Driving circuit of touch screen, touch chip and vehicle-mounted terminal equipment

Abstract

The invention discloses a driving circuit of a touch screen, a touch chip and vehicle-mounted terminal equipment. The touch screen comprises a plurality of emission electrodes; the driving circuit comprises a first voltage domain circuit and a second voltage domain circuit, and the second voltage domain circuit is connected with the first voltage domain circuit and the emitting electrode; the first voltage domain circuit is used for generating and outputting a first reference voltage and a first sine wave signal; the second voltage domain circuit is used for amplifying the first reference voltage into a second reference voltage according to a first multiple, performing proportional amplification processing on the first sine wave signal according to the second reference voltage, and generating and outputting a second sine wave signal; wherein the second sine wave signal is used for driving the transmitting electrode, and the amplitude of the second sine wave signal is larger than that of the first sine wave signal. When the touch screen is applied to the vehicle-mounted terminal, the vehicle-mounted anti-electromagnetic interference standard can be met, and the touch screen can effectively detect the touch point in the scene that a user needs to wear gloves for operation.

Description

Technical Field

[0001] This application relates to the field of touch technology, specifically to a touch screen driving circuit, touch chip, and vehicle terminal device. Background Technology

[0002] Currently, with the rapid development of the automotive industry, in-vehicle touch screens are being used more and more widely, not only as instrument panel displays, but also carrying functions such as vehicle control and in-vehicle entertainment. These changes have placed higher demands on touch chips.

[0003] Existing automotive touchscreens typically use square wave or trapezoidal wave signals to drive the transmitting electrodes, resulting in significant harmonic components that fail to meet automotive electromagnetic interference (EMI) standards. Furthermore, automotive touchscreens have a heavy load; when users touch the screen with thick gloves, the signal strength for touch detection becomes insufficient, hindering effective touch point detection. Summary of the Invention

[0004] Therefore, this application provides a driving circuit for a touch screen, a touch chip, and an in-vehicle terminal device. The technical solution of this application is as follows: This application provides a driving circuit for a touch screen, the touch screen including multiple transmitting electrodes; the driving circuit includes a first voltage domain circuit and a second voltage domain circuit, the second voltage domain circuit being connected to the first voltage domain circuit and the transmitting electrodes; the first voltage domain circuit is used to generate and output a first reference voltage and a first sine wave signal; the second voltage domain circuit is used to amplify the first reference voltage by a first factor to obtain a second reference voltage, and to perform proportional amplification processing on the first sine wave signal according to the second reference voltage to generate and output a second sine wave signal; wherein the second sine wave signal is used to drive the transmitting electrodes, and the amplitude of the second sine wave signal is greater than the amplitude of the first sine wave signal.

[0005] In one embodiment of this application, the first voltage domain circuit includes an adjustable operational amplifier unit, which is connected to the second voltage domain circuit; the adjustable operational amplifier unit is used to receive a reference voltage source and an adjustment command, and amplify the reference voltage source to the first reference voltage according to the adjustment command and output it.

[0006] In one embodiment of this application, the first voltage domain circuit further includes a digital-to-analog converter, a programmable gain amplifier, and a low-pass filter. The programmable gain amplifier is connected to the digital-to-analog converter and the low-pass filter, and the low-pass filter is connected to the second voltage domain circuit. The digital-to-analog converter is used to receive digital signals and generate a stepped wave signal based on the digital signals. The programmable gain amplifier is used to receive the stepped wave signal and amplify the stepped wave signal by a second factor. The low-pass filter is used to perform smoothing filtering on the stepped wave signal to generate the first sine wave signal.

