Touch control chip, screen module and electronic equipment

Abstract

The embodiment of the utility model provides a touch chip, a screen module and electronic equipment. The touch chip comprises a driving unit and an identification unit, the driving unit is electrically connected with the plurality of electrodes through a plurality of touch pins of the touch chip, the identification unit is electrically connected with the plurality of electrodes through the plurality of touch pins, and different touch pins are electrically connected with different electrodes; the driving unit is used for outputting a driving signal to the electrode through the touch pin; the recognition unit is used for receiving induction signals generated by the electrodes through the touch pins and converting the induction signals into recognition signals, the touch chip conducts touch detection according to the recognition signals, and the induction signals are generated by the electrodes receiving the driving signals. According to the scheme, the accuracy of touch recognition can be improved.

Description

Technical Field

[0001] This application relates to the field of touch chip technology, and more particularly to a touch chip, a screen module, and an electronic device. Background Technology

[0002] Touch technology is a human-computer interaction method. Users interact with electronic devices by touching or gesturing on the touch area of ​​the electronic device. With the development of smart devices, touch technology has become the mainstream operation method for mobile phones and other electronic devices. Mobile phones and other electronic devices receive touch commands input by users on the display screen and recognize the corresponding touch operations according to the touch commands.

[0003] Currently, touch detection in electronic device displays uses an electrode self-capacitance scheme, which detects touch by detecting changes in the electrode's capacitance to ground after a finger touches the screen.

[0004] However, when using a self-capacitive electrode scheme for touch detection, the electrode driving signal is sent from the recognition unit to the electrode. The amplifier in the recognition unit amplifies the flicker noise in the driving signal, resulting in significant noise interference during touch detection and low accuracy of touch recognition. Utility Model Content

[0005] In view of this, embodiments of this application provide a touch chip, a screen module, and an electronic device to at least partially solve the above-mentioned problems.

[0006] According to a first aspect of the present application, a touch chip is provided, disposed in an electronic device, the electronic device including a plurality of electrodes, the touch chip including: a driving unit and a recognition unit; the driving unit is electrically connected to the plurality of electrodes respectively through a plurality of touch pins of the touch chip, the recognition unit is electrically connected to the plurality of electrodes through the plurality of touch pins, different touch pins being electrically connected to different electrodes; the driving unit is used to output driving signals to the electrodes through the touch pins; the recognition unit is used to receive sensing signals generated by the electrodes through the touch pins and convert the sensing signals into recognition signals, the touch chip performing touch detection according to the recognition signals, wherein the sensing signals are generated by the electrodes that receive the driving signals.

[0007] In one possible implementation, the plurality of electrodes includes a plurality of lateral electrodes and / or a plurality of vertical electrodes, at least one of the plurality of lateral electrodes and the plurality of vertical electrodes serving as both a transmitting electrode and a receiving electrode. The touch chip sends the driving signal to the transmitting electrode through the touch pin and receives the sensing signal generated by the receiving electrode.

[0008] In one possible implementation, the driving unit includes: multiple current sources, multiple chopper sub-units, and multiple first filters; the first and second input terminals of each chopper sub-unit are electrically connected to two current sources, respectively; the first and second output terminals of each chopper sub-unit are connected to the input terminals of two first filters, respectively; the output terminals of the first filters are electrically connected to the electrodes; different first filters are electrically connected to different electrodes; different chopper sub-units are connected to different first filters; and different chopper sub-units are connected to different current sources; the current sources are used to generate first driving sub-signals; the chopper sub-units are used to chop the first driving sub-signals output from the two current sources to obtain two second driving sub-signals corresponding to the two connected first filters; the first filters are used to filter the second driving sub-signals to obtain driving signals corresponding to the connected electrodes.

[0009] In one possible implementation, the chopper subunit includes a first switch, a second switch, a third switch, and a fourth switch; the first terminal of the first switch serves as the first input terminal of the chopper subunit, the second terminal of the first switch serves as the first output terminal of the chopper subunit, the first terminal of the second switch is connected to the first terminal of the first switch, the second terminal of the second switch serves as the second output terminal of the chopper subunit, the first terminal of the third switch serves as the second input terminal of the chopper subunit, the second terminal of the third switch is connected to the second terminal of the first switch, the first terminal of the fourth switch is connected to the first terminal of the third switch, and the second terminal of the fourth switch is connected to the second terminal of the second switch; the first switch and the fourth switch have the same on / off state, the second switch and the third switch have the same on / off state, and the first switch and the third switch have opposite on / off states.

[0010] In one possible implementation, the driving unit further includes: a plurality of first buffers; the input terminal of the first buffer is connected to the output terminal of the first filter, the output terminal of the first buffer is connected to the touch pin, different first buffers are connected to different first filters, and different first buffers are connected to different touch pins; the first buffer is used to improve the driving capability of the driving signal.

[0011] In one possible implementation, the driving unit includes: at least one voltage source and a plurality of second buffers; the input terminals of the plurality of second buffers are all connected to the at least one voltage source, the output terminals of the plurality of second buffers are connected to the plurality of touch pins, and different second buffers are connected to different touch pins; the voltage source is used to generate the driving signal and transmit the driving signal to the touch pin through the second buffers.

[0012] In one possible implementation, the identification unit includes: an amplification module and a feedback module; the amplification module includes multiple amplification sub-modules, with different amplification sub-modules connected to different touch pins; the feedback module is configured to generate an error signal based on the output signal of each amplification sub-module, and transmit the error signal to each amplification sub-module respectively, wherein the error signal is used to indicate the average intensity of the interference signal coupled to each electrode; the amplification sub-module is configured to output an output signal based on the induced signal generated by the electrode connected to the amplification sub-module and the error signal, wherein the output signal is used to generate the identification signal corresponding to the electrode connected to the amplification sub-module.

[0013] In one possible implementation, the feedback module includes an accumulation submodule, a signal generation submodule, and a averaging submodule; multiple input terminals of the accumulation submodule are respectively connected to each of the amplification submodules; two input terminals of the averaging submodule are respectively connected to the accumulation submodule and the signal generation submodule, and the output terminal of the averaging submodule is respectively connected to the input terminals of each of the amplification submodules; the signal generation submodule is used to generate a reference voltage signal; the accumulation submodule is used to obtain an accumulated current based on the output signals of each of the amplification submodules and transmit the accumulated current to the averaging submodule, wherein the accumulated current is used to indicate the total strength of the interference signals coupled to each of the electrodes; the signal generation submodule is used to transmit the reference voltage signal to the averaging submodule; the averaging submodule is used to generate the error signal based on the accumulated current and the reference voltage signal and transmit the error signal to each of the amplification submodules respectively.

[0014] In one possible implementation, the amplification submodule includes a first amplifier, a first resistor, a second resistor, and a first capacitor; a first end of the first resistor is connected to the touch pin, and a second end of the first resistor is connected to the inverting input of the first amplifier; a first end of the second resistor is connected to the inverting input of the first amplifier, and a second end of the second resistor is connected to the output of the first amplifier; a first end of the first capacitor is connected to the inverting input of the first amplifier, and a second end of the first capacitor is connected to the output of the first amplifier; the non-inverting input of the first amplifier is connected to the averaging amplification submodule, and the output of the first amplifier is connected to the accumulator submodule; the first amplifier transmits the output signal to the accumulator submodule through its output terminal, and the averaging amplification submodule transmits the error signal to the non-inverting input of the first amplifier.

[0015] In one possible implementation, the accumulator submodule includes a plurality of third resistors; the first end of the third resistor is connected to the output of the first amplifier, the second end of the third resistor is connected to the input of the averaging submodule, the first ends of different third resistors are connected to different first amplifiers, and the second ends of different third resistors are connected to the same input of the averaging submodule.

[0016] In one possible implementation, the averaging submodule includes: a second amplifier, a second capacitor, a third capacitor, a fourth resistor, and a fifth resistor; the non-inverting input of the second amplifier is connected to the signal generation submodule, the inverting input of the second amplifier is connected to the first terminal of the fifth resistor, and the second terminal of the fifth resistor is connected to the second terminal of each of the third resistors; the output of the second amplifier is connected to the non-inverting input of each of the first amplifiers, the first terminal of the fourth resistor is connected to the output of the second amplifier, the second terminal of the fourth resistor is connected to the first terminal of the third capacitor, and the second terminal of the third capacitor is connected to the inverting input of the second amplifier; the first terminal of the second capacitor is connected to the output of the second amplifier, and the second terminal of the second capacitor is connected to the inverting input of the second amplifier.

