Touch state detection circuit, method and electronic system

Abstract

The present application relates to a touch state detection circuit, method, and electronic system. The touch state detection circuit includes: a controller, a voltage regulator, a capacitor circuit, and a processing circuit. The controller is used to control the charging and discharging of the capacitor circuit, and to control the voltage regulator to enter an operating state when the capacitor circuit is in a touched state. The controller is also used to detect the touch state of the capacitor circuit based on a first control signal output by the processing circuit. During the touch state detection process of a capacitive touch key, the above-mentioned touch state detection circuit can be used to control the voltage regulator not to enter an operating state before first determining that the capacitor circuit is in a touched state. In other words, part of the circuit in the detection circuit does not enter an operating state, thereby reducing the power consumption of the touch state detection circuit during the detection process.

Description

Technical Field

[0001] The present application relates to the field of signal detection technology, and in particular to a touch state detection circuit, method, and electronic system. Background Art

[0002] With the development of electronic technology, most electronic systems now use capacitive touch buttons as a medium for human-computer interaction.

[0003] Generally, whether the capacitive touch key is touched is determined based on whether the capacitance value of the capacitive touch key changes within a specific time period, and the electronic system outputs a corresponding response result based on the touch state of the capacitive touch key.

[0004] However, in the related art, the power consumption of the circuit for detecting the change in the capacitance value of the capacitive touch button in the electronic system is relatively high. Summary of the Invention

[0005] Based on this, it is necessary to provide a touch state detection circuit, method and electronic system to address the above technical problems, which can reduce the power consumption of the detection circuit.

[0006] In a first aspect, an embodiment of the present application provides a touch state detection circuit, the touch state detection circuit comprising: a controller, a voltage regulator, a capacitor circuit, and a processing circuit; wherein a first control terminal of the controller is connected to a first input terminal of the capacitor circuit, a second control terminal of the controller is connected to an output terminal of the voltage regulator and a second input terminal of the capacitor circuit respectively through a first switch, a third control terminal of the controller is connected to a control terminal of the voltage regulator, and a fourth control terminal of the controller is connected to the output terminal of the capacitor circuit through a second switch; a fifth control terminal of the controller is connected to a first input terminal of the processing circuit and to ground respectively through a third switch; and a signal input terminal of the controller is connected to an output terminal of the processing circuit;

[0007] The controller is used to control the charging and discharging of the capacitor circuit, and to control the voltage regulator to enter the working state when the capacitor circuit is in the touched state, and is also used to detect the touch state of the capacitor circuit according to the first control signal output by the processing circuit.

[0008] In one embodiment, the voltage stabilizer includes a voltage stabilizing component and a voltage stabilizing switch; the voltage stabilizing switch is connected in parallel with the voltage stabilizing component, a first end of the voltage stabilizing switch and a first end of the voltage stabilizing component are both connected to a power source, a second end of the voltage stabilizing switch and a second end of the voltage stabilizing component are both connected to one end of the first switch; the voltage stabilizing switch is connected to a third control terminal of the controller;

[0009] The voltage regulating switch is used to be disconnected when the capacitor circuit is in a touched state, and closed when the capacitor circuit is in an untouched state.

[0010] In one embodiment, the voltage stabilizing switch includes a switching tube and a fourth switch, wherein a first end of the switching tube and one end of the fourth switch are connected to a power source, a second end of the switching tube and the other end of the fourth switch are connected to one end of the first switch, a third end of the switching tube is connected to a first end of the voltage stabilizing component, and a control end of the fourth switch is connected to a third control end of the controller;

[0011] The fourth switch is used to close after the capacitor circuit is touched for the first time; the switch tube is used to turn on when the voltage between the second end of the switch tube and the third end of the switch tube reaches the turn-on voltage of the switch tube.

[0012] In one embodiment, the voltage stabilizing component includes a driving circuit, a buffer and an error amplifier, the first end of the driving circuit is connected to the second end of the voltage stabilizing switch, the second end of the driving circuit is respectively connected to the input end of the buffer and the output end of the error amplifier, the third end of the driving circuit is connected to the negative input end of the error amplifier, the fourth end of the driving circuit is grounded, and the buffer is connected to the first end of the voltage stabilizing switch through the first end of the voltage stabilizing component.

[0013] In one embodiment, the driving circuit includes a compensation circuit and a voltage divider circuit, the first end of the voltage divider circuit is respectively connected to the second end of the switch tube, the second end of the fourth switch and one end of the compensation circuit, the second end of the voltage divider circuit is grounded, the third end of the voltage divider circuit is connected to the negative input end of the error amplifier, and the other end of the compensation circuit is respectively connected to the output end of the error amplifier and the input end of the buffer.

[0014] In one embodiment, the voltage divider circuit includes: a first resistor and a second resistor; one end of the first resistor is respectively connected to the second end of the switch tube, the second end of the fourth switch and one end of the compensation circuit, the other end of the first resistor is respectively connected to one end of the second resistor and the negative input end of the error amplifier, and the other end of the second resistor is grounded.

[0015] In one embodiment, the touch state detection circuit further includes: a fifth switch, the fifth switch being connected in parallel to a common end of the second switch and the third switch and in a path between the first input end of the processing circuit, the first end of the fifth switch being connected to the common end of the second switch and the third switch, and the second end of the fifth switch being connected to the first input end of the processing circuit; and a control end of the fifth switch being connected to a second control end of the controller.

[0016] In one embodiment, the capacitive circuit includes at least one touch branch, the touch branch includes a touch capacitor and a touch switch, the touch capacitor and the touch switch are connected in series, one end of the touch capacitor is grounded, the other end of the touch capacitor is connected to one end of the touch switch, and the other end of the touch switch is connected to the first switch and the second switch respectively;

[0017] When the touch switch is closed, the touch capacitor is charged; when the touch switch is disconnected, the touch capacitor is discharged.

[0018] In one embodiment, the processing circuit includes a charging capacitor, a comparator, and a reference voltage generating circuit; one end of the charging capacitor is grounded, and the other end of the charging capacitor is connected to a common end of the fifth switch and the third switch and an inverting input of the comparator, respectively; a positive input of the comparator is connected to the reference voltage generating circuit, and an output of the comparator is connected to a signal input of the controller;

[0019] When the third switch is closed, the charging capacitor is discharged; when the second switch is closed and the third switch is open, the charging capacitor is charged according to the discharged charge of the touch capacitor in the working state in the capacitive circuit;

[0020] The comparator is used for comparing the voltage across the charging capacitor with the reference voltage output by the reference voltage generating circuit, and outputting a first control signal to the controller.

[0021] In one embodiment, the controller includes: a state machine and a bi-phase clock signal generating circuit;

[0022] The state machine is used to generate a clock signal and send the clock signal to the two-phase clock signal generating circuit to instruct the two-phase clock signal generating circuit to output a first clock signal through the second control terminal of the controller and to output a second clock signal through the fifth control terminal of the controller, wherein the first clock signal and the second clock signal are anti-phase clock signals;

[0023] The state machine is also used to output a first switching signal through the third control terminal of the controller to control the voltage regulator to enter the working state when the capacitor circuit is in the touched state, and to output a second switching signal through the fifth control terminal of the controller to close the first switch and open the second switch when the capacitor circuit is charging, and to open the first switch and close the second switch after the capacitor circuit completes charging; the state machine is also used to receive a first control signal through the signal input terminal of the controller, and to start a detection program according to the first control signal to detect the current touch state of the capacitor circuit.

[0024] In a second aspect, an embodiment of the present application provides a touch detection method, which is implemented by the touch state detection circuit in any embodiment of the first aspect, and includes:

[0025] Acquire a first control signal output by a processing circuit in a touch state detection circuit;

[0026] According to the first control signal, the touch state of the capacitor circuit in the touch state detection circuit is determined; wherein, during the detection process, when it is determined that the capacitor circuit is in the touched state, the regulator in the touch state detection circuit is controlled to enter the working state.

[0027] In one embodiment, when determining that the capacitive circuit is in a touched state, controlling a voltage regulator in the touch state detection circuit to enter an operating state includes:

[0028] When it is determined for the first time that the capacitive circuit is in the touched state, the voltage regulator is controlled to enter the working state according to the second control signal.

[0029] In one embodiment, obtaining a first control signal output by a processing circuit in a touch state detection circuit includes:

[0030] Get the voltage across the charging capacitor;

[0031] A first control signal output by the processing circuit is determined according to the voltage across the charging capacitor and a reference voltage.

[0032] In one embodiment, before obtaining the first control signal output by the processing circuit in the touch state detection circuit, the method further includes:

[0033] At the beginning of the detection process, controlling the discharge of the charging capacitor of the processing circuit in the touch state detection circuit;

[0034] After the charging capacitor is discharged, the capacitor circuit is controlled to charge and discharge according to the clock signal.

[0035] In one embodiment, the clock signal includes a first clock signal and a second clock signal, and controlling the charging and discharging of the capacitor circuit according to the clock signal includes:

[0036] generating a first clock signal and a second clock signal according to the clock signal;

[0037] The capacitor circuit is controlled to charge and discharge according to the first clock signal and the second clock signal.

[0038] In a third aspect, an embodiment of the present application provides an electronic system, which includes the touch state detection circuit in the embodiment of the first aspect above.