[0007] In one embodiment of this application, the second voltage domain circuit includes a voltage amplification unit, a proportional amplification unit, and a driving unit. The voltage amplification unit is connected to the first voltage domain circuit, and the proportional amplification unit is connected to the voltage amplification unit, the driving unit, and the first voltage domain circuit. The voltage amplification unit is used to receive the first reference voltage and amplify the first reference voltage by a first factor to obtain the second reference voltage. The proportional amplification unit is used to perform proportional amplification processing on the first sine wave signal according to the second reference voltage to generate and output the second sine wave signal. The driving unit is used to transmit the second sine wave signal to the transmitting electrode and match the capacitive reactance of the second sine wave signal with that of the transmitting electrode.

[0008] In one embodiment of this application, the adjustable operational amplifier unit includes a first operational amplifier, a first resistor, and an adjustable resistor; the positive input terminal of the first operational amplifier is used to receive the reference voltage source, the inverting input terminal of the first operational amplifier is grounded through the first resistor, the inverting input terminal of the first operational amplifier is also connected to the output terminal of the first operational amplifier through the adjustable resistor, and the output terminal of the first operational amplifier is connected to the second voltage domain circuit; the adjustable resistor is used to adjust to the corresponding resistance value according to the adjustment command.

[0009] In one embodiment of this application, the voltage amplification unit includes a second operational amplifier, a second resistor, and a third resistor; the positive input terminal of the second operational amplifier is used to receive the first reference voltage, the inverting input terminal of the second operational amplifier is grounded through the second resistor, the inverting input terminal of the second operational amplifier is also connected to the output terminal of the second operational amplifier through the third resistor, and the output terminal of the second operational amplifier is connected to the proportional amplification unit.

[0010] In one embodiment of this application, the proportional amplification unit includes a third operational amplifier, a first capacitor, a second capacitor, a fourth resistor, a first switch, and a second switch; the positive input terminal of the third operational amplifier is used to receive the second reference voltage, the inverting input terminal of the third operational amplifier is used to receive the first sine wave signal through the first capacitor, the inverting input terminal of the third operational amplifier is also connected to the output terminal of the third operational amplifier through the first switch, and the inverting input terminal of the third operational amplifier is also connected in series to the output terminal of the third operational amplifier through the second switch and the fourth resistor, and the output terminal of the third operational amplifier is connected to the driving unit; the second capacitor is connected in parallel with the first switch.

[0011] In one embodiment of this application, the driving unit includes a fourth operational amplifier, the positive input terminal of the fourth operational amplifier is used to receive the second sine wave signal, the inverting input terminal of the fourth operational amplifier is connected to the output terminal of the fourth operational amplifier, and the output terminal of the fourth operational amplifier is connected to the transmitting electrode.

[0012] In one embodiment of this application, the first voltage domain circuit further includes an analog multiplier, which is connected to the output terminal of the low-pass filter and the second voltage domain circuit respectively; the analog multiplier is used to receive a time-domain window function, multiply the time-domain window function with the signal output by the low-pass filter, and obtain and output the first sine wave signal.

[0013] A second aspect of this application provides a touch chip, including the aforementioned driving circuit.

[0014] A third aspect of this application provides an in-vehicle terminal device, including a touch screen and the aforementioned touch chip.

[0015] It is understood that the driving circuit of this application embodiment generates and outputs a second sine wave signal to drive the transmitting electrode of the touch screen through the first voltage domain circuit and the second voltage domain circuit. This enables the touch screen to meet the control requirements of multiple frequency points in a large frequency range of the vehicle anti-electromagnetic interference standard when applied to vehicle terminals, and also enables the touch screen to effectively detect touch points in scenarios where users need to wear gloves to operate. Attached Figure Description

[0016] Figure 1 This is a schematic block diagram of a touch screen provided in an embodiment of this application.

[0017] Figure 2 This is a schematic block diagram of a driving circuit for a touch screen provided in an embodiment of this application.

[0018] Figure 3 This is a schematic block diagram of a first voltage domain circuit provided in an embodiment of this application.

[0019] Figure 4 This is a schematic block diagram of a second voltage domain circuit provided in an embodiment of this application.

[0020] Figure 5 This is a circuit diagram of a driving circuit for a touch screen provided in an embodiment of this application.