[0017] In one possible implementation, the averaging submodule includes: a third amplifier, a fourth capacitor, a fifth capacitor, a sixth capacitor, a sixth resistor, a seventh resistor, and an eighth resistor; the non-inverting input of the third amplifier is connected to the signal generation submodule, the inverting input of the third amplifier is connected to the first terminal of the eighth resistor, and the second terminal of the eighth resistor is connected to the second terminal of each of the third resistors; the output of the third amplifier is connected to the non-inverting input of each of the first amplifiers; the first terminal of the sixth resistor is connected to the output of the third amplifier; the second terminal of the sixth resistor is connected to the first terminal of the fifth capacitor; the second terminal of the fifth capacitor is connected to the first terminal of the fourth capacitor; the second terminal of the fourth capacitor is connected to the first terminal of the seventh resistor; the second terminal of the seventh resistor is connected to the second terminal of the eighth resistor; the first terminal of the sixth capacitor is connected to the output of the third amplifier, and the second terminal of the sixth capacitor is connected to the second terminal of the fifth capacitor and the inverting input of the third amplifier.

[0018] In one possible implementation, the averaging submodule includes: a fourth amplifier, a seventh capacitor, an eighth capacitor, a ninth resistor, a tenth resistor, and an eleventh resistor; the non-inverting input of the fourth amplifier is connected to the signal generation submodule, the inverting input of the fourth amplifier is connected to the first terminal of the eleventh resistor, and the second terminal of the eleventh resistor is connected to the second terminals of each of the third resistors; the output of the fourth amplifier is connected to the non-inverting input of each of the first amplifiers, the first terminal of the ninth resistor is connected to the output of the fourth amplifier, the second terminal of the ninth resistor is connected to the first terminal of the eighth capacitor, the second terminal of the eighth capacitor is connected to the first terminal of the seventh capacitor and the inverting input of the fourth amplifier, the second terminal of the seventh capacitor is connected to the first terminal of the tenth resistor, and the second terminal of the tenth resistor is connected to the second terminal of the eleventh resistor.

[0019] In one possible implementation, the averaging submodule includes: a fifth amplifier, a ninth capacitor, a twelfth resistor, and a thirteenth resistor; the non-inverting input of the fifth amplifier is connected to the signal generation submodule, the inverting input of the fifth amplifier is connected to the first terminal of the thirteenth resistor, and the second terminal of the thirteenth resistor is connected to the second terminal of each of the third resistors; the first terminal of the twelfth resistor is connected to the output terminal of the fifth amplifier, the second terminal of the twelfth resistor is connected to the first terminal of the ninth capacitor, and the second terminal of the ninth capacitor is connected to the inverting input of the fifth amplifier.

[0020] In one possible implementation, the identification unit further includes multiple processing modules, each including a second filter, a sample-and-hold circuit, a third buffer, and an analog-to-digital converter (ADC). The output of the second filter is connected to the input of the sample-and-hold circuit, the output of the sample-and-hold circuit is connected to the input of the third buffer, and the output of the third buffer is connected to the input of the ADC. Different second terminals of the third resistor are connected to the inputs of the second filters in different processing modules, and the outputs of the third buffers in different processing modules are connected to the inputs of different ADCs. The second filter filters the input signal and removes the reference voltage signal from the input signal to obtain a touch voltage signal. The sample-and-hold circuit samples the touch voltage signal to obtain a target signal and holds the target signal. The third buffer transmits the target signal unchanged to the ADC module, allowing the ADC module to convert the target signal into the identification signal.

[0021] In one possible implementation, the non-inverting input of each of the first amplifiers is connected to the input of the second filter in one of the processing modules. According to a second aspect of this application, a touch chip is provided, including the touch chip described in the first aspect above.

[0022] According to a second aspect of the present application, a screen module is provided, including: a plurality of electrodes and a touch chip as described in the first aspect above; the electrodes are used to receive touch driving signals output by the touch chip, so that the screen module can recognize touch commands, wherein the electrodes are horizontal electrodes and / or vertical electrodes arranged on the touch screen.

[0023] According to a third aspect of the embodiments of this application, an electronic device is provided, including: a screen module as described in the second aspect above.

[0024] According to the embodiment of this application, the touch chip includes a driving unit and a recognition unit. The driving unit can send a driving signal to the electrode through the touch pin. The recognition unit can receive the sensing signal generated by the electrode through the touch pin and convert the sensing signal into a recognition signal. The touch chip can perform touch detection based on the recognition signal. Since the driving signal is not generated by the recognition unit but by the driving unit, the 1 / f noise in the driving signal will not be amplified by the amplifier inside the recognition unit. The 1 / f noise in the driving signal is small, thereby giving the effective touch signal in the sensing signal a larger dynamic range and improving the accuracy of touch recognition. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings.

[0026] Figure 1 This is a schematic diagram of a touch chip provided in an embodiment of this application;

[0027] Figure 2 This is a schematic diagram of a driving unit provided in an embodiment of this application;

[0028] Figure 3 This is a schematic diagram of a chopper processing method provided in an embodiment of this application;

[0029] Figure 4 This is a schematic diagram of a chopper subunit provided in an embodiment of this application;

[0030] Figure 5 This is a schematic diagram of another driving unit provided in an embodiment of this application;

[0031] Figure 6 This is a schematic diagram of yet another driving unit provided in an embodiment of this application;

[0032] Figure 7 This is a schematic diagram of another touch chip provided in an embodiment of this application;

[0033] Figure 8 This is a schematic diagram of another touch chip provided in an embodiment of this application;

[0034] Figure 9 This is a schematic diagram of another touch chip provided in an embodiment of this application;

[0035] Figure 10 This is a schematic diagram of a mean amplification submodule provided in an embodiment of this application;

[0036] Figure 11 This is a schematic diagram of another mean amplification submodule provided in an embodiment of this application;

[0037] Figure 12 This is a schematic diagram of another mean amplification submodule provided in an embodiment of this application;

[0038] Figure 13 This is a schematic diagram of another mean amplification submodule provided in an embodiment of this application;

[0039] Figure 14 This is a schematic diagram of the phase margin evaluation result of a touch chip provided in an embodiment of this application;

[0040] Figure 15 This is a schematic diagram illustrating the base suppression effect of the coding scheme provided in an embodiment of this application;

[0041] Figure 16 This is a schematic diagram illustrating the interference suppression effect provided in an embodiment of this application;

[0042] Figure 17 This is a schematic diagram of a self-contained touch diff effect provided in an embodiment of this application;

[0043] Figure 18 This is a schematic diagram of another self-contained touch diff effect provided in an embodiment of this application;

[0044] Figure 19 This is a schematic diagram of a screen module provided in an embodiment of this application;

[0045] Figure 20 This is a schematic diagram of a screen module provided in an embodiment of this application. Detailed Implementation

[0046] To enable those skilled in the art to better understand the technical solutions in the embodiments of this application, 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 only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art should fall within the protection scope of the embodiments of this application.

[0047] 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” 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.

[0048] It should be understood that although the terms first, second, third, etc., may be used in this application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0049] As mentioned earlier, touch technology is a human-computer interaction method. Users interact with electronic devices by touching or gesturing on the touch area. With the development of smart devices, touch technology has become the mainstream operating method for mobile phones and other electronic devices. Mobile phones and other electronic devices receive touch commands input by users on the display screen and recognize the corresponding touch operations based on the commands. Currently, touch detection in electronic device display screens uses an electrode self-capacitance scheme, which detects touch by detecting changes in the capacitance of the electrodes to ground after a finger touches the screen. However, when using the electrode self-capacitance scheme for touch detection, the electrode driving signal is sent from the recognition unit to the electrode. The amplifier in the recognition unit amplifies the flicker noise in the driving signal, resulting in significant noise interference during touch detection and low accuracy of touch recognition.

[0050] This application provides a touch chip, which includes a driving unit and a recognition unit. The driving unit can send driving signals to electrodes through touch pins, and the recognition unit can receive sensing signals generated by the electrodes through touch pins and convert the sensing signals into recognition signals. The touch chip can perform touch detection based on the recognition signals. Since the driving signals are not generated by the recognition unit but by the driving unit, the 1 / f noise in the driving signals will not be amplified by the amplifier inside the recognition unit. The 1 / f noise in the driving signals is small, thereby giving the effective touch signals in the sensing signals a larger dynamic range and improving the accuracy of touch recognition.

[0051] Figure 1 This is a schematic diagram of a touch chip 10 provided in an embodiment of this application. The touch chip 10 is disposed in an electronic device, which includes multiple electrodes 21, such as... Figure 1 As shown, the touch chip 10 includes a driving unit 12 and a recognition unit 13. The driving unit 12 is electrically connected to multiple electrodes 21 through multiple touch pins 11 of the touch chip 10. The recognition unit 13 is electrically connected to multiple electrodes 21 through multiple touch pins 11. Different touch pins 11 are electrically connected to different electrodes 21. The driving unit 12 can output driving signals to the electrodes 21 through the touch pins 11. The recognition unit 13 can receive the sensing signals generated by the electrodes through the touch pins 11 and convert the sensing signals into recognition signals. The touch chip 10 performs touch detection based on the recognition signals. The sensing signals are generated by the electrodes 21 that receive the driving signals.

