WO2023226475A1 - 触控电路、触控检测放大电路以及触控装置 - Google Patents

触控电路、触控检测放大电路以及触控装置 Download PDF

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Publication number
WO2023226475A1
WO2023226475A1 PCT/CN2023/075076 CN2023075076W WO2023226475A1 WO 2023226475 A1 WO2023226475 A1 WO 2023226475A1 CN 2023075076 W CN2023075076 W CN 2023075076W WO 2023226475 A1 WO2023226475 A1 WO 2023226475A1
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WIPO (PCT)
Prior art keywords
circuit
voltage
touch
capacitor
charging
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Application number
PCT/CN2023/075076
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English (en)
French (fr)
Inventor
史爱焕
黄健男
刘军桥
Original Assignee
敦泰科技(深圳)有限公司
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Publication of WO2023226475A1 publication Critical patent/WO2023226475A1/zh

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Classifications

    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
    • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
    • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
    • G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
    • G06F3/0416—Control or interface arrangements specially adapted for digitisers
    • G06F3/0418—Control or interface arrangements specially adapted for digitisers for error correction or compensation, e.g. based on parallax, calibration or alignment
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
    • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
    • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
    • G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
    • G06F3/044—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by capacitive means
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
    • Y02D30/00—Reducing energy consumption in communication networks
    • Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks

