TW201203058A - Capacitive touching apparatus - Google Patents

Abstract

A capacitive touching apparatus is disclosed. The capacitive touching apparatus includes at least one equivalent capacitive module, a first comparator, a first reference current generator, a first detecting capacitive module and selecting switch module. The equivalent capacitive module receives a periodical driving signal and generates output voltage according to the driving signal. The first comparator generates a first compare result according to the output voltage and a first reference voltage. The first reference current generator generates a first and second reference current according to a basic current. The first reference current generator decides to output the first and second reference current separately or not according to the first compare result. The first reference current is output to the equivalent capacitive module. The first detecting capacitive module generates a first detecting output signal according to the second reference current.

Description

201203058

A-*-k>73 twf.doc/I VI. Description of the Invention: [Technical Field] The present invention relates to a capacitive touch device, and more particularly to a capacitance change detection of a capacitive touch device Measuring circuit. [Prior Art] With the popularization of electronic technology, providing an electronic device that is highly interactive with users has become an important function of today's electronic products. The most effective technology that directly provides human-computer interaction is the first touch panel technology. Touch devices can be broadly classified into several categories, including, for example, resistive touch devices, capacitive touch devices, and projection touch devices. For a capacitive touch device as an example, please refer to the circuit diagram of the conventional capacitive touch device 100 illustrated in FIG. 1 . The conventional capacitive touch device 10 includes an integrator 110 for connecting and detecting changes in capacitance values of a plurality of touch capacitors 120-140. When the detection of the change in the capacitance value is performed on one of the touch capacitors 120 to 140, it is necessary to provide a periodic oscillation signal IN to one of the touch capacitors 120 to 140, and the integrator 110 is provided by the integrator 110. The voltage change of the detected touch capacitor under the plurality of periodic oscillating signals IN is obtained to obtain a change in the capacitance value of the detected touch capacitor. SUMMARY OF THE INVENTION The present invention provides two types of capacitive touch devices, which effectively detect capacitance changes of an equivalent capacitance module on a touch device. The invention provides a capacitive touch device comprising at least one equivalent

201203058 i w 34673twf.doc/I The capacitor module, the first comparator, the first reference current generator and the first detecting capacitor module. The equivalent capacitance mode _ first end receives the periodic driving signal, and generates an output dust at the second end of the equivalent capacitance module according to the driving signal. The first comparator is connected to the equivalent capacitor module to receive the output voltage and based on the comparison output and the first reference voltage to generate a first comparison result. The first reference current generates an II-equivalent equivalent capacitance module and a 帛-bijian, according to the reference = to generate the first and second reference currents, and the first-reference current generator and according to the first-comparison of the silkworms respectively output the _, Two reference currents. The first reference current is output to the second end of the equivalent capacitor module. The first detection, electrical reference current generation 11 is connected to (four) two reference electric power, ", and according to the first detection output signal. Electricity - a capacitive touch device comprising at least a touch-capacitor, a selection switch module, a comparator, a current 'selection switch module _ control capacitor == charge; =_ to ground to discharge or make Electricity = group === comparison, comparison of the first capacitor and the selection switch mode test voltage, and the result of the charge distribution of the control capacitor 4 mesh and the participation and hunting to produce a comparison result. Lost 4 冗 device redundancy; =, according to the base; current to generate: signal to determine whether to divide; output; twin, test current output to the first capacitor. _ electricity; mode _: reference = 5