[0052] The driving unit 12 in the touch chip 10 can send driving signals to multiple electrodes 21 through multiple touch pins 11. Different touch pins 11 are connected to different electrodes 21. The electrodes 21 generate sensing signals in response to the driving signals. Specifically, after the driving unit 12 sends driving signals to the electrodes 21 through the touch pins 11, the electrodes 21 receive the driving signals. When the finger is not touching, due to the capacitance to ground of the electrodes 21, the electrodes 21 generate a first sensing signal after receiving the driving signal. When the finger touches, the capacitance to ground of the electrodes 21 changes, and the first sensing signal generated by the electrodes 21 changes to a second sensing signal. The difference between the first sensing signal and the second sensing signal is the effective touch signal generated after the finger touches. The touch chip 10 can determine the touch position of the finger based on the amount of signal change between the first sensing signal and the second sensing signal.

[0053] It should be understood that the sensing signal in this embodiment is generated by the electrode 21 that receives the driving signal. That is, the touch detection scheme in this embodiment is to perform touch detection through the self-capacitance of the electrode 21. Unlike the self-capacitance detection scheme in the prior art, the driving signal in this embodiment is not generated by the recognition unit 13, but by the driving unit 12. Therefore, the flicker noise (1 / f noise) in the driving signal will not be amplified by the amplifier inside the recognition unit 13, and the 1 / f noise in the driving signal is relatively small.

[0054] In this embodiment, the touch chip 10 includes a driving unit 12 and a recognition unit 13. The driving unit 12 can send a driving signal to the electrode 21 through the touch pin 11. The recognition unit 13 can receive the sensing signal generated by the electrode through the touch pin 11 and convert the sensing signal into a recognition signal. The touch chip 10 can perform touch detection based on the recognition signal. Since the driving signal is not generated by the recognition unit 13 but by the driving unit 12, the 1 / f noise in the driving signal will not be amplified by the amplifier inside the recognition unit 13. The 1 / f noise in the driving signal is small, thereby giving the effective touch signal in the sensing signal a larger dynamic range and improving the accuracy of touch recognition.

[0055] In one possible implementation, the plurality of electrodes 21 include a plurality of lateral electrodes and / or a plurality of longitudinal electrodes, at least one of the plurality of lateral electrodes and the plurality of longitudinal electrodes serving as both a driving electrode 21 and a receiving electrode. The touch chip 10 sends a driving signal to the driving electrode 21 through the touch pin 11 and receives a sensing signal generated by the transmitting electrode, which serves as the receiving electrode.

[0056] At least one of the multiple horizontal electrodes and multiple vertical electrodes serves as both a transmitting electrode and a receiving electrode. The touch chip 10 sends a driving signal to the transmitting electrode through the driving unit 12 and performs touch detection based on the sensing signal output by the receiving electrode. Specifically, the driving unit 12 outputs driving signals to the multiple horizontal electrodes (transmitting electrodes), and the recognition unit 13 receives the sensing signals output by the multiple horizontal electrodes (receiving electrodes); or the driving unit 12 outputs driving signals to the multiple vertical electrodes (transmitting electrodes), and the recognition unit 13 receives the sensing signals output by the multiple vertical electrodes (receiving electrodes); or the driving unit 12 simultaneously outputs driving signals to the multiple horizontal electrodes and the multiple vertical electrodes, and the recognition unit 13 simultaneously receives the sensing signals output by the multiple horizontal electrodes and the multiple vertical electrodes.

[0057] In one example, the touch chip 10 can simultaneously output drive signals to the horizontal and vertical electrodes, and obtain the X-axis and Y-axis coordinates of the touch position based on the second sensing signals generated by the horizontal and vertical electrodes. In another example, the touch chip 10 can output drive signals to only the horizontal or vertical electrodes, and detect the X-axis or Y-axis coordinates of the touch position based on the sensing signals generated by the horizontal or vertical electrodes. That is, only detecting the X-axis or Y-axis coordinates of the touch position can be applied to scenarios with low detection accuracy requirements. The specific detection method can be set as needed and is not limited here.

[0058] In this embodiment, the driving unit 12 can send a driving signal to the electrode 21 via the touch pin 11. The electrode 21 can generate a sensing signal through self-capacitance. The recognition unit 13 receives the sensing signal transmitted by the electrode and generates a recognition signal based on the sensing signal. The touch chip 10 performs touch detection based on the recognition signal, thus realizing touch detection through the self-capacitance of the electrode 21. Since the driving signal is generated by the driving unit 12 rather than the recognition unit 13, the 1 / f noise in the driving signal will not be amplified by the amplifier inside the recognition unit 13. The 1 / f noise in the driving signal is small, thereby giving the effective touch signal in the sensing signal a larger dynamic range and improving the accuracy of touch recognition.

[0059] In one possible implementation, the driving unit 12 can output a driving signal in the form of a current to the driving electrode 21. Figure 2 This is a schematic diagram of a driving unit provided in an embodiment of this application, such as... Figure 2 As shown, the driving unit 12 includes multiple current sources 121, multiple chopper subunits 122, and multiple first filters 123.

[0060] The first and second input terminals of the chopper subunit 122 are electrically connected to two current sources 121, respectively. The first and second output terminals of the chopper subunit 122 are connected to the input terminals of two first filters 123, respectively. The output terminal of the first filter 123 is electrically connected to the electrode 21. Different first filters 123 are electrically connected to different electrodes 21. Different chopper subunits 122 are connected to different first filters 123, and different chopper subunits 122 are connected to different current sources 121.

[0061] The current source 121 can generate a first driving sub-signal. The chopper sub-unit 122 can chop the first driving sub-signals output by the two current sources 121 to obtain two second driving sub-signals corresponding to the two connected first filters 123. The first filter 123 can filter the second driving sub-signals to obtain a driving signal corresponding to the connected electrode 21.

[0062] The driving unit 12 can output a driving signal in the form of current. The driving unit 12 generates a first driving sub-signal through the current source 121. In one example, the current source 121 can generate a sine wave current signal. The peak value of the sine wave current signal is 1 to 15 mA, preferably 5 mA, and the frequency of the current signal is 50 kHz to 500 kHz, preferably 100 kHz. In order to reduce the 1 / f noise in the first driving sub-signal generated by the current source 121, multiple chopper sub-units 122 and multiple first filters 123 are provided. The input terminal of a chopper sub-unit 122 includes a first input terminal and a second input terminal. The output terminal of a chopper sub-unit 122 includes a first output terminal and a second output terminal. The first input terminal and the second input terminal of the chopper sub-unit 122 are respectively connected to different current sources 121. The first output terminal and the second output terminal of the chopper sub-unit 122 are respectively connected to different first filters 123. That is, the number of current sources 121 and the number of first filters 123 are the same. The number of chopper sub-units 122 is half the number of current sources 121 and the number of first filters 123.

[0063] The chopper subunit 122 can chop the signal according to the first driving signal generated by the two current sources 121, modulating the 1 / f noise in the first driving signal to a high frequency to obtain the second driving signal. In one example, the frequency range of the chopper subunit 122 is 1MHz to 10MHz, preferably 5MHz. The second driving signal can be filtered by the first filter 123 to remove the 1 / f noise modulated to the high frequency to obtain the driving signal. In one example, the first filter 123 can be a low-pass filter. Optionally, the cutoff frequency of the first filter 123 is greater than or equal to 500kHz and less than the frequency of the chopper subunit 122. Figure 3 This is a schematic diagram of a chopper processing method provided in an embodiment of this application, as shown below. Figure 3 As shown, the 1 / f noise originally in the low-frequency band is modulated to the frequency points of 1*fchopper, 3*fchopper...N*fchopper after being chopped by the chopper subunit 122. fchopper is used to characterize the frequency of the chopper subunit 122. Since the cutoff frequency of the first filter 123 is greater than or equal to the frequency of the drive signal and less than the frequency of the chopper subunit 122, the 1 / f noise of the current source 121 can be reduced without affecting the drive signal, thereby reducing the power consumption requirements of the design area of ​​the current source 121.

[0064] In this embodiment, the driving unit 12 includes multiple current sources 121, multiple chopper subunits 122, and multiple first filters 123. The multiple chopper subunits 122 and the multiple first filters 123 can filter out 1 / f noise in the current driving signal generated by the current sources 121, reducing the 1 / f noise in the driving signal and making the 1 / f noise in the sensing signal smaller. This results in a larger dynamic range for the effective touch signal in the sensing signal, improving the accuracy of touch recognition. Furthermore, it reduces the power consumption requirements on the design area of ​​the current sources 121, lowers the design difficulty of the current sources 121, and reduces costs.