[0021] Figure 6 This is a schematic block diagram of the second type of first voltage domain circuit provided in the embodiments of this application.

[0022] Figure 7 This is a schematic block diagram of a touch chip provided in an embodiment of this application.

[0023] Figure 8 This is a schematic block diagram of an in-vehicle terminal device provided in an embodiment of this application. Detailed Implementation

[0024] It should be noted that in the embodiments of this application, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone, where A and B can be singular or plural. The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and drawings of this application are used to distinguish similar objects, not to describe a specific order or sequence.

[0025] It should also be noted that the methods disclosed in the embodiments of this application or the methods shown in the flowcharts include one or more steps for implementing the method. Without departing from the scope of the claims, the execution order of multiple steps can be interchanged, and some steps can also be deleted.

[0026] Currently, with the rapid development of the automotive industry, in-vehicle touch screens are being used more and more widely, not only as instrument panel displays, but also carrying functions such as vehicle control and in-vehicle entertainment. These changes have placed higher demands on touch chips.

[0027] Existing automotive touchscreens typically use square wave or trapezoidal wave signals to drive the transmitting electrodes, resulting in significant harmonic components that fail to meet automotive electromagnetic interference standards. Furthermore, automotive touchscreens have high load requirements; when users touch the screen with thick gloves, the signal strength for touch detection becomes insufficient, hindering effective touch point detection.

[0028] For example, when the driving signal transmitted to the transmitting electrode of the touch screen is a 100kHz trapezoidal wave signal, the harmonic component at 300kHz after normalization will still be large, which cannot meet the standard for vehicle electromagnetic interference.

[0029] This application provides a driving circuit, a touch chip, and an in-vehicle terminal device for a touch screen, which enables the touch screen to meet the standards for in-vehicle electromagnetic interference and ensures the amount of touch detection signal even when a user touches the touch screen with thick gloves.

[0030] Please refer to Figure 1 , Figure 1 This is a schematic block diagram of a touch screen provided in an embodiment of this application, wherein the touch screen 10 includes multiple emitting electrodes TX.

[0031] In this embodiment, the touchscreen 10 may further include multiple receiving electrodes, which are arranged intersectingly with the transmitting electrodes TX. The transmitting electrodes TX and the receiving electrodes are connected to the touch chip. The touch chip transmits a drive signal to the transmitting electrodes TX. The drive signal is transmitted from the transmitting electrodes TX to the receiving electrodes via capacitive coupling, and is converted into a detection signal on the receiving electrodes. The touch chip receives the detection signal from the receiving electrodes for touch detection.

[0032] The touch chip includes a driving circuit, which generates and outputs driving signals to each transmitting electrode TX in the touch screen 10.

[0033] Next, combined Figure 1 This application describes a driving circuit 200 for a touchscreen 10, as illustrated in an embodiment. Please refer to [link / reference]. Figure 2 The driving circuit 200 includes a first voltage domain circuit 210 and a second voltage domain circuit 220.

[0034] In this embodiment, the first voltage domain circuit 210 is connected to the second voltage domain circuit 220, and the second voltage domain circuit 220 is connected to the transmitting electrode TX. The first voltage domain circuit 210 is used to generate and output a first reference voltage and a first sine wave signal.

[0035] For example, the first voltage domain circuit 210 may include a voltage amplifier circuit and a digital-to-analog converter circuit. The voltage amplifier circuit receives and amplifies a reference voltage source to generate the aforementioned first reference voltage, and the digital-to-analog converter circuit converts a pre-stored sine wave sample value into the aforementioned first sine wave signal. The reference voltage source and the sine wave sample value may be provided by a touch chip.

[0036] The second voltage domain circuit 220 receives a first reference voltage and a first sine wave signal, amplifies the first reference voltage by a first factor to obtain a second reference voltage, and proportionally amplifies the first sine wave signal according to the second reference voltage to generate and output a second sine wave signal to the transmitting electrode TX. The second sine wave signal is used to drive the transmitting electrode TX. The amplitude of the second sine wave signal is greater than the amplitude of the first sine wave signal.