K>73twf.doc/I 201203058 The generator receives the second reference current and generates a detection output number accordingly. Based on the above, the capacitive touch device proposed by the present invention needs to use the integrator circuit to perform capacitance change _ 'but the profit (4) when the measurement number is falling, the color change generated by the equivalent capacitance module is used as the capacitance type The basis for the amount of capacitance change of the touch device. In addition, the present invention also provides a side mode of self-capacitance capacitance variation, which is an effect of an offset voltage. The above described features and advantages of the present invention will become more apparent from the description of the appended claims. [Embodiment] Hereinafter, referring to FIG. 2, FIG. 2 is a schematic diagram of a capacitive touch device 200 according to an embodiment of the present invention. The capacitive touch device 2 includes at least one equivalent valley module 210, a comparator 220, a reference current generator 230, a detection capacitor module 240, a selection switch module 250, and an analog digital converter 270. The first end of the equivalent capacitor module 21A receives the periodic driving signal DRV, and generates an output voltage VI at the first end of the equivalent capacitor module 21A according to the driving signal DRV. The equivalent capacitance module 210 includes a mutual inductance capacitor CM, a touch capacitor CF, and a parasitic capacitance CP. The mutual inductance capacitor CM is connected in series. At the first and second ends of the equivalent capacitance module 210, the touch capacitor CF is connected in parallel with the mutual inductance capacitor CM, and is used to provide a negative capacitance value when a touch event occurs. The parasitic capacitance CP is connected in series between the second end of the equivalent capacitance module 210 and the ground voltage GND. The comparator 220 is coupled to the equivalent capacitor module 210 and passes through the selection switch 201203058

The 393TW 34673twf.doc/I module 250 receives the output voltage VI and generates a comparison result CMPR based on the comparison output voltage V1 and the reference voltage Vref1. The reference current generator 230 is connected to the comparator 220 and coupled to the equivalent capacitor module 210 and the detecting capacitor module 24 through the selection switch module 250. The reference current generator 230 generates a reference current η and an n reference current generator 230 according to the reference current and receives the comparison result CMPR ' generated by the comparator 220 according to the comparison result CMPR to determine whether to output the reference currents 11 and 12, respectively. The reference current II is output to the second end of the equivalent capacitor module 21A, and the reference current 12 is output to the detecting capacitor module 24A. The capacitance module 240 is detected and generates a detection output signal DR according to the reference current π. The analog-to-digital converter 270 receives the detected output signal Dr and converts the analog output detected signal DR into a digital formatted detected output signal DR. The selection switch module 250 includes two selection switches SW1 and SW2 for directly connecting the second end of the equivalent capacitance module 21A to the comparator 220 or directly receiving the reference voltage Vref1 according to the driving signal DRV. For the overall operation of the capacitive touch device 200, please refer to FIGS. 2 and 2A at the same time. FIG. 2A shows the action waveform of the capacitive touch device 2〇〇. When the capacitance change of the equivalent capacitance module 21 is to be detected, first, the OFF SW2 is turned on and the OFF SW1 is turned off to cause the parasitic capacitance CP to be charged by the reference voltage Vref1. At the same time, detecting the capacitive mode, the reset switch s W3 in 240 is turned on to cause the detecting capacitor CD to be discharged. Then, before the drive signal DRV is about to fall from the high level to the low level Fedgel, the switch SW1 is turned on and the SW2 is turned off.

201203058 -------^73twf.doc/I (At this time, the reset switch SW3 is turned off), and the output voltage VI is lowered, so that the output voltage VI is smaller than the reference voltage Vref1. In this way, the comparator 220 will generate the comparison result cjyjpR and transmit the reference current generated by the reference U generation H ' to the second end of the equivalent capacitance module 21G through the conduction selection switch SW1 through the comparison result. And the reference money generated by the ship is 12 to the side residual module 24 也就是说. That is, when the output voltage V1 is decreased and the output voltage V1 is less than the test voltage Vref1, the reference currents n, 12 will flow to the parasitic respectively. The electric valley CP and the detection capacitor cd cause the output voltage to rise back to be equal to the reference voltage Vrefl. Since the reference currents II, 12 are generated by mirroring the same base current, the reference currents 12, 12 have a specific The ratio (for example, 1:1). Therefore, in the equivalent capacitance module 210, the output voltage νι is raised back to the reference voltage Vref1, and the amount of charge is coupled to the detection capacitor CD at this specific ratio. The voltage on the CD can be determined by the ratio of the mutual capacitance αν [and the capacitance of the touch capacitor CF and the ratio of the capacitance of the detection capacitor to the capacitance of the CD. If you want to detect the light and high voltage value on the CD The measured output signal DR can be obtained by repeatedly switching the drive number DRV, the selection switches SW1 and SW2, or by adjusting the ratio of the reference current 12 to the reference current II. = ° A > 2B, FIG. 2B is a schematic diagram of another embodiment of the capacitive touch panel 200 of the present invention. In the pictorial diagram of FIG. 2B, the reference current generator 230 in the two-t capacitive touch device 200 includes: electricity: electricity P1 ~P3 formed current mirror and current source IA. Current source identification

