TWI412229B - Multi-channel integrator - Google Patents

Abstract

A multi-channel integrator is provided. The multi-channel integrator includes an integrator and a plurality of channels. Each of the channels includes an input selector and a unit-gain amplifier. The input selector has a common terminal, a first selecting terminal and a second selecting terminal. The input selector selectively electrically connects the common terminal to the first selecting terminal or the second selecting terminal. The first selecting terminal of the input selector is coupled to an input terminal of the integrator. The second selecting terminal of the input selector is coupled to an input terminal of the unit-gain amplifier.

Description

Multichannel integrator

This invention relates to an integrator, and more particularly to an integrator for a plurality of channels.

With the rapid development of electronic technology and the popularization of wireless communication and networks, various electronic devices have become an indispensable tool for life. However, common input/output (I/O) interfaces, such as keyboards or mice, have considerable operational difficulties. In contrast, the touch panel is an intuitive and simple input and output interface. Therefore, the touch panel is often applied as a human-machine interface between a person and an electronic device to perform control.

In general, the touch panel can be divided into a resistive touch panel, an optical touch panel, a capacitive touch panel, and the like. According to the readout means, it can be classified into a current type touch panel and a charge type touch panel. FIG. 1 illustrates a schematic diagram of a capacitive touch panel and a conventional readout circuit. Generally, the capacitive touch panel 110 has a plurality of sensor lines in the Y-axis direction and the X-axis direction. A coupling capacitor Cp is formed between a sensing line in the Y-axis direction and a sensing line in the X-axis direction.

Each of the sensing lines is provided with an integrator 120, and each integrator 120 is provided with an operational amplifier 122 and a feedback capacitor Cfb. Initially all non-inverting inputs of operational amplifier 122 receive a reference voltage _{Vref of} 0V, and all switches 123 are turned on, so all sense lines are charged to 0V. Each of the integrators 120 then turns off the switch 123 for a read operation. During the off period of the switch 123, it is assumed that no conductor (for example, a finger) approaches the touch panel 110. When the reference voltage V _{ref is} switched from 0 V to 5 V, the integrator 120 in the Y-axis direction and the X-axis direction causes the coupling capacitance Cp. Both terminals have a voltage of 5V. Since the coupling capacitor Cp is not required to be charged and discharged, this change is reflected at the output of the integrator 120 when the reference voltage _{Vref is} shifted to 5V. After each integrator 120 completes the read operation, all of the switches 123 will be turned on again, so that they are repeated.

When an electrical conductor (such as a finger) approaches the touch panel 110, an additional capacitance Cf (shown in FIG. 1) is formed at the corresponding position. During the off period of the switch 123, when the reference voltage V _ref transitions from 0 V to 5 V, the corresponding integrator 120 needs to charge and discharge the additional capacitance Cf via the sensing line. Therefore, when the reference voltage V _ref transitions to 5V, the output OUT of the integrator 120 corresponding to the additional capacitance Cf changes, and its formula is OUT=5+[(5V-0V)×Cfl/Cfb. The integrator 120 passes the readout result to a subsequent circuit (including an analog digital converter and an image processing circuit, not shown here) to determine the position coordinates. The difference between the signal read by the sensing line forming the additional capacitance Cf and the signal read by the sensing line without the additional capacitance Cf can thus locate the contacted position.

It can be seen from the above formula that if the extra capacitance Cf is larger, the feedback capacitance Cfb is larger, otherwise it is easy to make the output of the integrator 120 saturated and it is impossible to determine the touch position. However, in order to avoid saturation of the output of the integrator 120, the feedback capacitance Cfb of the integrator 120 must also increase the capacitance (i.e., increase the area of the feedback capacitance Cfb). Since each sense line requires an integrator 120, the area of the wafer occupied by the integrator 120 will be substantial.

The present invention provides a multi-channel integrator to save wafer area.

The present invention provides a multi-channel integrator comprising an integrator and a plurality of channels. Each of the channels includes an input selector and a unity gain amplifier. An input selector selectively connects the input or reference voltage of the integrator to the common terminal of the input selector.