[0037] For example, the second voltage domain circuit 220 may include a voltage amplification circuit and a proportional amplification circuit. The voltage amplification circuit receives the first reference voltage from the first voltage domain circuit 210, amplifies the first reference voltage into a second reference voltage, and the proportional amplification circuit performs proportional amplification processing on the first sine wave signal according to the second reference voltage to generate and output a second sine wave signal to the transmitting electrode TX.

[0038] In some embodiments, the frequencies of the first and second sine wave signals are 100kHz. In the application scenario of the vehicle terminal touch screen 10, the driving signal transmitted to the transmitting electrode TX of the touch screen 10 is the aforementioned 100kHz second sine wave signal, that is, the main frequency of the second sine wave signal is 100kHz, and after normalization, it is attenuated to 0dB. Its noise floor amplitude is -240dB. Since the energy is concentrated at the main frequency of 100kHz, the harmonic components of the second sine wave signal are very small and close to the noise floor, so that the vehicle terminal touch screen 10 can meet the control requirements of multiple frequency points in a wide frequency range (such as 100kHz~2.5GHz) of the vehicle electromagnetic interference resistance standard (CISPR25).

[0039] The first sine wave signal is proportionally amplified by the second reference voltage generated through amplification processing to obtain a second sine wave signal to drive the emitting electrode TX of the touch screen 10. This increases the voltage range of the driving signal of the emitting electrode TX, thereby increasing the amount of detection signal of the touch screen 10, so that the touch screen 10 can effectively detect touch points even in scenarios where the user needs to wear gloves to operate.

[0040] It is understood that the driving circuit 200 of this application embodiment generates and outputs a second sine wave signal to drive the transmitting electrode TX of the touch screen 10 through the first voltage domain circuit 210 and the second voltage domain circuit 220. This enables the touch screen 10 to meet the control requirements of multiple frequency points in a large frequency range of the vehicle anti-electromagnetic interference standard when applied to vehicle terminals, and also enables the touch screen 10 to effectively detect touch points in scenarios where users need to wear gloves to operate.

[0041] Please refer to Figure 3 , Figure 3This is a schematic block diagram of a first voltage domain circuit 210 provided in an embodiment of this application, wherein the first voltage domain circuit 210 includes an adjustable operational amplifier unit 211.

[0042] In this embodiment, the adjustable operational amplifier unit 211 is connected to the second voltage domain circuit 220. The adjustable operational amplifier unit 211 is used to receive a reference voltage source and an adjustment command, amplify the reference voltage source to a first reference voltage according to the adjustment command, and output it. The first voltage domain circuit 210 can be packaged inside the touch chip, and the reference voltage source and adjustment command are provided by the touch chip.

[0043] In some embodiments, the adjustable operational amplifier unit 211 can adjust the magnitude of the first reference voltage in multiple levels according to the adjustment command. For example, the reference voltage source can be 0.1V, and the adjustable operational amplifier unit 211 can amplify the reference voltage source by 2.5 to 10 times, and the output first reference voltage is 0.25V to 1V, with a total of 13 levels. The step size between each level is 62.5mV, which is not limited here.

[0044] The first voltage domain circuit 210 further includes a digital-to-analog converter 212, a programmable gain amplifier 213, and a low-pass filter 214. The programmable gain amplifier 213 is connected to the digital-to-analog converter 212 and the low-pass filter 214, and the low-pass filter 214 is connected to the second voltage domain circuit 220. The digital-to-analog converter 212 receives digital signals and generates a stepped wave signal based on these signals. The digital signals include sine wave sample values ​​pre-stored in the touch chip. The programmable gain amplifier 213 receives the stepped wave signal and amplifies it by a second factor. The low-pass filter 214 performs smoothing filtering on the stepped wave signal to generate a first sine wave signal.