[0039] Embodiments of the present application provide a touch state detection circuit, method, and electronic system. The touch state detection circuit includes a controller, a voltage regulator, a capacitor circuit, and a processing circuit. The controller is configured to control the charging and discharging of the capacitor circuit and to control the voltage regulator to enter an operating state when the capacitor circuit is in a touched state. The controller is further configured to detect the touch state of the capacitor circuit based on a first control signal output by the processing circuit. During the touch state detection process of a capacitive touch key, the touch state detection circuit can be used to control the voltage regulator from entering an operating state before the capacitor circuit is first determined to be in a touched state. In other words, part of the detection circuit is not operated, thereby reducing power consumption of the touch state detection circuit during the detection process. Furthermore, the touch state detection circuit controls the voltage regulator to enter an operating state as soon as the capacitor circuit is first determined to be in a touched state. In this case, the noise of the charging voltage received by the capacitor circuit can be reduced and relatively stable, thereby improving the sensitivity of the touch state detection process, the accuracy of the detection results, and the detection sensitivity. In addition, the touch state detection circuit can be applied to a wide range of detection environments, resulting in high stability of touch state detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 1 is a schematic structural diagram of a touch state detection circuit in one embodiment;

[0041] Figure 2 is a structural diagram of a touch state detection circuit in another embodiment;

[0042] Figure 3 is a structural diagram of a touch state detection circuit in another embodiment;

[0043] Figure 4 is a structural diagram of a touch state detection circuit in another embodiment;

[0044] Figure 5 is a structural diagram of a touch state detection circuit in another embodiment;

[0045] Figure 6 is a structural diagram of a touch state detection circuit in another embodiment;

[0046] Figure 7 is a structural diagram of a touch state detection circuit in another embodiment;

[0047] Figure 8 This is a waveform diagram showing changes in different signals output by a state machine, a clock signal generated by a reference voltage generating circuit, and a voltage across a charging capacitor during a detection process of a touch state detection circuit in one embodiment;

[0048] Figure 91 is a flow chart of a touch state detection method according to an embodiment;

[0049] Figure 10 is a flow chart of a touch state detection method according to another embodiment;

[0050] Figure 11 is a flow chart of a touch state detection method according to another embodiment;

[0051] Figure 12 FIG. 4 is a flow chart of a touch state detection method in another embodiment.

[0052] Description of reference numerals:

[0053] Power supply 01; Touch state detection circuit 10;

[0054] Controller 11; State machine 111;

[0055] Bi-phase clock signal generating circuit 112; Voltage regulator 12;

[0056] Voltage stabilizing component 121; Driving circuit 1211;

[0057] Compensation circuit 1211a; Voltage divider circuit 1211b;

[0058] Buffer 1212; Error amplifier 1213;

[0059] Voltage stabilizing switch 122; Switch tube 1221;

[0060] Fourth switch 1222; Capacitor circuit 13;

[0061] Touch branch 131; Touch capacitor 1311;

[0062] Touch switch 1312; Processing circuit 14;

[0063] Charging capacitor 141; Comparator 142;

[0064] Reference voltage generating circuit 143; First switch 15;

[0065] A second switch 16; A third switch 17;

[0066] The fifth switch 18 . DETAILED DESCRIPTION

[0067] In order to make the purpose, technical solutions and advantages of this application more clear, the following is a further detailed description of this application in conjunction with the accompanying drawings and examples. It should be understood that the specific embodiments described here are only used to explain this application and are not intended to limit this application.

[0068] In the field of human-computer interaction, capacitive touch buttons serve as one of the media for human-computer interaction in electronic systems. Capacitive touch buttons achieve human-computer interaction primarily through a touch state detection circuit within the electronic system that detects whether the capacitive touch button is touched. However, touch state detection circuits in related technologies suffer from high power consumption during the detection process. Therefore, embodiments of the present application provide a touch state detection circuit with low power consumption during the detection process.

[0069] Figure 1 This is a schematic diagram of the overall structure of the touch state detection circuit 10 provided in an embodiment of the present application. The touch state detection circuit 10 includes: a controller 11, a voltage regulator 12, a capacitor circuit 13, and a processing circuit 14; wherein, a first control terminal of the controller 11 is connected to a first input terminal of the capacitor circuit 13, a second control terminal of the controller 11 is connected to an output terminal of the voltage regulator 12 and a second input terminal of the capacitor circuit 13 via a first switch 15, a third control terminal of the controller 11 is connected to a control terminal of the voltage regulator 12, and a fourth control terminal of the controller 11 is connected to an output terminal of the capacitor circuit 13 via a second switch 16; a fifth control terminal of the controller 11 is connected to a first input terminal and ground of the processing circuit 14 via a third switch 17; and a signal input terminal of the controller 11 is connected to an output terminal of the processing circuit 14.

[0070] The controller 11 is used to control the charging and discharging of the capacitor circuit 13 and to control the voltage regulator 12 to enter the working state when the capacitor circuit 13 is in the touched state. The controller 11 is also used to detect the touch state of the capacitor circuit 13 according to the first control signal output by the processing circuit 14.

[0071] Specifically, the touch state detection circuit 10 can be a detection circuit for detecting the touch state of a capacitive touch button in an electronic system. Optionally, the electronic system can be a touch-screen smart door lock, a touch-screen smart computer, a touch-screen smart phone, etc. Of course, it can also be other touch-screen smart electronic devices, which is not limited in this embodiment of the application.

[0072] Optionally, the type of controller 11 in the touch state detection circuit 10 can be a combinational logic controller 11, a central processing unit controller 11, a microprogrammed logic controller 11, or a complex programmable logic controller 11, etc., which is not limited in the embodiments of the present application. Optionally, the controller 11 can be implemented by at least one of a signal generator, a signal processor, and a signal converter.

[0073] In actual applications, the controller 11 in the touch state detection circuit 10 is connected to the voltage regulator 12, the capacitor circuit 13, the first switch 15, the second switch 16, and the processing circuit 14. In the embodiment of the present application, the first switch 15 and the second switch 16 cannot be opened or closed at the same time. At any given time, only one switch is closed and the other is open.

[0074] Optionally, during the operation of the touch state detection circuit 10, the controller 11 in the touch state detection circuit 10 can control the voltage regulator 12 or the external power supply to charge the capacitor circuit 13, and control the capacitor circuit 13 to discharge to charge the processing circuit 14, and can determine whether it is necessary to start the detection program based on the first control signal output by the processing circuit 14 in the touch state detection circuit 10. If necessary, the detection program is started to detect the touch state of the capacitor circuit 13.

[0075] At the same time, when the controller 11 determines that the capacitor circuit 13 is in a touched state, it controls the voltage regulator 12 to enter the working state. The voltage regulator 12 entering the working state can be understood as the functional circuit in the voltage regulator 12 is in the awake state. At this time, the voltage regulator 12 can convert the voltage output by the external power supply into a stable voltage to charge the capacitor circuit 13.

[0076] Optionally, before determining that the capacitor circuit 13 is in a touched state, the voltage regulator 12 does not enter the working state, that is, the functional circuit in the voltage regulator 12 is in a standby state (that is, a sleep state). In this case, the voltage regulator 12 only acts as a switch, which can short-circuit the functional circuit in the voltage regulator 12, thereby reducing the power consumption of the touch state detection circuit 10 during the subsequent detection process.

[0077] It should be noted that when the capacitive touch button in the electronic system is not touched by the user, the functional circuit in the voltage regulator 12 is also in a standby state. During this process, the processing task of the electronic system is relatively small, and there is no large operating load in the electronic system. However, when the capacitive touch button in the electronic system is touched by the user, the processing task of the electronic system is relatively large, and the noise of the external power supply in the touch state detection circuit 10 will also increase. Therefore, in the embodiment of the present application, the function of the voltage regulator 12 provided in the touch state detection circuit 10 is to convert the voltage output by the external power supply into a stable voltage, thereby improving the stability of the capacitor charging in the capacitor circuit 13 during the charge transfer of the external power supply. Among them, when the functional circuit in the voltage regulator 12 is in the standby state, the circuit modules that need to be powered in the touch state detection circuit 10 are reduced, thereby reducing the noise in the detection circuit, and further significantly reducing the power consumption of the touch state detection circuit 10.

[0078] In the embodiment of the present application, the controller 11 starts to control the voltage regulator 12 to enter the working state when it is first determined that the capacitor circuit 13 is in the touched state. The controller 11 controls the voltage regulator 12 to be in the short-circuit state before it is first determined that the capacitor circuit 13 is in the touched state.

[0079] Furthermore, the controller 11 can send the touch state of the capacitor circuit 13 to a host computer or a main processor in the electronic system, and the host computer or the main processor can control each capacitive touch button to make a corresponding response based on the touch state of the capacitor circuit 13. Optionally, the touch state of the capacitor circuit 13 can be a touched state or an untouched state.

[0080] In addition, during a complete detection process, the controller 11 in the touch state detection circuit 10 can execute the detection program at least once, and the specific number of executions is determined according to the internal structure of the capacitor circuit 13. After the controller 11 executes the detection program for the first time, it can be determined that the capacitor circuit 13 is in a touched state, or the controller 11 executes the detection program multiple times before it can be determined that the capacitor circuit 13 is in a touched state. This embodiment of the present application does not limit this.