201203058 JVJ l w 34673twf.doc/I base current ' and the current mirror formed by transistors PI~P3 mirrors the base current to generate reference currents II and π, respectively. Here, the ratio values of the reference currents n and 12 can be obtained by adjusting the aspect ratio of the transistors P1 and P2. Among them, the transistors P1 P P3 receive the power supply voltage VDD as the power source. The 'transistors P4 and P5 are current control switches for determining whether or not the reference currents II, 12 are turned on or off. The gates of the transistors P4 and P5 collectively receive the comparison result CMPR and are turned on or off at the same time. The eight comparator 250 is constructed by an operational amplifier having a first input terminal, a second input terminal, and an output terminal. The output terminal produces a comparison result CMPR, and the first and second input terminals respectively receive the reference current u and Reference voltage Vrefl. The reference voltage vref1 can be generated by a reference voltage generator (not shown) and provided to the second input of the comparator 250. The reference voltage Vref1 can also be provided directly to the equivalent capacitance module 210 or through the single gain buffer 290 to the equivalent capacitance module 21A. Referring to FIG. 3, FIG. 3 is a schematic diagram of a capacitive touch device 300 according to another embodiment of the present invention. The capacitive touch device 3 includes a touch capacitor Cdut, a charging current source IP, a capacitor c selection switch module 31, a comparator 350, a reference current generator 33A, and a detection capacitor module 32A. The charging current source ip is used to supply the charging current, and is selected according to the selection switch module 31. The signal SEL causes the capacitor C1 to be charged according to the charging current, so that the touch power Cdut_j_ grounding electricity (10) is discharged to make the capacitor 〇 Subtracting from the touch capacitor Cdut for charge distribution. The comparator 35 is connected to the capacitor C1 and the selection switch module 310. Comparator 350 is based on capacitor C1 and 201203058

~·ή, d673twf.doc/I The result of charge distribution by the touch capacitor Cdut is compared with the reference voltage Vref and the comparison result CMPR is generated. The reference current generator 330 is coupled to the comparator 350 and the capacitor C1, generates a reference current nj according to the reference m, and determines whether to output the reference currents η, 12 according to the comparison result CMPR and the control signal CTRL. The reference current u is output to the capacitor C1, and the reference current π is output to the detecting capacitor module 32 (the N detecting capacitor module 32 receives the reference current 12 correspondingly to generate the detected output signal v〇. The selecting switch module 310 includes selection The switches SW1 SWSW3 and the selection switch swi are connected in series between the touch keyboard Cdut and the ground voltage GND. One end of the selection switch SW2 is coupled to the contact control capacitor Cdut and the selection switch SW1, and the other end thereof is coupled to the capacitor C1. The reference current generator 330 The method includes a current source IA for generating a reference current, a current mirror composed of transistors _ρι to p3, a current control switch module composed of transistors p4 and p5, and a current control switch module composed of switches SW4 and SW5. The current mirror formed by the transistors P1 to P3 generates a reference current II, 12 according to the mirror reference current, a current control switch module composed of the transistors P4 and P5, and a current control formed by the switches SW4 and SW5. The switch module is coupled between the current mirror and the capacitor C1 and the detecting capacitor module 320, and turns on or off the flow paths of the reference currents II and 12 according to the comparison result CMPR and the control signal CTRL, respectively. The capacitor module 320 includes a detection capacitor CD and a reset switch SW6. The debt measurement capacitor CD is coupled to the reference current generator 33A to receive the reference current 12. The reset switch SW6 is connected with the detection capacitor CD for use in detecting 201203058