[0065] The following provides a specific implementation of the chopper subunit 122. Figure 4 This is a schematic diagram of a chopper subunit provided in an embodiment of this application, as shown below. Figure 4 As shown, the chopper subunit 122 includes a first switch K1, a second switch K2, a third switch K3, and a fourth switch K4.

[0066] The first terminal of the first switch K1 serves as the first input terminal of the chopper subunit 122, and the second terminal of the first switch K1 serves as the first output terminal of the chopper subunit 122. The first terminal of the second switch K2 is connected to the first terminal of the first switch K1, and the second terminal of the second switch K2 serves as the second output terminal of the chopper subunit 122. The first terminal of the third switch K3 serves as the second input terminal of the chopper subunit 122, and the second terminal of the third switch K3 is connected to the second terminal of the first switch K1. The first terminal of the fourth switch K4 is connected to the first terminal of the third switch K3, and the second terminal of the fourth switch K4 is connected to the second terminal of the second switch K2. The on / off states of the first switch K1 and the fourth switch K4 are the same, the on / off states of the second switch K2 and the third switch K3 are the same, and the on / off states of the first switch K1 and the third switch K3 are opposite.

[0067] The chopper subunit 122 can perform chopping processing on the first drive signals output from the two current sources 121 through four switches. The first switch K1 is connected to the first current source 121 and the first first filter 123 respectively. The second switch K2 is connected to the second current source 121 and the first first filter 123 respectively. The third switch K3 is connected to the first current source 121 and the second first filter 123 respectively. The fourth switch K4 is connected to the second current source 121 and the second first filter 123 respectively. The first switch K1 and the fourth switch K4 have the same on / off state. The second switch K2 and the third switch K3 have the same on / off state. The first switch K1 and the third switch K3 have opposite on / off states. By alternately switching the first switch K1 and the third switch K3 on and off, the first drive signal received at the first terminal of the first switch K1 and the first drive signal received at the first terminal of the third switch K3 can be chopping processed.

[0068] It should be understood that the embodiments of this application provide a specific implementation of a chopper subunit 122. The chopper subunit 122 in this application may also be of other structures, and the specific structure of the chopper subunit 122 is not limited in this application.

[0069] In this embodiment, the chopper subunit 122 includes a first switch K1, a second switch K2, a third switch K3, and a fourth switch K4. By switching the first switch K1, the second switch K2, the third switch K3, and the fourth switch K4 on and off, the first driving signal output by the two current sources 121 can be chopper-processed. The 1 / f noise in the first driving signal can be modulated to a high frequency, so that the 1 / f noise modulated to a high frequency can be filtered out by the first filter 123, making the 1 / f noise in the sensing signal smaller. This results in the effective touch signal in the sensing signal having a larger dynamic range and improving the accuracy of touch recognition.

[0070] In one possible implementation, the drive unit 12 may further include a first buffer 124. Figure 5 This is a schematic diagram of another driving unit provided in an embodiment of this application, such as... Figure 5 As shown, the driving unit 12 also includes a plurality of first buffers 124. The input terminal of the first buffer 124 is connected to the output terminal of the first filter 123, and the output terminal of the first buffer 124 is connected to the touch pin 11. Different first buffers 124 are connected to different first filters 123, and different first buffers 124 are connected to different touch pins 11. The first buffer 124 can improve the driving capability of the driving signal.

[0071] In one example, the first buffer 124 can be a buffer, which can improve the driving capability of the drive signal.

[0072] In this embodiment of the application, the driving unit 12 further includes a plurality of first buffers 124. The first buffers 124 can transmit the driving signal to the touch pin 11, thereby transmitting the driving signal to the electrode 21 through the touch pin 11. The first buffers 124 can make the driving signal unaffected by the attenuation of the signal due to the input impedance, thereby improving the driving capability of the driving signal.

[0073] In one possible implementation, the driving unit 12 can also generate a voltage signal to drive the electrode 21. Figure 6 This is a schematic diagram of another driving unit provided in the embodiments of this application, as shown below. Figure 6As shown, the driving unit 12 includes at least one voltage source 125 and multiple second buffers 126. The input terminals of the multiple second buffers 126 are all connected to at least one voltage source 125, and the output terminals of the multiple second buffers 126 are connected to multiple touch pins 11. Different second buffers 126 are connected to different touch pins 11. The voltage source 125 can generate a driving signal and transmit the driving signal to the touch pin 11 through the second buffers 126.

[0074] Voltage source 125 can generate one of the following drive signals: square wave, sine wave, or trapezoidal wave. After generating the drive signal, voltage source 125 can transmit the drive signal to touch pin 11 through second buffer 126, thereby driving electrode 21 through touch pin 11. In one example, second buffer 126 can be a buffer.

[0075] Optionally, the drive unit 12 may include only one voltage source 125, which is connected to multiple second buffers 126. Alternatively, the drive unit 12 may include multiple voltage sources 125, which are connected to multiple second buffers 126. Different voltage sources 125 are connected to different second buffers 126. Or, the drive unit 12 may include multiple voltage sources 125, with one voltage source 125 connected to multiple second buffers 126.

[0076] In this embodiment, the driving unit 12 includes at least one voltage source 125 and a plurality of second buffers 126. The at least one voltage source 125 can generate a driving signal, and the plurality of second buffers 126 can transmit the driving signal to a plurality of touch pins 11, thereby driving a plurality of electrodes 21 through the plurality of touch pins 11. Since the driving signal does not pass through the amplifier inside the recognition unit 13, the 1 / f noise in the driving signal will not be amplified by the amplifier inside the recognition unit 13, and the 1 / f noise in the driving signal is small, thereby giving the effective touch signal in the sensing signal a larger dynamic range and improving the accuracy of touch recognition.

[0077] Figure 7 This is a schematic diagram of another touch chip provided in an embodiment of this application. Figure 7 As shown, the recognition unit 13 includes an amplification module 131 and a feedback module 132. The amplification module 131 includes multiple amplification sub-modules 1311, and different amplification sub-modules 1311 are connected to different touch pins.

[0078] A feedback module 132 is connected to the output terminals of multiple amplification submodules 1311. The feedback module 132 can generate an error signal based on the output signal from each amplification submodule 1311 and transmit the error signal to each amplification submodule 1311 respectively. The error signal can indicate the average intensity of the interference signal coupled to each electrode 21. After receiving the induced signal and error signal input from the connected electrode 21, the amplification submodule 1311 can output an output signal based on the received input signal and error signal. The output signal is used to generate an identification signal corresponding to the electrode 21 connected to the amplification submodule 1311.

[0079] In this embodiment, the amplification submodule 1311 can receive the sensing signal generated by the electrode through the touch pin and output the output signal based on the sensing signal. The feedback module 132 can generate an error signal according to the output signal of each amplification submodule 1311, so that the error signal can indicate the average intensity of the interference signal coupled by each electrode 21. After the error signal is fed back to the amplification submodule 1311, the amplification submodule 1311 can suppress the interference signal in the sensing signal according to the error signal, thereby reducing the interference signal in the output signal, so that the effective touch signal in the output signal has a larger dynamic range, thereby improving the accuracy of touch recognition when touch recognition is based on the output signal.

[0080] In one possible implementation, the feedback module 132 can accumulate the output signals of each amplification submodule 1311 and then calculate the average of the accumulated results as the error signal.

[0081] Figure 8 This is a schematic diagram of another touch chip provided in an embodiment of this application. Figure 8 As shown, the feedback module 132 includes an accumulation submodule 1321, a signal generation submodule 1322, and an average amplification submodule 1323.

[0082] The multiple input terminals of the accumulator submodule 1321 are connected to each amplifier submodule 1311 respectively. The two input terminals of the averaging amplifier submodule 1323 are connected to the accumulator submodule 1321 and the signal generation submodule 1322 respectively, and the output terminal of the averaging amplifier submodule 1323 is connected to the input terminals of each amplifier submodule 1311 respectively.

[0083] The accumulator submodule 1321 can obtain the accumulated current based on the output signals of each amplifier submodule 1311, and transmit the accumulated current to the averaging amplifier submodule 1323. The accumulated current can indicate the total strength of the interference signals coupled to each electrode 21. The signal generation submodule 1322 can transmit a reference voltage signal to the averaging amplifier submodule 1323. The averaging amplifier submodule 1323 can generate an error signal based on the accumulated current and the reference voltage signal, and transmit the error signal to each amplifier submodule 1311 respectively.

[0084] The output signal of the amplification submodule 1311 is a voltage signal. The accumulation submodule 1321 can convert the voltage signal into a current signal, and then accumulate the converted current signals to obtain the accumulated current, so that the accumulated current can indicate the total strength of the interference signal coupled to each electrode 21.