Definitions

  • the invention relates to a touch circuit, a touch detection amplifier circuit and a touch device.
  • Capacitive touch detection solutions are mainly divided into two directions: self-capacitance sensing and mutual capacitance sensing. Among them, self-capacitance sensing is more widely used.
  • the touch detection solution simply adopts Self-capacitance scheme, and in some detection schemes based on mutual capacitance, self-capacitance auxiliary detection is also required.
  • a touch circuit including a charge generation circuit, a charging circuit, a control circuit, a touch detection amplification circuit and a data processing circuit; the charge generation circuit is used to scan according to a certain timing control to detect the contact between the user's touch and the sensing electrode The generated sensing capacitance; the control circuit is used to control the charging circuit to charge the charge generation circuit or control the charge generation circuit to discharge; the touch detection amplifier circuit and the charging circuit and the The control circuit is electrically connected; the charging circuit includes a charging capacitor, and the charging capacitor is electrically connected to the control circuit and the touch detection amplifier circuit through a node; the touch detection amplifier circuit is used to convert the The sensing capacitance output by the charge generation circuit is converted into a sensing voltage to identify the touch operation and touch position; the data processing circuit is electrically connected to the touch detection amplifier circuit and the charging circuit; the data processing circuit is A control signal is output according to the sensing voltage output by the touch detection amplifier circuit to adjust the capacitance value of the charging capacitor so that the sensing voltage output by the touch detection amplifier
  • a touch detection amplification circuit electrically connected to a charge generation circuit, the touch detection amplification circuit Roads include:
  • An amplifier used to convert the sensing capacitance output by the charge generation circuit into a sensing voltage; the first input end of the amplifier is electrically connected to the charge generation circuit;
  • a sampling module used to sample the output voltage of the amplifier and output the sampled voltage
  • a reset switch one end of the reset switch is electrically connected to the first input terminal of the amplifier, and the other end is electrically connected to the output terminal of the amplifier;
  • a main capacitor connected in parallel between the first input terminal and the output terminal of the amplifier
  • a plurality of auxiliary capacitors one end of each of the auxiliary capacitors is electrically connected to the first input terminal of the amplifier through a first switching element, and is electrically connected to the output terminal through a second switching element; wherein, When the reset switch is in the on state and there is a difference between the sampling voltage and the target voltage, at least one of the auxiliary capacitors is time-shared and multiplexed as a common mode capacitor to store charge and store charge when the reset switch is in the off state. When in the on state, the voltage at the output terminal of the amplifier is adjusted; when the reset switch is in the off state, the first switching elements and the second switching elements of the plurality of auxiliary capacitors are turned on, causing the plurality of auxiliary capacitors to conduct.
  • the capacitor is connected in parallel with the main capacitor as an access capacitor;
  • a common mode parameter adjustment module is electrically connected to the sampling module; when there is a difference between the sampling voltage and the target voltage, the common mode parameter adjustment module controls at least one of the first switching elements to conduct, setting Determine at least one of the auxiliary capacitors to be time-division multiplexed as the common mode capacitor, and output a translation control signal;
  • a translation driving module is electrically connected to the common mode parameter adjustment module, and is electrically connected to each of the auxiliary capacitors through a plurality of third switching elements; when the reset switch is in a conductive state, the translation driving module The module is used to control the third switching element corresponding to the common mode capacitor to be turned on, and to charge the common mode capacitor according to the translation control signal.
  • a touch device which includes a touch circuit; the touch circuit includes a charge generation circuit, a charging circuit, a control circuit, a touch detection amplifier circuit and a data processing circuit; the charge generation circuit is used to control according to a certain timing sequence Scanning is performed to detect the sensing capacitance generated by the sensing electrode after the user touches it; the control circuit is used to control the charging circuit to charge the charge generation circuit or control the charge generation circuit to discharge; the touch The detection amplifier circuit is electrically connected to the charging circuit and the control circuit; the charging circuit includes a charging capacitor, and the charging capacitor is electrically connected to the control circuit and the touch detection amplifier circuit through a node; The touch detection amplification circuit is used to convert the sensing capacitance output by the charge generation circuit into a sensing voltage to identify touch operations and touch positions; the data processing circuit, the touch detection amplification circuit and the charging The circuit is electrically connected; the data processing circuit is used to output a control signal according to the sensing voltage output by the touch detection amplifier circuit to adjust the capacitance value of the charging
  • a touch device includes a touch detection amplification circuit electrically connected to a charge generation circuit.
  • the touch detection amplification circuit includes:
  • An amplifier used to convert the sensing capacitance output by the charge generation circuit into a sensing voltage; the first input end of the amplifier is electrically connected to the charge generation circuit;
  • a sampling module used to sample the output voltage of the amplifier and output the sampled voltage
  • a reset switch one end of the reset switch is electrically connected to the first input terminal of the amplifier, and the other end is electrically connected to the output terminal of the amplifier;
  • a main capacitor connected in parallel between the first input terminal and the output terminal of the amplifier
  • a plurality of auxiliary capacitors one end of each of the auxiliary capacitors is electrically connected to the first input terminal of the amplifier through a first switching element, and is electrically connected to the output terminal through a second switching element; wherein, When the reset switch is in the on state and there is a difference between the sampling voltage and the target voltage, at least one of the auxiliary capacitors is time-shared and multiplexed as a common mode capacitor to store charge and store charge when the reset switch is in the off state. When in the on state, the voltage at the output terminal of the amplifier is adjusted; when the reset switch is in the off state, the first switching elements and the second switching elements of the plurality of auxiliary capacitors are turned on, causing the plurality of auxiliary capacitors to conduct.
  • the capacitor is connected in parallel with the main capacitor as an access capacitor;
  • a common mode parameter adjustment module is electrically connected to the sampling module; when there is a difference between the sampling voltage and the target voltage, the common mode parameter adjustment module controls at least one of the first switching elements to conduct, setting Determine at least one of the auxiliary capacitors to be time-division multiplexed as the common mode capacitor, and output a translation control signal;
  • a translation driving module is electrically connected to the common mode parameter adjustment module, and is electrically connected to each of the auxiliary capacitors through a plurality of third switching elements; when the reset switch is in a conductive state, the translation driving module The module is used to control the third switching element corresponding to the common mode capacitor to be turned on, and to charge the common mode capacitor according to the translation control signal.
  • the above-mentioned touch circuit, touch detection amplifier circuit and touch device can use the data processing circuit to adjust the capacitance value of the charging capacitor in the charging circuit according to the sensing voltage according to the application environment of the touch circuit or adjust the
  • the capacitance value of the common mode capacitor in the touch detection amplification circuit enables the adjustment of the sensing voltage at the output end of the amplifier in different ways and with different precisions, maximizing the use of the voltage of the touch detection amplification circuit.
  • the output range improves the sensitivity and working speed of the touch detection amplifier circuit.
  • FIG. 1 is a schematic three-dimensional view of a touch device according to a preferred embodiment of the present invention.
  • FIG. 2 is a module schematic diagram of the touch circuit of the preferred embodiment in FIG. 1 .
  • FIG. 3 is a schematic diagram of the sensing electrode of the preferred embodiment in FIG. 2 .
  • FIG. 4 is an equivalent circuit diagram of the touch circuit of the first embodiment in FIG. 2 .
  • FIG. 5 is a schematic diagram of the changing trend of the capacitance value of the charging capacitor and the sensing voltage in FIG. 4 .
  • FIG. 6 is a schematic diagram of the equivalent circuit of the charging capacitor in FIG. 4 .
  • FIG. 7 is a schematic waveform diagram of the reset switch, the sensing voltage and the charging capacitor in FIG. 4 .
  • FIG. 8 is an equivalent circuit schematic diagram of the touch circuit of the second embodiment in FIG. 2 in the first stage or the third stage.
  • FIG. 9 is an equivalent circuit schematic diagram of the touch circuit in the second stage or the fourth stage of the second embodiment in FIG. 8 .
  • Figure 10 shows the first control switch, the second control switch, the third control switch, the first current source, the second current source, the reset switch and the sensing in Figure 8 Voltage waveform diagram.
  • FIG. 11 is an equivalent circuit diagram of the touch circuit of the third embodiment in FIG. 2 .
  • FIG. 12 is a schematic waveform diagram of the reset switch and the first translation control signal in FIG. 11 .
  • FIG. 13 is a schematic waveform diagram of the reset switch and the second translation control signal in FIG. 11 .
  • FIG. 14 is a schematic waveform diagram of the first control switch, the second control switch, the third control switch, the pulse voltage, the reset switch and the sensing voltage in FIG. 11 .
  • Touch device 100 Touch circuit 200, 200a, 200b, 200c Charge generation circuit 10 Charging circuit 20, 20a, 20b, 20c Control circuit 30 Touch detection amplifier circuit 40 Data processing circuit 50 Sensing electrode 12 Self capacitance Csensor Human body capacitance Cfinger First control switch ⁇ 11 Second control switch ⁇ 12 Third control switch ⁇ 22 amplifier 41 Main capacitor Ca reset switch rst Charging capacitor Cb First switching elements S1-1 ⁇ S1-p Second switching elements S2-1 ⁇ S2-p Charging subcapacitor Cb-1 ⁇ Cb-p Buffer 21 Node N Sense voltage Vout Pulse voltage Vtx First current source Ibp Second current source Ibn Auxiliary capacitor C1-1 ⁇ C1-p Third switching element S3-1 ⁇ S3-p Sampling module 43 Common mode parameter adjustment module 45 Translation drive module 47
  • connection should be understood in a broad sense.
  • it can be a fixed connection, a detachable connection, or an integral connection.
  • It can be a mechanical connection, an electrical connection or mutual communication; it can be a direct connection, or it can be an indirect connection through an intermediate connection, it can be the internal connection of two components or the interaction between two components.
  • connection can be a fixed connection, a detachable connection, or an integral connection.
  • It can be a mechanical connection, an electrical connection or mutual communication
  • it can be a direct connection, or it can be an indirect connection through an intermediate connection, it can be the internal connection of two components or the interaction between two components.
  • FIG. 1 is a three-dimensional schematic diagram of a touch device 100 according to an embodiment of the present invention.
  • the touch device 100 can be a personal computer, a tablet computer, a smart phone, a personal digital assistant (Personal Digital Assistant, PDA), a game console, an interactive network Mobile devices such as Internet Protocol Television (IPTV), smart wearable devices, navigation devices, etc., or fixed devices such as desktop computers, servers, digital TVs, etc.
  • the touch device 100 may further include one or a combination of one or more of a fingerprint recognition function, a display function, and a camera function.
  • the touch device 100 includes a touch circuit 200 (as shown in FIG. 2 ).
  • the touch circuit 200 may include at least one integrated circuit board and a plurality of electronic components electrically connected to the integrated circuit board, such as capacitors, resistors, chips, and so on.
  • FIG. 2 is a schematic module diagram of the touch circuit 200 in a preferred embodiment.
  • the touch circuit 200 includes a charge generation circuit 10 , a charging circuit 20 , a control circuit 30 , a touch detection amplifier circuit 40 and a data processing circuit 50 .
  • the touch device 100 operates in a specified voltage domain.
  • the specified voltage domain is used to limit the voltage variation range of the touch device 100 .
  • the specified voltage domain uses the power supply voltage VDD as the upper limit voltage and the low-level voltage VSS as the lower limit voltage.
  • the charge generation circuit 10 performs scanning according to a certain timing control to detect the user's touch operation to generate the sensing capacitance.
  • the charge generation circuit 10 includes the sensing electrodes 12 arranged in an m*n matrix. Among them, m and n are positive integers, and they can be the same or different.
  • a self-capacitance Csensor is formed between the sensing electrode 12 and the ground (as shown in FIG. 4 ).
  • a human body capacitance Cfinger is formed between the sensing electrode 12 in the touch area and the finger (as shown in Figure 4).
  • the self-capacitance Csensor and the human body capacitance Cfinger are connected in parallel to form the sensing capacitance. .
  • the sensing electrode 12 is electrically connected to the touch detection amplifier circuit 40 through a sensing line (not shown).
  • the touch device 100 has a capacitive touch screen.
  • the sensing capacitance corresponding to each sensing electrode 12 is the self-capacitance Csensor, and the self-capacitance Csensor serves as the reference capacitance, that is, the The capacitance of the sensing electrodes 12 relative to ground is a fixed value.
  • the sensing capacitance corresponding to each sensing electrode 12 is the self-capacitance Csensor superimposed on the human body capacitance Cfinger.
  • the touch detection amplifier circuit 40 can determine the touch position by detecting changes in the capacitance value of the sensing capacitance of each of the sensing electrodes 12 during the touch period.
  • the self-capacitance Csensor is large, the relative change amount of the sensing capacitance is small. Therefore, the reference capacitance needs to be reduced or eliminated during the touch period to avoid adverse effects on touch detection.
  • FIG. 4 is an equivalent circuit diagram of the touch circuit 200a in the first embodiment.
  • the charging circuit 20a is electrically connected to the charge generation circuit 10 and the control circuit 30 .
  • the charging circuit 20a is used to charge the charge generation circuit 10 under the control of the control circuit 30.
  • the charging circuit 20a is used to adjust the sensing voltage Vout output by the touch detection amplifier circuit 40 according to the control signal of the data processing circuit 50, so that the sensing voltage Vout output by the touch detection amplifier circuit 40 Vout is within the common-mode voltage valid signal range. That is, the effective swing amplitude of the sensing voltage Vout output by the touch detection amplifier circuit 40 is maximized.
  • the effective signal range of the common mode voltage is within the specified voltage domain.
  • the sensing voltage Vout when the sensing voltage Vout is located at the middle level of the specified voltage domain, it can obtain the maximum swing amplitude within the specified voltage domain. For example, assuming that the specified voltage domain is that the low-level voltage VSS is 0 volts (V) and the power supply voltage VDD is 1.5V For example, when the sensing voltage Vout is at 1.5V, it has a maximum swing amplitude of 1.5V upward and downward.
  • the effective signal range of the common mode voltage may be 1.3V-1.7V. In other embodiments, multiple common-mode voltage effective signal ranges of different ranges can also be set in the touch device 100 , and one of the common-mode voltage effective signal ranges is selected through user settings to measure the touch device 100 of the sensing voltage Vout.
  • the charging circuit 20 a includes a charging capacitor Cb and a buffer 21 .
  • One end of the charging capacitor Cb is electrically connected to the sensing electrode 12 through the node N and the control circuit 30 , and is electrically connected to the touch detection amplifier circuit 40 through the node N.
  • the other end of the charging capacitor Cb is electrically connected to the buffer 21 .
  • the buffer 21 receives the pulse voltage Vtx.
  • the charging capacitor Cb performs charging/discharging operations according to the pulse voltage Vtx output by the buffer 21 .
