Touch sensing circuit and compensation method for touch sensing circuit

Abstract

The invention provides a touch sensing circuit and a compensation method for the touch sensing circuit. The touch sensing circuit comprises a comparator, a first signal generator, a second signal generator and a control circuit. The comparator is provided with a first input end, a second input end and an output end. The first signal generator provides a first compensation signal to the first input terminal. The second signal generator provides a second compensation signal to the second input terminal. The control circuit controls the first signal generator to adjust the voltage value of the first compensation signal according to the sensing results of the first signal and the second signal, and controls the second signal generator to adjust the voltage value of the second compensation signal.

Description

Technical Field

[0001] The present invention relates to a sensing circuit and a compensation method for the sensing circuit, and in particular to a touch sensing circuit and a compensation method for the touch sensing circuit. Background Art

[0002] Generally speaking, the touch sensing circuit can provide a corresponding touch sensing signal according to whether the touch key is touched. Figure 1 , Figure 1 is a schematic diagram of an existing touch sensing circuit. The touch sensing circuit includes a touch key TK, a comparator CMP and a reference pad RP. The first input terminal of the comparator CMP is coupled to the touch key TK. The second input terminal of the comparator CMP is coupled to the reference pad RP. The voltage value at the first input terminal and the voltage value at the second input terminal are respectively set to a predetermined value. For example, when the touch key TK is not touched, the voltage value at the first input terminal is set to a voltage value higher than the voltage value at the second input terminal. Therefore, the touch sensing signal SCP has a low voltage level. When the touch key TK is touched, the voltage value at the first input terminal is lower than the voltage value at the second input terminal. Therefore, the touch sensing signal SCP has a high voltage level.

[0003] There is a parasitic capacitance value CP between the touch key TK and the reference low voltage VSS. There is a parasitic capacitance value CR between the reference foot pad RP and the reference low voltage VSS. Based on the change of the routing setting (layout, length or width of the routing) between the touch key TK and the comparator CMP and the routing setting between the reference foot pad RP and the comparator CMP, the parasitic capacitance values ​​CP and CR will also change. In general, when the voltage value at the first input terminal and the voltage value at the second input terminal are not set to a predetermined value, the design of the above-mentioned routing can be changed so that the voltage value at the first input terminal and the voltage value at the second input terminal are compensated to a predetermined value. However, based on the above-mentioned method, once the routing setting is modified, the voltage value at the first input terminal and the voltage value at the second input terminal cannot be compensated to a predetermined value. The routing setting needs to be modified again. In addition, if the parasitic capacitance value at the first input terminal is too large or the parasitic capacitance value at the second input terminal is too large, the compensation effect produced by the above-mentioned method is not large. Summary of the invention

[0004] The present invention provides a touch sensing circuit and a compensation method for the touch sensing circuit, which can automatically compensate the voltage value at the first input terminal of a comparator in the touch sensing circuit and the voltage value at the second input terminal of the comparator in the touch sensing circuit.

[0005] The touch sensing circuit of the present invention includes a comparator, a touch key, a first signal generator, a second signal generator and a control circuit. The comparator has a first input terminal, a second input terminal and an output terminal. The comparator outputs a sensing signal through the output terminal according to a first signal at the first input terminal and a second signal at the second input terminal. The touch key is coupled to the first input terminal. The first signal generator is coupled to the first input terminal. The first signal generator provides a first compensation signal to the first input terminal. The second signal generator is coupled to the second input terminal. The second signal generator provides a second compensation signal to the second input terminal. The control circuit is coupled to the first input terminal, the second input terminal, the first signal generator and the second signal generator. The control circuit controls the first signal generator to adjust the voltage value of the first compensation signal according to the sensing results of the first signal and the second signal, and controls the second signal generator to adjust the voltage value of the second compensation signal.

[0006] The compensation method of the present invention is used for a touch sensing circuit. The touch sensing circuit includes a touch key, a comparator, a first signal generator and a second signal generator. The comparator has a first input terminal, a second input terminal and an output terminal. The comparator outputs a sensing signal through the output terminal according to a first signal at the first input terminal and a second signal at the second input terminal. The compensation method includes: receiving a first signal at the first input terminal and a second signal at the second input terminal; controlling the first signal generator to adjust the voltage value of the first compensation signal according to the sensing results of the first signal and the second signal, and controlling the second signal generator to adjust the voltage value of the second compensation signal; and providing the first compensation signal to the first input terminal, and providing the second compensation signal to the second input terminal.