The present invention provides a multi-channel integrator comprising an integrator and a plurality of channels. Each channel includes an input selector. The input selector has a common terminal, a first selection terminal and a second selection terminal for selectively connecting the common terminal to the first selection terminal or the second selection terminal. The first selection end of the input selector is coupled to the input end of the integrator, and the second selection end of the input selector receives a reference voltage.

In an embodiment of the invention, the integrator includes a first operational amplifier, a feedback capacitor, and a feedback switch. A first input of the first operational amplifier is used as an input of the integrator, a second input of the first operational amplifier receives the reference voltage, and an output of the first operational amplifier serves as an output of the integrator. The first end and the second end of the feedback capacitor are respectively coupled to the first input end and the output end of the first operational amplifier. The first end and the second end of the feedback switch are respectively coupled to the first input end and the output end of the first operational amplifier.

In an embodiment of the invention, when the feedback switch is turned off during the first channel, the input selector of the first channel of the channels selectively connects its common terminal to its first selection end. And the input selectors of the remaining channels in the channels select to electrically connect their common terminals to their second select terminals.

Based on the above, by sharing a set of integrators in turn between a plurality of channels, the wafer area can be greatly saved, thereby saving costs.

The above described features and advantages of the present invention will be more apparent from the following description.

The following embodiment will illustrate the application of the multi-channel integrator of the present invention by taking a capacitive touch panel 110 as an example. However, the scope of application of the present invention should not be limited thereto. Any chargeable touch panel, even any circuit or electronic product that requires a multi-channel integrator, can be applied in accordance with the teachings of this specification.

2 is a circuit diagram illustrating a multi-channel integrator in accordance with an embodiment of the present invention. This multi-channel integrator 200 has n channels 210-1~210-n. Only the first channel 210-1 and the nth channel 210-n are depicted in the figure, and other channels can be analogized with reference to the description of the first channel 210-1. In addition to this, the multi-channel integrator 200 still has an integrator 220. A set of integrators 220 is shared between the channels 210-1~210-n in turn, so that the wafer area can be greatly saved, thereby saving costs. The following will explain in detail how the channels 210-1~210-n use this integrator 220 in turn.

Referring to FIG. 2, in the embodiment, the implementation manners of the channels 210-1~210-n are the same. For example, channel 210-1 includes an input selector 211 and a unit-gain amplifier 212. The input selector 211 has a common terminal, a first selection terminal and a second selection terminal, and an input terminal of the unity gain amplifier 212 is coupled to the second selection terminal of the input selector 211. The input of the integrator 220 is coupled to the first selection of the input selector 211 of all of the channels 210-1~210-n. In the channel 210-1, the common end of the input selector 211 is coupled to the first sensing line of the touch panel 110. In the channel 210-n, the common end of the input selector 211 is coupled to the nth sensing line of the touch panel 110. The input selector 211 of the channel 210-1 is controlled by the control signal S1, while the input selector 211 of the channel 210-n is controlled by the control signal Sn. The input selector 211 selectively connects the common terminal to the first selection terminal according to the corresponding control signal, or selectively connects the common terminal to the second selection terminal.

FIG. 3 is a timing diagram showing control of each of the control signals S1 to Sn in FIG. 2 according to an embodiment of the present invention. Please refer to FIG. 2 and FIG. 3 at the same time. When the system is in the power on period or during the system reset, the system resets the reset signal to the enable state (for example). It is a logic low level). When the reset signal Reset is at a logic low level, the input selectors 211 of all the channels 210-1~210-n select to electrically connect the common terminal to the second selection terminal, so that the unity gain amplifier 212 is coupled to the touch. The sensing line of the control panel 110.

When entering the first channel period T1, the control signal S1 will transition to the logic high level, while the other control signals S2~Sn remain at the logic low level. Thus, during the first channel period T1, the input selector 211 of the first channel 210-1 selects an input selector that electrically connects its common terminal to its first select terminal, while the remaining channels (eg, channel 210-n) 211 selects to electrically connect its common terminal to its second selection terminal. Therefore, during the first channel period T1, the channel 210-1 can use the integrator 220, and the remaining channels are coupled to the corresponding sensing lines of the touch panel 110 with the input ends of the internal unity gain amplifiers 212 to prepare the integrals. The input of the device.