  • the capacitance value of the charging capacitor Cb can be adjusted according to the correction signal output by the data processing circuit 50 to ensure that the sensing voltage Vout is within the effective signal range of the common mode voltage.
  • the capacitance value of the charging capacitor Cb changes in proportion to the sensing voltage Vout detected by the data processing circuit 50 . That is, when it is necessary to increase the sensing voltage Vout, the capacitance value of the charging capacitor Cb is increased according to the control signal output by the data processing circuit 50; when it is necessary to decrease the sensing voltage Vout , the capacitance value of the charging capacitor Cb decreases according to the control signal output by the data processing circuit 50 .
  • the charging capacitor Cb includes a plurality of charging sub-capacitors Cb-1 to Cb-p, a plurality of first switching elements S1-1 to S1-p, and a plurality of second switching elements S2-1 to S2-p.
  • p is a positive integer greater than 1.
  • One end of each charging subcapacitor Cb-1 ⁇ Cb-p is electrically connected to the first input terminal of the amplifier 41 through the corresponding first switching element S1-1 ⁇ S1-p.
  • the second switching elements S2-1 ⁇ S2-p corresponding to the other end of each of the charging sub-capacitors Cb-1 ⁇ Cb-p are electrically connected to the buffer 21.
  • the capacitance values of the plurality of charging sub-capacitors Cb-1 to Cb-p are encoded in a binary format in order of arrangement. Wherein, the capacitance values of each of the charging sub-capacitors Cb-1 to Cb-p are different from each other and arranged in a geometric sequence.
  • the correction signal when the correction signal is in units of bits, at least one of the first switching elements S1-k and the corresponding at least one of the first switching elements S1-k are controlled according to the correction signal.
  • the two switching elements S2-K are turned on, so that at least one corresponding charging sub-capacitor Cb-k serves as the charging capacitor Cb, so as to adjust the capacitance value of the charging capacitor Cb using binary coding.
  • k is a positive integer and less than p.
  • the first switching element S1-2 and the corresponding second switching element S2-2 are controlled to be turned on according to the coding sequence to select
  • the second charging sub-capacitor Cb-2 serves as the common mode capacitor; when the bit is 3, that is, the corresponding binary code is 011, the first switching element S1-1 ⁇ is controlled according to the coding sequence.
  • the first switching element S1-3 and the corresponding second switching element S2-3 are controlled to be turned on according to the coding sequence to select the third switching element S1-3.
  • the charging sub-capacitor Cb-3 is used as the charging capacitor Cb.
  • multiple charging sub-capacitors Cb-1 to Cb-p can also be encoded using a one-hot code format.
  • Each charging sub-capacitor Cb-1 ⁇ Cb-p are independently controlled.
  • the capacitance value of each of the charging sub-capacitors Cb-1 to Cb-p is the same.
  • one of the charging sub-capacitors Cb-1 ⁇ Cb-p is selected as the charging
  • the number of capacitor Cb is used to realize the capacitance adjustment of the charging capacitor Cb using the one-hot code method.
  • the three charging subcapacitors Cb-1 to Cb -3 together serve as the charging capacitor Cb; when the first switching elements S1-1 to S1-4 and the corresponding second switching elements S2-1 to S2-4 are turned on, the four charging elements Capacitors Cb-1 to Cb-4 together serve as the charging capacitor Cb.
  • the control circuit 30 is electrically connected to the charge generation circuit 10 , the charging circuit 20 a and the touch detection amplifier circuit 40 .
  • the control circuit 30 is used to control the charging circuit 20a to perform charging/discharging operations on the charge generation circuit 10 according to the power supply voltage VDD and the ground voltage VSS, so as to reduce the impact of the self-capacitance Csensor on the touch detection amplifier circuit 40
  • the output is affected by the sensing voltage Vout.
  • the control circuit 30 includes a first control switch ⁇ 11, a second control switch ⁇ 12, and a third control switch ⁇ 22. One end of the first control switch ⁇ 11 receives the power supply voltage VDD, and the other end is electrically connected to the sensing electrode 12 .
  • One end of the second control switch ⁇ 12 is grounded, and the other end is electrically connected to the sensing electrode 12 .
  • One end of the third control switch ⁇ 22 is electrically connected to the sensing electrode 12 , and the other end is electrically connected to the touch detection amplifier circuit 40 through the node N of the charging circuit 20 a .
  • the touch detection amplifier circuit 40 is electrically connected to the control circuit 30 and the data processing circuit 50 .
  • the touch detection amplification circuit 40 is used to convert the capacitance value of the sensing capacitor into a voltage signal and perform integral amplification and then output the sensing voltage Vout to the data processing circuit 50, so that the data processing circuit 50 processes the sensing voltage Vout to determine whether the sensing electrode 12 is touched, and obtains the corresponding touch position.
  • the touch detection amplifier circuit 40 includes an amplifier 41, a main capacitor Ca, and a reset switch rst.
  • the amplifier 41 is electrically connected to the control circuit 30 .
  • the amplifier 41 is used to convert the capacitance value of the sensing capacitor into the voltage signal and then perform an integration operation to output the sensing voltage Vout.
  • the first input terminal of the amplifier 41 is electrically connected to the sensing electrode 12 through the third control switch ⁇ 22, the second input terminal of the amplifier 41 receives the reference voltage Vcm, and the output terminal of the amplifier 41 is connected to the sensing electrode 12.
  • the data processing circuit 50 is electrically connected.
  • the reference voltage Vcm is half of the power supply voltage VDD.
  • One end of the main capacitor Ca is electrically connected to the first input terminal of the amplifier 41 , and the other end is electrically connected to the output terminal of the amplifier 41 .
  • One end of the reset switch rst is electrically connected to the first input terminal of the amplifier 41 , and the other end is electrically connected to the output terminal of the amplifier 41 .
  • the data processing circuit 50 is electrically connected to the charging circuit 20a and the touch detection amplifier circuit 40.
  • the data processing circuit 50 is configured to output the control signal according to the sensing voltage Vout output by the touch detection amplifier circuit 40 to adjust the capacitance value of the charging capacitor Cb in the charging circuit 20a, thereby achieving Adjustment of the sensing voltage Vout.
  • an analog to digital converter (Analog to Digital converter) is used in the data processing circuit 50.
  • Converter converts the sensing voltage Vout and obtains the control signal.
  • the data processing circuit 50 detects the sensing voltage Vout and adjusts the capacitance value of the charging capacitor Cb in the charging circuit 20a according to the detection result to maintain the touch
  • the sensing voltage Vout output by the control detection amplifier circuit 40 achieves a maximum swing within the effective signal range of the common mode voltage.
  • the data processing circuit 50 detects the sensing voltage Vout output by the touch detection amplifier circuit 40 and determines whether the difference between the sensing voltage Vout and the preset common mode voltage is within a predetermined difference range.
  • the predetermined difference range may be within the effective signal range of the common mode voltage. For example, assuming that the preset common mode voltage is 1.5V, the effective common mode voltage Taking the signal range as 1.3V-1.7V as an example, the predetermined difference range may be -0.2V-0.2V. When the difference between the sensing voltage Vout and the preset common mode voltage is within the predetermined difference range, it is identified that the capacitance value of the charging capacitor Cb does not require correction, and the current charging capacitor Cb is stored.
  • the capacitance value correction of the charging capacitor Cb is identified, and the data processing circuit 50 performs the correction according to the sensing voltage Vout.
  • the difference between the measured voltage Vout and the preset common mode voltage adjusts the capacitance value of the charging capacitor Cb.
  • the capacitance value of the charging capacitor Cb is reduced according to the control signal output by the data processing circuit 50; when the difference When it is a negative number, the capacitance value of the charging capacitor Cb is increased according to the control signal output by the data processing circuit 50 .
  • FIG. 7 is a schematic waveform diagram of the reset switch rst, the sensing voltage Vout, and the charging capacitor Cb.
  • the touch detection amplifier circuit 40 implements detection of the sensing electrode 12 .
  • the touch device 100 sequentially operates in the first phase T1, the second phase T2, the third phase T3 and the fourth phase T4 in any one of the working cycles.
  • the first phase T1 and the second phase T2 constitute a positive half cycle
  • the third phase T3 and the fourth phase T4 constitute a negative half cycle.
  • the data processing circuit 50 controls the capacitance value of the charging capacitor Cb to maintain a constant preset capacitance value; during the negative half period , the data processing circuit 50 controls the capacitance value of the charging capacitor Cb to be adjusted according to the sensing voltage Vout. In other embodiments, in both the positive half period and the negative half period, the data processing circuit 50 controls the capacitance value of the charging capacitor Cb to be adjusted according to the sensing voltage Vout.
  • the following takes one of the working cycles as an example to describe the working principle of the touch device 100 .
  • the first control switch ⁇ 11 and the third control switch ⁇ 22 are in the off state, and the second control switch ⁇ 12 and the reset switch rst are in the on state. , so that the charges on the main capacitance Ca and the self-capacitance Csensor are released, so as to realize the reset of the touch device 100 .
  • the buffer 21 outputs the ground voltage VSS to the charging capacitor Cb.
  • the data processing circuit 50 sets the capacitance value of the charging capacitor Cb in the charging circuit 20a to the preset capacitance value.
  • the first control switch ⁇ 11, the second control switch ⁇ 12 and the reset switch rst are in the off state, and the third control switch ⁇ 22 is in the on state, so that the automatic The capacitor Csensor is charged.
  • the buffer 21 outputs the power supply voltage VDD to the charging capacitor Cb, so that the charging capacitor Cb discharges to charge the self-capacitance Csensor when there is no finger touch or to charge the self-capacitance Csensor when there is a finger touch.
  • the self-capacitance Csensor and the human body capacitance Cfinger are charged, thereby reducing the influence of the self-capacitance Csensor on the human body capacitance Cfinger.
  • the second control switch ⁇ 12 and the third control switch ⁇ 22 are in the off state, and the first control switch ⁇ 11 and the reset switch rst are in the on state, so that the power supply
  • the voltage VDD charges the self-capacitance Csensor when there is no finger touch or charges the self-capacitance Csensor and the human body capacitance Cfinger when there is a finger touch, and the main capacitor Ca discharges.
  • the buffer 21 maintains outputting the power voltage VDD to the charging capacitor Cb.
  • the first control switch ⁇ 11, the second control switch ⁇ 12 and the reset switch rst are in the off state, and the third control switch ⁇ 22 is in the on state, so that when there is no finger
  • the self-capacitance Csensor discharges when touched or the self-capacitance Csensor and the human body capacitance Cfinger discharge when a finger touches, and then the charge stored on the self-capacitance Csensor is transferred to the touch detection amplifier circuit 40 on the main capacitor Ca.
  • the buffer 21 again outputs the ground voltage VSS to the charging capacitor Cb, and the charging capacitor Cb discharges to compensate the self-capacitance Csensor and reduce the impact of the self-capacitance Csensor on the human body capacitance. Cfinger's influence.
  • the data processing circuit 50 maintains the capacitance value of the charging capacitor Cb constant at the preset capacitance value.
  • FIG. 8 is a schematic equivalent circuit diagram of the touch circuit 200b in the first stage or the third stage of the second embodiment.
  • the charging circuit 20b in the touch circuit 200b of the second embodiment includes a first current source Ibp and a second current source Ibn.
  • the first current source Ibp provides a first charging current
  • the second current source Ibn provides a second charging current.
  • the control circuit 30 is electrically connected to the charge generation circuit 10 , the charging circuit 20 b and the touch detection amplifier circuit 40 .
  • the control circuit 30 is used to control the charging circuit 20b to perform charging/discharging operations on the charge generation circuit 10 according to the power supply voltage VDD and the ground voltage VSS, so as to reduce the impact of the self-capacitance Csensor on the touch detection amplifier circuit 40 The influence of the output sensing voltage Vout.
  • the control circuit 30 operates in the first stage T1, the second stage T2, the third stage T3 and the fourth stage T4 in sequence. In the first stage T1, the control circuit 30 establishes an electrical connection between the charge generation circuit 10 and the charging circuit 20b, and the power supply voltage VDD charges the self-capacitance Csensor.
  • the control circuit 30 establishes an electrical connection between the charge generation circuit 10 and the charging circuit 20b, and the first current source Ibp charges the self-capacitance Csensor to Reduce the influence of the self-capacitance Csensor on the human body capacitance Cfinger.
  • the self-capacitance Csensor is discharged, causing the charges on the self-capacitance Csensor and the human body capacitance Cfinger to be transferred to the touch detection amplification circuit 40 .
  • the control circuit 30 disconnects the electrical connection between the charge generation circuit 10 and the charging circuit 20b, and The self-capacitance Csensor is discharged.
  • the control circuit 30 establishes an electrical connection between the charge generation circuit 10 and the charging circuit 20b, and the second current source Ibn charges the self-capacitance Csensor to Reduce the influence of the self-capacitance Csensor on the human body capacitance Cfinger. At the same time, the charge stored in the capacitor in the touch detection amplifier circuit 40 is transferred to the self-capacitance Csensor.
  • the control circuit 30 includes a first control switch ⁇ 11, a second control switch ⁇ 12, and a third control switch ⁇ 22. One end of the first control switch ⁇ 11 receives the power supply voltage VDD, and the other end is electrically connected to the sensing electrode 12 .
  • One end of the second control switch ⁇ 12 is grounded, and the other end is electrically connected to the sensing electrode 12 .
  • One end of the third control switch ⁇ 22 is electrically connected to the sensing electrode 12 , and the other end is electrically connected to the charging circuit 20 b and the touch detection amplifier circuit 40 .
  • the touch detection amplifier circuit 40 is electrically connected to the control circuit 30 and the data processing circuit 50 .
  • the touch detection amplification circuit 40 is used to convert the capacitance value of the sensing capacitor into a voltage signal and perform integral amplification and then output the sensing voltage Vout to the data processing circuit 50, so that the data processing circuit 50 processes the sensing voltage Vout to determine whether the sensing electrode 12 is touched, and obtains the corresponding touch position. Further, the touch detection amplifier circuit 40 can adjust the sensing voltage within the specified voltage domain.
  • the specified voltage domain defines the voltage variation range of the touch device 100 , with the power supply voltage VDD as the upper limit voltage and the low-level signal VSS as the lower limit voltage.
  • the high-level signal VDD can also be used as the operating voltage of the touch device 100, and the low-level signal VSS can also be used as the ground voltage.
  • the touch detection amplifier circuit 40 includes an amplifier 41, a main capacitor Ca, a reset switch rst, a plurality of auxiliary capacitors C1-1 ⁇ C1-p, and a plurality of first switching elements S1- 1 to S1-p, a plurality of second switching elements S2-1 to S2-p, a plurality of third switching elements S3-1 to S3-p, a sampling module 43, a common mode parameter adjustment module 45 and a translation driving module 47.
  • p is a positive integer greater than 1.
  • the sampling module 43 , the common mode parameter adjustment module 45 and the translation driving module 47 can also be integrated in the data processing circuit 50 .
  • the amplifier 41 is electrically connected to the control circuit 30 .
  • the amplifier 41 is used to convert the capacitance value of the sensing capacitor into the voltage signal and then perform an integration operation to output the sensing voltage Vout.
  • the first input terminal of the amplifier 41 is electrically connected to the sensing electrode 12 through the third control switch ⁇ 22, the second input terminal of the amplifier 41 receives the reference voltage Vcm, and the output terminal of the amplifier 41 is connected to the sensing electrode 12.
  • the sampling module 43 and the data processing circuit 50 are electrically connected.
  • the reference voltage Vcm is half of the power supply voltage VDD.
  • One end of the main capacitor Ca is electrically connected to the first input terminal of the amplifier 41 , and the other end is electrically connected to the output terminal of the amplifier 41 .