[0007] Based on the above, the present invention receives a first signal at a first input terminal and a second signal at a second input terminal, and controls a first signal generator and a second signal generator according to the sensing results of the first signal and the second signal. The first signal generator adjusts the voltage value of the first compensation signal. The second signal generator adjusts the voltage value of the second compensation signal. In this way, the voltage value of the first input terminal and the voltage value of the second input terminal of the comparator are compensated by the first signal generator and the second signal generator. The touch sensing circuit and the compensation method realize automatic compensation of the voltage value of the first input terminal and the voltage value of the second input terminal of the comparator located in the touch sensing circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a schematic diagram of an existing touch sensing circuit.

[0009] Figure 2 is a schematic diagram of a touch sensing circuit according to an embodiment of the present invention.

[0010] Figure 3FIG. 4 is a schematic diagram of a first signal and a second signal of a touch sensing circuit according to an embodiment of the present invention.

[0011] Figure 4 is a schematic diagram of a touch sensing circuit according to an embodiment of the present invention.

[0012] Figure 5 is a schematic diagram of a first variable capacitance circuit according to an embodiment of the present invention.

[0013] Figure 6 is a schematic diagram of a second variable capacitance circuit according to an embodiment of the present invention.

[0014] Figure 7 is a flow chart of a compensation method according to an embodiment of the present invention.

[0015] Description of Reference Numerals

[0016] 100, 200: Touch sensing circuit

[0017] 110: First signal generator

[0018] 120: Second signal generator

[0019] 130, 230: Control circuit

[0020] 240: First variable capacitance circuit

[0021] 250: Second variable capacitance circuit

[0022] C1~C8:Capacitor

[0023] CB1: First set capacitance value

[0024] CB2: Second set capacitance value

[0025] CMP: Comparator

[0026] CP, CR: parasitic capacitance value

[0027] P1~P4: Example

[0028] RP: Reference Pads

[0029] S100: Compensation Method

[0030] S110~S130: Steps

[0031] SC1: First compensation signal

[0032] SC2: Second compensation signal

[0033] SCB1, SCB2, SCC1, SCC2: control signals

[0034] SCP: Sensing Signal

[0035] SD1: First signal

[0036] SD2: Second signal

[0037] ST: Touch key scan timing

[0038] SW1~SW8:Switch

[0039] TI1: First input terminal

[0040] TI2: Second input terminal

[0041] TK: Touch Key

[0042] TO: Output terminal

[0043] VDD: Reference high voltage

[0044] VSS: Reference low voltage DETAILED DESCRIPTION

[0045] Some embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. The component symbols cited in the following description will be regarded as the same or similar components when the same component symbols appear in different drawings. These embodiments are only part of the present invention and do not disclose all possible implementation methods of the present invention. More specifically, these embodiments are only examples within the scope of the patent application of the present invention.

[0046] Please refer to Figure 2 , Figure 2 1 is a schematic diagram of a touch sensing circuit according to an embodiment of the present invention. In this embodiment, the touch sensing circuit 100 includes a comparator CMP, a touch key TK, a first signal generator 110, a second signal generator 120 and a control circuit 130. The comparator CMP has a first input terminal TI1, a second input terminal TI2 and an output terminal TO. The comparator CMP outputs a sensing signal SCP through the output terminal TO according to a first signal SD1 at the first input terminal TI1 and a second signal SD2 at the second input terminal TI2. The touch key TK is coupled to the first input terminal TI1.

[0047] For example, the first input terminal TI1 is an inverting input terminal "-". The second input terminal TI2 is an inverting input terminal "+". When the touch key TK is not touched, the voltage value of the first signal SD1 is higher than the voltage value of the second signal SD2. Therefore, the touch sensing signal SCP has a low voltage level. When the touch key TK is touched, the voltage value of the first signal SD1 is lower than the voltage value of the second signal SD2. Therefore, the touch sensing signal SCP has a high voltage level.