[0045] In some embodiments, the digital-to-analog converter 212, programmable gain amplifier 213, and low-pass filter 214 of the first voltage domain circuit 210 can generate and output a first sine wave signal with a VPP value ranging from 0.4V to 1.4V. Here, VPP is the difference between the peaks and troughs of the sine wave.

[0046] Please refer to Figure 4 , Figure 4 This is a schematic block diagram of a second voltage domain circuit 220 provided in an embodiment of the present application. The second voltage domain circuit 220 includes a voltage amplification unit 221, a proportional amplification unit 222, and a driving unit 223.

[0047] In this embodiment, voltage amplification unit 221 is connected to the first voltage domain circuit 210, and proportional amplification unit 222 is connected to voltage amplification unit 221, driving unit 223, and the first voltage domain circuit 210. Voltage amplification unit 221 receives a first reference voltage and amplifies it by a first factor to obtain a second reference voltage. Proportional amplification unit 222 amplifies the first sine wave signal proportionally according to the second reference voltage, generating and outputting a second sine wave signal. Driving unit 223 transmits the second sine wave signal to the transmitting electrode TX and matches the capacitive reactance of the second sine wave signal to that of the transmitting electrode TX.

[0048] It is understood that the second voltage domain circuit 220 in this embodiment of the application performs proportional amplification processing on the first sine wave signal through the voltage amplification unit 221 and the proportional amplification unit 222 to obtain a second sine wave signal to drive the transmitting electrode TX of the touch screen 10. This increases the voltage range of the driving signal of the transmitting electrode TX, thereby increasing the amount of detection signal of the touch screen 10, enabling the touch screen 10 to effectively detect touch points even in scenarios where the user needs to wear gloves. Furthermore, the second voltage domain circuit 220 also uses the driving unit 223 to match the capacitive reactance of the second sine wave signal with that of the transmitting electrode TX, thereby reducing the bandwidth loss of the second sine wave signal during transmission in the transmitting electrode TX, and thus enhancing the driving capability of the second sine wave signal on the transmitting electrode TX.

[0049] Please refer to Figure 5 , Figure 5 The present application provides a schematic diagram of a driving circuit 200 for a touch screen 10, wherein the driving circuit 200 includes a first voltage domain circuit 210 and a second voltage domain circuit 220.

[0050] In this embodiment, the first voltage domain circuit 210 includes an adjustable operational amplifier unit 211, a digital-to-analog converter 212, a programmable gain amplifier 213, and a low-pass filter 214. The second voltage domain circuit 220 includes a voltage amplification unit 221, a proportional amplification unit 222, and a driving unit 223, with the voltage amplification unit 221 connected to the first voltage domain circuit 210.

[0051] The adjustable operational amplifier unit 211 includes a first operational amplifier U1, a first resistor R1, and an adjustable resistor R0. The non-inverting input of the first operational amplifier U1 receives a reference voltage source, and the inverting input of the first operational amplifier U1 is grounded through the first resistor R1. The inverting input of the first operational amplifier U1 is also connected to its output through the adjustable resistor R0. The output of the first operational amplifier U1 is connected to the second voltage domain circuit 220. The adjustable resistor R0 is used to adjust the resistance to a corresponding value according to the adjustment command.

[0052] It can be understood that the first operational amplifier U1, the first resistor R1, and the adjustable resistor R0 constitute a non-inverting proportional amplifier. Since the first resistor R1 has a fixed resistance value and the adjustable resistor R0 has a variable resistance value, the amplification factor of the non-inverting proportional amplifier is β1 = (R0 + R1) / R1. In some embodiments, by adjusting the adjustable resistor R0, β1 can be made to be 2.5~10. When the reference voltage source is 0.1V, the first reference voltage range output by the adjustable operational amplifier unit 211 can be 0.25V~1V.