  • One end of the reset switch rst is electrically connected to the first input terminal of the amplifier 41 , and the other end is electrically connected to the output terminal of the amplifier 41 .
  • the reset switch rst is in a conducting state in the first stage T1 and the third stage T3.
  • the reset switch rst is in a conducting state in the second stage T2.
  • the fourth stage T4 is in the off state.
  • each auxiliary capacitor C1-1 ⁇ C1-p is electrically connected to the first input terminal of the amplifier 41 through the corresponding first switching element S1-1 ⁇ S1-p.
  • Each of the auxiliary capacitors The corresponding second switching elements S2-1 to S2-p at the other ends of C1-1 to C1-p are electrically connected to the output end of the amplifier 41, and pass through the corresponding third switching element S3-1 ⁇ S3-p is electrically connected to the translation driving module 47.
  • the auxiliary capacitors C1-1 ⁇ C1-p serve as access capacitors when the reset switch rst is in the off state, and can transfer charges, thereby adjusting the voltage at the output end of the amplifier 41 upward or downward.
  • At least one of the auxiliary capacitors C1-1 ⁇ C1-p can be reused as a common mode capacitor when the reset switch rst is in the on state to discharge the stored charges to realize the sensing voltage Vout. adjustment.
  • the capacitance values of the plurality of auxiliary capacitors C1-1 to C1-p are encoded in a binary format in order of arrangement. Wherein, the capacitance values of each of the auxiliary capacitors C1-1 to C1-p are different from each other and arranged in a geometric sequence.
  • a bit is set to select at least one of the third switching elements S3-1 to S3-p to be turned on, so that at least one corresponding auxiliary capacitor C1-k serves as the common mode capacitor, so as to realize the use of Binary encoding selects the common mode capacitor.
  • k is a positive integer and less than p.
  • the third switching element S3-2 is controlled to be turned on according to the coding sequence to select the second auxiliary capacitor C1-2 as the common mode capacitor; when the bit is 3, that is, the corresponding binary code is 011, the third switching elements S3-1 and S3-2 are controlled to be turned on according to the coding sequence to select the first auxiliary capacitor C1- 1 and the second auxiliary capacitor C1-2 together serve as the common mode capacitor.
  • the third switching element S3-3 is controlled to be turned on according to the coding sequence to select the third auxiliary capacitor C1-3 as the common mode capacitor.
  • the plurality of auxiliary capacitors C1-1 to C1-p can also be encoded in a one-hot code format, and each of the auxiliary capacitors C1-1 to C1-p is independently controlled. .
  • the capacitance value of each of the auxiliary capacitors C1-1 to C1-p is the same.
  • the number of the auxiliary capacitors C1-1 to C1-p is selected as the common mode capacitance, so as to realize selection using a one-hot code method. the common mode capacitor.
  • the three auxiliary capacitors C1-1 to C1-3 together serve as the common mode capacitor; when the third switching element When S3-1 to S3-4 are turned on, the four auxiliary capacitors C1-1 to C1-4 together serve as the common mode capacitor.
  • the sampling module 43 is electrically connected to the output end of the amplifier 41 .
  • the sampling module 43 is used to sample the sensing voltage Vout, and output the sampled voltage to the common mode parameter adjustment module 45 .
  • the sampling module 43 uses an analog to digital converter (Analog to Digital Converter, ADC) for sampling.
  • ADC Analog to Digital Converter
  • the common mode parameter adjustment module 45 is electrically connected to the sampling module 43 and the translation driving module 47 .
  • the common mode parameter adjustment module 45 is used to set the number of the auxiliary capacitors C1-1 ⁇ C1-p that are multiplexed as the common mode capacitor according to the sampling voltage and the target voltage.
  • the target voltage is the specified common mode voltage of the amplifier 41 .
  • the common mode parameter adjustment module 45 uses the difference between the sampling voltage and the target voltage as the translation amount and calculates the common mode capacitance value based on the translation amount and the capacitance value of the access capacitor. According to The common mode capacitance value is obtained by looking up the table to obtain the corresponding bit value, and then the number of the auxiliary capacitors C1-1 ⁇ C1-p multiplexed as the common mode capacitor is adjusted.
  • the common mode capacitance value can be calculated according to the following formula 1.
  • Cp Vdiff/Vt*Cfb Formula 1
  • Cp is the common mode capacitance value
  • Vdiff is the difference between the sampling voltage and the target voltage
  • Vt is the target voltage
  • Cfb is the sum of the capacitance values of the access capacitors.
  • the target voltage is half of the supply voltage VDD.
  • the common mode parameter adjustment module 45 stores a lookup table.
  • the lookup table records correspondences between a plurality of common mode capacitance values and values of different bits.
  • the common mode parameter adjustment module 45 compares the sampling voltage and the target voltage and outputs a translation control signal according to the comparison result to determine the translation direction.
  • the sampling voltage is greater than the target voltage, it is recognized that the voltage at the output end of the amplifier 41 is high, and the common mode parameter adjustment module 45 outputs a first translation control signal to downwardly adjust the voltage at the output end of the amplifier 41 .
  • the sampling voltage is less than the target voltage, it is recognized that the voltage at the output end of the amplifier 41 is low, and the common mode parameter adjustment module 45 outputs a second translation control signal to upwardly adjust the voltage at the output end of the amplifier 41 .
  • the first translation control signal is the ground voltage GND; the second translation control signal is the power supply voltage VDD.
  • the first translation control signal Vtx1 and the second translation control signal Vtx2 are pulse signals with the same frequency and opposite phases.
  • the first translation control signal Vtx1 and the control signal of the reset switch rst are synchronization pulse signals, and have the same phase;
  • the second translation control signal Vtx2 and the control signal of the reset switch rst are synchronization pulse signals, And the phase is opposite.
  • the translation driving module 47 is electrically connected to the common mode parameter adjustment module 45, and is electrically connected to the auxiliary capacitors C1-1 to C1-p through the third switching elements S3-1 to S3-p respectively. .
  • the translation driving module 47 is used to control the first switching element S1-1 corresponding to the common mode capacitor when the reset switch rst is turned on and there is a difference between the sampling voltage and the target voltage. ⁇ S1-p and the third switching elements S3-1 ⁇ S3-p are turned on, and provide the first translation control signal or the second translation control signal to the common mode capacitor.
  • Figures 9 and 10 are the first control switch ⁇ 11, the second control switch ⁇ 12, the third control switch ⁇ 22, the first current source Ibp, the second current source Ibn , the waveform diagram of the reset switch rst and the sensing voltage Vout.
  • the specific working principle of the touch detection amplifier circuit 40 is as follows:
  • the first control switch ⁇ 11 is turned on, and the second control switch ⁇ 12 and the third control switch ⁇ 22 are turned off.
  • the reset switch rst is in a conductive state, and the charges on the main capacitor Ca and the auxiliary capacitors C1-1 ⁇ C1-p are released.
  • the first control switch ⁇ 11 and the second control switch ⁇ 12 are opened, and the third control switch ⁇ 22 is closed.
  • the reset switch rst is in an off state, and the charge on the human body capacitor Cfinger is transferred to the main capacitor Ca and the auxiliary capacitors C1-1 ⁇ C1-p.
  • the amplifier 41 converts the charge on the human body capacitance Cfinger into a voltage signal and outputs it through the output terminal.
  • the sampling module 43 samples the voltage at the output end of the amplifier 41 and then outputs the sampled voltage to the common mode parameter adjustment module 45 .
  • the common mode parameter adjustment module 45 calculates the translation capacitance value according to the sampling voltage, the target voltage and the capacitance value of the access capacitor.
  • the common mode parameter adjustment module 45 does not need to access the auxiliary capacitor.
  • the common mode parameter adjustment module 45 obtains the value of the corresponding bit by looking up the table, and then sets at least one of the auxiliary capacitors C1-1 ⁇ C1-p. as the common mode capacitor.
  • the common mode parameter adjustment module 45 sets the capacitance value of the common mode capacitor to be smaller.
  • the second control switch ⁇ 12 is turned on, and the first control switch ⁇ 11 and the third control switch ⁇ 22 are turned off.
  • the reset switch rst is in the on state, and the translation driving module 47 provides the first translation control signal or the second translation control signal to the common mode capacitor, so that the common mode capacitor performs Charge.
  • the first control switch ⁇ 11 and the second control switch ⁇ 12 are opened, and the third control switch ⁇ 22 is closed.
  • the reset switch rst is in the off state.
  • the charge stored on the common mode capacitor is transferred to the main capacitor Ca to adjust the voltage at the output end of the amplifier 41 upward or downward.
  • the above-mentioned touch circuit 200b sets a plurality of auxiliary capacitors C1-1 ⁇ C1-p connected in parallel and adjusts the voltage at the output end of the amplifier 41 in a time-division multiplexing manner to maximize the use of the
  • the voltage output range of the touch detection amplifier circuit 40 improves the sensitivity and working speed of the touch detection amplifier circuit 40 .
  • FIG. 11 is a schematic equivalent circuit diagram of the touch circuit 200c in the third embodiment.
  • the touch circuit 200c is basically the same as the touch circuit 200b. That is to say, the description of the touch circuit 200b described in the second embodiment can basically be applied to the touch circuit 200c of the third embodiment. The main difference between the two is: the charging Structure of circuit 20c.
  • the charging circuit 20c includes a charging capacitor Cb and a buffer 21.
  • One end of the charging capacitor Cb is electrically connected to the sensing electrode 12 through the control circuit 30 , and the other end is electrically connected to the buffer 21 .
  • the buffer 21 receives the pulse voltage Vtx.
  • FIG. 14 shows the first control switch ⁇ 11, the second control switch ⁇ 12, the third control switch ⁇ 22, the pulse voltage Vtx, the reset switch rst and the sensing voltage. Waveform diagram of Vout.
  • the first control switch ⁇ 11 is turned on, and the second control switch ⁇ 12 and the third control switch ⁇ 22 are turned off.
  • the buffer 21 charges the charging capacitor Cb.
  • the reset switch rst is in a conductive state, causing the charges on the main capacitor Ca and the auxiliary capacitors C1-1 to C1-p to be released.
  • the first control switch ⁇ 11 and the second control switch ⁇ 12 are opened, and the third control switch ⁇ 22 is closed.
  • the buffer 21 stops charging the charging capacitor Cb.
  • the charging capacitor Cb is discharged to reduce the influence of the self-capacitance Csensor on the human body capacitance Cfinger.
  • the reset switch rst is in an off state, and the charge on the human body capacitor Cfinger is transferred to the main capacitor Ca and the auxiliary capacitors C1-1 ⁇ C1-p.
  • the amplifier 41 converts the charge on the human body capacitance Cfinger into a voltage signal and outputs it through the output terminal.
  • the sampling module 43 samples the voltage at the output end of the amplifier 41 and then outputs the sampled voltage to the common mode parameter adjustment module 45 .
  • the common mode parameter adjustment module 45 adjusts the The translation capacitance value is calculated by calculating the voltage and the capacitance value of the connected capacitor, and the value of the corresponding bit is obtained by looking up the table. Therefore, when the translation capacitance value is 0, the auxiliary capacitor does not need to be connected. When the translation capacitance value is not 0, the common mode parameter adjustment module 45 obtains the value of the corresponding bit by looking up the table, and then sets at least one of the auxiliary capacitors C1-1 ⁇ C1-p. as the common mode capacitor. When the translation capacitance value is smaller, the common mode parameter adjustment module 45 sets the capacitance value of the common mode capacitor to be smaller.
  • the second control switch ⁇ 12 is turned on, and the first control switch ⁇ 11 and the third control switch ⁇ 22 are turned off.
  • the buffer 21 stops charging the charging capacitor Cb.
  • the charging capacitor Cb is discharged to reduce the influence of the self-capacitance Csensor on the human body capacitance Cfinger.
  • the reset switch rst is in a conductive state, so that the translation driving module 47 provides the first translation control signal or the second translation control signal to the common mode capacitor, so that the common mode capacitor to charge.
  • the first control switch ⁇ 11 and the second control switch ⁇ 12 are opened, and the third control switch ⁇ 22 is closed.
  • the buffer 21 charges the charging capacitor Cb again.
  • the reset switch rst is in the off state.
  • the charge stored on the common mode capacitor is transferred to the main capacitor Ca to adjust the voltage at the output end of the amplifier 41 upward or downward.
  • the above-mentioned touch circuit 200c sets a plurality of auxiliary capacitors C1-1 ⁇ C1-p connected in parallel and adjusts the voltage at the output end of the amplifier 41 in a time-division multiplexing manner to maximize the use of the
  • the voltage output range of the touch detection amplifier circuit 40 improves the sensitivity and working speed of the touch detection amplifier circuit 40 .
  • the charging circuit 20 adopts a switched capacitor circuit to reduce the influence of the self-capacitance Csensor of the sensing electrode 12 on the human body capacitance Cfinger, thereby improving the application range of the touch device 100 .
  • the touch circuit 200 may also adopt the structure of the charging circuit 20a having the charging sub-capacitors Cb-1 ⁇ Cb-p in the first embodiment and the structure of the third embodiment.
  • the structure of the touch detection amplifier circuit 40 that is, the touch circuit 200 simultaneously includes the charging circuit 20a (shown in FIG. 4 ) having the charging sub-capacitors Cb-1 ⁇ Cb-p and the touch detection amplifier circuit in the third embodiment. 40 (as shown in Figure 11).
  • the touch circuit 200 with the above structure can select at least one of the charging circuit 20 or the touch detection amplifier circuit 40 to adjust the sensing voltage Vout according to the voltage value of the sensing voltage Vout.
  • the charging circuit 20 at the front end of the touch circuit 200 can be used to provide charging current (as shown in Figure 8). It is still used to provide the charging capacitor Cb (as shown in Figure 4), and it is selected to correct the charging capacitor Cb or perform common mode correction on the feedback capacitance.
  • the main capacitor Ca and the common mode capacitor C1 constitute the feedback capacitance of the touch detection amplifier circuit 40 . By adjusting the capacitance value of the common mode capacitor C1 , the feedback capacitance value of the touch detection amplifier circuit 40 can be adjusted. .
  • the charging circuit 20 at the front end of the touch circuit 200 is used to provide charging current (as shown in Figure 14), that is, the front end of the touch circuit 200 is the current base. At this time, there is no capacitance base or base in the circuit. The range of the charging capacitor Cb is too small to adjust the sensing voltage Vout. At this time, the feedback capacitance value is adjusted by adjusting the capacitance value of the common mode capacitor C1, thereby achieving a common adjustment of the sensing voltage Vout. Module correction.
  • the charging circuit 20 at the front end of the touch circuit 200 is used to provide a charging capacitor, that is, the front end of the touch circuit 200 is a capacitor base, and the capacitance value range of the charging capacitor Cb is large. At this time, by adjusting the The capacitance value of the charging capacitor Cb performs common mode correction on the sensing voltage Vout.
  • the capacitance value of the charging capacitor Cb can be set to be in the first capacitance adjustment range, and there is a certain difference between the second capacitance adjustment range corresponding to the capacitance value of the common mode capacitor. , so that the feedback capacitance value adjustment range of the touch detection amplifier circuit 40 is smaller than the first capacitance adjustment range of the charging capacitor Cb, so that when the capacitance value of the feedback capacitor changes, the change amplitude of the sensing voltage Vout is smaller than The change amplitude of the sensing voltage Vout when the capacitance value of the charging capacitor Cb changes. Therefore, adjusting the capacitance value of the charging capacitor Cb according to the sensing voltage Vout can improve the adjustment accuracy of the sensing voltage Vout.
  • the above-mentioned touch device 100 uses the data processing circuit 50 to adjust the capacitance value of the charging capacitor Cb in the charging circuit 20 according to the sensing voltage Vout, so as to realize the sensing voltage Vout at the output end of the amplifier 41. Adjustments are made to maximize the voltage output range of the touch detection amplification circuit 40 and improve the sensitivity and working speed of the touch detection amplification circuit 40 .