[0048] In the present embodiment, the first signal generator 110 is coupled to the first input terminal TI1. The first signal generator 110 provides the first compensation signal SC1 to the first input terminal TI1. The second signal generator 120 is coupled to the second input terminal TI2. The second signal generator 120 provides the second compensation signal SC2 to the second input terminal TI2. The control circuit 130 is coupled to the first input terminal TI1, the second input terminal TI2, the first signal generator 110 and the second signal generator 120. The control circuit 130 controls the first signal generator 110 and the second signal generator 120 according to the sensing results of the first signal SD1 and the second signal SD2. Therefore, the first signal generator 110 adjusts the voltage value of the first compensation signal SC1. The second signal generator 120 adjusts the voltage value of the second compensation signal SC2.

[0049] It is worth mentioning here that the control circuit 130 controls the first signal generator 110 and the second signal generator 120 according to the sensing results of the first signal SD1 at the first input terminal TI1 and the second signal SD2 at the second input terminal TI2. In other words, the control circuit 130 controls the first signal generator 110 and the second signal generator 120 according to the current sensing results at the first input terminal TI1 and the second input terminal TI2. The first signal generator 110 adjusts the voltage value of the first compensation signal SC1 in response to the control of the control circuit 130. The second signal generator 120 adjusts the voltage value of the second compensation signal SC2 in response to the control of the control circuit 130. In this way, the touch sensing circuit 100 realizes automatic compensation of the voltage value at the first input terminal TI1 and the voltage value at the second input terminal TI2.

[0050] In the present embodiment, the touch sensing circuit 100 further includes a reference pad RP. The reference pad RP is coupled to the second input terminal TI2. The reference pad RP may be coupled to the second signal generator 120, for example. A parasitic capacitance value CP is provided between the touch key TK and the reference low voltage VSS. A parasitic capacitance value CR is provided between the reference pad RP and the reference low voltage VSS. Generally speaking, a change in the wiring arrangement (layout, length or width of the wiring) between the touch key TK and the first input terminal TI1 will change the parasitic capacitance value CP. A change in the wiring arrangement between the reference pad RP and the second input terminal TI2 will change the parasitic capacitance value CR. In addition, the parasitic capacitance values ​​CP and CR will affect the first signal SD1 and the second signal SD2. It should be noted that the first signal generator 110 adjusts the voltage value of the first compensation signal SC1 in response to the control of the control circuit 130. The second signal generator 120 adjusts the voltage value of the second compensation signal SC2 in response to the control of the control circuit 130. Therefore, in this embodiment, it is not necessary to modify the wiring arrangement between the touch key TK and the first input terminal TI1 and the wiring arrangement between the reference pad RP and the second input terminal TI2 to adjust the first signal SD1 and the second signal SD2.

[0051] In this embodiment, the control circuit 130 is, for example, a central processing unit (CPU), or other programmable general-purpose or special-purpose microprocessor (Microprocessor), digital signal processor (Digital Signal Processor, DSP), programmable controller, application specific integrated circuits (Application Specific Integrated Circuits, ASIC), programmable logic device (Programmable Logic Device, PLD) or other similar devices or a combination of these devices, which can load and execute computer programs.

[0052] In this embodiment, for the sake of convenience, this embodiment is exemplified by a single touch key TK, a single comparator CMP, a single first signal generator 110, and a single second signal generator 120. However, the present invention is not limited thereto. In some embodiments, the number of touch keys of the touch sensing circuit 100 can be multiple. Therefore, the number of comparators, the number of first signal generators 110, and the number of second signal generators 120 can be multiple, respectively. The control circuit 130 can control multiple first signal generators 110 and multiple second signal generators 120.

[0053] Please also refer to Figure 2 as well as Figure 3 , Figure 3is a schematic diagram of a first signal and a second signal of a touch sensing circuit according to an embodiment of the present invention. In this embodiment, Figure 3 A plurality of examples P1 to P4 of the first signal SD1 and the second signal SD2 are shown. The timing of the first signal SD1 and the second signal SD2 is the same as the touch key scanning timing ST of the touch sensing circuit 100. The touch key scanning timing ST is a square wave signal. Therefore, the first signal SD1 and the second signal SD2 are square wave signals respectively.