When the current channel period (for example, the first channel period T1) ends but has not yet entered the next channel period (for example, the second channel period T2) (equivalent to the reset period), the system sets the reset signal Reset to a logic low level. As shown in FIG. 3, at this time, the control signal S1 will transition to a logic low level. During this time, the input selectors 211 of all the channels 210-1~210-n select to electrically connect the common terminal to the second selection end, so that the input end of the unity gain amplifier 212 is coupled to the touch panel 110. Line measurement.

Then enter the second channel period T2. During the second channel period T2, the control signal S2 will transition to a logic high level, while the other control signals S1, S3~Sn remain at a logic low level. Therefore, the second channel (not shown in FIG. 2, which can be analogized by the description of channel 210-1) can use integrator 220 during the second channel period T2, while the remaining channels are united by its internal unity gain amplifier 212. The input end is coupled to the sensing line corresponding to the touch panel 110 to fit the input end of the integrator. By the way, when the nth channel period Tn is entered, the nth channel 210-n can use the integrator 220, and the remaining channels are coupled to the touch panel 110 with the input end of the internal unity gain amplifier 212. Sensing line. The detailed operation of the second channel period T2, the third channel period T3, ..., the nth channel period Tn can be referred to the related description of the first channel period T1, and therefore will not be described again.

A subsequent stage circuit (not shown, which may be an analog digital converter and/or an image processing circuit) is coupled to the output of the integrator 220. Therefore, the subsequent stage circuit can sequentially receive the read signals of the plurality of sensing lines of the touch panel 110, thereby positioning the touched position of the touch panel 110.

4 is a circuit diagram illustrating another multi-channel integrator in accordance with an embodiment of the present invention. This multi-channel integrator 400 has n channels 410-1~410-n. Only the first channel 410-1 and the nth channel 410-n are depicted in the figure, and other channels can be analogized with reference to channel 410-1. This embodiment is similar to FIG. 2, so some of the contents will not be described again. 4 is different from FIG. 2 in that the sampling switch 413 and the sampling capacitor 414 are further disposed in the channel.

Referring to FIG. 4, the implementations of the channels 410-1 to 410-n are the same. Channel 410-1 will be taken as an illustrative example below. In channel 410-1, the first end of sampling switch 413 is coupled to the output of integrator 220. The sampling switches 413 of the channels 410-1 to 410-n are respectively controlled by the control signals SS1, SS2, SS3, ..., SSn (please refer to FIG. 3). The first end of the sampling capacitor 414 is coupled to the second end of the sampling switch 413, and the second end of the sampling capacitor 414 receives the second reference voltage (eg, a ground voltage).

Please refer to FIG. 3 and FIG. 4 simultaneously. When entering the first channel period T1, the control signals S1 and SS1 will transition to the logic high level, while the other control signals S2~Sn and SS2~SSn remain at the logic low level. . Therefore, during the first channel period T1, the input selector 211 of the first channel 410-1 selects to electrically connect its common terminal to its first selection terminal, and the sampling switch 413 of the first channel 410-1 is turned on. Therefore, the output of the integrator 220 is stored in the sampling capacitor 414. During the first channel period T1, the input selector 211 of the remaining channels (e.g., channel 410-n) selects to electrically connect its common terminal to its second select terminal, while the sampling switch 413 is off. By analogy, when entering the nth channel period Tn, the nth channel 410-n can use the integrator 220 and store the output of the integrator 220 in the sampling capacitor 414 of the channel 410-n. The detailed operation of the second channel period T2, the third channel period T3, ..., the nth channel period Tn can be referred to the related description of the first channel period T1, and therefore will not be described again.

Since the sampling capacitor 414 of each channel 410-1~410-n already stores the read signals of the plurality of sensing lines of the touch panel 110, the subsequent circuit (not shown, which may be an analog digital converter and/or image) The processing circuit can read the signals of the respective sampling capacitors 414 to locate the contacts in the touch panel 110.

FIG. 5 is a circuit diagram showing the multi-channel integrator 400 of FIG. 4 in accordance with an embodiment of the present invention. Referring to FIG. 5, the unity gain amplifier 212 includes a second operational amplifier OP2. The first input terminal of the operational amplifier OP2 is coupled to the second selection terminal of the input selector 211, the second input terminal of the operational amplifier OP2 receives the reference voltage V _ref , and the output terminal of the operational amplifier OP2 is coupled to the operational amplifier OP2 An input. In this embodiment, the first input of the operational amplifier OP2 is an inverting input, and the second input of the operational amplifier OP2 is a non-inverting input.