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Abstract

一种触控电路、触控检测放大电路以及触控装置，触控电路(200)和触控装置(100)包括电荷产生电路(10)、充电电路(20)、控制电路(30)、触控检测放大电路(40)以及数据处理电路(50)。电荷产生电路(10)检测用户触摸产生的感测电容。控制电路(30)控制充电电路(20)对电荷产生电路(10)进行充电，以减少电荷产生电路(10)内的自电容对触控检测放大电路(40)输出的感测电压的影响。充电电路(20)包括充电电容(Cb)以及缓冲器(21)。触控检测放大电路(40)将电荷产生电路(10)输出的感测电容转换为感测电压，以识别触摸操作以及触摸位置。数据处理电路(50)用于根据触控检测放大电路(40)输出的感测电压输出控制信号，以调整充电电容(Cb)的电容值或触控检测放大电路(40)内共模电容的电容值，以使得触控检测放大电路(40)输出的感测电压处于共模电压有效信号范围。

Description

触控电路、触控检测放大电路以及触控装置 技术领域
本发明涉及一种触控电路、触控检测放大电路以及触控装置。
背景技术
随着智能手机的发展,电容式触摸检测应用越来越广泛。电容式触摸检测方案主要分为两个方向：自电容感测和互电容感测，其中自电容感测应用更为广泛，在触控显示合一的检测芯片中，触控检测方案是单纯采用的自容方案，而在一些以互容为主的检测方案中，也需要进行自电容辅助检测。
自电容检测中需要测量电荷的大小，在电路中需要将电荷信号转换成电压信号，这就需要CA(charge amplifier，电荷放大)电路进行转换，但是在集成电路生产过程中,由于制造工艺中每一道工序的不确定性,标称相同的器件都会存在失配。而器件的失配会改变CA转换的有效信号范围，从而影响CA的精度以及限制应用环境。现有技术大多采用加大器件尺寸的办法，但这样会造成面积浪费，也会导致电路电容增加，进而降低电路的速率并增加电路功耗。
发明内容
有鉴于此，有必要提供一种触控电路、触控检测放大电路以及触控装置，旨在解决现有技术中避免器件制造工艺的差异影响触控检测放大电路输出信号的有效范围的技术问题。
一种触控电路，包括电荷产生电路、充电电路、控制电路、触控检测放大电路以及数据处理电路；所述电荷产生电路用于按照一定的时序控制进行扫描以检测用户触摸后与感测电极产生的感测电容；所述控制电路用于控制所述充电电路对所述电荷产生电路进行充电或控制所述电荷产生电路进行放电；所述触控检测放大电路与所述充电电路以及所述控制电路电性连接；所述充电电路包括充电电容，所述充电电容通过结点与所述控制电路以及所述触控检测放大电路电性连接；所述触控检测放大电路用于将所述电荷产生电路输出的感测电容转换为感测电压，以识别触摸操作以及触摸位置；所述数据处理电路与所述触控检测放大电路以及所述充电电路电性连接；所述数据处理电路用于根据所述触控检测放大电路输出的所述感测电压输出控制信号，以调整所述充电电容的电容值，以使得所述触控检测放大电路输出的所述感测电压处于共模电压有效信号范围。
一种触控检测放大电路，与电荷产生电路电性连接，所述触控检测放大电 路包括：
放大器，用于将所述电荷产生电路输出的感测电容转换为感测电压；所述放大器的第一输入端与所述电荷产生电路电性连接；
采样模块，用于对所述放大器的输出电压进行采样并输出采样电压；
复位开关，所述复位开关的一端与所述放大器的第一输入端电性连接，另一端与所述放大器的输出端电性连接；
主电容，并联连接在所述放大器的第一输入端以及输出端之间；
多个辅助电容，每个所述辅助电容的一端通过第一开关元件与所述放大器的所述第一输入端电性连接，并通过第二开关元件与所述输出端电性连接；其中，在所述复位开关处于导通状态且所述采样电压与目标电压之间存在差值时，至少一个所述辅助电容分时复用为共模电容，以存储电荷并在所述复位开关处于断开状态时对所述放大器的输出端的电压进行调整；在所述复位开关处于断开状态时，多个所述辅助电容的第一开关元件和第二开关元件导通，使多个所述辅助电容与所述主电容并联连接作为接入电容；
共模参数调整模块，与所述采样模块电性连接；所述共模参数调整模块在所述采样电压与目标电压之间存在差值时通过控制至少一个所述第一开关元件导通，设定所述辅助电容中的至少一个分时复用为所述共模电容，并输出平移控制信号；
平移驱动模块，与所述共模参数调整模块电性连接，且通过多个第三开关元件与每个所述辅助电容电性连接；在所述复位开关处于导通状态时，所述平移驱动模块用于控制与所述共模电容对应的所述第三开关元件导通，并根据所述平移控制信号对所述共模电容进行充电。
一种触控装置，其包括触控电路；所述触控电路包括电荷产生电路、充电电路、控制电路、触控检测放大电路以及数据处理电路；所述电荷产生电路用于按照一定的时序控制进行扫描以检测用户触摸后与感测电极产生的感测电容；所述控制电路用于控制所述充电电路对所述电荷产生电路进行充电或控制所述电荷产生电路进行放电；所述触控检测放大电路与所述充电电路以及所述控制电路电性连接；所述充电电路包括充电电容，所述充电电容通过结点与所述控制电路以及所述触控检测放大电路电性连接；所述触控检测放大电路用于将所述电荷产生电路输出的感测电容转换为感测电压，以识别触摸操作以及触摸位置；所述数据处理电路与所述触控检测放大电路以及所述充电电路电性连接；所述数据处理电路用于根据所述触控检测放大电路输出的所述感测电压输出控制信号，以调整所述充电电容的电容值，以使得所述触控检测放大电路输出的所述感测电压处于共模电压有效信号范围。
一种触控装置，包括与电荷产生电路电性连接的触控检测放大电路，所述触控检测放大电路包括：
放大器，用于将所述电荷产生电路输出的感测电容转换为感测电压；所述放大器的第一输入端与所述电荷产生电路电性连接；
采样模块，用于对所述放大器的输出电压进行采样并输出采样电压；
复位开关，所述复位开关的一端与所述放大器的第一输入端电性连接，另一端与所述放大器的输出端电性连接；
主电容，并联连接在所述放大器的第一输入端以及输出端之间；
多个辅助电容，每个所述辅助电容的一端通过第一开关元件与所述放大器的所述第一输入端电性连接，并通过第二开关元件与所述输出端电性连接；其中，在所述复位开关处于导通状态且所述采样电压与目标电压之间存在差值时，至少一个所述辅助电容分时复用为共模电容，以存储电荷并在所述复位开关处于断开状态时对所述放大器的输出端的电压进行调整；在所述复位开关处于断开状态时，多个所述辅助电容的第一开关元件和第二开关元件导通，使多个所述辅助电容与所述主电容并联连接作为接入电容；
共模参数调整模块，与所述采样模块电性连接；所述共模参数调整模块在所述采样电压与目标电压之间存在差值时通过控制至少一个所述第一开关元件导通，设定所述辅助电容中的至少一个分时复用为所述共模电容，并输出平移控制信号；
平移驱动模块，与所述共模参数调整模块电性连接，且通过多个第三开关元件与每个所述辅助电容电性连接；在所述复位开关处于导通状态时，所述平移驱动模块用于控制与所述共模电容对应的所述第三开关元件导通，并根据所述平移控制信号对所述共模电容进行充电。
上述触控电路、触控检测放大电路以及触控装置，根据所述触控电路的应用环境可利用所述数据处理电路根据所述感测电压调整所述充电电路中充电电容的电容值或调整所述触控检测放大电路中所述共模电容的电容值，实现对所述放大器输出端的所述感测电压进行不同方式以及不同精度的调整，最大化利用所述触控检测放大电路的电压输出范围，提高所述触控检测放大电路的灵敏度以及工作速率。
附图说明
图1为本发明较佳实施例之触控装置的立体示意图。
图2为图1中较佳实施方式之所述触控电路的模块示意图。
图3为图2中较佳实施方式之所述感测电极的示意图。
图4为图2中第一实施方式之所述触控电路的等效电路示意图。
图5为图4中所述充电电容的电容值与所述感测电压的变化趋势示意图。
图6为图4中所述充电电容的等效电路示意图。
图7为图4中所述复位开关、所述感测电压以及所述充电电容的波形示意图。
图8为图2中第二实施方式之所述触控电路在第一阶段或第三阶段时的等效电路示意图。
图9为图8中第二实施方式之所述触控电路在第二阶段或第四阶段时的等效电路示意图。
图10为图8中所述第一控制开关、所述第二控制开关、所述第三控制开关、所述第一电流源、所述第二电流源、所述复位开关以及所述感测电压的波形示意图。
图11为图2中第三实施方式之所述触控电路的等效电路示意图。
图12为图11中所述复位开关和所述第一平移控制信号的波形示意图。
图13为图11中所述复位开关和所述第二平移控制信号的波形示意图。
图14为图11中所述第一控制开关、所述第二控制开关、所述第三控制开关、所述脉冲电压、所述复位开关以及所述感测电压的波形示意图。
主要元件符号说明
触控装置                         100
触控电路                         200、200a、200b、200c
电荷产生电路                     10
充电电路                         20、20a、20b、20c
控制电路                         30
触控检测放大电路                 40
数据处理电路                     50
感测电极                         12
自电容                           Csensor
人体电容                         Cfinger
第一控制开关                     φ11
第二控制开关                     φ12
第三控制开关                     φ22
放大器                           41
主电容                           Ca
复位开关                         rst
充电电容                         Cb
第一开关元件                     S1-1～S1-p
第二开关元件                     S2-1～S2-p
充电子电容                       Cb-1～Cb-p
缓冲器                           21
结点                              N
感测电压                          Vout
脉冲电压                          Vtx
第一电流源                        Ibp
第二电流源                        Ibn
辅助电容                          C1-1～C1-p
第三开关元件                      S3-1～S3-p
采样模块                          43
共模参数调整模块                  45
平移驱动模块                      47
如下具体实施方式将结合上述附图进一步说明本发明。
具体实施方式
为了使本技术领域的人员更好地理解本发明方案，下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅仅是本发明一部分的实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都应当属于本发明保护的范围。
在本发明的实施方式的描述中，需要说明的是，除非另有明确的规定和限定，术语“连接”应做广义理解，例如，可以是固定连接，也可以是拆卸连接，或一体地连接；可以是机械连接，也可以是电连接或可以相互通讯；可以是直接连接，也可以通过中间没接间接连接，可以是两个元件内部的连通或两个元件的相互作用关系。对于本领域的普通技术人员而言，可以根据具体情况立即上述术语在本发明中的具体含义。
本发明的说明书及上述附图中的术语“第一”、“第二”和“第三”等是用于区别不同对象，而非用于描述特定顺序。此外，术语“包括”以及它们任何变形，意图在于覆盖不排他的包含。
除非另有定义，本文所使用的所有的技术和科学术语与属于本发明的技术领域的技术人员通常理解的含义相同。本文中在本发明的说明书中所使用的术语只是为了描述具体的实施例的目的，不是旨在于限制本发明。
下面结合附图对本发明的触控电路、触控检测放大电路以及触控装置的具体实施方式进行说明。
请参照图1，其为本发明一实施方式的触控装置100的立体示意图。在本发明的至少一个实施方式中，所述触控装置100可以为个人计算机、平板电脑、智能手机、个人数字助理(Personal Digital Assistant，PDA)、游戏机、交互式网 络电视(Internet Protocol Television,IPTV)、智能式穿戴式设备、导航装置等等的可移动设备，也可以为台式电脑、服务器、数字电视等等的固定设备。所述触控装置100可进一步包括指纹识别功能、显示功能以及摄像功能中的一种或多种的结合。触控装置100包括触控电路200(如图2所示)。在本发明的至少一个实施方式中，所述触控电路200可以包括至少一块集成电路板以及电性连接在集成电路板上的多个电子元件，例如电容、电阻以及芯片等等。
请一并参阅图2，其为较佳实施方式之所述触控电路200的模块示意图。所述触控电路200包括电荷产生电路10、充电电路20、控制电路30、触控检测放大电路40以及数据处理电路50。在本发明的至少一个实施方式中，所述触控装置100工作在指定电压域。所述指定电压域用于限定所述触控装置100的电压变化范围，所述指定电压域以所述电源电压VDD为上限电压，低电平电压VSS为下限电压。
所述电荷产生电路10按照一定的时序控制进行扫描以检测用户的触摸操作以产生所述感测电容。如图3所示，所述电荷产生电路10包括呈m*n矩阵排列的所述感测电极12。其中，m，n为正整数，且二者可以相同也可以不同。其中，所述感测电极12与地之间形成自电容Csensor(如图4所示)。用户手指触摸后，触摸区域的所述感测电极12与手指之间形成人体电容Cfinger(如图4所示)，所述自电容Csensor以及所述人体电容Cfinger并联连接共同构成所述感测电容。所述感测电极12通过感测线(图未示)与所述触控检测放大电路40电性连接。
在本发明的至少一个实施方式中，所述触控装置100具有电容式触控屏。对于电容式触摸屏而言，当人体未触碰屏幕时，每个所述感测电极12对应的所述感测电容为所述自电容Csensor，且所述自电容Csensor作为基准电容，即所述感测电极12相对地的电容为一固定值，当人体触碰屏幕时，每个所述感测电极12对应的所述感测电容为所述自电容Csensor叠加所述人体电容Cfinger，所述触控检测放大电路40在触控时间段通过检测每个所述感测电极12的感测电容的电容值变化可以判断出触控位置。但在所述自电容Csensor较大时，所述感测电容的相对变化量就较小，因此在触控时间段需减小或者消除基准电容，避免对触摸检测产生不利影响。
请一并参阅图4，其为第一实施方式之所述触控电路200a的等效电路示意图。所述充电电路20a与所述电荷产生电路10以及所述控制电路30电性连接。所述充电电路20a用于在所述控制电路30的控制下对所述电荷产生电路10进行充电。所述充电电路20a用于根据所述数据处理电路50的控制信号调整所述触控检测放大电路40输出的感测电压Vout，以使得所述触控检测放大电路40输出的所述感测电压Vout处于共模电压有效信号范围。即，所述触控检测放大电路40输出的所述感测电压Vout的有效摆动幅度最大化。所述共模电压有效信号范围位于所述指定电压域内。其中，所述感测电压Vout位于所述指定电压域的中间电平时，其可在所述指定电压域内获得最大摆动幅度。例如，以所述指定电压域为所述低电平电压VSS为0伏特(V)和所述电源电压VDD为1.5V 为例，所述感测电压Vout处于1.5V时，其向上和向下具有最大摆动幅度1.5V。在本发明的至少一个实施方式中，所述共模电压有效信号范围可以为1.3V-1.7V。在其他实施方式中，所述触控装置100内也可设置多个不同范围的共模电压有效信号范围，通过用户设定选择其中一个所述共模电压有效信号范围衡量所述触控装置100的所述感测电压Vout。
请一并参阅图2及图4，所述充电电路20a包括充电电容Cb以及缓冲器21。其中，所述充电电容Cb的一端通过结点N以及所述控制电路30与所述感测电极12电性连接，且通过所述结点N与所述触控检测放大电路40电性连接。所述充电电容Cb的另一端与所述缓冲器21电性连接。所述缓冲器21接收脉冲电压Vtx。所述充电电容Cb根据所述缓冲器21输出的所述脉冲电压Vtx进行充电/放电操作。所述充电电容Cb的电容值可根据所述数据处理电路50输出的所述校正信号进行调整，以保证所述感测电压Vout位于所述共模电压有效信号范围内。在本发明的至少一个实施方式中，如图5所示，所述充电电容Cb的电容值与所述数据处理电路50检测到的所述感测电压Vout呈正比变化。即，在需要将所述感测电压Vout增大时，所述充电电容Cb的电容值根据所述数据处理电路50输出的所述控制信号增大；在需要将所述感测电压Vout减小时，所述充电电容Cb的电容值根据所述数据处理电路50输出的所述控制信号减小。
请一并参阅图4及图6，其为所述充电电容Cb的等效电路图。所述充电电容Cb包括多个充电子电容Cb-1～Cb-p、多个第一开关元件S1-1～S1-p、多个第二开关元件S2-1～S2-p。其中，p为大于1的正整数。每个所述充电子电容Cb-1～Cb-p的一端通过对应的所述第一开关元件S1-1～S1-p与所述放大器41的第一输入端电性连接。每个所述充电子电容Cb-1～Cb-p的另一端对应的所述第二开关元件S2-1～S2-p与所述缓冲器21电性连接。在本发明的第一实施方式中，多个所述充电子电容Cb-1～Cb-p的电容值按照排列顺序采用二进制格式进行编码。其中，每个所述充电子电容Cb-1～Cb-p的电容值互不相同，且呈等比数列排列。在本发明的至少一个实施方式中，在所述校正信号采用比特位(bit)为单位时，根据所述校正信号控制至少一个所述第一开关元件S1-k以及对应的至少一个所述第二开关元件S2-K导通，使得至少一个对应的所述充电子电容Cb-k作为所述充电电容Cb，以实现采用二进制编码方式调整所述充电电容Cb的电容值。其中，k为正整数，且小于p。举例来讲，在bit为2时，即，对应的二进制编码为010，则按照编码顺序控制所述第一开关元件S1-2以及对应的所述第二开关元件S2-2导通，以选择第2个所述充电子电容Cb-2作为所述共模电容；在所述bit为3时，即，对应的二进制编码为011，则按照编码顺序控制所述第一开关元件S1-1～S1-2以及对应的所述第二开关元件S2-1～S2-2导通，以选择第一个所述充电子电容Cb-1和第2个所述充电子电容Cb-2共同作为所述充电电容Cb。在bit为4时，即，对应的二进制编码为100，则按照编码顺序控制所述第一开关元件S1-3以及对应的所述第二开关元件S2-3导通，以选择第三个所述充电子电容Cb-3作为充电电容Cb。在其他实施方式中，多个所述充电子电容Cb-1～Cb-p还可采用独热码格式进行编码，每个所述充电子电容 Cb-1～Cb-p为独立控制。每个所述充电子电容Cb-1～Cb-p的电容值相同。通过控制至少一个所述第一开关元件S1-k以及对应的至少一个所述第二开关元件S2-K的导通数量选择所述充电子电容Cb-1～Cb-p中的作为所述充电电容Cb的数量，以实现采用独热码方式所述充电电容Cb的电容调整。举例来讲，在所述第一开关元件S1-1～S1-3以及对应的所述第二开关元件S2-1～S2-3导通时，3个所述充电子电容Cb-1～Cb-3共同作为所述充电电容Cb；在所述第一开关元件S1-1～S1-4以及对应的所述第二开关元件S2-1～S2-4导通时，4个所述充电子电容Cb-1～Cb-4共同作为所述充电电容Cb。
所述控制电路30与所述电荷产生电路10、所述充电电路20a以及触控检测放大电路40电性连接。所述控制电路30用于根据电源电压VDD以及接地电压VSS控制所述充电电路20a对所述电荷产生电路10进行充电/放电操作，以减少所述自电容Csensor对所述触控检测放大电路40输出的所述感测电压Vout的影响。所述控制电路30包括第一控制开关φ11、第二控制开关φ12以及第三控制开关φ22。所述第一控制开关φ11的一端接收所述电源电压VDD，另一端与所述感测电极12电性连接。所述第二控制开关φ12的一端接地，另一端与所述感测电极12电性连接。所述第三控制开关φ22的一端与所述感测电极12电性连接，另一端通过所述充电电路20a的结点N与所述触控检测放大电路40电性连接。
所述触控检测放大电路40与所述控制电路30以及所述数据处理电路50电性连接。所述触控检测放大电路40用于将所述感测电容的电容值转换为电压信号并进行积分放大后输出所述感测电压Vout给所述数据处理电路50，以使得所述数据处理电路50对所述感测电压Vout进行处理以判断该感测电极12是否被触摸，并得到对应的触摸位置。所述触控检测放大电路40包括放大器41、主电容Ca以及复位开关rst。
所述放大器41与所述控制电路30电性连接。所述放大器41用于将所述感测电容的电容值转换为所述电压信号后进行积分操作输出所述感测电压Vout。所述放大器41的第一输入端通过所述第三控制开关φ22与所述感测电极12电性连接，所述放大器41的第二输入端接收参考电压Vcm，所述放大器41的输出端与所述数据处理电路50电性连接。在本发明的至少一个实施方式中，所述参考电压Vcm为所述电源电压VDD的一半。
所述主电容Ca的一端与所述放大器41的第一输入端电性连接，另一端与所述放大器41的输出端电性连接。
所述复位开关rst的一端与所述放大器41的第一输入端电性连接，另一端与所述放大器41的输出端电性连接。
所述数据处理电路50与所述充电电路20a以及所述触控检测放大电路40电性连接。所述数据处理电路50用于根据所述触控检测放大电路40输出的所述感测电压Vout输出所述控制信号，以调整所述充电电路20a内所述充电电容Cb的电容值，进而实现对所述感测电压Vout的调整。在本发明的至少一个实施方式中，所述数据处理电路50内采用模拟数字转换器(Analog to Digital  Converter，ADC)对所述感测电压Vout进行转换并得到所述控制信号。
由于存在偏置电压，会导致所述放大器41的第一输入端的电压发生向上或向下偏移，进而导致所述触控检测放大电路40输出的所述感测电压Vout超出所述共模电压有效信号范围。在本发明的至少一个实施方式中，通过所述数据处理电路50检测所述感测电压Vout并根据检测结果调整所述充电电路20a中的所述充电电容Cb的电容值，以维持所述触控检测放大电路40输出的所述感测电压Vout在所述共模电压有效信号范围内实现最大摆幅。