[0054] First, in example P1, before compensation, when the touch key TK is not touched, the high voltage value of the first signal SD1 is significantly higher than the high voltage value of the second signal SD2. The touch sensing signal SCP has a low voltage level. Therefore, the touch sensing circuit 100 determines that the touch key TK is not touched based on the low voltage level of the touch sensing signal SCP.

[0055] When the touch key TK is touched, even if the high voltage value of the first signal SD1 is reduced, the high voltage value of the first signal SD1 is still higher than the high voltage value of the second signal SD2, as shown in Example P2. Therefore, the touch sensing signal SCP has a low voltage level. The touch sensing circuit 100 determines that the touch key TK is not touched based on the low voltage level of the touch sensing signal SCP. It should be understood that the determination of the touch sensing circuit 100 is wrong.

[0056] In the present embodiment, the timing of the first compensation signal SC1 and the timing of the second compensation signal SC2 are the same as the touch key scanning timing ST of the touch sensing circuit 100. Therefore, the first compensation signal SC1 and the second compensation signal SC2 are square wave signals, respectively. Therefore, the first signal generator 110 and the second signal generator 120 are square wave signal generators, respectively. The control circuit 130 determines the high voltage value of the first signal SD1. In example P1, when the high voltage value of the first signal SD1 is not equal to the first predetermined voltage value VD1, the control circuit 130 controls the first signal generator 110 so that the high voltage value of the first signal SD1 is adjusted to the first predetermined voltage value VD1. For example, when the high voltage value of the first signal SD1 is not equal to the first predetermined voltage value VD1, the control circuit 130 provides the control signal SCC1. The first signal generator 110 changes the voltage value of the first compensation signal SC1 in response to the control signal SCC1, thereby adjusting the high voltage value of the first signal SD1 to the first predetermined voltage value VD1. On the other hand, when the high voltage value of the first signal SD1 is substantially equal to the first predetermined voltage value VD1, it means that the high voltage value of the first signal SD1 does not need to be compensated. Therefore, the control circuit 130 does not provide the control signal SCC1.

[0057] In example P1, when the high voltage value of the second signal SD2 is not equal to the second predetermined voltage value VD2, the control circuit 130 controls the second signal generator 120 so that the high voltage value of the second signal SD2 is adjusted to the second predetermined voltage value VD2. For example, when the high voltage value of the second signal SD2 is not equal to the second predetermined voltage value VD2, the control circuit 130 provides the control signal SCC2. The second signal generator 120 changes the voltage value of the second compensation signal SC2 in response to the control signal SCC2, thereby adjusting the high voltage value of the second signal SD2 to the second predetermined voltage value VD2. On the other hand, when the high voltage value of the second signal SD2 is substantially equal to the second predetermined voltage value VD2, this indicates that the high voltage value of the second signal SD2 does not need to be compensated. Therefore, the control circuit 130 does not provide the control signal SCC2.

[0058] Example P3 is the result after the first signal SD1 and the second signal SD2 are compensated and the touch key TK is not touched. When the touch key TK is not touched, the high voltage value of the first signal SD1 is substantially equal to the first predetermined voltage value VD1. The high voltage value of the second signal SD2 is substantially equal to the second predetermined voltage value VD2. Taking this embodiment as an example, the first predetermined voltage value VD1 is slightly higher than the second predetermined voltage value VD2. For example, the first predetermined voltage value VD1 is, for example, 1.2 volts. The second predetermined voltage value VD2 is, for example, 1.15 volts. When the touch key TK is not touched, the high voltage value of the first signal SD1 is slightly higher than the high voltage value of the second signal SD2. The touch sensing signal SCP has a low voltage level. Therefore, the touch sensing circuit 100 determines that the touch key TK is not touched based on the low voltage level of the touch sensing signal SCP.

[0059] On the other hand, when the touch key TK is touched, the high voltage value of the first signal SD1 is lower than the high voltage value of the second signal SD2 (i.e., lower than the second predetermined voltage value VD2), as shown in Example P4. Therefore, the touch sensing signal SCP has a high voltage level. Therefore, the touch sensing circuit 100 determines that the touch key TK is touched according to the high voltage level of the touch sensing signal SCP.