i w 34673twf.doc/I Measure the initial signal to conduct and provide a detection of the electrical gCD discharge path. In the overall operation of the electric valley type touch device 300, when the capacitive touch control device 300 does not have a touch event, the reference voltage is first set to be equal to the power supply voltage VDD received by the electric valley type touch device 3. Next, the selection switch SW SW and the reset switch SW6 are turned on and the selection switch SW2 and the switches SW4 and SW5 are turned off. At this time, the charge in the debt measurement capacitor CD will be discharged, the capacitor C1 is being charged according to the charging current source, and • After detecting that the charge in the CD is cleared, the reset switch SW6 is turned off. In succession, the switching of the switching switches SW1 and SW2 ’ is repeated according to a specific frequency, and the charging current supplied by the charging current source 1 is balanced with the leakage current of the touch capacitor Cdut. Then, the selection switches SW2 and SW3 are turned off and the switches SW4 and SW5 are turned on, and at the same time, the voltage level of the detection output signal is detected. If the detected voltage level of the detected output signal v 此时 is not 〇 volts, then the reference voltage Vref is lowered accordingly so that the power level of the detected output signal v 等于 is equal to 0 volts. _ I. After the above-mentioned action of making the voltage level of the detection output signal v〇 equal to 〇 volt, the capacitive touch device has completed the preliminary correction operation, that is, the next capacitive touch The device 3 can begin to accept the user's touch event and effectively detect the user's touch event occurrence state. When the capacitive touch device 300 performs the touch event occurrence state, the voltage value of the preset reference voltage Vref is maintained, and the selection switch SW3 is turned on, the switches SW4 and SW5 are turned off, and the reset switch is turned on.

201203058 a ▼▼ ^4673tw£doc/I In addition to detecting the charge in the capacitance CD. After the charge in the detection capacitor CD is cleared, the reset switch SW6 is turned off. Then, the selection switches SW1 and SW2 are turned on or off according to the specific frequency described above, and the charging current supplied from the charging current source IP and the leakage current of the touch capacitor Cdut can be balanced. Then, the selection switches SW2 and SW3 are turned off and the switches S4 and S5 are turned on so that the reference currents η and 12 can flow to the capacitor C1 and the detection capacitor cd according to the comparison result CMpR. At this point, note that since the capacitance of the touch capacitor Cdut changes after the touch event occurs, the voltage at the end of the capacitor ci coupled to the comparator 350 when the touch event is detected will be different. The reference voltage core # causes the comparator 350 to generate a comparison result CMPR to control the current formed by the energized crystals p4, p5 to control the switch module, thereby causing the capacitor C1 and the sensed CD to be charged according to the reference currents n, 12. In the power generation, after the CD is charged according to the reference current 12, the detection capacitor (:1) generates a detection round-out signal Vo. And through this is not the volts of the test output V. It is possible to know the state of occurrence of the contact of the capacitive device 3 (8).

. Stone sentence ^ can increase the detection output signal Vo voltage Cui re-switch SW4, SW5 it turn on the selection switch · and re-execute "based on the frequency to turn on or off the selection switch S Cd w,, and charge Current source 1P _ charge f flow and touch 1 sw: J current can be balanced. Then the selection switch SW is turned off. The result is (10)^OFF^% so that the reference currents 11, 12 can flow to the capacitor C1 according to only R / knives and Detection of capacitance CD" step collapse 201203058

Jyjiw 34673twf.doc/I improves the voltage value of the detection output signal Vo, which is beneficial to the detection action of the capacitive touch device 300 touch event. Referring to FIG. 4, FIG. 4 is a schematic diagram of a capacitive touch device 400 according to another embodiment of the present invention. The capacitive touch device 3 includes an equivalent valley module 410, comparators 451, 452, reference current generators 431, 432, debt capacitance modules 441, 442, equalization switch modules 42 and levels. Detector 480. Φ Regarding the operation of the capacitive touch device 4A, when the driving voltage DRV is at the high level, the switches SW5, SW6, SW7, and SW8 are turned off and the switches SW3, SW4, SW9, and SW10 are turned on. At this time, the detecting valley modules 441 and 442 are charged by the reference voltage Vref2, and when the capacitor modules 441 and 442 to be detected are charged to a voltage equal to the reference voltage Vref2, the switches SW9 and SW10 are turned off. Then, first open the switches SW3, SW4 and turn on the switches SW6, SW7' and then alternately open and turn on the switches SW3, SW4 and sw6, sw7 to make the output voltage according to the reference current η - 丨, ^ charging or reference current 13 -1 and The discharge of 13 falls within the range of the operating bias (equal to the reference voltage Vrefl) 'and the switches SW6, SW7 are stopped in the open state, the switches SW3, SW4 are stopped in the on state, and then the switch SW3 is turned off and Turn on the switch SW5. After the above operation is completed, the driving voltage DRV is waited for the high-level transition to the low level. At the same time, the comparator 451 starts to operate and generates a comparison result CMPR1 to cause the reference current II to flow to the equivalent capacitance module 41. The reference current 12 flows to the detection capacitor module 442 and pulls up the voltage level on the detection capacitor module 442. 13

