Patent application number | Description | Published |
20090243631 | Circuit for capacitance measurement and method therefor - A measurement method for capacitance includes the following steps. First, a voltage on at least one end of a to-be-measured capacitor is switched in response to a first set of clock signals such that a level of an integrated voltage is adjusted from a start voltage level to an end voltage level in a first integration period, wherein a capacitance of the to-be-measured capacitor is relevant to a difference between the end voltage level and the start voltage level. Next, the level of the integrated voltage is adjusted from the end voltage level to the start voltage level in a second integration period in response to a second set of clock signals. Then, the capacitance of the to-be-measured capacitor is obtained according to the first and second integration periods and a known characteristic parameter. | 10-01-2009 |
20100013502 | EVALUATION CIRCUIT FOR CAPACITANCE AND METHOD THEREOF - In an evaluation method, voltages at ends of a to-be-measured capacitor and a capacitance-adjustable circuit are switched in response to a first set of clock signals so as to adjust an integrated voltage to be a sum of the integrated voltage and a first difference voltage. Next, whether a first control event is received is judged. If not, the previous step is performed. If yes, an integration operation is performed to switch a voltage of an end of a known capacitor in order to adjust the integrated voltage to be a sum of the integrated voltage and a second difference voltage. Next, whether an integrating period ends is judged. If not, the first step is repeated. If yes, a capacitance of the to-be-measured capacitor is obtained according to the number of times that the integration operation is performed in the integrating period and a capacitance of the known capacitor. | 01-21-2010 |
20100042346 | CAPACITANCE EVALUATION CIRCUIT AND ELECTRONIC DEVICE USING THE SAME - A capacitance evaluation circuit includes a capacitive voltage divider, an analog-to-digital converter (ADC) and a processing module. The capacitive voltage divider includes a switch circuit, a known capacitor and a capacitor under test. The switch circuit is controlled by first and second clock signals. A voltage variation at a first terminal of the known capacitor is coupled to a first terminal of the capacitor under test based on a conduction state of the switch circuit. The ADC converts a voltage on the first terminal of the capacitor under test into a digital signal. The processing module detects a capacitance and a capacitance variation of the capacitor under test according to the digital signal from the ADC and a parameter of the ADC. | 02-18-2010 |
20100102831 | Capacitance Measurement Circuit and Capacitance Measurement Method Thereof - A capacitance measurement circuit and a capacitance measurement method thereof. The capacitance measurement circuit for measuring a capacitor under test includes a capacitance to time unit, a continuous time integrator and an analog to digital converter. The capacitance to time unit generates a first clock signal and a second clock signal reverse to the first clock signal according to a first charge time of the capacitor under test and a second charge time of a variable capacitor. The continuous time integrator receives the first clock signal and outputs an integral signal according to the first clock signal. When the number of clocks of the second clock signal is equal to a default value, the analog to digital converter outputs a digital signal corresponding to a capacitance difference between the capacitor under test and the variable capacitor according to the integral signal. | 04-29-2010 |
20100321336 | TOUCH INPUT DEVICE AND TOUCH SENSOR CIRCUIT - The invention discloses a touch input device and a touch sensor circuit. The touch input device includes a touch panel, a selection module and a differential detection module. The touch panel includes a plurality of capacitive nodes thereon. The selection module is electrically connected with the capacitive nodes of the touch panel. The selection module selects a first capacitive node and a second capacitive node from the capacitive nodes. The second capacitive node is close to the first capacitive node. The differential detection module, electrically connected to the selection module, is used for detecting a capacitance difference between the first capacitive node and the second capacitive node. According to the capacitance difference, the differential detection module generates a touch detection signal. | 12-23-2010 |
20110063249 | TOUCH SENSING APPARATUS AND TOUCH SENSING METHOD - A touch sensing apparatus applied to a capacitance touch panel includes a sensing module, a signal generating module, a comparing module, and a processing module. When a first and a second touch point formed on the capacitance touch panel correspond to two first and second touch pad sets, the sensing module generates a request signal. The signal generating module respectively outputs two test signals with reverse phases to the two first touch pad sets according to the request signal. After the comparing module generates a compared result according to two voltage values corresponding to the two second touch pad sets, the processing module will determine the positions of the first and the second touch point according to the compared result. When touch points are more than two, the touch sensing apparatus repeats the above-mentioned steps until all positions of the touch points are defined and the ghost points are removed. | 03-17-2011 |