[0060] Please also refer to Figure 4 , Figure 4 2 is a schematic diagram of a touch sensing circuit according to an embodiment of the present invention. In this embodiment, the touch sensing circuit 200 includes a comparator CMP, a reference pad RP, a touch key TK, a first signal generator 110, a second signal generator 120, a control circuit 230, a first variable capacitance circuit 240, and a second variable capacitance circuit 250. The implementation of the first signal generator 110 and the second signal generator 120 can be Figure 2 as well as Figure 3In the present embodiment, the first variable capacitance circuit 240 is coupled to the reference high voltage VDD, the first input terminal TI1 and the control circuit 230. The first variable capacitance circuit 240 provides a first set capacitance value CB1 to the first input terminal TI1. The second variable capacitance circuit 250 is coupled to the reference high voltage VDD, the second input terminal TI2 and the control circuit 230. The second variable capacitance circuit 250 provides a second set capacitance value CB2 to the second input terminal TI2.

[0061] A parasitic capacitance value CP is provided between the touch key TK and the reference low voltage VSS. A parasitic capacitance value CR is provided between the reference pad RP and the reference low voltage VSS. The first set capacitance value CB1 and the parasitic capacitance value CP can adjust the capacitance value at the first input terminal TI1. The second set capacitance value CB2 and the parasitic capacitance value CR can adjust the capacitance value at the second input terminal TI2.

[0062] In the present embodiment, the control circuit 230 controls the first variable capacitance circuit 240 and the second variable capacitance circuit 250 to adjust the capacitance value at the first input terminal TI1 and the capacitance value at the second input terminal TI2. In the present embodiment, the control circuit 230 may provide control signals SCB1 and SCB2. The first variable capacitance circuit 240 responds to the control signal SCB1 to provide the first set capacitance value CB1. The second variable capacitance circuit 250 responds to the control signal SCB2 to provide the second set capacitance value CB2. Therefore, when the capacitance value at the first input terminal TI1 is too large or small, the first variable capacitance circuit 240 may respond to the control signal SCB1 to adjust the capacitance value at the first input terminal TI1. Similarly, when the capacitance value at the second input terminal TI2 is too large or small, the second variable capacitance circuit 250 may respond to the control signal SCB2 to adjust the capacitance value at the second input terminal TI2.

[0063] Please also refer to Figure 4 as well as Figure 5 , Figure 5 2 is a schematic diagram of a first variable capacitance circuit according to an embodiment of the present invention. In this embodiment, the first variable capacitance circuit 240 includes switches SW1-SW4 and capacitors C1-C4. The first ends of the switches SW1-SW4 are commonly coupled to the reference high voltage VDD. The capacitor C1 is coupled between the second end of the switch SW1 and the first input terminal TI1. The capacitor C2 is coupled between the second end of the switch SW2 and the first input terminal TI1. The capacitor C3 is coupled between the second end of the switch SW3 and the first input terminal TI1. The capacitor C4 is coupled between the second end of the switch SW4 and the first input terminal TI1. The capacitance values ​​of the capacitors C1-C4 are the same or different from each other.

[0064] The control ends of the switches SW1 to SW4 receive the control signal SCB1. In the present embodiment, the switches SW1 to SW4 are implemented by transistor switches or transmission gates, respectively. In the present embodiment, the control signal SCB1 can be a multi-bit digital signal. The switches SW1 to SW4 correspond to different bits of the control signal SCB1, respectively. Therefore, the switches SW1 to SW4 perform switching operations in response to different bits of the control signal SCB1, respectively. At least one of the switches SW1 to SW4 that is turned on determines at least one capacitor that is selected. For example, when the switches SW1 and SW2 are turned on, the sum of the capacitance values ​​of the capacitors C1 and C2 is substantially equal to the first set capacitance value CB1.

[0065] In addition, in this embodiment, the providing timing of the first setting capacitance value CB1 is the same as the touch key scanning timing of the touch sensing circuit 200 (eg Figure 3 The touch key scanning timing ST shown in FIG.

[0066] This embodiment takes four switches SW1 - SW4 and four capacitors C1 - C4 as an example, but the present invention is not limited to the number of switches and capacitors of the first variable capacitance circuit 240 .