201203058 v " ▲,," 673twf.doc/I After the comparator 451 completes the above operation, the switches _, SW5 are turned off and the switches SW6 and SW8 are turned on to lower the output voltage to be equal to the voltage Vrefi. When the output voltage drops to be equal to the reference voltage, the switch SW6 is turned off and the switch SW8 is turned on, and the driving voltage drv is switched from the low level to the high level. After the driving voltage DRV is from the low level = to the high level, the comparator 452 will start to generate a comparison 砝; CMPR2 causes the reference currents 13 and 14 to flow out from the equivalent capacitance 41 〇 The voltage of the detecting capacitor 441 is lowered. After the driving voltage DRV completes and the side transition state, the level detector 480 can determine the touch state of the capacitive touch device 400 according to the difference between the voltage levels between the detecting capacitors 441 and 442. . Of course, if the interpretation operation of the level detector 480 is more accurate, the difference between the voltage levels of the detection capacitors 441 and 442 can be determined after repeating the transition state of the driving voltage DRV for a plurality of cycles. The voltage of the detecting capacitor (10) 442 is also charged more times; there is a larger voltage difference and it is easier to be interpreted. Incidentally, the reference voltages Vref1 VVref3 in the capacitive touch device 4A of the embodiment of the present invention can be generated by dividing the power supply voltage VDD by a resistor string. In this embodiment, the reference voltage Vref1>Vref2>;Vref3. Referring to FIG. 5, FIG. 5 is a schematic diagram of a touch screen device 500 according to still another embodiment of the present invention. The capacitive touch device 5A includes an equivalent capacitance module 510, a selection switch module 520, comparators 551 and 552, a reference current generator 531, 532, a detection capacitance module CoP, CoN, and a single 14 201203058

iVilW 34673twf.doc/I Gain Buffer 580 and Equalization Switch Module 57〇. The most different difference from the capacitive touch device 400 of the previous embodiment is that the capacitive touch device 500 of the present embodiment is provided with a selection switch module 52 and for detecting the equalization of the electric valley modules CoP and CoN. The single gain buffer of the action is s8〇. The selection switch module 520 provides the reference voltage Vref2 to the equivalent capacitor module 51 through the single gain buffer 580 when the selection switch SW1 is turned on, and the reference current generator 531 when the selection switch SW2 is turned on. The reference current provided flows through the equivalent capacitance module 510. Moreover, in the aspect of providing the reference voltage Vref2 to the detecting capacitor modules c〇p, c〇N for equalization, in the embodiment, it is further provided that the reference voltage Vref2′ is provided through a single gain buffer to improve, etc. The stability of the action. The details of the operation of the capacitive touch device 5 of the present embodiment are similar to those of the capacitive touch device 400 of the previous embodiment, and will not be described herein. According to the above description, the present invention detects the change of the capacitance of the capacitive module by using the transition state of the periodic driving signal, and detects the capacitance change of the capacitive touch device. The electrical changes produced by this change in capacitance are coupled to the detection capacitor module. In this way, the touched state of the capacitive type device can be known by the electric power of the test module, and the touch capacitor of the capacitive type rf is also proposed according to the non-touch state. To set the reference, and according to this reference, the capacitance of the residual control capacitor is changed when the capacitive touch device is purchased. The present invention has been disclosed in the above embodiments, but it is not used to limit x ' Anyone with ordinary knowledge in the technical field, without departing from 15

K>73 twf.doc/I 201203058 In the spirit and scope of the present invention, when a certain change can be made, the scope of protection of the invention is considered to be the scope of the appended patent application, and this [simplified illustration] A circuit diagram of a conventional capacitive touch device 1 绘 is shown. FIG. 2 is a schematic diagram of a capacitive touch device according to an embodiment of the present invention.