In addition, the application of this embodiment can determine the level of the reference voltage V _ref depending on its design requirements. For example, set the reference voltage V _ref to half of the system voltage VDDA level (ie VDDA/2), or set to the band-gap voltage, or set to +5V, or set to other Fixed voltage. This embodiment sets the reference voltage V _ref to a time varying voltage in response to the reset signal Reset. When the reset signal Reset is at a logic low level, the reference voltage V _ref is a ground voltage (ie, 0V). After the reset signal Reset transitions to a logic high level, the reference voltage V _ref transitions to half of the system voltage VDDA (ie, VDDA/2, eg, +5V) in response to the reset signal Reset.

Referring to FIG. 5, the integrator 220 includes a first operational amplifier OP1, a feedback capacitor Cfb, and a feedback switch SWfb. The first input terminal of the operational amplifier OP1 is coupled to the first selection terminal of the input selector 211 of all the channels 410-1~410-n, and the second input terminal of the operational amplifier OP1 receives the reference voltage _Vref . In this embodiment, the first input of the operational amplifier OP1 is an inverting input, and the second input of the operational amplifier OP1 is a non-inverting input. The first end and the second end of the feedback capacitor Cfb are respectively coupled to the first input end and the output end of the operational amplifier OP1. The first end and the second end of the feedback switch SWfb are also coupled to the first input end and the output end of the operational amplifier OP1, respectively. The feedback switch SWfb is controlled by a signal ResetB, wherein the signal ResetB is an inverted signal of the reset signal Reset.

Please refer to FIG. 3 and FIG. 5 simultaneously. When the system is in the initial state of the power supply, or during the reset period, the system will set the reset signal Reset to a logic low level (ie, the signal ResetB is set to a logic high level). ), the feedback switch SWfb is turned on to reset the feedback capacitor Cfb. In addition, since the control signals S1 SSn are all logic low levels, the input selectors 211 of all the channels 410-1~410-n select to electrically connect the sensing lines of the touch panel 110 to the unity gain amplifier 212.

When entering the first channel period T1, the system sets the reset signal Reset to a logic high level (ie, the signal ResetB is set to a logic low level) to turn off the feedback switch SWfb, so that the integrator 220 can perform an integration operation. During this period, the control signal S1 will transition to a logic high level in response to the reset signal Reset, while the other control signals S2~Sn remain at a logic low level. Therefore, during the first channel period T1, the inverting input terminal of the operational amplifier OP1 is electrically connected to the sensing line corresponding to the first channel 410-1 of the touch panel 110, and the output of the operational amplifier OP1 is stored in the first A sampling capacitor 414 of a channel 410-1. The unity gain amplifiers 212 of the remaining channels (eg, channels 410-n) are electrically coupled to other sense lines of the touch panel 110.

When the current channel period (for example, the first channel period T1) ends but has not yet entered the next channel period (for example, the second channel period T2) (equivalent to the reset period), the system sets the reset signal Reset to a logic low level. As shown in FIG. 3, at this time, the control signal S1 will transition to a logic low level. During this period, the input selectors 211 of all the channels 410-1~410-n select to electrically connect the common terminal to the second selection terminal, so that the unity gain amplifier 212 is coupled to the sensing line of the touch panel 110. In the integrator 220, the signal ResetB controls the feedback switch SWfb to be turned on to reset the feedback capacitor Cfb. By analogy, when entering the nth channel period Tn, the nth channel 410-n can use the integrator 220 and store the output of the integrator 220 in the sampling capacitor 414 of the channel 410-n. The detailed operation of the second channel period T2, the third channel period T3, ..., the nth channel period Tn can be referred to the related description of the first channel period T1, and therefore will not be described again.