[0085] Since touch chips typically use a single power supply, the signal generation submodule 1322 transmits a reference voltage signal as a bias to the averaging amplification submodule 1323, so that the averaging amplification submodule 1323 performs averaging and amplification processing based on the reference voltage signal and the accumulated current, and the generated error signal is a positive signal, which in turn makes the output signal of the amplification submodule 1311 also a positive signal, ensuring that the subsequent circuit can process normally.

[0086] The average amplification submodule 1323 generates an error signal that indicates the average intensity of the interference signal coupled to each electrode 21 based on the reference voltage signal and the accumulated current, and makes the error signal a positive signal. Then, the error signal is fed back to each amplification submodule 1311. The amplification submodule 1311 can suppress the interference signal in the input signal based on the error signal, thereby reducing the interference signal in the output signal of the amplification submodule 1311.

[0087] In this embodiment, the accumulator submodule 1321 obtains the accumulated current based on the output signals of each amplifier submodule 1311, so that the accumulated current can indicate the total intensity of the interference signals coupled to each electrode. After transmitting the accumulated current to the averaging amplifier submodule 1323, the averaging amplifier submodule 1323 obtains the error signal by amplification, so that the error signal can indicate the average intensity of the interference signals coupled to each electrode 21. Then, the error signal is fed back to each amplifier submodule 1311, so that the amplifier submodule 1311 suppresses the display interference and the basic signal in the input signal, thereby reducing the interference signal included in the output signal of the amplifier submodule 1311.

[0088] In one possible implementation, the amplification submodule 1311 can use negative feedback to suppress display interference and the fundamental signal in the input signal.

[0089] Figure 9 This is a schematic diagram of another touch chip provided in an embodiment of this application. Figure 9 As shown, the amplification submodule 1311 includes a first amplifier A1, a first resistor R1, a second resistor R2, and a first capacitor C1.

[0090] The first end of the first resistor R1 is connected to the touch pin, and the second end of the first resistor R1 is connected to the inverting input of the first amplifier A1. Multiple touch pins are connected to different amplification submodules 1311, and the first end of the first resistor R1 in different amplification submodules 1311 is connected to different touch pins.

[0091] The first end of the second resistor R2 is connected to the inverting input terminal of the first amplifier A1, and the second end of the second resistor R2 is connected to the output terminal of the first amplifier A1.

[0092] The first terminal of the first capacitor C1 is connected to the inverting input terminal of the first amplifier A1, and the second terminal of the first capacitor C1 is connected to the output terminal of the first amplifier A1.

[0093] The non-inverting input of the first amplifier A1 is connected to the averaging submodule 1323, and multiple non-inverting inputs of the first amplifier A1 are connected to the output of the averaging submodule 1323. The output of the first amplifier A1 is connected to the accumulator submodule 1321, and the outputs of multiple first amplifier A1 are respectively connected to multiple inputs of the accumulator submodule 1321. The first amplifier A1 transmits its output signal to the accumulator submodule 1321 through its output, and the averaging submodule 1323 transmits the error signal to the non-inverting input of the first amplifier A1.

[0094] The amplification submodule 1311 includes a first amplifier A1. The inverting input terminal of the first amplifier A1 is connected to the electrode 21 through a first resistor R1. The voltage signal output by the electrode 21 is converted into a current signal after passing through the first resistor R1 and input to the first amplifier A1. The first amplifier A1 outputs a voltage signal. Therefore, the amplification submodule 1311 is implemented as a transimpedance amplifier.

[0095] It should be noted that the first amplifier A1 can be a programmable gain amplifier (PGA).

[0096] In this embodiment, the amplification submodule 1311 includes a first amplifier A1. The non-inverting input of the first amplifier A1 is connected to the averaging amplification submodule 1323. The inverting input of the first amplifier A1 is connected to the electrode via a touch pin through a first resistor R1. The averaging amplification submodule 1323 transmits the error signal to the non-inverting input of the first amplifier A1. The induced signal input from the touch pin is input to the inverting input of the first amplifier A1 after passing through the first resistor R1. When the amplification submodule 1311 reaches a steady state, the non-inverting and inverting inputs of the first amplifier A1 are virtually shorted, and the interference signal in the voltage signal input to the inverting input of the first amplifier A1 is suppressed, so that the voltage signal output from the first amplifier A1 includes less interference signal. The interference signal in the input signal is eliminated through negative feedback, so that the effective touch signal in the voltage signal output by the first amplifier A1 has a large dynamic range. The voltage signal output by the first amplifier A1 is processed by the subsequent circuit and used for touch recognition, thereby improving the accuracy of touch recognition.

[0097] In one possible implementation, such as Figure 9 As shown, the accumulator submodule 1321 includes multiple third resistors R3. The first end of each third resistor R3 is connected to the output of the first amplifier A1, and the second end of each third resistor R3 is connected to the input of the averaging amplifier submodule 1323. Each of the multiple third resistors R3 can be matched to each first amplifier A1. The first ends of different third resistors R3 are connected to the outputs of different first amplifiers A1, and the second ends of different third resistors R3 are connected to the same input of the averaging amplifier submodule 1323.

[0098] Each third resistor R3 may have the same resistance value or different resistance values. In this embodiment, the resistance value of the third resistor R3 is not limited.

[0099] In this embodiment, the amplification submodule 1311 is implemented as a transimpedance amplifier. The first amplifier A1 outputs a voltage signal, which is converted into a current signal through the third resistor R3. The second terminal of each third resistor R3 is connected to the same input terminal of the averaging amplification submodule 1323, that is, the current input to the averaging amplification submodule 1323 of the accumulation submodule 1321 is the accumulated current of each channel. Since the voltage signal output by the first amplifier A1 includes interference signals, and the current signal converted from the voltage signal through the third resistor R3 also includes interference signals, the accumulated current can indicate the total intensity of the interference signals coupled by each electrode 21. Since the interference signals coupled by different electrodes 21 are basically the same, an error signal is determined based on the accumulated current to indicate the average intensity of the interference signals coupled by each electrode 21, ensuring that the error signal can accurately reflect the interference signals coupled by the electrode 21.

[0100] In one possible implementation, the mean amplification submodule 1323 amplifies the mean error (error signal) of different channels and then feeds it back to the amplification submodule 1311 of each channel for displaying the suppression of interference and the fundamental signal. Figure 9 As shown, the averaging submodule 1323 includes an amplifier 13231 and a loop stability compensation unit 13232. When the resistance values ​​of each third resistor R3 are the same, the ratio of the resistance value of the third resistor R3 to the resistance value of the loop stability compensation unit 13232 is equal to the number of third resistors R3. Each amplification submodule 1311, together with the accumulation submodule 1321, the signal generation submodule 1322, and the averaging submodule 1323, can form a feedback loop. The loop stability compensation unit 13232 can achieve stability compensation of the feedback loop through a combination of resistors and capacitors, making the phase margin greater than 45° and the gain margin greater than 10dB, thereby ensuring that the feedback loop will not oscillate and ensuring the stability of the touch chip 10 in processing the touch signal.

[0101] Since the loop stability compensation unit 13232 can compensate for the stability of the feedback loop through a combination of resistors and capacitors, the loop stability compensation unit 13232 has a variety of different forms, which in turn makes the average amplification submodule 1323 have a variety of circuit structures. Figures 10 to 13 Four circuit structures of the averaging submodule are shown. The possible circuit structures of the averaging submodule 1323 are described below.

[0102] like Figure 10 As shown, the averaging submodule 1323 includes a second amplifier A2, a second capacitor C2, a third capacitor C3, a fourth resistor R4, and a fifth resistor R5. The non-inverting input of the second amplifier A2 is connected to the signal generation submodule 1322. The inverting input of the second amplifier A2 is connected to the first terminal of the fifth resistor R5. The second terminal of the fifth resistor R5 is connected to the second terminal of each of the third resistors R3. The output of the second amplifier A2 is connected to the non-inverting input of each of the first amplifiers A1. The first terminal of the fourth resistor R4 is connected to the output of the second amplifier A2. The second terminal of the fourth resistor R4 is connected to the first terminal of the third capacitor C3. The second terminal of the third capacitor C3 is connected to the inverting input of the second amplifier A2. The first terminal of the second capacitor C2 is connected to the output of the second amplifier A2. The second terminal of the second capacitor C2 is connected to the inverting input of the second amplifier A2.

