground node or the driving electrode. The switching circuit includes: The output node is configured to connect to the driving electrode; A first switch is disposed between the first node and the output node; A second switch is disposed between the second node and the output node; A third switch is disposed between the ground node and the output node; A fourth switch is disposed between the ground node and the second terminal of the energy storage capacitor; The fifth switch is located between the ground node and the first terminal of the energy storage capacitor; A sixth switch is disposed between the ground node and the second terminal of the energy storage capacitor; and The seventh switch is located between the ground node and the first terminal of the energy storage capacitor.

2. The driving circuit according to claim 1, characterized in that, The switching circuit is used for During a first time period, the driving electrode is controlled to be connected to the first node, and the first node charges the driving electrode so that the voltage of the driving electrode is equal to the first positive voltage. During the second time period, the driving electrode is controlled to be connected to the first terminal of the energy storage capacitor, and the energy storage capacitor stores the charge released by the driving electrode, so that the voltage of the driving electrode is equal to the second positive voltage. During the third time period, the driving electrode is controlled to be connected to the ground node, so that the voltage of the driving electrode is equal to zero voltage; During the fourth time period, the driving electrode is controlled to be connected to the second terminal of the energy storage capacitor, and the energy storage capacitor transfers charge to the driving electrode, so that the voltage of the driving electrode is equal to the second negative voltage; as well as During the fifth time period, the driving electrode is controlled to connect to the second node, and the second node charges the driving electrode so that the voltage of the driving electrode is equal to the first negative voltage. Wherein, the second positive voltage is lower than the first positive voltage and higher than the zero voltage; the second negative voltage is higher than the first negative voltage and lower than the zero voltage.

3. The driving circuit according to claim 2, characterized in that, During the second time period, the switching circuit controls the second terminal of the energy storage capacitor to be connected to the ground node; during the fourth time period, the switching circuit controls the first terminal of the energy storage capacitor to be connected to the ground node.

4. The driving circuit according to claim 3, characterized in that, The switching circuit is also used for During the sixth time period, the driving electrode is controlled to be connected to the second terminal of the energy storage capacitor, and the energy storage capacitor stores the charge released by the driving electrode, so that the voltage of the driving electrode is equal to the third negative voltage; During the seventh time period, the driving electrode is controlled to be connected to the ground node, such that the voltage of the driving electrode is equal to zero voltage; as well as During the eighth time period, the driving electrode is controlled to be connected to the first terminal of the energy storage capacitor, and the energy storage capacitor transfers charge to the driving electrode, such that the voltage of the driving electrode is equal to the third positive voltage. Specifically, during the sixth time period, the switching circuit controls the first terminal of the energy storage capacitor to be connected to the ground node; during the eighth time period, the switching circuit controls the second terminal of the energy storage capacitor to be connected to the ground node.

5. The driving circuit according to any one of claims 2-4, characterized in that, During the first time period, the first switch and the fourth switch are turned on, while the second switch, the third switch, the fifth switch, the sixth switch, and the seventh switch are turned off. During the second time period, the fourth switch and the seventh switch are turned on, while the first switch, the second switch, the third switch, the fifth switch, and the sixth switch are turned off. During the third time period, the third switch and the fifth switch are turned on, while the first switch, the second switch, the fourth switch, the sixth switch, and the seventh switch are turned off. During the fourth time period, the fifth and sixth switches are turned on, while the first, second, third, fourth, and seventh switches are turned off. During the fifth time period, the second switch and the fifth switch are turned on, while the first switch, the third switch, the fourth switch, the sixth switch, and the seventh switch are turned off. During the sixth time period, the fifth and sixth switches are turned on, while the first, second, third, fourth, and seventh switches are turned off. During the seventh time period, the third switch and the fourth switch are turned on, while the first switch, the second switch, the fifth switch, the sixth switch, and the seventh switch are turned off. During the eighth time period, the fourth and seventh switches are turned on, while the first, second, third, fifth, and sixth switches are turned off.