[0081] It should also be noted here that even if the controller 11 determines that the capacitor circuit 13 is in a touched state after executing a detection program once, the voltage regulator 12 does not enter the working state during the period from when the touch state detection circuit 10 starts to enter the working state to when the controller 11 completes the first detection program. This can also reduce the power consumption of the touch state detection circuit 10 during the entire detection process.

[0082] It is understood that the voltage regulator 12 in the touch state detection circuit 10 can be implemented by at least one of a switching regulator 12 and a linear regulator 12. Of course, it can also be implemented by a combination of a voltage regulation circuit and a control circuit. It should be noted that the voltage regulator 12 is electrically connected to the capacitor circuit 13 via the first switch 15.

[0083] In an embodiment of the present application, the voltage stabilizer 12 is a circuit that stabilizes the output voltage of an external power supply. In the touch state detection circuit 10, the voltage stabilizer 12 is used to provide a relatively pure voltage to the capacitor circuit 13 in the touch state detection circuit 10, so that the noise of the voltage received by the capacitor circuit 13 is as close to zero as possible, thereby further increasing the detection accuracy of the touch state detection circuit 10 and improving the detection efficiency.

[0084] It should be noted here that the external power supply that supplies power to the electronic system may have a large amount of noise, which may lead to problems such as slow touch state detection and slow response speed of the capacitive touch button, that is, the problem of low sensitivity of touch state detection. Based on this, a voltage regulator 12 is provided in the touch state detection capacitor in the embodiment of the present application. The voltage regulator 12 filters the large noise in the voltage input from the external power supply and provides a relatively pure voltage to the capacitor circuit 13 in the touch state detection circuit 10 to improve the sensitivity of touch state detection.

[0085] The capacitive circuit 13 in the touch state detection circuit 10 can be implemented using a variety of combinations of components such as capacitors, resistors, connectors, inductors, and sensors. In the embodiment of the present application, the capacitive circuit 13 can be understood as the circuit under test in the touch state detection circuit 10. It should be noted that the capacitive circuit 13 is electrically connected to the processing circuit 14 via the second switch 16.

[0086] In practical applications, the capacitive circuit 13 may correspond to at least one capacitive touch button. Accordingly, the controller 11 may ultimately determine at least one touch state, and each touch state corresponds to a capacitive touch button.

[0087] Meanwhile, the processing circuit 14 in the touch state detection circuit 10 may be formed by various combinations of comparators, resistors, connectors, processors, signal generating circuits, etc. Optionally, a communication connection may be established between the processor circuit and the controller 11 .

[0088] In the embodiment of the present application, the types of the first switch 15, the second switch 16, and the third switch 17 in the touch state detection circuit 10 may be the same or different. Correspondingly, the first switch 15, the second switch 16, and the third switch 17 may be single-pole single-throw switches, or the first switch 15, the second switch 16, and the third switch 17 may be single-pole multi-throw switches, which is not limited in the embodiment of the present application.

[0089] In the embodiment of the present application, the touch state detection circuit 10 can also be applied to a wide range of detection environments, thereby achieving high stability in touch state detection. The above-mentioned detection environment can be understood as a detection environment corresponding to a situation where a user touches a capacitive touch button in an electronic system with a finger and there is water, oil, or dust on the user's finger or the touch pen or touch stick due to environmental factors.

[0090] The touch state detection circuit in the embodiment of the present application may include a controller, a voltage regulator, a capacitor circuit, and a processing circuit. The controller is configured to control the charging and discharging of the capacitor circuit, and to control the voltage regulator to enter an operating state when the capacitor circuit is in a touched state. The controller is further configured to detect the touch state of the capacitor circuit based on a first control signal output by the processing circuit. During the touch state detection process of a capacitive touch key, the touch state detection circuit can be used to control the voltage regulator from entering an operating state before the capacitor circuit is first determined to be in a touched state. In other words, part of the detection circuit is not operated, thereby reducing power consumption of the touch state detection circuit during the detection process. At the same time, the touch state detection circuit controls the voltage regulator to enter an operating state as soon as the capacitor circuit is first determined to be in a touched state. In this case, the noise of the charging voltage received by the capacitor circuit can be reduced and relatively stable, thereby improving the sensitivity of the touch state detection process, the accuracy of the detection results, and the detection sensitivity. In addition, the touch state detection circuit can be applicable to a wide range of detection environments, resulting in high stability of touch state detection.

[0091] The internal structure of the voltage regulator 12 in the touch state detection circuit 10 is described below. Figure 2 As shown, the voltage regulator 12 in the touch state detection circuit 10 includes a voltage stabilizing component 121 and a voltage stabilizing switch 122; the voltage stabilizing switch 122 is connected in parallel with the voltage stabilizing component 121, a first end of the voltage stabilizing switch 122 and a first end of the voltage stabilizing component 121 are both connected to the power supply 01, and a second end of the voltage stabilizing switch 122 and a second end of the voltage stabilizing component 121 are both connected to one end of the first switch 15; the voltage stabilizing switch 122 is connected to the third control terminal of the controller 11;

[0092] The voltage stabilizing switch 122 is configured to be disconnected when the capacitor circuit 13 is in a touched state, and closed when the capacitor circuit 13 is in an untouched state.

[0093] Specifically, the voltage regulator 12 includes a voltage stabilizing component 121 and a voltage stabilizing switch 122. Optionally, the voltage stabilizing component 121 can be implemented by a combination of at least one of components such as capacitors, resistors, comparators, processors, sensors, voltage stabilizing diodes, and inductors. The voltage stabilizing component 121 and the voltage stabilizing switch 122 are connected in parallel within the voltage regulator 12. One end of the voltage stabilizing switch 122 is connected to a power supply 01, which can be called an external power supply. The power supply 01 can be an uninterruptible power supply system, a switching power supply, a variable frequency power supply, or a voltage regulating power supply, etc., which is not limited in the embodiments of the present application.

[0094] Optionally, the voltage stabilizing switch 122 in the voltage stabilizer 12 and the first switch 15, the second switch 16 and the second switch 16 in the touch state detection circuit 10 may be of the same type or different types. In the embodiment of the present application, the voltage stabilizing switch 122 may be implemented by a combination of multiple different types of switches. The voltage stabilizing switch 122 may also be connected to the controller 11 for communication.

[0095] Since the human-computer interaction module of the electronic system is waiting for user touch most of the time and is not actually working, based on the actual application scenario of the human-computer interaction module, a corresponding voltage regulator switch 122 can be set in the voltage regulator 12 to make the electronic system have very low power consumption in the touch state detection circuit 10 working mode, and can also reduce the power consumption and carbon emissions of the electronic system.

[0096] In actual application, when the controller 11 first determines that the capacitor circuit 13 is in a touched state, it controls the voltage regulator switch 122 to be disconnected, so that the voltage regulator 12 enters the working state; when the controller 11 determines that the capacitor circuit 13 is always in an untouched state, it always controls the voltage regulator switch 122 to be closed, so that the voltage regulator 12 is in a short-circuit state.

[0097] In the embodiment of the present application, the voltage regulator within the touch state detection circuit includes a voltage regulator component and a voltage regulator switch. When the capacitor circuit is in the touched state, the voltage regulator switch can be controlled to be disconnected, causing the voltage regulator to enter an operating state. This ensures that the charging voltage received by the capacitor circuit has less noise and is more stable, thereby improving the sensitivity of the touch state detection process and the accuracy of the detection results, as well as the sensitivity of the detection. At the same time, the touch state detection circuit can also control the voltage regulator switch to be closed before determining that the capacitor circuit is in the touched state, causing the voltage regulator to be in a short-circuit state, that is, part of the circuit in the touch state detection circuit is in a closed state, thereby reducing the power consumption of the touch state detection circuit during the detection process.

[0098] The internal structure of the voltage regulator 12 in the touch state detection circuit 10 is described below. Figure 3 In the touch state detection circuit shown, the voltage stabilizing switch 122 in the voltage regulator 12 includes a switch tube 1221 and a fourth switch 1222. The first end of the switch tube 1221 and one end of the fourth switch 1222 are connected to the power supply 01, the second end of the switch tube 1221 and the other end of the fourth switch 1222 are connected to one end of the first switch 15, the third end of the switch tube 1221 is connected to the first end of the voltage stabilizing component 121, and the control end of the fourth switch 1222 is connected to the third control end of the controller 11;

[0099] The fourth switch 1222 is configured to close after the capacitor circuit 13 is touched for the first time; the switch tube 1221 is configured to be turned on when the voltage between the second end and the third end of the switch tube 1221 reaches the turn-on voltage of the switch tube 1221 .

[0100] Specifically, the switch transistor 1221 in the voltage regulator 12 can be a P-channel transistor or an N-channel transistor. The P-channel transistor can be a P-channel depletion-mode MOS transistor or a P-channel enhancement-mode MOS transistor, and the N-channel transistor can be an N-channel depletion-mode MOS transistor or an N-channel enhancement-mode MOS transistor. However, in the embodiment of the present application, the switch transistor 1221 can be an N-channel enhancement-mode MOS transistor, that is, an NMOS transistor.