6 is a circuit diagram illustrating a multi-channel integrator in accordance with another embodiment of the present invention. This embodiment is similar to FIG. 5, so the same portions will not be described again. The difference between FIG. 6 and FIG. 5 is that the unity gain amplifier 212 is omitted in each channel. Referring to FIG. 6, the multi-channel integrator 600 includes an integrator 220 and a plurality of channels 610-1~610-n. Only the first channel 610-1 and the nth channel 610-n are depicted in the figure, and other channels can be analogized with reference to the description of the first channel 610-1. In this embodiment, the implementations of the channels 610-1~610-n are the same. Channel 610-1 will be taken as an illustrative example below. Channel 610-1 includes an input selector 211, a sampling switch 413, and a sampling capacitor 414. In other embodiments, sampling switch 413 and sampling capacitor 414 may be omitted (similar to that shown in FIG. 2).

Referring to FIG. 6 , the first selection end of the input selector 211 is coupled to the input end of the integrator 220 , and the second selection end of the input selector 211 receives the reference voltage V _ref . According to the control of the control signal S1, the input selector 211 of the channel 610-1 selectively connects the common terminal to the first selection terminal, or selectively connects the common terminal to the second selection terminal. Therefore, when the control signal S1 is at a logic high level, the input selector 211 of the channel 610-1 selects to electrically connect the sensing line of the touch panel 110 to the input of the integrator 220. Then, when the control signal SS1 is at a logic high level, the sampling switch 413 of the channel 610-1 transmits the output of the integrator 220 to the sampling capacitor 414. When the control signal S1 is at a logic low level, the input selector 211 of the channel 610-1 selects to electrically connect the sensing line of the touch panel 110 to the reference voltage V _ref . Then, the control signal SS1 is at a logic low level, and the sampling switch 413 of the channel 610-1 is turned off.

FIG. 7 is a circuit diagram showing the input selector 211 of FIG. 6 according to another embodiment of the present invention. In this embodiment, the input selectors 211 of the channels 610-1~610-n can be implemented in the same manner. Referring to FIG. 7, the input selector 211 of the channel 610-1 includes a first reverse gate 710, a second reverse gate 720, a first AND gate 730, a second AND gate 740, a first switch 750, a second switch 760, and a Three switches 770. The first ends of the switches 750-770 are coupled to the corresponding sensing lines in the touch panel 110. The second end of the third switch 770 is coupled to the integrator 220. The reference voltage V _ref includes a high voltage V _ref+ and a low voltage V _ref− . The second end of the second switch 760 is coupled to the high voltage V _ref+ , wherein the high voltage V _ref+ is set to a logic high level of the reference voltage V _ref (ie, VDDA/2). The second end of the first switch 750 is coupled to the low voltage V _ref− , wherein the low voltage V _ref− is set to a logic low level (ie, 0V) of the reference voltage V _ref . Switches 750-770 are controlled by reverse gate 710, and gate 730 and gate 740, respectively.

The input of the first reverse gate 710 receives the reset signal Reset. The output end of the first reverse gate 710 is coupled to the control end of the first switch 750. The first input of the AND gate 730 and the AND gate 740 receives the reset signal Reset. The output of the second reverse gate 720 is coupled to the second input of the first AND gate 730. The output end of the first AND gate 730 is coupled to the control end of the second switch 760. The output end of the second AND gate 740 is coupled to the control end of the third switch 770. In channel 610-1, the input of the second reverse gate 720 and the second input of the second AND gate 740 receive the control signal S1. Similarly, the input of the second reverse gate 720 and the second input of the second AND gate 740 in the channel 610-n receive the control signal Sn.

Referring to FIG. 3 and FIG. 7, when the system sets the reset signal Reset to a logic low level, the first switch 750 is turned on and the switches 760 and 770 are turned off. When the system sets the reset signal Reset to a logic high level and the control signal S1 is set to a logic high level, the third switch 770 is turned on and the switches 750 and 760 are turned off. When the system sets the reset signal Reset to a logic high level and the control signal S1 is set to a logic low level, the second switch 760 is turned on and the switches 750 and 770 are turned off.