[0053] The voltage amplification unit 221 includes a second operational amplifier U2, a second resistor R2, and a third resistor R3. The positive input terminal of the second operational amplifier U2 is used to receive a first reference voltage, the inverting input terminal of the second operational amplifier U2 is grounded through the second resistor R2, the inverting input terminal of the second operational amplifier U2 is also connected to the output terminal of the second operational amplifier U2 through the third resistor R3, and the output terminal of the second operational amplifier U2 is connected to the proportional amplification unit 222.

[0054] In this embodiment, the second operational amplifier U2, the second resistor R2, and the third resistor R3 constitute a positive-inverting amplifier with a gain of β2 = (R2 + R3) / R2. For example, the first reference voltage range received at the positive input terminal of the second operational amplifier U2 is 0.25V to 1V. When β2 = 16, the second reference voltage range output by the voltage amplification unit 221 is 4V to 16V.

[0055] The proportional amplifier unit 222 includes a third operational amplifier U3, a first capacitor C1, a second capacitor C2, a fourth resistor R4, a first switch K1, and a second switch K2. The positive input terminal of the third operational amplifier U3 receives a second reference voltage, and the inverting input terminal receives a first sine wave signal through the first capacitor C1. The inverting input terminal of the third operational amplifier U3 is also connected to its output terminal via the first switch K1. Furthermore, the inverting input terminal of the third operational amplifier U3 is connected in series with its output terminal via the second switch K2 and the fourth resistor R4. The output terminal of the third operational amplifier U3 is connected to the drive unit 223. The second capacitor C2 is connected in parallel with the first switch K1.

[0056] In this embodiment, the third operational amplifier U3, together with the first capacitor C1 and the second capacitor C2, constitutes an inverting proportional amplifier with an amplification factor of β3=C1 / C2, which is reset and amplified by the first switch K1.

[0057] For example, the VPP value of the first sine wave signal received at the inverting input terminal of the third operational amplifier U3 ranges from 0.4V to 1.4V, and β3=20. During the reset phase, the first switch K1 is turned on, and the inverting input terminal of the third operational amplifier U3 is directly connected to the output terminal to form a unity-gain amplifier. The voltages at its positive input terminal, inverting input terminal, and output terminal are approximately equal, and the static operating point of each terminal of the proportional amplifier unit 222 is set to the second reference voltage, thus being in a reset state. During the amplification and transmission phase, the first switch K1 is turned off, and the third operational amplifier U3, together with the first capacitor C1 and the second capacitor C2, forms an inverting proportional amplifier with an amplification factor of β3=20. After the first sine wave signal with a VPP value range of 0.4V to 1.4V is amplified 20 times, the output terminal of the third operational amplifier U3 outputs a second sine wave signal with a VPP value range of 8V to 28V.

[0058] The driving unit 223 includes a fourth operational amplifier U4. The positive input terminal of the fourth operational amplifier U4 is used to receive the second sine wave signal. The inverting input terminal of the fourth operational amplifier U4 is connected to the output terminal of the fourth operational amplifier U4. The output terminal of the fourth operational amplifier U4 is connected to the transmitting electrode TX.

[0059] In this embodiment, the inverting input terminal of the fourth operational amplifier U4 is connected to the output terminal of the fourth operational amplifier U4 to form a unity-gain amplifier, thereby reducing the bandwidth loss of the second sine wave transmitted to the transmitting electrode TX, and thus enhancing the driving capability of the second sine wave signal to the transmitting electrode TX.

[0060] Please refer to Figure 6 , Figure 6 This is a schematic block diagram of a second type of first voltage domain circuit 210 provided in an embodiment of this application, wherein, Figure 6 The first voltage domain circuit 210 shown is... Figure 3 Compared to the first voltage domain circuit 210 shown, Figure 6 The first voltage domain circuit 210 shown also includes an analog multiplier 215.