[0101] Optionally, the switch 1221 may include three terminals, namely a first terminal, a second terminal, and a third terminal, which may be the gate (G terminal), source (S terminal), and drain (D terminal) of an NMOS transistor, respectively. In the embodiment of the present application, the first terminal of the switch 1221 may be the D terminal, the second terminal of the switch 1221 may be the S terminal, and the third terminal of the switch 1221 may be the G terminal.

[0102] Among them, after the voltage stabilizing part in the voltage regulator 12 enters the working state, the switch tube 1221 is turned on when the voltage between the second end of the switch tube 1221 and the third end of the switch tube 1221 reaches the turn-on voltage of the switch tube 1221 to control the voltage output by the voltage regulator 12.

[0103] In actual applications, during the operation of the touch state detection circuit 10 , after the controller 11 determines for the first time that the capacitive circuit 13 is touched, the controller 11 sends a control signal to the fourth switch 1222 to control the fourth switch 1222 to be closed.

[0104] It should be noted here that the switching frequency of the first switch 15 and the second switch 16 in the touch state detection circuit 10 will affect the detection time of the touch state. Among them, when the switching frequency of the first switch 15 and the second switch 16 is low, the detection time of the touch state will be longer. Therefore, the embodiment of the present application improves the response speed of the voltage regulator 12 by setting the switch tube 1221 in the voltage regulator 12, so as to shorten the charging and stabilization time of the capacitor circuit 13, further balance the detection time of the touch state, and make the detection time of the touch state meet the target detection requirements.

[0105] In one embodiment, if Figure 4The touch state detection circuit shown in the figure, wherein the voltage stabilizing component 121 in the voltage regulator 12 includes a driving circuit 1211, a buffer 1212 and an error amplifier 1213, a first end of the driving circuit 1211 is connected to the second end of the voltage stabilizing switch 122, a second end of the driving circuit 1211 is respectively connected to the input end of the buffer 1212 and the output end of the error amplifier 1213, a third end of the driving circuit 1211 is connected to the negative input end of the error amplifier 1213, a fourth end of the driving circuit 1211 is grounded, and the buffer 1212 is connected to the first end of the voltage stabilizing switch 122 through the first end of the voltage stabilizing component 121.

[0106] In the embodiment of the present application, the voltage stabilizing component 121 in the voltage regulator 12 includes a driving circuit 1211, a buffer 1212, and an error amplifier 1213. Specifically, the voltage stabilizing component 121 includes the driving circuit 1211, and the driving circuit 1211 is implemented by at least one of components such as a capacitor, a resistor, an inductor, a sensor, a transistor, a potentiometer, and a switch.

[0107] Optionally, the error amplifier 1213 may compare the received voltage with a corresponding reference voltage and output an error amplified signal. In an embodiment of the present application, the error amplifier 1213 is used to lock the output voltage of the voltage regulator 12 within a certain voltage range as much as possible.

[0108] The buffer 1212 is used to convert the signal output by the error amplifier 1213 to increase the voltage output by the error amplifier 1213 .

[0109] Among them, continue to see Figure 4 As shown, the driving circuit 1211 in the voltage stabilizing component 121 includes a compensation circuit 1211a and a voltage divider circuit 1211b. The first end of the voltage divider circuit 1211b is respectively connected to the second end of the switch tube 1221, the second end of the fourth switch 1222 and one end of the compensation circuit 1211a, the second end of the voltage divider circuit 1211b is grounded, the third end of the voltage divider circuit 1211b is connected to the negative input end of the error amplifier 1213, and the other end of the compensation circuit 1211a is respectively connected to the output end of the error amplifier 1213 and the input end of the buffer 1212.

[0110] Specifically, the compensation circuit 1211a in the driving circuit 1211 can be implemented by at least one of a capacitor, an inductor, a sensor, and other components. However, in the embodiment of the present application, the compensation circuit 1211a in the driving circuit 1211 includes a capacitor. It should be noted that the compensation circuit 1211a is used to compensate for the stability of the output voltage of the voltage regulator 12.

[0111] The voltage divider circuit 1211b in the driving circuit 1211 can control the charging speed of the compensation circuit 1211a. It should be noted that the voltage divider circuit 1211b in the driving circuit 1211 can include multiple conventional resistors. The voltage divider circuit 1211b in the driving circuit 1211 can limit the voltage across the compensation circuit 1211a.

[0112] Also, see Figure 4 As shown, the voltage divider circuit 1211b in the driving circuit 1211 includes: a first resistor R1 and a second resistor R2; one end of the first resistor R1 is respectively connected to the second end of the switch tube 1221, the second end of the fourth switch 1222 and one end of the compensation circuit 1211a, the other end of the first resistor R1 is respectively connected to one end of the second resistor R2 and the negative input end of the error amplifier 1213, and the other end of the second resistor R2 is grounded.

[0113] In the embodiment of the present application, the voltage divider circuit 1211 b in the driving circuit 1211 includes two fixed resistors, namely, a first resistor R1 and a second resistor R2 .

[0114] In practical applications, the positive input terminal of the error amplifier 1213 can receive a reference voltage Vref, which can be determined based on the voltage between the first resistor R1 and the second resistor R2. The reference voltage Vref can be equal to or different from the reference voltage received by the comparator, which is not limited in this embodiment of the present application.

[0115] The touch state detection circuit in the embodiment of the present application includes a voltage regulator. When the capacitor circuit is in the touched state, the voltage regulator switch in the voltage regulator can put the voltage regulator into an operating state, so that the charging voltage of the voltage regulator received by the capacitor circuit has less noise and is relatively stable, thereby improving the sensitivity of the touch state detection processing, improving the accuracy of the detection results, and improving the sensitivity of the detection; at the same time, before determining that the capacitor circuit is in the touched state, the voltage regulator switch in the voltage regulator can put the voltage regulator into a short-circuit state, that is, part of the circuit in the touch state detection circuit is in a closed state, thereby reducing the power consumption of the touch state detection circuit during the detection process.

[0116] The internal circuit structure of the capacitor circuit 13 is described below. Figure 5As shown, the capacitive circuit 13 in the touch state detection circuit 10 includes at least one touch branch 131. The touch branch 131 includes a touch capacitor 1311 and a touch switch 1312. The touch capacitor 1311 and the touch switch 1312 are connected in series, and one end of the touch capacitor 1311 is grounded, and the other end of the touch capacitor 1311 is connected to one end of the touch switch 1312. The other end of the touch switch 1312 is connected to the first switch 15 and the second switch 16 respectively.

[0117] When the touch switch 1312 is turned off, the touch capacitor 1311 is charged; when the touch switch 1312 is turned off, the touch capacitor 1311 is discharged.

[0118] Specifically, the capacitive circuit 13 in the touch state detection circuit 10 includes at least one touch branch 131, each of which includes a touch capacitor 1311 and a touch switch 1312. Optionally, the touch capacitor 1311 and the capacitor in the compensation circuit 1211a can be of the same type, but their capacitance values ​​can be the same or different. One touch branch 131 corresponds to one capacitive touch button, and naturally, one touch capacitor 1311 corresponds to one capacitive touch button.

[0119] In practical applications, the touch state detection circuit 10 is provided on a printed circuit board (PCB), and the capacitance of the touch capacitor 1311 can be determined based on the size of the pad corresponding to the touch capacitor 1311 on the PCB, the material of the corresponding pad, and the parasitic effect of the touch capacitor 1311. The PCB can be provided on a capacitive touch key chip within an electronic system. Optionally, the parasitic effect of the touch capacitor 1311 can be understood as the change in capacitance of the touch capacitor 1311 before and after a user touches the capacitive touch key 1311.

[0120] Typically, the capacitance of the touch capacitor 1311 is on the order of 10 pF, but can range from 5 pF to 40 pF. When a user touches a capacitive touch button corresponding to the touch capacitor 1311, the capacitance of the touch capacitor 1311 increases by tens of fF to tens of pF. In practical applications, the capacitance of the charging capacitor divided by the number of times the touch capacitor 1311 has been charged can approximately equal the capacitance of the touch capacitor 1311 when it is touched.

[0121] The touch switch 1312 in the touch branch 131 and other switches in the touch state detection circuit 10 may be of the same type or may be of different types, which is not limited in this embodiment of the present application.

[0122] In actual applications, the controller 11 can poll and control the closing state of each touch switch 1312 in the capacitor circuit 13 according to a preset polling detection sequence, wherein only one touch switch 1312 in the capacitor circuit 13 can be controlled to be closed and the other touch switches 1312 can be controlled to be opened at each moment.

[0123] Optionally, the preset polling detection sequence can be understood as the order in which the controller 11 controls all touch branches 131 in the capacitor circuit 13 to detect the touch state. The polling detection order can be from the first touch branch 131 in the capacitor circuit 13 to the last touch branch 131 in sequence, or it can be any order in which all touch branches 131 in the capacitor circuit 13 are arranged. This embodiment of the present application does not limit this.

[0124] During the entire detection process performed by the touch state detection circuit 10, polling can be performed n times, where n is equal to the total number of touch branches 131 in the capacitor circuit 13. Performing one detection process can determine the touch state of any touch branch 131 in the capacitor circuit 13. After performing one detection process, the next detection process can be continued, that is, the touch state of the next touch branch 131 in the capacitor circuit 13 is detected.