6. The driving circuit according to claim 2, characterized in that, During the second time period, the switching circuit controls the second terminal of the energy storage capacitor to be connected to the ground node; during the fourth time period, the switching circuit controls the first terminal of the energy storage capacitor to be connected to the second node.

7. The driving circuit according to claim 6, characterized in that, The switching circuit is also used for During the sixth time period, the driving electrode is controlled to be connected to the second terminal of the energy storage capacitor, and the energy storage capacitor stores the charge released by the driving electrode, so that the voltage of the driving electrode is equal to the third negative voltage; During the seventh time period, the driving electrode is controlled to be connected to the ground node, such that the voltage of the driving electrode is equal to zero voltage; as well as During the eighth time period, the driving electrode is controlled to be connected to the first terminal of the energy storage capacitor, and the energy storage capacitor transfers charge to the driving electrode, such that the voltage of the driving electrode is equal to the third positive voltage. During the sixth time period, the switching circuit controls the first terminal of the energy storage capacitor to be connected to the ground node; during the eighth time period, the switching circuit controls the second terminal of the energy storage capacitor to be connected to the first node.

8. The driving circuit according to claim 7, characterized in that, The switching circuit includes: The output node is configured to connect to the driving electrode; A first switch is disposed between the first node and the output node; A second switch is disposed between the second node and the output node; A third switch is disposed between the ground node and the output node; A fourth switch is disposed between the ground node and the second terminal of the energy storage capacitor; The fifth switch is located between the ground node and the first terminal of the energy storage capacitor; The sixth switch is disposed between the ground node and the second terminal of the energy storage capacitor; The seventh switch is disposed between the ground node and the first terminal of the energy storage capacitor; An eighth switch is disposed between the second terminal of the energy storage capacitor and the first node; and The ninth switch is located between the first end of the energy storage capacitor and the second node.

9. The driving circuit according to claim 8, characterized in that, During the first time period, the first switch and the fourth switch are turned on, while the second switch, the third switch, the fifth switch, the sixth switch, the seventh switch, the eighth switch, and the ninth switch are turned off. During the second time period, the fourth switch and the seventh switch are turned on, while the first switch, the second switch, the third switch, the fifth switch, the sixth switch, the eighth switch, and the ninth switch are turned off. During the third time period, the third switch and the ninth switch are turned on, while the first switch, the second switch, the fourth switch, the fifth switch, the sixth switch, the seventh switch, and the eighth switch are turned off. During the fourth time period, the sixth switch and the ninth switch are turned on, while the first switch, the second switch, the third switch, the fourth switch, the fifth switch, the seventh switch, and the eighth switch are turned off. During the fifth time period, the second switch and the fifth switch are turned on, while the first switch, the third switch, the fourth switch, the sixth switch, the seventh switch, the eighth switch, and the ninth switch are turned off. During the sixth time period, the fifth and sixth switches are turned on, while the first, second, third, fourth, seventh, eighth, and ninth switches are turned off. During the seventh time period, the third switch and the eighth switch are turned on, while the first switch, the second switch, the fourth switch, the fifth switch, the sixth switch, the seventh switch, and the ninth switch are turned off. During the eighth time period, the seventh and eighth switches are turned on, while the first, second, third, fourth, fifth, sixth, and ninth switches are turned off.

10. The driving circuit according to claim 1, characterized in that, The capacitance value of the energy storage capacitor is greater than the capacitance value of the equivalent capacitance of the driving electrode to ground.

11. A touch-sensitive driving device, characterized in that, Includes the drive circuit according to any one of claims 1 to 10.

12. The touch driving device according to claim 11, characterized in that, The switching circuit of the drive circuit is formed on the die, wherein the energy storage capacitor is encapsulated with the die, or the energy storage capacitor is disposed outside the package of the die.

13. An electronic device, characterized in that, Includes a touch screen and a touch driving device according to claim 11 or 12.

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