具体地，所述数据处理电路50检测所述触控检测放大电路40输出的所述感测电压Vout并判断所述感测电压Vout与预设共模电压的差值是否位于预定差值范围。在本发明的至少一个实施方式中，所述预定差值范围可以位于所述共模电压有效信号范围内，举例来讲，以所述预设共模电压为1.5V，所述共模电压有效信号范围为1.3V-1.7V为例，所述预定差值范围可以为-0.2V-0.2V。在所述感测电压Vout与所述预设共模电压的差值位于所述预定差值范围之内，则识别所述充电电容Cb的电容值无需校正，并存储当前的所述充电电容Cb的电容值。在所述感测电压Vout与所述预设共模电压的差值位于所述预定差值范围之外，则识别所述充电电容Cb的电容值校正，所述数据处理电路50根据所述感测电压Vout与所述预设共模电压的差值调整所述充电电容Cb的电容值。在本发明的至少一个实施方式中，在所述差值为正数时，则根据所述数据处理电路50输出的所述控制信号减小所述充电电容Cb的电容值；在所述差值为负数时，则根据所述数据处理电路50输出的所述控制信号增大所述充电电容Cb的电容值。
请参阅图7，其为所述复位开关rst、所述感测电压Vout以及所述充电电容Cb的波形示意图。在每一个工作周期内，所述触控检测放大电路40实现所述感测电极12检测。所述触控装置100在任意一个所述工作周期内依次工作在第一阶段T1、第二阶段T2、第三阶段T3以及第四阶段T4。其中，所述第一阶段T1和所述第二阶段T2构成正半周期，所述第三阶段T3和所述第四阶段T4构成负半周期。在本发明的至少一个实施方式中，在所述正半周期内，所述数据处理电路50控制所述充电电容Cb的电容值维持在预设电容值恒定不变；在所述负半周期内，所述数据处理电路50控制所述充电电容Cb的电容值根据所述感测电压Vout进行调整。在其他实施方式中，在所述正半周期和所述负半周期内，所述数据处理电路50均控制所述充电电容Cb的电容值根据所述感测电压Vout进行调整。下面以一个所述工作周期为例，对所述触控装置100的工作原理进行说明。
请参阅图4，在所述第一阶段T1，所述第一控制开关φ11以及所述第三控制开关φ22处于断开状态，所述第二控制开关φ12以及所述复位开关rst处于导通状态，使得所述主电容Ca和所述自电容Csensor上的电荷被释放，以实现所述触控装置100的复位。同时，所述缓冲器21输出所述接地电压VSS给所述充电电容Cb。所述数据处理电路50设定所述充电电路20a内的所述充电电容Cb的电容值为所述预设电容值。
在所述第二阶段T2，所述第一控制开关φ11、所述第二控制开关φ12以及所述复位开关rst处于断开状态，所述第三控制开关φ22处于导通状态，使得所述自电容Csensor被充电。同时，所述缓冲器21输出所述电源电压VDD给所述充电电容Cb，使得所述充电电容Cb进行放电以在没有手指触摸时对所述自电容Csensor充电或在有手指触摸时对所述自电容Csensor和所述人体电容Cfinger充电，减少所述自电容Csensor对所述人体电容Cfinger的影响。
在所述第三阶段T3，所述第二控制开关φ12以及所述第三控制开关φ22处于断开状态，所述第一控制开关φ11以及所述复位开关rst处于导通状态，使得所述电源电压VDD在没有手指触摸时对所述自电容Csensor充电或在有手指触摸时对所述自电容Csensor和所述人体电容Cfinger充电，且所述主电容Ca进行放电。同时，所述缓冲器21维持输出所述电源电压VDD给所述充电电容Cb。
在所述第四阶段T4，所述第一控制开关φ11、所述第二控制开关φ12以及所述复位开关rst处于断开状态，所述第三控制开关φ22处于导通状态，使得在没有手指触摸时所述自电容Csensor放电或在有手指触摸时所述自电容Csensor和所述人体电容Cfinger放电，进而将所述自电容Csensor上存储的电荷转移至所述触控检测放大电路40中的所述主电容Ca上。同时，所述缓冲器21再次输出所述接地电压VSS给所述充电电容Cb，所述充电电容Cb进行放电，以对所述自电容Csensor进行补偿，减少所述自电容Csensor对所述人体电容Cfinger的影响。同时，所述数据处理电路50维持所述充电电容Cb的电容值维持在所述预设电容值恒定不变。
请参阅图8，其为第二实施方式之所述触控电路200b在第一阶段或第三阶段时的等效电路示意图。
在所述第二实施方式的所述触控电路200b中的所述充电电路20b包括第一电流源Ibp和第二电流源Ibn。其中，所述第一电流源Ibp提供第一充电电流，所述第二电流源Ibn提供第二充电电流。
所述控制电路30与所述电荷产生电路10、所述充电电路20b以及触控检测放大电路40电性连接。所述控制电路30用于根据电源电压VDD以及接地电压VSS控制所述充电电路20b对所述电荷产生电路10进行充电/放电操作，以减少所述自电容Csensor对所述触控检测放大电路40输出的感测电压Vout的影响。所述控制电路30依次工作在第一阶段T1、第二阶段T2、第三阶段T3以及第四阶段T4。其中，在所述第一阶段T1，所述控制电路30建立所述电荷产生电路10与所述充电电路20b之间的电性连接，电源电压VDD对所述自电容Csensor进行充电。在所述第二阶段T2，所述控制电路30建立所述电荷产生电路10与所述充电电路20b之间的电性连接，所述第一电流源Ibp对所述自电容Csensor进行充电，以减少所述自电容Csensor对所述人体电容Cfinger的影响。所述自电容Csensor放电，使得所述自电容Csensor以及所述人体电容Cfinger上的电荷转移至所述触控检测放大电路40中。在所述第三阶段T3，所述控制电路30断开所述电荷产生电路10与所述充电电路20b之间的电性连接，并对 所述自电容Csensor进行放电。在所述第四阶段T4，所述控制电路30建立所述电荷产生电路10与所述充电电路20b之间的电性连接，所述第二电流源Ibn对所述自电容Csensor进行充电，以减少所述自电容Csensor对所述人体电容Cfinger的影响。同时，所述触控检测放大电路40中电容存储的电荷转移至所述自电容Csensor上。所述控制电路30包括第一控制开关φ11、第二控制开关φ12以及第三控制开关φ22。所述第一控制开关φ11的一端接收电源电压VDD，另一端与所述感测电极12电性连接。所述第二控制开关φ12的一端接地，另一端与所述感测电极12电性连接。所述第三控制开关φ22的一端与所述感测电极12电性连接，另一端与所述充电电路20b以及所述触控检测放大电路40电性连接。
所述触控检测放大电路40与所述控制电路30以及所述数据处理电路50电性连接。所述触控检测放大电路40用于将所述感测电容的电容值转换为电压信号并进行积分放大后输出所述感测电压Vout给所述数据处理电路50，以使得所述数据处理电路50对所述感测电压Vout进行处理以判断该感测电极12是否被触摸，并得到对应的触摸位置。进一步地，所述触控检测放大电路40可在所述指定电压域内对所述感测电压进行调整。所述指定电压域限定所述触控装置100的电压变化范围，所述指定电压域以所述电源电压VDD为上限电压，低电平信号VSS为下限电压。其中，所述高电平信号VDD还可作为所述触控装置100的工作电压，所述低电平信号VSS还可作为接地电压。
请一并参阅图8及图9，所述触控检测放大电路40包括放大器41、主电容Ca、复位开关rst、多个辅助电容C1-1～C1-p、多个第一开关元件S1-1～S1-p、多个第二开关元件S2-1～S2-p、多个第三开关元件S3-1～S3-p、采样模块43、共模参数调整模块45以及平移驱动模块47。其中，p为大于1的正整数。在其他实施方式中，所述采样模块43、所述共模参数调整模块45以及所述平移驱动模块47还可集成在所述数据处理电路50中。
所述放大器41与所述控制电路30电性连接。所述放大器41用于将所述感测电容的电容值转换为所述电压信号后进行积分操作输出所述感测电压Vout。所述放大器41的第一输入端通过所述第三控制开关φ22与所述感测电极12电性连接，所述放大器41的第二输入端接收参考电压Vcm，所述放大器41的输出端与所述采样模块43以及所述数据处理电路50电性连接。在本发明的至少一个实施方式中，所述参考电压Vcm为所述电源电压VDD的一半。
所述主电容Ca的一端与所述放大器41的第一输入端电性连接，另一端与所述放大器41的输出端电性连接。
所述复位开关rst的一端与所述放大器41的第一输入端电性连接，另一端与所述放大器41的输出端电性连接。其中，如图8所示，所述复位开关rst在所述第一阶段T1以及所述第三阶段T3处于导通状态，如图9所示，所述复位开关rst在所述第二阶段T2以及所述第四阶段T4处于断开状态。
每个所述辅助电容C1-1～C1-p的一端通过对应的所述第一开关元件S1-1～S1-p与所述放大器41的第一输入端电性连接。每个所述辅助电容 C1-1～C1-p的另一端对应的所述第二开关元件S2-1～S2-p与所述放大器41的输出端电性连接，并通过对应的所述第三开关元件S3-1～S3-p与所述平移驱动模块47电性连接。所述辅助电容C1-1～C1-p在所述复位开关rst处于断开状态时作为接入电容，可以转移电荷，从而对所述放大器41的输出端的电压进行向上或向下的调整。至少一个所述辅助电容C1-1～C1-p在所述复位开关rst处于所述导通状态时可复用为共模电容，以将存储的电荷进行放电，实现对所述感测电压Vout的调整。在本实施方式的一个实施例中，多个所述辅助电容C1-1～C1-p的电容值按照排列顺序采用二进制格式进行编码。其中，每个所述辅助电容C1-1～C1-p的电容值互不相同，且呈等比数列排列。同时，设定比特位(bit)选择至少一个所述第三开关元件S3-1～S3-p导通，使得至少一个对应的所述辅助电容C1-k作为所述共模电容，以实现采用二进制编码方式选择所述共模电容。其中，k为正整数，且小于p。举例来讲，在bit为2时，即，对应的二进制编码为010，则按照编码顺序控制第三开关元件S3-2导通，以选择第2个所述辅助电容C1-2作为所述共模电容；在所述bit为3时，即，对应的二进制编码为011，则按照编码顺序控制第三开关元件S3-1以及S3-2导通，以选择第一个所述辅助电容C1-1和第2个所述辅助电容C1-2共同作为所述共模电容。在bit为4时，即，对应的二进制编码为100，则按照编码顺序控制第三开关元件S3-3导通，以选择第三个所述辅助电容C1-3作为共模电容。在本实施方式的另一个实施例中，多个所述辅助电容C1-1～C1-p还可采用独热码格式进行编码，每个所述辅助电容C1-1～C1-p为独立控制。每个所述辅助电容C1-1～C1-p的电容值相同。通过控制所述第三开关元件S3-1～S3-p的导通数量选择所述辅助电容C1-1～C1-p中的作为所述共模电容的数量，以实现采用独热码方式选择所述共模电容。举例来讲，在所述第三开关元件S3-1～S3-3导通时，3个所述辅助电容C1-1～C1-3共同作为所述共模电容；在所述第三开关元件S3-1～S3-4导通时，4个所述辅助电容C1-1～C1-4共同作为所述共模电容。
所述采样模块43与所述放大器41的输出端电性连接。所述采样模块43用于对所述感测电压Vout进行采样，并输出采样电压给所述共模参数调整模块45。在本发明的至少一个实施方式中，所述采样模块43采用模拟数字转换器(Analog to Digital Converter，ADC)进行采样。
所述共模参数调整模块45与所述采样模块43以及所述平移驱动模块47电性连接。所述共模参数调整模块45用于根据所述采样电压以及目标电压设定所述辅助电容C1-1～C1-p中复用为所述共模电容的数量。所述目标电压为所述放大器41的指定共模电压。
具体地，所述共模参数调整模块45根据所述采样电压与所述目标电压的差值作为平移量并根据所述平移量以及所述接入电容的电容值计算得到共模电容值，根据所述共模电容值通过查表得到对应的比特位的数值，进而调整所述辅助电容C1-1～C1-p中复用为所述共模电容的数量。其中，所述共模电容值可根据如下公式一计算得出。
Cp＝Vdiff/Vt*Cfb    公式一
其中，Cp为所述共模电容值，Vdiff为所述采样电压与所述目标电压的差值，Vt为所述目标电压，Cfb为所述接入电容的电容值之和。在本发明的至少一个实施方式中，所述目标电压为所述电源电压VDD的一半。
所述共模参数调整模块45内存储有查找表。所述查找表内记录多个所述共模电容值与不同比特位的数值之间的对应关系。
进一步地，所述共模参数调整模块45比较所述采样电压和所述目标电压并根据比较结果输出平移控制信号，以确定平移方向。在所述采样电压大于所述目标电压时，则识别所述放大器41输出端的电压偏高，所述共模参数调整模块45输出第一平移控制信号，以向下调整所述放大器41输出端的电压。在所述采样电压小于所述目标电压时，则识别所述放大器41输出端的电压偏低，所述共模参数调整模块45输出第二平移控制信号，以向上调整所述放大器41输出端的电压。在本实施方式的一个实施例中，所述第一平移控制信号为接地电压GND；所述第二平移控制信号为所述电源电压VDD。在本发明的第三种实施方式中，如图12及图13所示，所述第一平移控制信号Vtx1与所述第二平移控制信号Vtx2为具有相同频率且相位相反的脉冲信号。其中，所述第一平移控制信号Vtx1与所述复位开关rst的控制信号为同步脉冲信号，且相位相同；所述第二平移控制信号Vtx2与所述复位开关rst的控制信号为同步脉冲信号，且相位相反。
所述平移驱动模块47与所述共模参数调整模块45电性连接，并通过所述第三开关元件S3-1～S3-p分别与所述辅助电容C1-1～C1-p电性连接。所述平移驱动模块47用于在所述复位开关rst导通且所述采样电压与所述目标电压之间存在差值时控制与所述共模电容对应的所述第一开关元件S1-1～S1-p和第三开关元件S3-1～S3-p导通，并将所述第一平移控制信号或所述第二平移控制信号提供给所述共模电容。
请一并参阅图9和10，其为所述第一控制开关φ11、所述第二控制开关φ12、所述第三控制开关φ22、所述第一电流源Ibp、所述第二电流源Ibn、所述复位开关rst以及所述感测电压Vout的波形示意图。
所述触控检测放大电路40的具体工作原理如下：
在所述第一阶段T1，所述第一控制开关φ11导通，所述第二控制开关φ12以及所述第三控制开关φ22断开。同时，所述复位开关rst处于导通状态，所述主电容Ca和所述辅助电容C1-1～C1-p上的电荷被释放。
在所述第二阶段T2，所述第一控制开关φ11以及所述第二控制开关φ12断开，所述第三控制开关φ22闭合。同时，所述复位开关rst处于断开状态，所述人体电容Cfinger上的电荷转移至所述主电容Ca以及所述辅助电容C1-1～C1-p上。所述放大器41将所述人体电容Cfinger上的电荷转换为电压信号并通过输出端输出。同时，所述采样模块43对所述放大器41的输出端的电压进行采样后输出采样电压给所述共模参数调整模块45。所述共模参数调整模块45根据所述采样电压、目标电压以及接入电容的电容值计算得到平移电容值。在所述平移电容值为0时，所述共模参数调整模块45不需接入所述辅助电容。 在所述平移电容值不为0时，所述共模参数调整模块45通过查表得到设定对应的比特位的数值，进而设定所述辅助电容C1-1～C1-p中的至少一个作为所述共模电容。在本发明的至少一个实施方式中，在所述平移电容值越小时，所述共模参数调整模块45设置所述共模电容的电容值越小。
在所述第三阶段T3，所述第二控制开关φ12导通，所述第一控制开关φ11以及所述第三控制开关φ22断开。同时，所述复位开关rst处于导通状态，所述平移驱动模块47将所述第一平移控制信号或所述第二平移控制信号提供给所述共模电容，以使得所述共模电容进行充电。
在所述第四阶段T4，所述第一控制开关φ11以及所述第二控制开关φ12断开，所述第三控制开关φ22闭合。同时，所述复位开关rst处于断开状态。此时，将所述共模电容上存储的电荷转移到所述主电容Ca上，以对所述放大器41的输出端的电压进行向上或向下的调整。
上述所述触控电路200b，通过设置多个并联连接的所述辅助电容C1-1～C1-p并采用分时复用的方式对所述放大器41输出端的电压进行调整，最大化利用所述触控检测放大电路40的电压输出范围，提高所述触控检测放大电路40的灵敏度以及工作速率。
请一并参阅图11，其为第三实施方式之所述触控电路200c的等效电路示意图。其中，所述触控电路200c与所述触控电路200b基本相同。也就是说，所述第二实施方式描述的所述触控电路200b的描述基本上均可以适用于所述第三实施方式的所述触控电路200c，二者的主要差别在于：所述充电电路20c的结构。
所述充电电路20c包括充电电容Cb以及缓冲器21。其中，所述充电电容Cb的一端通过所述控制电路30与所述感测电极12电性连接，另一端与所述缓冲器21电性连接。所述缓冲器21接收脉冲电压Vtx。
请一并参阅图14，其为所述第一控制开关φ11、所述第二控制开关φ12、所述第三控制开关φ22、所述脉冲电压Vtx、所述复位开关rst以及所述感测电压Vout的波形示意图。
在所述第一阶段T1，所述第一控制开关φ11导通，所述第二控制开关φ12以及所述第三控制开关φ22断开。所述缓冲器21对所述充电电容Cb进行充电。同时，所述复位开关rst处于导通状态，使得所述主电容Ca和所述辅助电容C1-1～C1-p上的电荷被释放。
在所述第二阶段T2，所述第一控制开关φ11以及所述第二控制开关φ12断开，所述第三控制开关φ22闭合。所述缓冲器21停止对所述充电电容Cb进行充电。所述充电电容Cb放电，以减少所述自电容Csensor对所述人体电容Cfinger的影响。同时，所述复位开关rst处于断开状态，所述人体电容Cfinger上的电荷转移至所述主电容Ca以及所述辅助电容C1-1～C1-p上。所述放大器41将所述人体电容Cfinger上的电荷转换为电压信号并通过输出端输出。同时，所述采样模块43对所述放大器41的输出端的电压进行采样后输出采样电压给所述共模参数调整模块45。所述共模参数调整模块45根据所述采样电压、目标 电压以及接入电容的电容值计算得到平移电容值，并通过查表得到设定对应的比特位的数值，进而在所述平移电容值为0时不需接入所述辅助电容。在所述平移电容值不为0时，所述共模参数调整模块45通过查表得到设定对应的比特位的数值，进而设定所述辅助电容C1-1～C1-p中的至少一个作为所述共模电容。在所述平移电容值越小时，所述共模参数调整模块45设置所述共模电容的电容值越小。
在所述第三阶段T3，所述第二控制开关φ12导通，所述第一控制开关φ11以及所述第三控制开关φ22断开。所述缓冲器21停止对所述充电电容Cb进行充电。所述充电电容Cb放电，以减少所述自电容Csensor对所述人体电容Cfinger的影响。同时，所述复位开关rst处于导通状态，使得所述平移驱动模块47将所述第一平移控制信号或所述第二平移控制信号提供给所述共模电容，以使得所述共模电容进行充电。
在所述第四阶段T4，所述第一控制开关φ11以及所述第二控制开关φ12断开，所述第三控制开关φ22闭合。所述缓冲器21再次对所述充电电容Cb进行充电。同时，所述复位开关rst处于断开状态。此时，将所述共模电容上存储的电荷转移到所述主电容Ca上，以对所述放大器41的输出端的电压进行向上或向下的调整。
上述所述触控电路200c，通过设置多个并联连接的所述辅助电容C1-1～C1-p并采用分时复用的方式对所述放大器41输出端的电压进行调整，最大化利用所述触控检测放大电路40的电压输出范围，提高所述触控检测放大电路40的灵敏度以及工作速率。同时，通过所述充电电路20采用开关电容电路，以降低所述感测电极12的所述自电容Csensor对所述人体电容Cfinger的影响，提高了所述触控装置100的应用范围。
在其他实施方式中，触控电路200还可以采用所述第一实施方式中具有所述充电子电容Cb-1～Cb-p的所述充电电路20a的结构以及所述第三实施方式中的所述触控检测放大电路40的结构。即，所述触控电路200同时包括具有所述充电子电容Cb-1～Cb-p的所述充电电路20a(如图4所示)以及第三实施方式中的所述触控检测放大电路40(如图11)。上述结构的所述触控电路200可根据所述感测电压Vout的电压值选择所述充电电路20或所述触控检测放大电路40中的至少一者对所述感测电压Vout进行调整。
前端的所述充电电路20的差异会导致所述触控电路200的应用环境不同。为了保证所述感测电压Vout在预设共模电压有效范围内实现最大摆幅，可根据所述触控电路200中前端的所述充电电路20是用于提供充电电流(如图8)，还是用于提供所述充电电容Cb(如图4)，选择采用对所述充电电容Cb进行校正或者对反馈电容进行共模校正。其中，所述主电容Ca和所述共模电容C1构成触控检测放大电路40的反馈电容，通过调整所述共模电容C1的电容值可以实现对触控检测放大电路40反馈电容值的调整。
所述触控电路200中前端的所述充电电路20是用于提供充电电流时(如图14)，即所述触控电路200的前端是电流base，此时电路内没有电容base或者 所述充电电容Cb的范围过小，不足以进行感测电压Vout调整，此时通过调整所述共模电容C1的电容值实现反馈电容值的调整，进而实现对所述感测电压Vout的共模校正。
所述触控电路200中前端的所述充电电路20是用于提供充电电容时，即触控电路200的前端是电容base，所述充电电容Cb的电容值范围大，此时通过调整所述充电电容Cb的电容值对所述感测电压Vout进行共模校正。
在本发明的至少一个实施例中，可以通过设置所述充电电容Cb的电容值位于所述第一电容调整范围，且与所述共模电容的电容值对应的第二电容调整范围具有一定差异，以使得所述触控检测放大电路40反馈电容值调整范围小于所述充电电容Cb的第一电容调整范围，使得在所述反馈电容的电容值改变时所述感测电压Vout的变化幅度小于在所述充电电容Cb的电容值改变时所述感测电压Vout的变化幅度。因此，根据所述感测电压Vout对所述充电电容Cb的电容值进行调整可提高对所述感测电压Vout的调整精度。
上述所述触控装置100，利用所述数据处理电路50根据所述感测电压Vout调整所述充电电路20中充电电容Cb的电容值，实现对所述放大器41输出端的所述感测电压Vout进行调整，最大化利用所述触控检测放大电路40的电压输出范围，提高所述触控检测放大电路40的灵敏度以及工作速率。
本技术领域的普通技术人员应当认识到，以上的实施方式仅是用来说明本发明，而并非用作为对本发明的限定，只要在本发明的实质精神范围之内，对以上实施例所作的适当改变和变化都落在本发明要求保护的范围之内。