[0125] In an embodiment of the present application, if the touch switch 1312 and the first switch 15 in a touch branch 131 are both closed, the touch capacitor 1311 in the touch branch 131 can receive the voltage output by the power supply 01 or the voltage regulator 12, so that the touch capacitor 1311 in the touch branch 131 is charged; if the touch switch 1312 in a touch branch 131 is closed, the first switch 15 is disconnected, and the second switch 16 is closed, the touch capacitor 1311 in the touch branch 131 can output the charged charge to the processing circuit 14, so that the touch capacitor 1311 in the touch branch 131 is discharged.

[0126] The touch state detection circuit in the embodiment of the present application can count the number of charge and discharge times of the capacitor circuit by controlling the charge and discharge of the capacitor circuit, and further determine the touch state of the capacitive touch button simply and quickly based on the number of charge and discharge times of the capacitor circuit, thereby simplifying the detection method.

[0127] In one embodiment, Figure 6As shown, the processing circuit 14 in the touch state detection circuit 10 includes a charging capacitor 141, a comparator 142, and a reference voltage generating circuit 143; one end of the charging capacitor 141 is grounded, and the other end of the charging capacitor 141 is connected to the common end of the fifth switch and the third switch 17 and the inverting input end of the comparator 142 respectively; the positive input end of the comparator 142 is connected to the reference voltage generating circuit 143, and the output end of the comparator 142 is connected to the signal input end of the controller 11;

[0128] When the third switch 17 is closed, the charging capacitor 141 is discharged; when the second switch 16 is closed and the third switch 17 is open, the charging capacitor 141 is charged according to the discharged charge of the touch capacitor 1311 in the working state in the capacitive circuit 13;

[0129] The comparator 142 is used for comparing the voltage across the charging capacitor 141 with the reference voltage output by the reference voltage generating circuit 143 , and outputting a first control signal to the controller 11 .

[0130] Specifically, the processing circuit 14 in the touch state detection circuit 10 includes a charging capacitor 141, a comparator 142, and a reference voltage generating circuit 143. The charging capacitor 141 and the touch capacitor 1311 may be of the same or different types, which is not limited in this embodiment of the present application. Furthermore, the capacitance of the charging capacitor 141 and the touch capacitor 1311 may be the same or different. In this embodiment of the present application, the capacitance of the charging capacitor 141 is greater than that of the touch capacitor 1311. The capacitance of the charging capacitor 141 is fixed and may be any value between 1 nF and 100 nF.

[0131] Among them, the smaller the capacitance of the charging capacitor 141, the shorter the detection time required to detect a capacitive touch button, but the detection accuracy will be reduced. Therefore, the total number of touch branches 131 set in the capacitor circuit 13 in the touch state detection circuit 10 can be determined by comprehensively considering the detection time, detection accuracy and power consumption requirements of the touch state detection circuit 10.

[0132] At the same time, if the total number of capacitive touch buttons included in the electronic system is greater than the total number of touch branches 131 provided in the touch state detection circuit 10 when the detection time, detection accuracy and power consumption requirements are met, multiple touch state detection circuits 10 can be set in the electronic system to realize touch state detection of all capacitive touch buttons in the electronic system through multiple touch state detection circuits 10.

[0133] Optionally, the comparator 142 in the processing circuit 14 may be a voltage comparator, and the voltage comparator may be a single threshold comparator, a hysteresis comparator, a window comparator, etc., which is not limited in the embodiment of the present application.

[0134] In the embodiment of the present application, the comparator 142 is used to compare the voltage across the charging capacitor 141 with the reference voltage output by the reference voltage generating circuit 143, and output a first control signal based on the comparison result. Optionally, the voltage across the charging capacitor 141 can be understood as the voltage value at any point between the non-inverting input terminal of the comparator 142 and one end of the capacitor.

[0135] It should be noted here that if the voltage across the charging capacitor 141 is greater than or equal to the reference voltage output by the reference voltage generating circuit 143, the first control signal output by the comparator 142 can be a high-level signal; if the voltage across the charging capacitor 141 is less than the reference voltage output by the reference voltage generating circuit 143, the first control signal output by the comparator 142 can be a low-level signal.

[0136] In actual applications, the reference voltage generating circuit 143 in the processing circuit 14 can be implemented by at least one of the power supply circuit, the boost circuit, the buck circuit, the buffer circuit and the voltage divider circuit 1211b, wherein the reference voltage generating circuit 143 can output a reference voltage, and for the same touch branch 131, different reference voltages correspond to it, which are specifically determined according to the product of the capacitance C of the touch capacitor 1311 in the touch branch 131 and the output voltage V01 of the regulator 12.

[0137] It should be noted here that at the beginning of each round of detection, the controller 11 will first control the third switch 17 to close, and when the third switch 17 in the touch state detection circuit 10 is closed, the charging capacitor 141 is discharged to drain the charge stored in the charging capacitor 141 after the last detection process is completed, thereby further improving the accuracy of the touch state detection results.

[0138] Optionally, during the detection process of any touch branch 131 in the capacitance circuit 13 by the touch state detection circuit 10, the touch capacitor 1311 in the touch branch 131 can be charged and discharged multiple times, and the number of discharges and charging times of the touch capacitor 1311 are equal. In actual application, as the charging time and number of charging times of the touch capacitor 1311 in the touch branch 131 to the charging capacitor 141 increase, the charge amount of the charging capacitor 141 will gradually increase. Naturally, the touch capacitor 1311 in any touch branch 131 charges the charging capacitor 141 at least once, and the voltage across the charging capacitor 141 will be greater than or equal to the reference voltage output by the reference voltage generating circuit 143.

[0139] It should be noted here that during the detection process, the comparator 142 in the processing circuit 14 will output the first control signal in real time. However, the comparator 142 will output a high-level first control signal only when the voltage across the charging capacitor 141 is greater than or equal to the reference voltage output by the reference voltage generating circuit 143. Otherwise, the comparator 142 will output a low-level first control signal. When the state machine receives the first control signal output by the comparator 142 as a high-level signal, the control pauses the output of the clock signal. At this time, the state machine can count the number of flips of different clock signals output during the current detection process. Optionally, the number of flips of different clock signals can be understood as the number of times the high-level clock signal and the low-level clock signal flip back and forth.

[0140] In actual applications, the product of the capacitance of the charging capacitor 141 and the voltage across the charging capacitor 141 is equal to the product of the capacitance of the touch capacitor 1311 in the current touch detection branch 131, the stable voltage output by the regulator 12, and the number of flips of different clock signals output by the state machine during the current detection process.

[0141] The touch state detection circuit in the embodiment of the present application charges the charging capacitor in the processing circuit through the touch capacitor in the capacitive circuit, so that when the charge amount of the charging capacitor reaches a specific value, it can be determined to start the detection program, and the touch state currently determined by the detection program can be determined as the final touch state of the touch capacitor. Under this condition, the detection result of the touch state obtained is relatively accurate.

[0142] In some scenarios, the second switch 16 in the touch state detection circuit 10 needs to be repeatedly closed and opened, thereby increasing the amount of charge injected into the charging capacitor 141, causing a charge transfer error in the charging capacitor 141, and making the obtained charging number of the charging capacitor 141 inaccurate. Based on this, a switch can be added to the touch state detection circuit 10 to offset the charge injection effect caused by the repeated closing and opening of the second switch 16 in the touch state detection circuit 10. Therefore, in one embodiment, the touch state detection circuit 10 further includes: a fifth switch 18, the fifth switch 18 is connected in parallel to the path between the common end of the second switch 16 and the third switch 17 and the first input end of the processing circuit 14, the first end of the fifth switch 18 is connected to the common end of the second switch 16 and the third switch 17, and the second end of the fifth switch 18 is connected to the first input end of the processing circuit 14; the control end of the fifth switch 18 is connected to the second control end of the controller 11.

[0143] The fifth switch 18 in the touch state detection circuit 10 may be of the same type or different from the first switch 15, the second switch 16, the third switch 17, and the fourth switch 1222 in the touch state detection circuit 10, and this is not limited in this embodiment of the present application. In this embodiment of the present application, the control terminal of the fifth switch 18 may receive a signal output by the second control terminal of the controller 11, that is, the signal received by the control terminal of the fifth switch 18 is the same as the signal received by the control terminal of the second switch 16.

[0144] The touch state detection circuit in the embodiment of the present application can offset the charge accumulation on the charging capacitor caused by the repeated closing and opening of the second switch through the fifth switch, thereby improving the accuracy of the amount of charge received by the charging capacitor from the touch capacitor, thereby further improving the accuracy of the touch state detection result.

[0145] In one embodiment, Figure 7 As shown, the controller 11 in the touch state detection circuit 10 includes: a state machine 111 and a two-phase clock signal generating circuit 112;

[0146] The state machine 111 is configured to generate a clock signal and send the clock signal to the bi-phase clock signal generating circuit 112 to instruct the bi-phase clock signal generating circuit 112 to output a first clock signal through the second control terminal of the controller 11 and to output a second clock signal through the fifth control terminal of the controller 11, wherein the first clock signal and the second clock signal are inverse-phase clock signals.