[0103] like Figure 11As shown, the averaging submodule 1323 includes a third amplifier A3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a sixth resistor R6, a seventh resistor R7, and an eighth resistor R8. The non-inverting input of the third amplifier A3 is connected to the signal generation submodule 1322. The inverting input of the third amplifier A3 is connected to the first terminal of the eighth resistor R8. The second terminal of the eighth resistor R8 is connected to the second terminal of each of the third resistors R3. The output of the third amplifier A3 is connected to the non-inverting input of each of the first amplifiers A1. The first terminal of the sixth resistor R6 is connected to the output of the third amplifier A3. The second terminal of the sixth resistor R6 is connected to the first terminal of the fifth capacitor C5. The second terminal of the fifth capacitor C5 is connected to the first terminal of the fourth capacitor C4. The second terminal of the fourth capacitor C4 is connected to the first terminal of the seventh resistor R7. The second terminal of the seventh resistor R7 is connected to the second terminal of the eighth resistor R8. The first terminal of the sixth capacitor C6 is connected to the output of the third amplifier A3. The second terminal of the sixth capacitor C6 is connected to the second terminal of the fifth capacitor C5 and the inverting input of the third amplifier A3.

[0104] like Figure 12 As shown, the averaging submodule 1323 includes a fourth amplifier A4, a seventh capacitor C7, an eighth capacitor C8, a ninth resistor R9, a tenth resistor R10, and an eleventh resistor R11. The non-inverting input of the fourth amplifier A4 is connected to the signal generation submodule 1322, and the inverting input of the fourth amplifier A4 is connected to the first terminal of the eleventh resistor R11. The second terminal of the eleventh resistor R11 is connected to the second terminal of each of the third resistors R3. The output of the fourth amplifier A4 is connected to the non-inverting input of each of the first amplifiers A1. The first terminal of the ninth resistor R9 is connected to the output of the fourth amplifier A4, and the second terminal of the ninth resistor R9 is connected to the first terminal of the eighth capacitor C8. The second terminal of the eighth capacitor C8 is connected to the first terminal of the seventh capacitor C7 and the inverting input of the fourth amplifier A4. The second terminal of the seventh capacitor C7 is connected to the first terminal of the tenth resistor R10, and the second terminal of the tenth resistor R10 is connected to the second terminal of the eleventh resistor R11.

[0105] like Figure 13 As shown, the average amplification submodule 1323 includes a fifth amplifier A5, a ninth capacitor C9, a twelfth resistor R12, and a thirteenth resistor R13. The non-inverting input of the fifth amplifier A5 is connected to the signal generation submodule 1322, and the inverting input of the fifth amplifier A5 is connected to the first terminal of the thirteenth resistor R13. The second terminal of the thirteenth resistor R13 is connected to the second terminal of each of the third resistors R3. The first terminal of the twelfth resistor R12 is connected to the output terminal of the fifth amplifier A5, and the second terminal of the twelfth resistor R12 is connected to the first terminal of the ninth capacitor C9. The second terminal of the ninth capacitor C9 is connected to the inverting input of the fifth amplifier A5.

[0106] In this embodiment, the mean amplification submodule 1323 includes a loop stability compensation unit formed by a combination of resistors and capacitors. While the mean amplification submodule 1323 obtains the mean error (error signal) of each channel by amplification, the loop stability compensation unit can correct the stability of the feedback loop, achieving a phase margin greater than 45° and a gain margin greater than 10dB, thereby ensuring that the feedback loop will not oscillate and ensuring the stability of the touch chip 10 in processing the touch signal.

[0107] In one possible implementation, the touch chip 10 also includes multiple processing modules. The output terminals of different amplification submodules 1311 are connected to different processing modules through accumulation submodules 1321. The multiple output terminals of accumulation submodules 1321 are respectively connected to different processing modules. After the output signal of amplification submodule 1311 is processed by accumulation submodule 1321, it is filtered by the corresponding processing module.

[0108] like Figure 9 As shown, the touch chip 10 includes multiple processing modules 133, each of which includes a second filter 1331, a sample-and-hold circuit 1332, a third buffer 1333, and an analog-to-digital converter 1334.

[0109] The output of the second filter 1331 is connected to the input of the sample-and-hold circuit 1332. The output of the sample-and-hold circuit 1332 is connected to the input of the third buffer 1333. The output of the third buffer 1333 is connected to the input of the analog-to-digital converter 1334. The second terminal of different third resistors R3 is connected to the input of the second filter 1331 in different processing modules 133. The output of the third buffer 1333 in different processing modules 133 is connected to the input of different analog-to-digital converters 1334.

[0110] The second filter 1331 filters the input signal and removes the reference voltage signal to obtain the touch voltage signal. The sample-and-hold circuit 1332 samples the touch voltage signal to obtain the target signal and holds the target signal. After the sample-and-hold circuit 1332 transmits the target signal to the third buffer 1333, the analog-to-digital converter 1334 can extract the target signal from the third buffer 1333. The third buffer 1333 ensures that the target signal remains unchanged during the extraction process by the analog-to-digital converter 1334, thereby ensuring that the target signal has sufficient driving capability so that the analog-to-digital converter 1334 can convert the target signal into a digital signal.

[0111] In this embodiment, the switching submodule 1322 transmits a reference voltage signal to the averaging amplification submodule 1323. The averaging amplification submodule 1323 transmits an error signal to the amplification submodule 1311 based on the accumulated current and the reference voltage signal. The amplification submodule 1311 outputs an output signal based on the error signal and the input signal from the electrode input. The output signal is converted into the input signal of the second filter 1331 through the third resistor R3. Therefore, the input signal of the second filter 1331 contains the reference voltage signal. While filtering its input signal, the second filter 1331 can remove the reference voltage signal mixed in its input signal, so that the touch voltage signal output by the second filter 1331 can accurately indicate the touch state, thereby ensuring the accuracy of touch recognition.

[0112] The analog-to-digital converter 1334 may not be able to process the touch voltage signal output by the second filter 1331 in a timely manner. The sample-and-hold circuit 1332 can hold the touch voltage signal, so that after processing the preceding signals, the analog-to-digital converter 1334 can process the touch voltage signal held by the sample-and-hold circuit 1332, ensuring that all touch voltage signals output by the second filter 1331 can be processed by the analog-to-digital converter 1334, and avoiding touch recognition errors caused by some touch voltage signals output by the second filter 1331 not being processed by the analog-to-digital converter 1334.

[0113] In one possible implementation, the non-inverting input of each first amplifier A1 is connected to the input of a second filter 1331 in a processing module 133.

[0114] The second end of each third resistor R3 is connected to a processing module 133. The second ends of different third resistors R3 are connected to different processing modules 133. The non-inverting input of each first amplifier A1 is connected to the same processing module 133. Therefore, the total number of processing modules 133 is equal to the number of third resistors R3 plus 1.

[0115] The non-inverting input of each first amplifier A1 is connected to the output of the averaging submodule 1323. Therefore, the processing module 133 is connected to the output of the averaging submodule 1323. The error signal output by the averaging submodule 1323 is transmitted to the processing module 133, which is connected to the non-inverting input of each first amplifier A1. Specifically, the error signal is transmitted to the input of the second filter 1331. The second filter 1331 filters the input error signal and removes the reference voltage signal from the error signal. Then, the processed error signal is transmitted to the connected sample-and-hold circuit 1332.

[0116] It should be noted that the processing module 133 processes the error signal in the same way as it processes the signal output from the second terminal of the third resistor R3, and will not be described again here.

[0117] When performing touch recognition, the touch position needs to be determined based on the difference (diff) between touch signals from different channels (digital signals converted from touch voltage signals). When the touchscreen or touchpad is touched over a large area, such as when a touchscreen phone is put into a pocket while unlocked or when an alarm clock is turned off by touching the screen with the palm of the hand, the difference between the touch signals from different channels will be equal to 0. Conversely, when the touchscreen or touchpad is not touched, the difference between the touch signals from different channels will also be equal to 0, making it impossible to determine whether the touchscreen or touchpad has been effectively touched. The output of the averaging submodule 1323 is connected to the processing module 133. The processing module 133 processes the error signal output by the averaging submodule 1323 and converts it into a digital signal. This digital signal differs between the states where the touchscreen or touchpad is heavily touched and when it is not touched, thus allowing the determination of whether the touchscreen or touchpad has been effectively touched.

[0118] The amplification submodule 1311 outputs an output signal based on the error signal and the input signal input from the electrode 21. Since the error signal is transmitted to the non-inverting input of the first amplifier A1, the output signal is boosted relative to the input signal by a reference base. When performing touch recognition based on the digital signal converted from the touch voltage signal, the software needs to perform diff compensation operations on different channels based on the reference base of the digital signal. Therefore, the processing module 133 converts the error signal into a corresponding digital signal, and the software can perform compensation operations on the digital signal converted from the touch voltage signal based on the digital signal converted from the error signal.

[0119] In this embodiment, the output of the mean amplification submodule 1323 is connected to a processing module 133. The processing module 133 filters the error signal output by the mean amplification submodule 1323 and converts it into a corresponding digital signal. This digital signal can be used as a data reference for software compensation of the diff of each channel, ensuring that touch recognition can be performed normally. Moreover, when the touch screen or touchpad is touched over a large area, the digital signal can be used to determine whether the touch screen or touchpad is effectively touched, ensuring the accuracy of touch recognition.