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  1. 一种触控电路，其特征在于，所述触控电路包括电荷产生电路、充电电路、控制电路、触控检测放大电路以及数据处理电路；所述电荷产生电路用于按照一定的时序控制进行扫描以检测用户触摸后与感测电极产生的感测电容；所述控制电路用于控制所述充电电路对所述电荷产生电路进行充电或控制所述电荷产生电路进行放电；所述触控检测放大电路与所述充电电路以及所述控制电路电性连接；所述充电电路包括充电电容，所述充电电容通过结点与所述控制电路以及所述触控检测放大电路电性连接；所述触控检测放大电路用于将所述电荷产生电路输出的感测电容转换为感测电压，以识别触摸操作以及触摸位置；所述数据处理电路与所述触控检测放大电路以及所述充电电路电性连接；所述数据处理电路用于根据所述触控检测放大电路输出的所述感测电压输出控制信号，以调整所述充电电容的电容值，以使得所述触控检测放大电路输出的所述感测电压处于共模电压有效信号范围。
  2. 如权利要求1所述的触控电路，其特征在于，所述数据处理电路判断所述感测电压与预设共模电压的差值是否位于预定差值范围；在所述感测电压与所述预设共模电压的差值位于所述预定差值范围之外，则识别所述充电电容的电容值需进行校正，所述数据处理电路根据所述感测电压与所述预设共模电压的差值调整所述充电电容的电容值；在所述感测电压与所述预设共模电压的差值位于所述预定差值范围之内，则识别所述充电电容的电容值无需校正，并存储当前的所述充电电容的电容值。
  3. 如权利要求2所述的触控电路，其特征在于，所述充电电容的电容值与所述数据处理电路检测到的所述感测电压呈正比变化；在所述差值为正数时，则根据所述数据处理电路输出的所述控制信号减小所述充电电容的电容值；在所述差值为负数时，则根据所述数据处理电路输出的所述控制信号增大所述充电电容的电容值。
  4. 如权利要求1所述的触控电路，其特征在于，所述控制电路包括第一控制开关、第二控制开关以及第三控制开关；
    所述第一控制开关的一端接收电源电压，另一端与所述感测电极电性连接，所述第二控制开关的一端接地，另一端与所述电荷产生电路的感测电极电性连接，所述第三控制开关的一端与所述感测电极电性连接，另一端通过所述充电电路的结点与所述触控检测放大电路电性连接。
  5. 如权利要求1所述的触控电路，其特征在于，所述触控检测放大电路包括：
    放大器，用于将所述电荷产生电路输出的感测电容转换为感测电压；所述放大器的第一输入端与所述电荷产生电路电性连接，所述放大器的第二输入端接收参考电压，所述放大器的输出端连接数据处理电路；
    复位开关，所述复位开关的一端与所述放大器的第一输入端电性连接，另 一端与所述放大器的输出端电性连接；
    主电容，并联连接在所述放大器的第一输入端以及输出端之间。
  6. 如权利要求5所述的触控电路，其特征在于，所述触控检测放大电路还包括：
    采样模块，用于对所述放大器的输出电压进行采样并输出采样电压；
    多个辅助电容，每个所述辅助电容的一端通过第一开关元件与所述放大器的所述第一输入端电性连接，并通过第二开关元件与所述输出端电性连接；其中，在所述复位开关处于导通状态且所述采样电压与目标电压之间存在差值时，至少一个所述辅助电容分时复用为共模电容，以存储电荷并在所述复位开关处于断开状态时对所述放大器的输出端的电压进行调整；在所述复位开关处于断开状态时，多个所述辅助电容的第一开关元件和第二开关元件导通，使多个所述辅助电容与所述主电容并联连接作为接入电容；
    共模参数调整模块，与所述采样模块电性连接；所述共模参数调整模块在所述采样电压与目标电压之间存在差值时通过控制至少一个所述第一开关元件导通，设定所述辅助电容中的至少一个分时复用为所述共模电容，并输出平移控制信号；
    平移驱动模块，与所述共模参数调整模块电性连接，且通过多个第三开关元件与每个所述辅助电容电性连接；在所述复位开关处于导通状态时，所述平移驱动模块用于控制与所述共模电容对应的所述第三开关元件导通，并根据所述平移控制信号对所述共模电容进行充电。
  7. 如权利要求6所述的触控电路，其特征在于，多个所述辅助电容采用二进制格式进行编码；每个所述辅助电容的电容值互不相同，且呈等比数列排列；通过设定比特位选择至少一个所述辅助电容作为所述共模电容，以实现采用二进制编码方式选择所述共模电容。
  8. 如权利要求6所述的触控电路，其特征在于，所述共模参数调整模块内存储有查找表；所述查找表内记录多个所述共模电容值与不同比特位的数值之间的对应关系；所述共模参数调整模块根据所述采样电压与所述目标电压的差值作为平移量并根据所述平移量以及所述接入电容的电容值计算得到共模电容值，根据所述共模电容值通过查表得到对应的所述比特位的数值，根据所述比特位的数值设定所述辅助电容中复用为所述共模电容的数量。
  9. 如权利要求1所述的触控电路，其特征在于，所述充电电容包括多个充电子电容、多个第一开关元件以及多个第二开关元件；每个所述充电子电容的一端通过一个所述第一开关元件与所述结点电性连接，并通过一个所述第二开关元件接收脉冲电压；多个所述充电子电容采用二进制格式进行编码；每个所述充电子电容的电容值互不相同，且呈等比数列排列；通过设定比特位选择至少一个所述充电子电容作为所述充电电容，以实现采用二进制编码方式调整所述充电电容的电容值。
  10. 如权利要求1所述的触控电路，其特征在于，所述充电电容包括多个充电子电容、多个第一开关元件以及多个第二开关元件；每个所述充电子电容 的一端通过一个所述第一开关元件与所述结点电性连接，并通过一个所述第二开关元件接收脉冲电压；多个所述充电子电容采用热独码格式进行编码；每个所述充电子电容的电容值相同。
  11. 如权利要求1所述的触控电路，其特征在于，在每个工作周期内，所述触控电路依次工作在正半周期以及负半周期；在所述正半周期内，所述数据处理电路控制所述充电电容的电容值维持在预设电容值恒定不变；在所述负半周期内，所述数据处理电路控制所述充电电容的电容值根据所述感测电压进行调整。
  12. 如权利要求11所述的触控电路，其特征在于，所述正半周期包括第一阶段以及第二阶段；在所述第一阶段，所述控制电路控制所述电荷产生电路以及所述触控检测放大电路复位；在所述第二阶段，所述控制电路控制所述充电电容进行放电以对所述电荷产生电路中的自电容进行充电；所述负半周期包括第三阶段和第四阶段；在所述第三阶段，所述控制电路提供电源电压对所述电荷产生电路进行充电，并控制所述触控检测放大电路进行放电；在所述第四阶段，所述控制电路控制所述电荷产生电路放电，以将所述电荷产生电路中人体电容存储的电荷转移至所述触控检测放大电路中。
  13. 如权利要求12所述的触控电路，其特征在于，所述充电电路还包括缓冲器；所述缓冲器将接收的脉冲电压提供给所述充电电容；在所述第二阶段以及所述第三阶段，所述缓冲器提供所述电源电压给所述充电电容；在所述第一阶段以及所述第四阶段，所述缓冲器提供接地电压给所述充电电容。
  14. 一种触控检测放大电路，与电荷产生电路电性连接，其特征在于，所述触控检测放大电路包括：
    放大器，用于将所述电荷产生电路输出的感测电容转换为感测电压；所述放大器的第一输入端与所述电荷产生电路电性连接；
    采样模块，用于对所述放大器的输出电压进行采样并输出采样电压；
    复位开关，所述复位开关的一端与所述放大器的第一输入端电性连接，另一端与所述放大器的输出端电性连接；
    主电容，并联连接在所述放大器的第一输入端以及输出端之间；
    多个辅助电容，每个所述辅助电容的一端通过第一开关元件与所述放大器的所述第一输入端电性连接，并通过第二开关元件与所述输出端电性连接；其中，在所述复位开关处于导通状态且所述采样电压与目标电压之间存在差值时，至少一个所述辅助电容分时复用为共模电容，以存储电荷并在所述复位开关处于断开状态时对所述放大器的输出端的电压进行调整；在所述复位开关处于断开状态时，多个所述辅助电容的第一开关元件和第二开关元件导通，使多个所述辅助电容与所述主电容并联连接作为接入电容；
    共模参数调整模块，与所述采样模块电性连接；所述共模参数调整模块在所述采样电压与目标电压之间存在差值时通过控制至少一个所述第一开关元件导通，设定所述辅助电容中的至少一个分时复用为所述共模电容，并输出平移控制信号；
    平移驱动模块，与所述共模参数调整模块电性连接，且通过多个第三开关元件与每个所述辅助电容电性连接；在所述复位开关处于导通状态时，所述平移驱动模块用于控制与所述共模电容对应的所述第三开关元件导通，并根据所述平移控制信号对所述共模电容进行充电。
  15. 如权利要求14所述的触控检测放大电路，其特征在于，多个所述辅助电容采用二进制格式进行编码；每个所述辅助电容的电容值互不相同，且呈等比数列排列；通过设定比特位选择至少一个所述辅助电容作为所述共模电容，以实现采用二进制编码方式选择所述共模电容。
  16. 如权利要求15所述的触控检测放大电路，其特征在于，所述共模参数调整模块内存储有查找表；所述查找表内记录多个所述共模电容值与不同比特位的数值之间的对应关系；所述共模参数调整模块根据所述采样电压与所述目标电压的差值作为平移量并根据所述平移量以及所述接入电容的电容值计算得到共模电容值，根据所述共模电容值通过查表得到对应的所述比特位的数值，根据所述比特位的数值设定所述辅助电容中复用为所述共模电容的数量。
  17. 如权利要求16所述的触控检测放大电路，其特征在于，所述共模电容值采用公式：Cp＝Vdiff/Vt*Cfb计算得出；其中，Cp为所述共模电容值，Vdiff为所述采样电压与所述目标电压的差值，Vt为所述目标电压，Cfb为所述接入电容的电容值之和。
  18. 如权利要求14所述的触控检测放大电路，其特征在于，所述共模参数调整模块进一步地比较所述采样电压与目标电压并根据比较结果输出平移控制信号，以确定平移方向；在所述采样电压大于所述目标电压时，所述共模参数调整模块输出第一平移控制信号，以向下调整所述放大器输出端的电压；在所述采样电压小于所述目标电压时，所述共模参数调整模块输出第二平移控制信号，以向上调整所述放大器输出端的电压。
  19. 如权利要求18所述的触控检测放大电路，其特征在于，所述第一平移控制信号为接地电压；所述第二平移控制信号为电源电压。
  20. 如权利要求18所述的触控检测放大电路，其特征在于，所述第一平移控制信号与所述第二平移控制信号为具有相同频率且相位相反的脉冲信号；所述第一平移控制信号与所述复位开关的控制信号为同步脉冲信号，且相位相同；所述第二平移控制信号与所述复位开关的控制信号为同步脉冲信号，且相位相反。
  21. 如权利要求14所述的触控检测放大电路，其特征在于，多个所述辅助电容采用热独码格式进行编码；每个所述辅助电容的电容值相同；通过控制所述第三开关元件的导通数量选择所述辅助电容中的作为所述共模电容的数量。
  22. 一种触控装置，其特征在于，所述触控装置包括如权利要求1至13中任意一项所述的所述触控电路。
  23. 一种触控装置，其特征在于，所述触控装置包括电荷产生电路、充电电路、控制电路、触控检测放大电路以及数据处理电路；所述电荷产生电路用于按照一定的时序控制进行扫描以检测用户接近感测电极所产生的感测电容； 所述充电电路用于提供充电电流；所述控制电路用于控制所述充电电路对所述电荷产生电路进行充电，以减少所述电荷产生电路内的自电容对所述触控检测放大电路输出的所述感测电压的影响，所述触控装置包括如权利要求14至21中任意一项所述的所述触控检测放大电路。
  24. 如权利要求23所述的触控装置，其特征在于，所述充电电路包括第一电流源和第二电流源；其中，所述第一电流源提供第一充电电流对所述电荷产生电路内的自电容进行充电，所述第二电流源提供第二充电电流对所述电荷产生电路内的自电容进行放电。
  25. 如权利要求23所述的触控装置，其特征在于，所述充电电路包括充电电容以及缓冲器；所述缓冲器通过所述充电电容与所述控制电路电性连接；所述缓冲器用于提供脉冲电压。
  26. 如权利要求23所述的触控装置，其特征在于，所述控制电路包括第一控制开关、第二控制开关以及第三控制开关；所述第一控制开关的一端接收电源电压，另一端与所述感测电极电性连接，所述第二控制开关的一端接地，另一端与所述电荷产生电路的感测电极电性连接，所述第三控制开关的一端与所述感测电极电性连接，另一端通过所述充电电路的结点与所述触控检测放大电路电性连接。
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117811561A (zh) * 2023-12-27 2024-04-02 武汉芯必达微电子有限公司 一种应用于通用微控制器的电容触摸按键检测电路及方法