[0067] Please also refer to Figure 4 as well as Figure 6 , Figure 6 2 is a schematic diagram of a second variable capacitance circuit according to an embodiment of the present invention. In the present embodiment, the second variable capacitance circuit 240 includes switches SW5-SW8 and capacitors C5-C8. The first ends of the switches SW5-SW8 are commonly coupled to the reference high voltage VDD. The capacitor C5 is coupled between the second end of the switch SW5 and the second input terminal TI2. The capacitor C6 is coupled between the second end of the switch SW6 and the second input terminal TI2. The capacitor C7 is coupled between the second end of the switch SW7 and the second input terminal TI2. The capacitor C8 is coupled between the second end of the switch SW8 and the second input terminal TI2. The capacitance values ​​of the capacitors C5-C8 are the same or different from each other.

[0068] The control ends of switches SW5-SW8 receive control signal SCB2. In the present embodiment, switches SW1-SW4 are implemented by transistor switches or transmission gates, respectively. In the present embodiment, control signal SCB2 can be a multi-bit digital signal. Switches SW5-SW8 correspond to different bits of control signal SCB2, respectively. Therefore, switches SW1-SW4 perform switching operations in response to different bits of control signal SCB1, respectively. At least one switch turned on among switches SW5-SW8 determines at least one capacitor selected. For example, when switches SW5 and SW6 are turned on, the sum of the capacitance values ​​of capacitors C5 and C6 is substantially equal to the second set capacitance value CB2.

[0069] In addition, in this embodiment, the providing timing of the second set capacitance value CB2 is the same as the touch key scanning timing of the touch sensing circuit 200 (eg Figure 3 The touch key scanning timing ST shown in FIG.

[0070] This embodiment takes four switches SW5 ˜ SW8 and four capacitors C5 ˜ C8 as an example, but the present invention is not limited to the number of switches and the number of capacitors of the second variable capacitance circuit 250 .

[0071] Please also refer to Figure 2 as well as Figure 7 , Figure 7 is a flow chart of a compensation method according to an embodiment of the present invention. The compensation method S100 is applicable to the touch sensing circuit 100. For example, the compensation method S100 can be performed in a compensation stage before the touch sensing circuit 100 is used. In this embodiment, the compensation method S100 includes steps S110 to S130. In step S110, the control circuit 130 receives a first signal SD1 at the first input terminal TI1 and a second signal SD2 at the second input terminal TI2. In step S120, the control circuit 130 controls the first signal generator 110 to adjust the voltage value of the first compensation signal SC1 according to the sensing results of the first signal SD1 and the second signal SD2, and controls the second signal generator 120 to adjust the voltage value of the second compensation signal SC2. In step S130, the first signal generator 110 provides the first compensation signal SC1 to the first input terminal TI1. The second signal generator 120 provides the second compensation signal SC2 to the second input terminal TI2.

[0072] In this embodiment, the implementation details of steps S110 to S130 can be found in Figure 2 as well as Figure 3 Sufficient teaching is obtained from the embodiments of the present invention, so it will not be repeated here.

[0073] In summary, the control circuit of the touch sensing circuit controls the first signal generator and the second signal generator according to the current sensing results at the first input terminal of the comparator and the second input terminal of the comparator. The first signal generator adjusts the voltage value of the first compensation signal in response to the control of the control circuit. The second signal generator adjusts the voltage value of the second compensation signal in response to the control of the control circuit. In this way, the touch sensing circuit realizes automatic compensation of the voltage value at the first input terminal and the voltage value at the second input terminal. The touch sensing circuit does not need to modify the routing to compensate for the voltage value at the first input terminal and the voltage value at the second input terminal. In addition, the touch sensing circuit may further include a first variable capacitance circuit and a second variable capacitance circuit. The control circuit can control the first variable capacitance circuit and the second variable capacitance circuit to adjust the capacitance value at the first input terminal of the comparator and the capacitance value at the second input terminal of the comparator.

[0074] Although the present invention has been disclosed as above by way of embodiments, it is not intended to limit the present invention. Any person skilled in the art may make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the scope defined by the attached claims.