[0147] The state machine 111 is also used to output a first switching signal through the third control terminal of the controller 11 to control the voltage regulator 12 to enter the working state when the capacitor circuit 13 is in the touched state, and to output a second switching signal through the fifth control terminal of the controller 11 to close the first switch and open the second switch 16 when the capacitor circuit 13 is charging, and to open the first switch 15 and close the second switch 16 after the capacitor circuit 13 completes charging; the state machine 111 is also used to receive a first control signal through the signal input terminal of the controller 11, and to start a detection program according to the first control signal to detect the current touch state of the capacitor circuit 13.

[0148] Specifically, the state machine 111 in the controller 11 can be called a digital control state machine, and the state machine 111 can be a mini state machine or a Moore state machine. In practical applications, the state machine 111 is used to generate a clock signal, which can be a periodically uniformly changing square wave signal, that is, a periodically uniformly changing high and low level signal.

[0149] It should be noted here that the state machine 111 can output the clock signal in two ways. The first way is: each time the state machine 111 performs the detection process, it starts to output the clock signal after a specific time interval starting from the moment the third switch 17 is closed. The specific time interval can be equal to the time required to drain the charge corresponding to when the charging capacitor 141 is fully charged; the second way is: after each detection process starts, after determining that the charge stored in the charging capacitor 141 is drained, that is, when the charge of the charging capacitor 141 is 0, the state machine 111 in the controller 11 starts to output the clock signal, wherein each time the detection process is performed, the charging capacitor 141 is not necessarily in a fully charged state, so the state machine 111 outputs the clock signal in the second way, which can shorten the detection time of the touch state.

[0150] Among them, the state machine 111 can send the generated clock signal to the dual-phase clock signal generating circuit 112 to instruct the dual-phase clock signal generating circuit 112 to output the first clock signal through the second control end of the controller 11 and output the second clock signal through the second control end of the controller 11.

[0151] Optionally, the first clock signal and the second clock signal can be inverted clock signals, that is, one is a high-level signal and the other is a low-level signal. The first clock signal can control the closed state of the first switch 15 and the fifth switch 18, and the second clock signal can control the closed state of the second switch 16.

[0152] It can be understood that the clock signal controls the generation of the first clock signal and the second clock signal, and further controls the switching states of the first switch 15 and the fifth switch 18 respectively through the first clock signal and the second clock signal. In the embodiment of the present application, the switching frequency of the first switch 15 and the fifth switch 18 is generally on the order of 100K to 10MHZ.

[0153] At the same time, the state machine 111 can start controlling the voltage regulator 12 to enter the working state when it is first determined that any touch branch 131 in the capacitor circuit 13 is in the touched state, that is, control the voltage regulator switch 122 to be disconnected until the detection process corresponding to the touch branch 131 is completed; and the state machine 111 can also control the voltage regulator switch 122 to be closed before it is first determined that any touch branch 131 in the capacitor circuit 13 is in the touched state, that is, before all multiple touch branches 131 detected in the capacitor circuit 13 are in the untouched state, so that the voltage regulator 12 is in the short-circuit state.

[0154] It should be noted here that the touch branch 131 being in the touched state can be understood as the capacitive touch button corresponding to the touch branch 131 being in the touched state; the touch branch 131 being in the untouched state can be understood as the capacitive touch button corresponding to the touch branch 131 being in the untouched state.

[0155] In actual applications, the state machine 111 can also receive the first control signal output by the comparator 142 in the processing circuit 14 in real time, and determine whether to start the detection program based on the first control signal to detect the current touch state of any touch branch 131 in the capacitive circuit 13 through the detection program.

[0156] Optionally, the first control signal output by the comparator 142 can be a high-level signal or a low-level signal, wherein when the first control signal is a high-level signal, the state machine 111 can determine to start the detection program, and when the first control signal is a low-level signal, the state machine 111 can determine not to start the detection program.

[0157] Since the capacitance of the touch capacitor 1311 increases after the user touches the touch capacitor 1311, the number of charge transfers from the touch capacitor 1311 to the charging capacitor 141 decreases when the touch capacitor 1311 is touched. Naturally, the number of times the charging capacitor 141 is charged decreases, and the charging capacitor 141 can be fully charged. Therefore, after the state machine 111 starts the detection program, the state machine 111 can subtract the number of times the touch capacitor 1311 in any detected touch branch 131 in the capacitor circuit 13 is fully charged when it is not touched from the number of times the touch capacitor 1311 in any detected touch branch 131 in the capacitor circuit 13 is discharged, the number of times the touch capacitor 1311 in any detected touch branch 131 in the capacitor circuit 13 is charged, or the number of toggle times of different clock signals from the start of the touch branch 131 detection to the current moment, and determine whether the difference is greater than or equal to a preset number threshold. If so, it is determined that the touch capacitor 1311 in the current touch branch 131 is in a touched state; otherwise, it is determined that the touch capacitor 1311 in the current touch branch 131 is in an untouched state.

[0158] It should be noted that the actual application environment of capacitive touch buttons varies significantly from moment to moment, so the preset threshold number of times can be adjusted appropriately based on the actual application environment. The preset threshold number of times can be user-defined or determined based on historical test values. The actual application environment can include ambient temperature and other environmental factors.

[0159] In an embodiment of the present application, the preset number threshold is a value determined based on the baseline value, which can be equal to the number of times the touch capacitor 1311 is fully charged to the charging capacitor 141 when the touch capacitor 1311 is not touched by the user. The preset number threshold can be equal to the difference between the baseline value and the number of times the touch capacitor 1311 is fully charged to the charging capacitor 141 when the touch capacitor 1311 is touched by the user.

[0160] Among them, the baseline value will be different in different actual application environments. Therefore, in the process of calculating the preset number threshold, the average baseline value corresponding to different time periods can be calculated first, and then the difference between the average baseline value and the average number of charges to fully charge the charging capacitor 141 when the touch capacitor 1311 is touched by the user is calculated, thereby obtaining a more accurate number threshold, further improving the accuracy of the detection result. Optionally, in the same actual application environment, the difference between the baseline value and the number of charges to fully charge the charging capacitor 141 when the touch capacitor 1311 is touched by the user is fixed.

[0161] During the detection process, the state machine 111 can obtain in real time the discharge count, charge count, and flip count of different clock signals of the touch capacitor 1311 in any touch branch 131 detected in the capacitive circuit 13 from the start of the touch branch 131 detection to the current moment. In the embodiment of the present application, these three are equal.

[0162] It should be noted here that the current touch state of the capacitor circuit 13 can be understood as the touch state of any touch branch 131 currently detected in the capacitor circuit 13, and can also be understood as the touch state of the capacitive touch button corresponding to the touch capacitor 1311 in any touch branch 131 currently detected in the capacitor circuit 13.

[0163] In actual applications, the charging capacitor 141 and each touch capacitor 1311 are all arranged on the same PCB, so some parasitic effects of the charging capacitor 141 and each touch capacitor 1311 or interference signals shared by the PCB can be offset at the same time, thereby greatly improving the signal-to-noise ratio of the touch state detection circuit 10 for touch state detection, and further improving the accuracy of the touch state detection result.

[0164] Optionally, the first switch signal and the second switch signal can both be high-level signals or low-level signals. At the start of each round of detection, the controller 11 can output a high-level signal, i.e., the second switch signal, through the fifth control terminal to control the third switch 17 to close, so that the charge stored in the last detection process or the current charging capacitor 141 is drained.

[0165] Typically, the response time of a capacitive touch button is longer than the touch state detection time of the capacitive touch button. Therefore, in order to reduce the power consumption of the electronic system, in the embodiment of the present application, after receiving the first controller 11 output from the comparator 142, the state machine 111 can control the shutdown of all internal circuits in the touch state detection circuit 10 except the state machine 111 to be in a standby state, that is, a non-operating state, to reduce the power consumption of the touch state detection circuit 10, thereby reducing the power consumption of the electronic system. When the next detection process begins, the state machine 111 can wake up the standby state of all internal circuits in the touch state detection circuit 10 except the state machine 111, so that these internal circuits enter the operating state to implement the detection process.

[0166] like Figure 8 The figures show, in one detection process, a waveform diagram showing changes in the fifth control terminal output signal EN_DISCHG of the state machine 111 in the touch state detection circuit 10, a waveform diagram showing changes in the first switch signal SW2 and the second switch signal SW1 generated by the two-phase clock signal generating circuit 112, a waveform diagram showing changes in the voltage Vccom across the charging capacitor, and a waveform diagram showing changes in the first control signal COUNT output by the comparator 142. Figure 8 The waveform corresponding to the dotted line segment in FIG is not shown.

[0167] The touch state detection circuit in the embodiment of the present application can control the implementation of the entire touch state detection process in an orderly manner through a state machine, so that the touch state detection circuit can accurately detect the touch state of the capacitive circuit, thereby further improving the accuracy and timeliness of the capacitive touch button response results.

[0168] like Figure 9 The figure shows a flow chart of a touch state detection method provided by another embodiment of the present application. The touch state detection method is implemented by the touch state detection circuit in any of the above embodiments. The implementation process of the touch state detection method is described below. The above touch state detection method may include the following steps:

[0169] S100: Acquire a first control signal output by a processing circuit in a touch state detection circuit.

[0170] Specifically, during the touch state detection process, the controller in the touch state detection circuit can periodically obtain the first control signal output by the processing circuit in the touch state detection circuit in real time. Optionally, the first control signal can be a high-level signal or a low-level signal.