[0061] In this embodiment, the analog multiplier 215 is connected to the output of the low-pass filter 214 and the second voltage domain circuit 220. The analog multiplier 215 receives a time-domain window function and multiplies it with the signal output from the low-pass filter 214 to obtain and output a first sine wave signal. That is, through the analog multiplier 215, a desired time-domain window function can be selected to multiply the first sine wave signal, completing the signal extraction of the first sine wave signal within the corresponding time-domain window, thereby enabling the touchscreen 10 to better meet the requirements of automotive electromagnetic interference standards.

[0062] The aforementioned time-domain window functions include rectangular window functions and Hann window functions. For example, when the first sine wave signal is a 100kHz sine wave, the output signal is obtained by multiplying it with a Hann window function. Since the main lobe of the Hann window function is twice as wide, while the amplitude of the side lobes is relatively small, the signal energy of the extracted output signal leaks from the main lobe to the side lobes, which can effectively suppress the generation of electromagnetic interference.

[0063] In some embodiments, since the first sine wave signal is generated by the digital-to-analog converter 212, the programmable gain amplifier 213, and the low-pass filter 214, the pre-stored sine wave sampled value can also be multiplied by the desired time-domain window function to obtain the target sampled value, which is then input to the digital-to-analog converter 212 to finally obtain the corresponding first sine wave signal truncated by the time-domain window function. Alternatively, multiple sets of target sampled values ​​can be pre-stored in the touch chip, and each set of target sampled values ​​can be obtained by multiplying the sine wave sampled value by one of the time-domain window functions to achieve the selection of the time-domain window function.

[0064] Please refer to Figure 7 , Figure 7 This is a schematic block diagram of a touch chip provided in an embodiment of this application, wherein the touch chip 20 includes the driving circuit 200 of any of the above embodiments.

[0065] Please refer to Figure 8 , Figure 8 This is a schematic block diagram of an in-vehicle terminal device provided in an embodiment of this application. The in-vehicle terminal device 1 includes a touch screen 10 and a touch chip 20 as described in the above embodiment.

[0066] It is understood that the beneficial effects of the touch chip 20 and the vehicle terminal device 1 in the embodiments of this application can be referred to the beneficial effects of the driving circuit 200 of the touch screen 10 in the foregoing embodiments, and will not be repeated here.

[0067] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. A computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the flow or function according to the embodiments of this application is generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer storage medium or transmitted through the computer storage medium. The computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available media may be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., Digital Versatile Discs (DVDs)), or semiconductor media (e.g., solid-state disks (SSDs)).

[0068] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. This program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the methods described above. The aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks. Unless otherwise specified, the technical features of this embodiment and its implementation can be combined arbitrarily.

[0069] The embodiments described above are merely preferred embodiments of this application and are not intended to limit the scope of this application. Any modifications and improvements made by those skilled in the art to the technical solutions of this application without departing from the spirit of this application should fall within the protection scope defined by the claims of this application.

Claims

1. A driving circuit for a touch screen, characterized in that, The touchscreen includes multiple transmitting electrodes; The driving circuit includes a first voltage domain circuit and a second voltage domain circuit, wherein the second voltage domain circuit is connected to the first voltage domain circuit and the transmitting electrode. The first voltage domain circuit is used to generate and output a first reference voltage and a first sine wave signal; The second voltage domain circuit is used to amplify the first reference voltage by a first factor to a second reference voltage, and to perform proportional amplification processing on the first sine wave signal according to the second reference voltage to generate and output the second sine wave signal; The second sine wave signal is used to drive the transmitting electrode, and the amplitude of the second sine wave signal is greater than the amplitude of the first sine wave signal.

2. The driving circuit as described in claim 1, characterized in that, The first voltage domain circuit includes an adjustable operational amplifier unit, which is connected to the second voltage domain circuit. The adjustable operational amplifier unit is used to receive a reference voltage source and an adjustment command, and amplify the reference voltage source to the first reference voltage according to the adjustment command and output it.