Claims

1. A touch sensing circuit, characterized in that: The touch sensing circuit comprises: a comparator having a first input terminal, a second input terminal and an output terminal, and configured to output a sensing signal through the output terminal according to a first signal at the first input terminal and a second signal at the second input terminal; A touch key, coupled to the first input terminal; A first signal generator, coupled to the first input terminal, configured to provide a first compensation signal to the first input terminal; A second signal generator, coupled to the second input terminal, configured to provide a second compensation signal to the second input terminal; and The control circuit is coupled to the first input terminal, the second input terminal, the first signal generator and the second signal generator, and is configured to control the first signal generator to adjust the voltage value of the first compensation signal according to the sensing results of the first signal and the second signal, and to control the second signal generator to adjust the voltage value of the second compensation signal.

2. The touch sensing circuit according to claim 1, characterized in that: The first compensation signal and the second compensation signal are square wave signals respectively, and The timing of the first compensation signal and the timing of the second compensation signal are the same as the touch key scanning timing of the touch sensing circuit.

3. The touch sensing circuit according to claim 2, characterized in that: The control circuit determines a high voltage value of the first signal, and When the high voltage value of the first signal is not equal to the first predetermined voltage value, the control circuit controls the first signal generator so that the high voltage value of the first signal is adjusted to the first predetermined voltage value.

4. The touch sensing circuit according to claim 2, characterized in that: The control circuit determines a high voltage value of the second signal, and When the high voltage value of the second signal is not equal to the second predetermined voltage value, the control circuit controls the second signal generator so that the high voltage value of the second signal is adjusted to the second predetermined voltage value.

5. The touch sensing circuit according to claim 1, characterized in that: The touch sensing circuit further includes: A first variable capacitance circuit coupled to a reference high voltage, the first input terminal and the control circuit, and configured to provide a first set capacitance value to the first input terminal; and The second variable capacitance circuit is coupled to the reference high voltage, the second input terminal and the control circuit, and is configured to provide a second set capacitance value to the second input terminal.

6. The touch sensing circuit according to claim 5, characterized in that: The control circuit controls the first variable capacitance circuit and the second variable capacitance circuit to adjust the capacitance value at the first input terminal and the capacitance value at the second input terminal.

7. The touch sensing circuit according to claim 6, characterized in that: The provision timing of the first set capacitance value and the provision timing of the second set capacitance value are the same as the touch key scanning timing of the touch sensing circuit.

8. A compensation method for a touch sensing circuit, characterized in that: The touch sensing circuit includes a touch key, a comparator, a first signal generator and a second signal generator, wherein the comparator has a first input terminal, a second input terminal and an output terminal, wherein the comparator outputs a sensing signal through the output terminal according to a first signal at the first input terminal and a second signal at the second input terminal, wherein the compensation method includes: receiving the first signal at the first input terminal and the second signal at the second input terminal; controlling the first signal generator to adjust the voltage value of the first compensation signal and controlling the second signal generator to adjust the voltage value of the second compensation signal according to the sensing results of the first signal and the second signal; and The first compensation signal is provided to the first input terminal, and the second compensation signal is provided to the second input terminal.

9. The compensation method according to claim 8, characterized in that: The first compensation signal and the second compensation signal are square wave signals respectively, wherein the timing of the first compensation signal and the timing of the second compensation signal are the same as the touch key scanning timing of the touch sensing circuit, wherein the steps of controlling the first signal generator to adjust the voltage value of the first compensation signal according to the sensing results of the first signal and the second signal, and controlling the second signal generator to adjust the voltage value of the second compensation signal include: determining a high voltage value of the first signal; and When the high voltage value of the first signal is not equal to the first predetermined voltage value, the first signal generator is controlled to adjust the high voltage value of the first signal to the first predetermined voltage value.

10. The compensation method according to claim 9, characterized in that: The step of controlling the first signal generator to adjust the voltage value of the first compensation signal according to the sensing results of the first signal and the second signal, and controlling the second signal generator to adjust the voltage value of the second compensation signal also includes: determining a high voltage value of the second signal; and When the high voltage value of the second signal is not equal to the second predetermined voltage value, the second signal generator is controlled to adjust the high voltage value of the second signal to the second predetermined voltage value.

Images