FIG. 2A is a waveform diagram showing the operation of the capacitive touch device. 2B is a schematic diagram of an embodiment of a capacitive touch device according to the present invention. 3 is a schematic diagram of a capacitive touch device 3A according to another embodiment of the present invention. 4 is a schematic diagram of a capacitive touch device 4A according to another embodiment of the present invention. FIG. 5 is a schematic diagram of a capacitive touch device according to still another embodiment of the present invention.

[Main component symbol description] 100, 200, 300, 400, 500: capacitive touch devices 120 to 140: touch capacitor IN: oscillation signals 210, 410, 510: equivalent capacitance modules 220, 350, 451, 452 , 551, 552: comparators 230, 330, 431, 432, 531, 532: reference current generator 16 201203058

393TW 34673twf.doc/I 240, 320, 441, 442, CoP, CoN: detection capacitor module 250, 310, 520: selection switch module 420, 570: equalization switch module 480: level detector 290 580: Single gain buffer DRV: drive signal CP, CM, CF, cn, CD: capacitor I GND: ground voltage VI: output voltage CMPR, CMPR1, CMPR2: comparison result Vref, Vrefl ~ Vref3: reference voltage II, 12 , 11_1 , 13 , 13_1 , 14 : Reference current DR : Detection output signal SW1 ~ SW10 : Off IP , IA : Current source Fedgel : Falling edge • P1 ~ P5 : Transistor VDD : Power supply voltage SEL : Selection signal Cdut : Touch Capacitor CTRL: Control Signal Vo: Output Signal 17

Claims (1)