In summary, the above embodiment shares a set of integrators 220 by alternately between a plurality of channels. If the channel number n of the multi-channel integrator is larger, the effect of saving the wafer area is more remarkable, so that the wafer area can be greatly saved, thereby saving costs.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art can make some modifications and refinements without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

110. . . Touch panel

120, 220. . . Integrator

Cfb. . . Feedback capacitor

122, OP1, OP2. . . Operational Amplifier

123. . . switch

200, 400, 600. . . Multichannel integrator

210-1, 210-n, 410-1, 410-n, 610-1, 610-n. . . aisle

211. . . Input selector

212. . . Unity gain amplifier

413. . . Sampling switch

414. . . Sampling capacitor

Cf. . . Extra capacitor

Cp. . . Coupling capacitor

Reset. . . Reset signal

S1~Sn. . . control signal

SWfb. . . Feedback switch

T1~Tn. . . Channel period

V _ref . . . Reference voltage

FIG. 1 illustrates a schematic diagram of a capacitive touch panel and a conventional read circuit.

2 is a circuit diagram illustrating a multi-channel integrator in accordance with an embodiment of the present invention.

FIG. 3 is a timing diagram showing the control of each control signal in FIG. 2 according to an embodiment of the present invention.

4 is a circuit diagram illustrating another multi-channel integrator in accordance with an embodiment of the present invention.

FIG. 5 is a circuit diagram showing the multi-channel integrator of FIG. 4 according to an embodiment of the invention.

6 is a circuit diagram illustrating a multi-channel integrator in accordance with another embodiment of the present invention.

FIG. 7 is a circuit diagram showing the input selector of FIG. 6 according to another embodiment of the present invention.

110. . . Touch panel

211. . . Input selector

212. . . Unity gain amplifier

220. . . Integrator

400. . . Multichannel integrator

410-1, 410-n. . . aisle

413. . . Sampling switch

414. . . Sampling capacitor

Cp. . . Coupling capacitor

S1~Sn. . . control signal

Claims (23)