[0171] S200: Determine the touch state of the capacitive circuit in the touch state detection circuit according to the first control signal. When the capacitive circuit is determined to be in the touched state during the detection process, control the voltage regulator in the touch state detection circuit to enter the working state.

[0172] The controller in the touch state detection circuit can compare the first control signal with a preset threshold value, and determine whether to start a detection program based on the comparison result. If it is determined to be started, the detection program is executed to detect the touch state of the capacitive circuit in the touch state detection circuit. If it is determined not to be started, the step of comparing the first control signal with the preset threshold value is continued until the detection program is determined to be started based on the comparison result, and the detection program is started to detect the touch state of the capacitive circuit in the touch state detection circuit. Optionally, the preset threshold value can be equal to 0.

[0173] In addition, the controller in the touch state detection circuit can also directly determine whether to start the detection program through the first control signal. If the judgment result is yes, the detection program is executed to detect the touch state of the capacitor circuit in the touch state detection circuit. If the judgment result is no, the step of directly determining whether to start the detection program through the first control signal is continued until the detection program is determined to be started according to the comparison result, and the detection program is started to detect the touch state of the capacitor circuit in the touch state detection circuit.

[0174] During the touch state detection process, the controller in the touch state detection circuit can control the voltage regulator in the touch state detection circuit to enter an operating state when determining that the capacitor circuit is in a touched state. The voltage regulator entering the operating state can be understood as the functional circuit in the voltage regulator being in an awake state, indicating that the voltage regulator can convert the voltage output by the external power supply into a stable voltage to charge the capacitor circuit. Before determining that the capacitor circuit is in a touched state, the controller controls the voltage regulator in the touch state detection circuit to be in a short-circuit state, that is, the functional circuit in the voltage regulator is in a standby state. In this case, the voltage regulator only acts as a switch, which can short-circuit the functional circuit in the voltage regulator, thereby reducing the power consumption of the touch state detection circuit during subsequent detection processes.

[0175] Furthermore, the controller can transmit the touch status of the capacitive circuit to a host computer or a main processor in the electronic system, which can then control each capacitive touch button to respond accordingly based on the touch status of the capacitive circuit. Optionally, the touch status of the capacitive circuit can be a touched state or an untouched state.

[0176] During a complete detection process, the controller in the touch state detection circuit can execute the detection program at least once. The specific number of executions is determined according to the internal structure of the capacitor circuit. After the controller executes the detection program for the first time, it can be determined that the capacitor circuit is in a touched state, or the controller can determine that the capacitor circuit is in a touched state only after executing the detection program multiple times. This embodiment of the present application does not limit this.

[0177] In order to determine whether multiple capacitive touch buttons in an electronic system are touched, the touch state detection circuit can perform multiple complete detection processes, and each complete detection process can determine the touch state of a capacitive touch button. For example, if the electronic system includes m capacitive touch buttons, the touch state detection circuit in the electronic system performs m complete detection processes to determine the touch state of the m capacitive touch buttons. In the embodiment of the present application, the touch state of the capacitive circuit can be understood as the touch state of the capacitive touch button.

[0178] In one embodiment, the step of controlling the voltage regulator in the touch state detection circuit to enter the working state when determining that the capacitor circuit is in the touched state may include: when determining for the first time that the capacitor circuit is in the touched state, controlling the voltage regulator to enter the working state according to the second control signal.

[0179] In an embodiment of the present application, when the controller in the touch state detection circuit first determines that the capacitive circuit is in the touched state, it can send a second control signal to the voltage regulator to control the voltage regulator to enter the working state. The second control signal is a high-level signal.

[0180] The technical solution in the embodiment of the present application can obtain a first control signal output by a processing circuit in a touch state detection circuit, determine the touch state of a capacitor circuit in the touch state detection circuit based on the first control signal, and control a voltage regulator in the touch state detection circuit to enter an operating state when the capacitor circuit is determined to be in a touched state during the detection process. During the touch state detection process of a capacitive touch key, the above method can be used to control the voltage regulator not to enter an operating state before determining that the capacitor circuit is in a touched state, that is, part of the circuit in the detection circuit does not enter an operating state, thereby reducing the power consumption of the touch state detection circuit during the detection process. At the same time, the above method controls the voltage regulator to enter an operating state as soon as it is determined that the capacitor circuit is in a touched state. In this case, the noise of the charging voltage received by the capacitor circuit can be reduced and relatively stable, thereby improving the sensitivity of the touch state detection process, improving the accuracy of the detection result, and improving the detection sensitivity. In addition, the above method can also be applied to a wider range of detection environments, making the touch state detection more stable.

[0181] The following describes the process of obtaining the first control signal output by the processing circuit in the touch state detection circuit.

[0182] In one embodiment, if Figure 10 As shown, the steps in the above S100 may include:

[0183] S110: Obtain the voltage across the charging capacitor.

[0184] Specifically, a comparator in the processing circuit of the touch state detection circuit can obtain the voltage across the charging capacitor in the processing circuit. Optionally, the voltage across the charging capacitor can be equal to the voltage at the non-inverting input terminal of the comparator.

[0185] S120 : Determine a first control signal output by the processing circuit according to the voltage across the charging capacitor and a reference voltage.

[0186] Specifically, the reference voltage may be equal to the voltage of the charging capacitor when it is fully charged. In practical applications, the comparator may process the voltage across the charging capacitor and the reference voltage to determine the first control signal output by the processing circuit.

[0187] The voltage across the charging capacitor and the reference voltage may be processed by pre-training an algorithm model, inputting the voltage across the charging capacitor and the reference voltage into the algorithm model, and the algorithm model outputs a first control signal.

[0188] In an embodiment of the present application, the voltage across the charging capacitor and the reference voltage are processed by comparing the voltage across the charging capacitor with the reference voltage to obtain a comparison result. When the comparison result shows that the voltage across the charging capacitor is greater than or equal to the reference voltage, the first control signal output by the comparator can be a high-level signal to instruct the controller to initiate a detection procedure; and when the comparison result shows that the voltage across the charging capacitor is less than the reference voltage, the first control signal output by the comparator can be a low-level signal to instruct the controller not to initiate the detection procedure.

[0189] In one embodiment, if Figure 11 As shown, before obtaining the first control signal output by the processing circuit in the touch state detection circuit, the above method may further include the following steps:

[0190] S300 : When the detection process starts, control the charging capacitor of the processing circuit in the touch state detection circuit to discharge.

[0191] Specifically, after each touch state detection process begins, the controller in the touch state detection circuit can first control the charging capacitor of the processing circuit in the touch state detection circuit to discharge so that the charge in the charging capacitor is emptied, preparing to improve the accuracy of the detection result.

[0192] The method for controlling the discharge of the charging capacitor of the processing circuit in the touch state detection circuit may be to control the charging capacitor to charge an external charging power supply so as to discharge the charge in the charging capacitor. Alternatively, the method for controlling the discharge of the charging capacitor of the processing circuit in the touch state detection circuit may be to control the charging capacitor to be grounded so as to discharge the charge in the charging capacitor.

[0193] S400 : After the charging capacitor is discharged, the capacitor circuit is controlled to charge and discharge according to the clock signal.

[0194] In the embodiment of the present application, after the charging capacitor has finished discharging, the controller in the touch state detection circuit can begin generating different clock signals that change periodically to control the charging and discharging of the capacitor circuit according to the different clock signals that change periodically. In actual applications, the controller can stop generating the clock signal after receiving the first control signal.

[0195] The charge of the charging capacitor can be detected by a charge detection sensor. When the charge of the charging capacitor is determined to be zero, the charge detection sensor can send a signal output instruction to the controller to instruct the controller to start generating a periodically changing different clock signal. Optionally, the periodically changing different clock signal can be a periodically changing square wave signal, i.e., a high-low level signal.

[0196] Alternatively, the controller may start outputting the clock signal after a specific time interval, starting from the moment the charging capacitor begins discharging. The specific time interval is intended to ensure that the charge currently stored in the charging capacitor is discharged within the specific time interval even when the charge currently stored in the charging capacitor is less than or equal to the maximum charge that the charging capacitor can store. Alternatively, the specific time interval may be equal to the time required to discharge the charge corresponding to a fully charged charging capacitor.

[0197] In one embodiment, if Figure 12 As shown, the step of controlling the capacitor circuit to charge and discharge according to the clock signal in the above S400 may include:

[0198] S410 , generating a first clock signal and a second clock signal according to a clock signal.

[0199] The controller can generate a two-phase clock signal according to the clock signal, namely a first clock signal and a second clock signal. It should be noted that one of the first clock signal and the second clock signal is a high-level signal and the other is a low-level signal.

[0200] S420 : Control the capacitor circuit to charge and discharge according to the first clock signal and the second clock signal.

[0201] In an embodiment of the present application, the controller can control the closed states of corresponding switches in the touch state detection circuit according to the first clock signal and the second clock signal, thereby controlling the charging and discharging of the capacitor circuit. Optionally, charging the capacitor circuit can be understood as the process of inputting the voltage output by the voltage regulator or power supply in the touch state detection circuit into the capacitor circuit for charging; discharging the capacitor circuit can be understood as the process of transferring the charge stored in the capacitor circuit to the charging capacitor in the processing circuit.