201203058 〆〆一在" ^-^TStwf.doc/I VII, application for patents: 1. A capacitive touch device, comprising: at least - equivalent capacitance module, the first end of which receives periodic signals' And according to the _ crane signal in the material efficiency frequency, a 蚣 赍瘀 哗 哗 〜 ~ - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Slot comparison result; Le 1-2 second-reference current generator, connected to the equivalent capacitance module and the first comparison a 'according to the reference current to generate - first and second test currents, the first reference current generates H According to the first-reading red-out, it is determined whether the first and second reference currents are the first reference current output to the second end of the equivalent capacitance module; and the first detecting capacitance module is coupled The first reference current generator is configured to receive the second reference current, and to generate a -first detection output signal. 2. The capacitive touch device according to claim 6, wherein the method further includes : ~ Select switch module 'According to the drive letter to verify the equivalent capacitor module The first end is connected to the first comparator or receives the second reference voltage. The capacitive touch device of claim 2, wherein the selection switch module comprises: a first selection switch Connected in series between the equivalent capacitor module and the first comparator; and a first selection switch connected in series between the equivalent capacitor module and the second reference voltage, 201203058 iw 34673twf.doc/I Wherein the first selection switch is complementary to the state in which the second selection switch is turned on or off. 4. The capacitive touch device of claim 2, wherein the driving edge of the driving money occurs in The selection/closing group causes the second end of the module to be connected to the first comparator, and the rising edge of the driving signal occurs in the selection switch module to make the equivalent capacitance module 5. The capacitive touch device of claim 1, wherein the first reference current generator comprises: a current source for generating the reference current; a current mirror coupled to the current source, Receiving and mirroring the reference current to generate the first and second reference currents; w a first current control switch coupled between the current mirror and the first comparator to turn on or off according to the first comparison result And a second electro-pneumatic switch, the scale between the current mirror and the first detection valley module, according to the first comparison result of Qin, the conduction is turned off. 6. The capacitance as described in claim 1 of the patent scope In the touch device, the first detecting capacitor module includes: eight picking electricity valleys 'lighting the first reference current generator to pick up the first reference current; and - repeating 'and the side The capacitance is connected in parallel, and the detection capacitor discharge path is provided when it is turned on. 8. The capacitive touch device according to the above-mentioned patent application scope, 19 201203058 7WH A ______ ^ l673twf.doc/I The first comparator is an operational amplifier having a first input terminal, a second input terminal and an output terminal, wherein the output terminal produces the comparison result, and the first and second input terminals respectively receive the first reference current And the first reference voltage. 8. The capacitive touch device of claim 1, wherein the equivalent capacitance module comprises: - a mutual inductance capacitor connected in series between the two ends of the equivalent capacitance module; The touch voltage valley is connected in parallel with the mutual inductance capacitor to provide a __ negative capacitance value; and the friend's parasitic capacitance is connected in series between the second end of the equivalent capacitance module and a ground voltage. 9. The capacitive touch device of claim 1, further comprising: a reference voltage generator coupled to the first comparator and the equivalent capacitor module to provide the first And a second reference voltage. 10. The capacitive touch device of claim 2, further comprising: a single gain buffer coupled between the first comparator and the equivalent capacitance module, the input end receiving the The first reference voltage is coupled to the equivalent capacitor module and generates the second reference voltage. 11. The capacitive touch device of claim 1, wherein the method further comprises: &amp; an analog-to-digital converter coupled to the first detection capacitor module to generate the digital format detection output signal. a 20 201203058 jyji w 34673tw£doc/I Patent _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Electric comparison result; spear - two comparison 'secret equivalent capacitance module, the third Γ-flute _, "moxibustion / test current generator, according to the reference current to produce _ raw one two, four / test current' The second reference current generator determines whether to output the third and fourth reference currents respectively according to the second comparison result, wherein the t reference current is output to the second end of the equivalent capacitance module; The group 'lights the second reference current generator to connect, the fourth> test current, and accordingly generates a second detection output signal; and the rural solid-state switching element' is respectively connected in series with the first reference current generator k for "the first, the reference current to the equivalent power supply group and the first detection f capacity module and the second reference current generator to provide the third, fourth reference test current bay equivalent electric power group And the second capacitor rib. The capacitor control device of claim 12, wherein the method further comprises: a level detector </ RTI> coupled to the first and second detecting capacitor modules, receiving and according to the first and second The difference of the output signals is detected to obtain a capacitance change of the equivalent capacitance module. 14' The capacitive touch device of claim 12, wherein the method further comprises: 21 u73twfd〇c/r 201203058 connected to the first and second _capacitor modules, i5t=14 patents The capacitive touch-mounted wheel has a == opening::: followed by reference, and the capacitive touch device described in item 2==::4 is connected to the material gain buffer (four). The origin and the fourth (4) in the Kokeng New Zealand rushing round and the second ΐ: when the conduction is turned on, the first - and the first "-- capacitive touch: set the first: the coffee tree position. At least one touch capacitance; a charging current source, providing a charging current; a first capacitor; connecting the charging capacitor and the charging current source to charge "_, the number of the first capacitor is based on the charging current into the first capacitor The touch capacitor is consumed to charge 2. The capacitor and the selection switch module compare the charge distribution according to the touch electric valley phase with a reference 22 34673 twf.doc/I 201203058 electric M. And by which a comparison result is generated; the reference current generator 'lights the comparator and the first-data-reference current to generate - the first- The second reference current, the reference current generator and the lion comparison result and - (4) letter to the mosquito is = test money, wherein the material - reference electrical readout to the first ^, and the tantalum capacitor module, _ the reference current generation ^ Receiving the &gt; test power L, and accordingly generating a detection output signal. 8. The device as claimed in claim 17, wherein the reference current generator comprises: a P裒 current source for generating the reference current; and the current source is subtracted from the reference current to generate The first and second reference currents; the current control group, _ in the current mirror and the first - and the _ capacitors are turned on, according to the comparison result is turned on or off; and the snow - the first current control switch mode The group is coupled to the current mirror and the first and the second side of the capacitor, and is turned on or off according to the control signal. The capacitive touch device of claim 17, wherein the capacitive module comprises: a detecting capacitor, the reference current generator is lightly connected to receive the second parameter current; The reset switch is connected in parallel with the detection capacitor for conducting to provide the measured capacitance discharge path. The capacitive touch device of claim 17, wherein the selection switch module comprises: a first selection switch connected in series between the touch capacitor and the ground voltage; The second selection switch has one end coupled to the touch capacitor and the first selection switch, the other end of which is coupled to the first capacitor; and a third selection switch connected in series between the first capacitor and the current source. 21. The capacitive touch device of claim 17, further comprising: an analog-to-digital converter coupled to the detection capacitor module for receiving and generating the detection output in a digital format signal. twenty four