A multi-channel integrator comprising: an integrator; and a plurality of channels including at least a first channel and a second channel, wherein the first channel comprises a first input selector and a first unity gain amplifier; The second channel includes a second input selector and a second unity gain amplifier; the first input selector has a common terminal, a first selection terminal and a second selection terminal for selectively electrically connecting the common terminal The first input selector is coupled to a first sensing line of the touch panel; the input end of the first unity gain amplifier is coupled to the first terminal or the second terminal; a second selection end of the first input selector; the second input selector has a common end, a first selection end and a second selection end for selectively connecting the common end to the first a common terminal of the second input selector is coupled to a second sensing line of the touch panel; an input end of the second unity gain amplifier is coupled to the second input selector Second choice End; and the first input selector to select a first end and a second end of the first selection input selector coupled to the common input of the integrator. The multi-channel integrator of claim 1, wherein the integrator comprises: a first operational amplifier, wherein a first input end of the first operational amplifier serves as an input of the integrator, the first The second input of the operational amplifier receives a reference voltage, and the output of the first operational amplifier serves as an output of the integrator; a feedback capacitor, the first end and the second end are respectively coupled to the first input end and the output end of the first operational amplifier; and a feedback switch, the first end and the second end are respectively coupled to the A first input and an output of the first operational amplifier. The multi-channel integrator of claim 2, wherein the feedback switch is turned on during a power-on initial period, and the input selectors of the channels selectively connect the common terminal to the Second choice. The multi-channel integrator of claim 2, wherein the feedback switch is turned on during a reset period, and the input selectors of the channels selectively connect the common terminal to the first Two selection ends. The multi-channel integrator of claim 2, wherein the feedback switch is turned off during one of the plurality of channel periods, and the input selector of a corresponding one of the channels selects The common terminal is electrically connected to its first selection terminal, and the input selectors of the remaining channels of the channels selectively connect their common terminals to their second selection terminals. The multi-channel integrator of claim 1, wherein the feedback switch is turned on when a current channel period ends but has not yet entered the next channel, and the input selectors of the channels select the common The terminal is electrically connected to the second selection end. The multi-channel integrator of claim 2, wherein the first input of the first operational amplifier is an inverting input, and the second input of the first operational amplifier is a non-inverting input. The multi-channel integrator of claim 1, wherein the first unity gain amplifier comprises a second operational amplifier, wherein the The first input end of the second operational amplifier is coupled to the second selection end of the first input selector, the second input end of the second operational amplifier receives a reference voltage, and the output end of the second operational amplifier is coupled to a first input of the second operational amplifier. The multi-channel integrator of claim 8, wherein the first input of the second operational amplifier is an inverting input, and the second input of the second operational amplifier is a non-inverting input. The multi-channel integrator of claim 1, wherein each of the channels further comprises: a sampling switch having a first end coupled to the output of the integrator; and a sampling capacitor having a first end coupled Connected to the second end of the sampling switch, and the second end of the sampling capacitor receives a second reference voltage. The multi-channel integrator of claim 10, wherein, during one of the plurality of channel periods, the sampling switches of a corresponding one of the channels are turned on, and the remaining channels of the channels are The sampling switch is cut off. The multi-channel integrator of claim 1, wherein the common ends of the input selectors of the channels are respectively coupled to corresponding sensing lines in a touch panel. A multi-channel integrator includes: an integrator; and a plurality of channels including at least a first channel and a second channel, wherein the first channel includes a first input selector; the second channel includes a first a first input selector, the first input selector selectively coupling the input end of the integrator or a reference voltage to a first sensing line of a touch panel through a common end of the first input selector; The second input selector selectively couples the input end of the integrator or the reference voltage through a common end of the second input selector to a second sensing line of the touch panel. The multi-channel integrator of claim 13, wherein the integrator comprises: a first operational amplifier, wherein a first input end of the first operational amplifier is an input of the integrator, the first The second input end of the operational amplifier receives the reference voltage, and the output end of the first operational amplifier serves as an output end of the integrator; and a feedback capacitor, the first end and the second end are respectively coupled to the first end a first input end and an output end of the operational amplifier; and a feedback switch, wherein the first end and the second end are respectively coupled to the first input end and the output end of the first operational amplifier. The multi-channel integrator of claim 14, wherein the feedback switch is turned on during a power-on initial period, and the input selectors of the channels selectively connect the common terminal to the Reference voltage. The multi-channel integrator of claim 14, wherein the feedback switch is conductive when a reset period is selected, and the input selectors of the channels selectively connect the common terminal to the reference Voltage. The multi-channel integrator of claim 14, wherein the feedback switch is turned off during one of the plurality of channel periods, and the input selector of a corresponding one of the channels selects Common end Electrically connected to the input of the integrator, and the input selectors of the remaining channels of the channels selectively connect their common terminals to the reference voltage. The multi-channel integrator of claim 14, wherein the feedback switch is turned on when a current channel period ends but has not yet entered the next channel, and the input selectors of the channels select the common The terminal is electrically connected to the reference voltage. The multi-channel integrator of claim 14, wherein the first input of the first operational amplifier is an inverting input, and the second input of the first operational amplifier is a non-inverting input. The multi-channel integrator of claim 13, wherein each of the channels further comprises: a sampling switch having a first end coupled to the output of the integrator; and a sampling capacitor coupled to the first end Connected to the second end of the sampling switch, and the second end of the sampling capacitor receives a second reference voltage. The multi-channel integrator of claim 20, wherein when one of the plurality of channel periods is in a period of time, a sampling switch of a corresponding one of the channels is turned on, and the remaining channels of the channels are The sampling switch is cut off. The multi-channel integrator of claim 13, wherein the reference voltage comprises a high voltage and a low voltage, and each of the channel input selectors comprises: a first switch having a control end, a first end and a second end, the first end of the first switch being a common end of the input selector, and the second end of the first switch being coupled to the a second switch having a control end, a first end and a second end, the first end of the second switch being coupled to the first end of the first switch, and the second switch The second end is coupled to the high voltage; the third switch has a control end, a first end and a second end, and the first end of the third switch is coupled to the first end of the first switch, and The second end of the third switch is coupled to the integrator; a first reverse gate, the input end of which receives a reset signal, and the output end of the first reverse gate is coupled to the control end of the first switch; a second reverse gate, the input end receives a control signal; a first AND gate, the first input terminal receives the reset signal, and the second input end of the first AND gate is coupled to the second reverse gate An output end, wherein the output end of the first AND gate is coupled to the control end of the second switch; and a second AND gate, the first input end receives the weight Signal, a second input terminal of the second AND gate receives the control signal, and the output of the second AND gate is coupled to the control terminal of the third switch. The multi-channel integrator of claim 13, wherein the common ends of the input selectors of the channels are respectively coupled to corresponding sensing lines in a touch panel.