[0202] In actual applications, if the first clock signal is a high-level signal and the second clock signal is a low-level signal, the controller controls the capacitor circuit to charge; if the first clock signal is a low-level signal and the second clock signal is a high-level signal, the controller controls the capacitor circuit to discharge to the charging capacitor.

[0203] The technical solution in the embodiment of the present application can control the discharge of the charging capacitor of the processing circuit in the touch state detection circuit at the beginning of the detection process, and after the discharge of the charging capacitor is completed, control the charging and discharging of the capacitor circuit according to the clock signal, so that the charging and discharging times of the capacitor circuit are counted synchronously with the flipping times of different clock signals output by the controller during the detection process, so as to start the execution of the detection program in time and obtain a touch state detection result with higher accuracy.

[0204] Based on the touch state detection circuit 10 provided above, the present application further provides an electronic system, which includes the touch state detection circuit 10 provided by any one of the above embodiments.

[0205] The touch state detection circuit 10 is provided within the electronic system and is used to detect the touch state of each capacitive touch button in the electronic system. Optionally, to improve the touch sensitivity of the capacitive touch buttons in the electronic system and enhance the aesthetics of the electronic system's exterior surface, an acrylic sheet may be provided on the exterior surface of the electronic system so that the capacitive touch buttons can be touched by touching the acrylic sheet.

[0206] The electronic system provided in the embodiment of the present application has similar implementation principles and technical effects to the touch state detection circuit provided in any of the above embodiments, and will not be described in detail here.

[0207] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0208] The above embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A touch state detection circuit, characterized in that: The detection circuit includes: a controller, a voltage regulator, a capacitor circuit and a processing circuit; wherein the first control terminal of the controller is connected to the first input terminal of the capacitor circuit, the second control terminal of the controller is connected to the output terminal of the voltage regulator and the second input terminal of the capacitor circuit respectively through a first switch, the third control terminal of the controller is connected to the control terminal of the voltage regulator, and the fourth control terminal of the controller is connected to the output terminal of the capacitor circuit through a second switch; the fifth control terminal of the controller is connected to the first input terminal and the ground of the processing circuit respectively through a third switch; and the signal input terminal of the controller is connected to the output terminal of the processing circuit; The controller is used to control the charging and discharging of the capacitor circuit, and to control the voltage regulator to enter a working state when the capacitor circuit is in a touched state, and is also used to detect the touch state of the capacitor circuit according to the control signal output by the processing circuit.

2. The touch state detection circuit according to claim 1, wherein: The voltage stabilizer includes a voltage stabilizing component and a voltage stabilizing switch; the voltage stabilizing switch is connected in parallel with the voltage stabilizing component, a first end of the voltage stabilizing switch and a first end of the voltage stabilizing component are both connected to a power source, a second end of the voltage stabilizing switch and a second end of the voltage stabilizing component are both connected to one end of the first switch; the voltage stabilizing switch is connected to a third control terminal of the controller; The voltage stabilizing switch is configured to be disconnected when the capacitor circuit is in a touched state, and closed when the capacitor circuit is in an untouched state.

3. The touch state detection circuit according to claim 2, wherein: The voltage stabilizing switch includes a switching tube and a fourth switch, wherein a first end of the switching tube and one end of the fourth switch are connected to the power supply, a second end of the switching tube and the other end of the fourth switch are connected to one end of the first switch, a third end of the switching tube is connected to the first end of the voltage stabilizing component, and a control end of the fourth switch is connected to the third control end of the controller; The fourth switch is configured to close after the capacitive circuit is touched for the first time; The switch tube is used to be turned on when the voltage between the second end of the switch tube and the third end of the switch tube reaches the turn-on voltage of the switch tube.

4. The touch state detection circuit according to claim 2, wherein: The voltage stabilizing component includes a driving circuit, a buffer and an error amplifier. The first end of the driving circuit is connected to the second end of the voltage stabilizing switch, the second end of the driving circuit is connected to the input end of the buffer and the output end of the error amplifier respectively, the third end of the driving circuit is connected to the negative input end of the error amplifier, the fourth end of the driving circuit is grounded, and the buffer is connected to the first end of the voltage stabilizing switch through the first end of the voltage stabilizing component.

5. The touch state detection circuit according to claim 4, wherein: The driving circuit includes a compensation circuit and a voltage divider circuit, wherein the first end of the voltage divider circuit is respectively connected to the second end of the switch tube, the second end of the fourth switch and one end of the compensation circuit, the second end of the voltage divider circuit is grounded, the third end of the voltage divider circuit is connected to the negative input end of the error amplifier, and the other end of the compensation circuit is respectively connected to the output end of the error amplifier and the input end of the buffer.

6. The touch state detection circuit according to claim 5, characterized in that: The voltage divider circuit includes: a first resistor and a second resistor; one end of the first resistor is respectively connected to the second end of the switch tube, the second end of the fourth switch and one end of the compensation circuit, the other end of the first resistor is respectively connected to one end of the second resistor and the negative input end of the error amplifier, and the other end of the second resistor is grounded.

7. The touch state detection circuit according to any one of claims 1 to 6, characterized in that: The touch state detection circuit further includes: a fifth switch connected in parallel in a path between a common end of the second switch and the third switch and the first input end of the processing circuit; a first end of the fifth switch is connected to the common end of the second switch and the third switch, and a second end of the fifth switch is connected to the first input end of the processing circuit; and a control end of the fifth switch is connected to the second control end of the controller.

8. The touch state detection circuit according to any one of claims 1 to 6, characterized in that: The capacitive circuit includes at least one touch branch, the touch branch includes a touch capacitor and a touch switch, the touch capacitor is connected in series with the touch switch, one end of the touch capacitor is grounded, the other end of the touch capacitor is connected to one end of the touch switch, and the other end of the touch switch is connected to the first switch and the second switch respectively; When the touch switch is closed, the touch capacitor is charged; when the touch switch is disconnected, the touch capacitor is discharged.

9. The touch state detection circuit according to any one of claims 1 to 6, characterized in that: The processing circuit includes a charging capacitor, a comparator, and a reference voltage generating circuit; one end of the charging capacitor is grounded, and the other end of the charging capacitor is connected to a common end of the fifth switch and the third switch, and an inverting input end of the comparator, respectively; a positive input end of the comparator is connected to the reference voltage generating circuit, and an output end of the comparator is connected to a signal input end of the controller; When the third switch is closed, the charging capacitor is discharged; When the second switch is closed and the third switch is open, the charging capacitor is charged according to the discharged charge of the touch capacitor in the working state in the capacitive circuit; The comparator is used to compare the voltage across the charging capacitor with the reference voltage output by the reference voltage generating circuit, and output a first control signal to the controller.

10. The touch state detection circuit according to any one of claims 1 to 6, characterized in that: The controller includes: a state machine and a bi-phase clock signal generating circuit; The state machine is used to generate a clock signal and send the clock signal to the two-phase clock signal generating circuit to instruct the two-phase clock signal generating circuit to output a first clock signal through the second control terminal of the controller and to output a second clock signal through the fifth control terminal of the controller, wherein the first clock signal and the second clock signal are anti-phase clock signals; The state machine is further configured to output a first switching signal through a third control terminal of the controller to control the voltage regulator to enter an operating state when the capacitor circuit is in a touched state, and to output a second switching signal through a fifth control terminal of the controller to close the first switch and open the second switch when the capacitor circuit is charging, and to open the first switch and close the second switch after the capacitor circuit completes charging; the state machine is further configured to receive a first control signal through a signal input terminal of the controller, and to start a detection program based on the first control signal to detect the current touch state of the capacitor circuit.

11. A touch state detection method, characterized in that: The method is implemented by the touch state detection circuit according to any one of claims 1 to 10, and the method includes: Acquire a first control signal output by a processing circuit in the touch state detection circuit; According to the first control signal, the touch state of the capacitive circuit in the touch state detection circuit is determined to be detected; wherein, during the detection process, when it is determined that the capacitive circuit is in the touched state, the regulator in the touch state detection circuit is controlled to enter the working state.

12. The method according to claim 11, characterized in that The step of controlling a voltage regulator in the touch state detection circuit to enter a working state when determining that the capacitive circuit is in a touched state includes: When it is determined for the first time that the capacitive circuit is in the touched state, the voltage regulator is controlled to enter the working state according to the second control signal.

13. The method according to claim 11 or 12, characterized in that The acquiring of the first control signal output by the processing circuit in the touch state detection circuit includes: Get the voltage across the charging capacitor; A first control signal output by the processing circuit is determined according to the voltage across the charging capacitor and a reference voltage.

14. The method according to claim 11 or 12, characterized in that Before acquiring the first control signal output by the processing circuit in the touch state detection circuit, the method further includes: At the beginning of the detection process, controlling the charging capacitor of the processing circuit in the touch state detection circuit to discharge; After the charging capacitor is discharged, the capacitor circuit is controlled to charge and discharge according to the clock signal.

15. The method according to claim 14, characterized in that The clock signal includes a first clock signal and a second clock signal, and controlling the capacitor circuit to charge and discharge according to the clock signal includes: generating a first clock signal and a second clock signal according to the clock signal; The capacitor circuit is controlled to charge and discharge according to the first clock signal and the second clock signal.

16. An electronic system, characterized in that: The electronic system includes the touch state detection circuit according to any one of claims 1 to 11.

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