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CN118068988B (zh) * 2024-04-25 2024-07-23 上海海栎创科技股份有限公司 一种自电容触摸检测电路及检测方法

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104216580A (zh) * 2013-06-05 2014-12-17 硕呈科技股份有限公司 一种以电荷分享达成触控电容感测的可集成化的电路
CN106201122A (zh) * 2014-10-14 2016-12-07 奇景光电股份有限公司 触控面板与其控制方法
WO2021016992A1 (zh) * 2019-08-01 2021-02-04 深圳市汇顶科技股份有限公司 电容检测方法
CN114355057A (zh) * 2021-04-27 2022-04-15 深圳曦华科技有限公司 电容检测电路、触摸装置和电子设备
CN114967977A (zh) * 2022-05-27 2022-08-30 敦泰科技(深圳)有限公司 触控检测放大电路以及触控装置

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104216580A (zh) * 2013-06-05 2014-12-17 硕呈科技股份有限公司 一种以电荷分享达成触控电容感测的可集成化的电路
CN106201122A (zh) * 2014-10-14 2016-12-07 奇景光电股份有限公司 触控面板与其控制方法
WO2021016992A1 (zh) * 2019-08-01 2021-02-04 深圳市汇顶科技股份有限公司 电容检测方法
CN114355057A (zh) * 2021-04-27 2022-04-15 深圳曦华科技有限公司 电容检测电路、触摸装置和电子设备
CN114967977A (zh) * 2022-05-27 2022-08-30 敦泰科技(深圳)有限公司 触控检测放大电路以及触控装置

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117811561A (zh) * 2023-12-27 2024-04-02 武汉芯必达微电子有限公司 一种应用于通用微控制器的电容触摸按键检测电路及方法

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