[0120] In one example, the amplification submodule 1311 adopts... Figure 9 The scheme shown employs the following approach: The accumulation submodule 1321 adopts... Figure 9 The scheme shown employs the mean amplification submodule 1323. Figure 10In the scheme shown, the capacitance of the first capacitor C1 is 60pF, the resistance of the first resistor R1 is 1KΩ, the resistance of the second resistor R2 is 10KΩ, the resistance of the third resistor R3 is 1KΩ, the capacitance of the second capacitor C2 is 2pF, the capacitance of the third capacitor is 100pF, and the resistance of the fourth resistor R4 is 5KΩ.

[0121] Figure 14 The phase margin evaluation results of the touch chip in this example are shown. Figure 14 As shown, when the loading of the touchscreen or touchpad is less than or equal to 500pF, by using capacitors with smaller capacitance values ​​and resistors with smaller resistance values ​​to reduce the cost of the touch chip, the phase margin can be maintained above 45°. Even when the loading of the touchscreen or touchpad is below 500pF, the phase margin remains above 45°, thus ensuring stable and normal operation of the touch chip. Phase margin (PM) refers to the difference (in degrees) between 180° and the phase of the amplifier output signal (relative to its input) when the gain is 0. The industry standard requires a phase margin greater than 45°. If the difference between 180° and the phase of the amplifier output signal is less than 135°, the system will oscillate and fail to operate normally.

[0122] Figure 15 This illustrates the effect of the touch chip in an embodiment of this application on suppressing the base coding. For example... Figure 15 As shown, under the test conditions of the first amplifier A1's maximum cutoff frequency GBW = 10MHz, maximum slew rate SR = 20V / μs, open-loop gain of 120dB, main node at 10Hz, and second pole at 100MHz, the coding base can be basically suppressed. With coding at the 10Vpp input electrode (TX), the remaining coding base is 0.4mVpp, which basically does not occupy the dynamic range of the 1311 amplifier submodule. When the first capacitor C1 is 500pF and coding is performed at 10Vpp, the remaining coding base is 20mVpp, and the suppression efficiency is approximately 0.4 / 20 / 20 = 99.9%.

[0123] Figure 16 The effect of the touch chip in an embodiment of this application on suppressing display interference is illustrated. For example... Figure 16As shown, under the test conditions of the first amplifier A1's maximum cutoff frequency GBW = 10MHz, maximum slew rate SR = 20V / μs, open-loop gain of 120dB, master node at 10Hz, and second pole at 100MHz, the display interference can be basically suppressed. With a 1Vpp display interference input, the output signal of amplifier submodule 1311 shows a remaining 4mVpp of display interference, which basically does not occupy the dynamic range of amplifier submodule 1311. When the first capacitor C1 is 500pF and the display interference input is 1Vpp, the output signal of amplifier submodule 1311 shows a remaining 4mVpp of display interference, with a suppression efficiency of approximately 0.4 / 1 / 20 = 99.8%.

[0124] Figure 15 and Figure 16 The experimental results from simulation and prototype platforms are shown. By suppressing the coding base and display interference, i.e., after obtaining the average values ​​of the coding base and display interference for each sensing electrode channel, the corresponding values ​​are subtracted. Since the differences in coding base and display interference between channels are small, and the coding base and display interference of each channel are basically near the average value, the residual amount of coding base and display interference after subtraction is small, and the experimental results show that it can be suppressed to within 1mVpp.

[0125] Figure 17 and Figure 18 This illustrates the self-capacitive touch diff effect of the touch chip in an embodiment of this application. Figure 17 In the diagram, the vertical axis V1 represents the input signal at the non-inverting input terminal of the first amplifier A1 in the amplification submodule 1311, and the vertical axis represents the input signal at the inverting input terminal of the first amplifier A1 in the amplification submodule 1311. According to the virtual short control of the operational amplifier, V1 and V2 are the same. Since the non-inverting input terminal of the first amplifier A1 is connected to the output terminal of the averaging amplification submodule 1323, V1 and V2 can also identify the output signal of the averaging amplification submodule 1323, that is, the average value of each channel signal.

[0126] like Figure 17 As shown, when there is no touch input, the output of each of the five channels' amplification submodule 1311 includes the output electrode (TX) base, as follows: Figure 17 In this case, TX = 2Vpp. For example... Figure 18 As shown, when one of the five channels is touched, the diff is approximately 1mVpp, where the first capacitor C1 = 300pF, the self-capacitance change is 0.35pF, the output electrode base is 2Vpp, and the coding frequency is 100kHz. Figure 17 and Figure 18 As can be seen, the touch chip can amplify the signal during touch normally, and the self-capacitance diff is about 1mVpp. Figure 17 and Figure 18 The actual test results of the touch chip provided in the embodiments of this application show that the self-capacitive diff has no loss. By suppressing the coding base and display interference, the amplification factor is increased while the display interference is reduced, thereby improving the SNR.

[0127] Figure 19 This is a schematic diagram of a screen module provided in an embodiment of this application. Figure 19 As shown, the screen module 20 includes the touch chip 10 and multiple electrodes 21 in the above embodiments.

[0128] Electrode 21 can receive touch drive signals output by touch chip 10, enabling screen module 20 to recognize touch commands. Electrode 21 can be a horizontal electrode and / or a vertical electrode arranged on the touch screen.

[0129] It should be noted that the screen module in this application embodiment is based on the touch chip 10 in the foregoing embodiment, and is a specific application of the touch chip 10 in the foregoing embodiment. For details and beneficial effects, please refer to the description in the foregoing touch chip embodiment, which will not be repeated here.

[0130] Figure 20 This is a schematic diagram of an electronic device provided in an embodiment of this application, such as... Figure 20 As shown, the electronic device includes the screen module 20 in the above embodiment.

[0131] It should be understood that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, for the method embodiments, since they are basically similar to the methods described in the apparatus and system embodiments, the description is relatively simple, and relevant parts can be referred to the descriptions of other embodiments.

[0132] It should be understood that the foregoing describes specific embodiments of this specification. Other embodiments are within the scope of the claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0133] It should be understood that the use of a singular form to describe an element or to show only one element in the accompanying drawings does not imply that the number of such element is limited to one. Furthermore, modules or elements described or shown as separate herein may be combined into a single module or element, and modules or elements described or shown as single herein may be broken down into multiple modules or elements.

[0134] It should also be understood that the terminology and expressions used herein are for descriptive purposes only, and one or more embodiments described herein should not be limited to these terms and expressions. The use of these terms and expressions does not exclude any illustrative and descriptive equivalent features (or parts thereof), and it should be recognized that various modifications that may exist should also be included within the scope of the claims. Other modifications, variations, and substitutions may also exist. Accordingly, the claims should be considered to cover all such equivalents.

Claims

1. A touch chip disposed in an electronic device, the electronic device comprising a plurality of electrodes, characterized in that, The touch chip includes: a driving unit and a recognition unit; The driving unit is electrically connected to the multiple electrodes through multiple touch pins of the touch chip, and the recognition unit is electrically connected to the multiple electrodes through the multiple touch pins, with different touch pins electrically connected to different electrodes; The driving unit is used to output a driving signal to the electrode through the touch pin; The identification unit is used to receive the sensing signal generated by the electrode through the touch pin and convert the sensing signal into an identification signal. The touch chip performs touch detection based on the identification signal, wherein the sensing signal is generated by the electrode that receives the driving signal.

2. The touch chip according to claim 1, characterized in that, The driving unit includes: multiple current sources, multiple chopper subunits, and multiple first filters; The first and second input terminals of the chopper subunit are electrically connected to two current sources, respectively. The first and second output terminals of the chopper subunit are connected to the input terminals of two first filters, respectively. The output terminals of the first filters are electrically connected to the electrodes. Different first filters are electrically connected to different electrodes. Different chopper subunits are connected to different first filters, and different chopper subunits are connected to different current sources. The current source is used to generate the first driving sub-signal; The chopper subunit is used to chop the first driving sub-signals output by the two current sources to obtain two second driving sub-signals corresponding to the two connected first filters. The first filter is used to filter the second driving sub-signal to obtain a driving signal corresponding to the connected electrode.

3. The touch chip according to claim 2, characterized in that, The chopper subunit includes a first switch, a second switch, a third switch, and a fourth switch; The first terminal of the first switch serves as the first input terminal of the chopper subunit, the second terminal of the first switch serves as the first output terminal of the chopper subunit, the first terminal of the second switch is connected to the first terminal of the first switch, the second terminal of the second switch serves as the second output terminal of the chopper subunit, the first terminal of the third switch serves as the second input terminal of the chopper subunit, the second terminal of the third switch is connected to the second terminal of the first switch, the first terminal of the fourth switch is connected to the first terminal of the third switch, and the second terminal of the fourth switch is connected to the second terminal of the second switch. The first switch and the fourth switch have the same on / off state, the second switch and the third switch have the same on / off state, and the first switch and the third switch have opposite on / off states.