3. The driving circuit as described in claim 2, characterized in that, The first voltage domain circuit further includes a digital-to-analog converter, a programmable gain amplifier, and a low-pass filter. The programmable gain amplifier is connected to the digital-to-analog converter and the low-pass filter, and the low-pass filter is connected to the second voltage domain circuit. The digital-to-analog converter is used to receive digital signals and generate stepped wave signals based on the digital signals. The programmable gain amplifier is used to receive the stepped wave signal and amplify the stepped wave signal by a second factor. The low-pass filter is used to smooth the stepped wave signal to generate the first sine wave signal.

4. The driving circuit as described in claim 1, characterized in that, The second voltage domain circuit includes a voltage amplification unit, a proportional amplification unit, and a driving unit. The voltage amplification unit is connected to the first voltage domain circuit, and the proportional amplification unit is connected to the voltage amplification unit, the driving unit, and the first voltage domain circuit. The voltage amplification unit is used to receive the first reference voltage and amplify the first reference voltage by a first factor to obtain the second reference voltage. The proportional amplification unit is used to proportionally amplify the first sine wave signal according to the second reference voltage, and generate and output the second sine wave signal. The driving unit is used to transmit the second sine wave signal to the transmitting electrode and to match the capacitive reactance of the transmitting electrode with the second sine wave signal.

5. The driving circuit as described in claim 2, characterized in that, The adjustable operational amplifier unit includes a first operational amplifier, a first resistor, and an adjustable resistor; The positive input terminal of the first operational amplifier is used to receive the reference voltage source, the inverting input terminal of the first operational amplifier is grounded through the first resistor, the inverting input terminal of the first operational amplifier is also connected to the output terminal of the first operational amplifier through the adjustable resistor, and the output terminal of the first operational amplifier is connected to the second voltage domain circuit. The adjustable resistor is used to adjust to the corresponding resistance value according to the adjustment command.

6. The driving circuit as described in claim 4, characterized in that, The voltage amplification unit includes a second operational amplifier, a second resistor, and a third resistor; The positive input terminal of the second operational amplifier is used to receive the first reference voltage, the inverting input terminal of the second operational amplifier is grounded through the second resistor, the inverting input terminal of the second operational amplifier is also connected to the output terminal of the second operational amplifier through the third resistor, and the output terminal of the second operational amplifier is connected to the proportional amplifier unit.

7. The driving circuit as described in claim 4, characterized in that, The proportional amplifier unit includes a third operational amplifier, a first capacitor, a second capacitor, a fourth resistor, a first switch, and a second switch; The positive input terminal of the third operational amplifier is used to receive the second reference voltage, and the negative input terminal of the third operational amplifier is used to receive the first sine wave signal through the first capacitor. The negative input terminal of the third operational amplifier is also connected to the output terminal of the third operational amplifier through the first switch. The negative input terminal of the third operational amplifier is also connected in series to the output terminal of the third operational amplifier through the second switch and the fourth resistor. The output terminal of the third operational amplifier is connected to the driving unit. The second capacitor is connected in parallel with the first switch.

8. The driving circuit as described in claim 4, characterized in that, The driving unit includes a fourth operational amplifier. The positive input terminal of the fourth operational amplifier is used to receive the second sine wave signal. The inverting input terminal of the fourth operational amplifier is connected to the output terminal of the fourth operational amplifier. The output terminal of the fourth operational amplifier is connected to the transmitting electrode.

9. The driving circuit as described in claim 3, characterized in that, The first voltage domain circuit further includes an analog multiplier, which is connected to the output of the low-pass filter and the second voltage domain circuit respectively. The analog multiplier is used to receive a time-domain window function, multiply the time-domain window function with the signal output by the low-pass filter, and obtain and output the first sine wave signal.

10. A touch chip, characterized in that, Includes the drive circuit as described in any one of claims 1 to 9.

11. A vehicle-mounted terminal device, characterized in that, Includes a touch screen and a touch chip as described in claim 10.

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