4. The touch chip according to claim 2, characterized in that, The driving unit further includes: a plurality of first buffers; The input terminal of the first buffer is connected to the output terminal of the first filter, and the output terminal of the first buffer is connected to the touch pin. Different first buffers are connected to different first filters, and different first buffers are connected to different touch pins. The first buffer is used to improve the driving capability of the driving signal.

5. The touch chip according to claim 1, characterized in that, The driving unit includes: at least one voltage source and multiple second buffers; The input terminals of the plurality of second buffers are all connected to the at least one voltage source, the output terminals of the plurality of second buffers are connected to the plurality of touch pins, and different second buffers are connected to different touch pins; The voltage source is used to generate the drive signal and transmit the drive signal to the touch pin through the second buffer.

6. The touch chip according to claim 1, characterized in that, The identification unit includes: an amplification module and a feedback module; The amplification module includes multiple amplification sub-modules, and different amplification sub-modules are connected to different touch pins; The feedback module is used to generate an error signal based on the output signal of each of the amplification submodules, and transmit the error signal to each of the amplification submodules respectively, wherein the error signal is used to indicate the average intensity of the interference signal coupled by each electrode; The amplification submodule is configured to output an output signal based on the sensing signal generated by the electrode connected to the amplification submodule and the error signal, wherein the output signal is used to generate the identification signal corresponding to the electrode connected to the amplification submodule.

7. The touch chip according to claim 6, characterized in that, The feedback module includes an accumulation submodule, a signal generation submodule, and a mean amplification submodule; The multiple input terminals of the accumulator submodule are respectively connected to each of the amplifier submodules; The two input terminals of the mean amplification submodule are respectively connected to the accumulation submodule and the signal generation submodule, and the output terminal of the mean amplification submodule is respectively connected to the input terminals of each of the amplification submodules; The signal generation submodule is used to generate a reference voltage signal; The accumulation submodule is used to obtain the accumulated current according to the output signal of each of the amplification submodules, and transmit the accumulated current to the averaging amplification submodule, wherein the accumulated current is used to indicate the total intensity of the interference signal coupled by each of the electrodes; The signal generation submodule is used to transmit a reference voltage signal to the averaging submodule; The mean amplification submodule is used to generate the error signal based on the accumulated current and the reference voltage signal, and to transmit the error signal to each of the amplification submodules respectively.

8. The touch chip according to claim 7, characterized in that, The amplification submodule includes a first amplifier, a first resistor, a second resistor, and a first capacitor; The first end of the first resistor is connected to the touch pin, and the second end of the first resistor is connected to the inverting input of the first amplifier. The first end of the second resistor is connected to the inverting input terminal of the first amplifier, and the second end of the second resistor is connected to the output terminal of the first amplifier. The first terminal of the first capacitor is connected to the inverting input terminal of the first amplifier, and the second terminal of the first capacitor is connected to the output terminal of the first amplifier. The non-inverting input of the first amplifier is connected to the averaging submodule, and the output of the first amplifier is connected to the accumulator submodule. The first amplifier transmits the output signal to the accumulator submodule through its output, and the averaging submodule transmits the error signal to the non-inverting input of the first amplifier.

9. The touch chip according to claim 8, characterized in that, The accumulation submodule includes multiple third resistors; The first end of the third resistor is connected to the output terminal of the first amplifier, and the second end of the third resistor is connected to the input terminal of the averaging submodule. The first ends of different third resistors are connected to different first amplifiers, and the second ends of different third resistors are connected to the same input terminal of the averaging submodule.

10. The touch chip according to claim 9, characterized in that, The mean amplification submodule includes: a second amplifier, a second capacitor, a third capacitor, a fourth resistor, and a fifth resistor; The non-inverting input of the second amplifier is connected to the signal generation submodule, the inverting input of the second amplifier is connected to the first end of the fifth resistor, and the second end of the fifth resistor is connected to the second end of each of the third resistors. The output terminal of the second amplifier is connected to the non-inverting input terminal of each of the first amplifiers, the first terminal of the fourth resistor is connected to the output terminal of the second amplifier, the second terminal of the fourth resistor is connected to the first terminal of the third capacitor, and the second terminal of the third capacitor is connected to the inverting input terminal of the second amplifier. The first terminal of the second capacitor is connected to the output terminal of the second amplifier, and the second terminal of the second capacitor is connected to the inverting input terminal of the second amplifier. Alternatively, the mean amplification submodule may include: a third amplifier, a fourth capacitor, a fifth capacitor, a sixth capacitor, a sixth resistor, a seventh resistor, and an eighth resistor; The non-inverting input terminal of the third amplifier is connected to the signal generation submodule, the inverting input terminal of the third amplifier is connected to the first terminal of the eighth resistor, and the second terminal of the eighth resistor is connected to the second terminal of each of the third resistors. The output terminal of the third amplifier is connected to the non-inverting input terminal of each of the first amplifiers. The first terminal of the sixth resistor is connected to the output terminal of the third amplifier. The second terminal of the sixth resistor is connected to the first terminal of the fifth capacitor. The second terminal of the fifth capacitor is connected to the first terminal of the fourth capacitor. The second terminal of the fourth capacitor is connected to the first terminal of the seventh resistor. The second terminal of the seventh resistor is connected to the second terminal of the eighth resistor. The first terminal of the sixth capacitor is connected to the output terminal of the third amplifier, and the second terminal of the sixth capacitor is connected to the second terminal of the fifth capacitor and the inverting input terminal of the third amplifier, respectively. Alternatively, the mean amplification submodule may include: a fourth amplifier, a seventh capacitor, an eighth capacitor, a ninth resistor, a tenth resistor, and an eleventh resistor; The non-inverting input terminal of the fourth amplifier is connected to the signal generation submodule, the inverting input terminal of the fourth amplifier is connected to the first terminal of the eleventh resistor, and the second terminal of the eleventh resistor is connected to the second terminal of each of the third resistors. The output terminal of the fourth amplifier is connected to the non-inverting input terminal of each of the first amplifiers. The first terminal of the ninth resistor is connected to the output terminal of the fourth amplifier. The second terminal of the ninth resistor is connected to the first terminal of the eighth capacitor. The second terminal of the eighth capacitor is connected to the first terminal of the seventh capacitor and the inverting input terminal of the fourth amplifier. The second terminal of the seventh capacitor is connected to the first terminal of the tenth resistor. The second terminal of the tenth resistor is connected to the second terminal of the eleventh resistor. Alternatively, the mean amplification submodule may include: a fifth amplifier, a ninth capacitor, a twelfth resistor, and a thirteenth resistor; The non-inverting input terminal of the fifth amplifier is connected to the signal generation submodule, the inverting input terminal of the fifth amplifier is connected to the first terminal of the thirteenth resistor, and the second terminal of the thirteenth resistor is connected to the second terminal of each of the third resistors. The first end of the twelfth resistor is connected to the output terminal of the fifth amplifier, the second end of the twelfth resistor is connected to the first end of the ninth capacitor, and the second end of the ninth capacitor is connected to the inverting input terminal of the fifth amplifier.

11. The touch chip according to any one of claims 6-10, characterized in that, The identification unit further includes multiple processing modules, including a second filter, a sample-and-hold circuit, a third buffer, and an analog-to-digital converter. The output of the second filter is connected to the input of the sample-and-hold circuit, the output of the sample-and-hold circuit is connected to the input of the third buffer, and the output of the third buffer is connected to the input of the analog-to-digital converter. The second terminals of different third resistors are connected to the inputs of the second filters in different processing modules, and the outputs of the third buffers in different processing modules are connected to the inputs of different analog-to-digital converters. The second filter is used to filter the input signal and remove the reference voltage signal included in the input signal to obtain the touch voltage signal; The sample-and-hold circuit is used to sample the touch voltage signal to obtain the target signal and hold the target signal. The third buffer is used to transmit the target signal unchanged to the analog-to-digital conversion module, so that the analog-to-digital conversion module converts the target signal into the identification signal.

12. The touch chip according to claim 11, characterized in that, The non-inverting input of each of the first amplifiers is connected to the input of the second filter in one of the processing modules.

13. A screen module, characterized in that, include: Multiple electrodes and a touch chip as described in any one of claims 1-12; The electrodes are used to receive the drive signals output by the touch chip, enabling the screen module to recognize touch commands. The electrodes are horizontal electrodes and / or vertical electrodes arranged on the touch screen.

14. An electronic device, characterized in that, include: The screen module as described in claim 13.

Images