20110074446 | Capacitance Measurement Circuit and Method Therefor - A capacitance measurement circuit includes an operation amplifier; a reference capacitor having a first terminal coupled to a first input terminal of the operation amplifier and a second terminal selectively coupled to a first or second reference voltage; a sensor capacitor having a first terminal coupled to a second input terminal of the operation amplifier and a second terminal selectively coupled to the first or second reference voltage; an approximation unit having an output terminal and an input terminal coupled to an output terminal of the operation amplifier; a conversion unit having an output terminal and an input terminal coupled to the output terminal of the approximation unit; and a coupling capacitor having a first terminal coupled to the first or second input terminal of the operation amplifier and a second terminal coupled to the output terminal of the conversion unit. | 03-31-2011 |
20110115503 | Capacitance Measurement Circuit and Method Therefor - A capacitance measurement circuit includes: a reference capacitor selectively coupled to a first reference voltage or a second reference voltage; a sensor capacitor selectively coupled to the first reference voltage or the second reference voltage; an operation amplifier coupled to the reference capacitor, the sensor capacitor and a third reference voltage; an approximation unit coupled to the operation amplifier; and a conversion unit coupled to the operation amplifier and the approximation unit. The reference capacitor and the sensor capacitor respectively couple a first charge amount and a second charge amount to a first input terminal of the operational amplifier to conduct an input voltage. The conversion unit couples a third charge amount to the first input terminal of the operation amplifier or charges/discharges the first input terminal of the operation amplifier until the input voltage approximates the third reference voltage. | 05-19-2011 |
20110210938 | Capacitance Offset Compensation for Electronic Device - An electronic device includes: a touch input device, a touch sensing circuit coupled to the touch input device and a capacitance offset compensation circuit. The capacitance offset compensation circuit includes: a first offset compensation capacitance array, coupled to a reference voltage or a driving signal in response to a control signal from the touch sensing circuit, coupled to one of a first coupling voltage and a second coupling voltage from the touch input device in response to the control signal. The first offset compensation capacitance array adjusts an output equivalent capacitance in response to the control signal, for compensating at least one of a GND parasitic capacitance and a cross coupling capacitance of the touch input device. | 09-01-2011 |
20110242049 | Touch Input Electronic Device - An touch input electronic device includes: a touch input device; a clock generation circuit, generating a first clock and a second clock; a touch sensing circuit, coupled to the touch input device, the touch sensing circuit operated under the first clock; a logic circuit, receiving a sensing output signal from the touch sensing circuit, the logic circuit operated under the second clock; and a conversion circuit, outputting an output voltage under control of the logic circuit, the output voltage coupled to the touch sensing circuit, the conversion circuit operated under the second clock. In response to the sensing output signal from the touch sensing circuit, the logic circuit controls the conversion circuit to adjust the output voltage to detect a capacitance variance of the touch input device. | 10-06-2011 |
20120038573 | Touch Input Device and Scanning Method Thereof - A touch panel includes a plurality of X-directional sensing lines and a plurality of Y-directional sensing lines. The X-directional sensing lines and the Y-directional sensing lines are arranged in a staggered manner, and a plurality of mutual capacitors are formed between every X-directional sensing line and every Y-directional sensing line. According to one embodiment of the present invention, the scanning method first selects the number of sensing lines to be measured to determine a measurement channel. Driving signals are applied to other sensing lines excluding the measurement channel in scanning procedures. After the driving signals are applied, two voltages at nodes of the measurement channel are detected to obtain a touch position on the touch panel. | 02-16-2012 |
20120068724 | CAPACITANCE EVALUATION CIRCUIT AND ELECTRONIC DEVICE USING THE SAME - A capacitance evaluation circuit includes a capacitive voltage divider, an analog-to-digital converter (ADC) and a processing module. The capacitive voltage divider includes a switch circuit, a known capacitor and a capacitor under test. The switch circuit is controlled by first and second clock signals. A voltage variation at a first terminal of the known capacitor is coupled to a first terminal of the capacitor under test based on a conduction state of the switch circuit. The ADC converts a voltage on the first terminal of the capacitor under test into a digital signal. The processing module detects a capacitance and a capacitance variation of the capacitor under test according to the digital signal from the ADC and a parameter of the ADC. | 03-22-2012 |
20120098786 | Control Device for a Touch Panel - A touch panel includes a plurality of X-directional sensing lines and a plurality of Y-directional sensing lines. The X-directional sensing lines and the Y-directional sensing lines are arranged in a staggered manner. The control device includes a clock generation circuit, a selection module, a drive signal generation circuit, a digital to analog conversion module, first and second capacitors and a differential detection circuit. The X-directional sensing lines and Y-directional sensing lines on the touch panel operate according to a predetermined scanning sequence. According to the control device and the predetermined scanning sequence of the present invention, the sensing speed of the touch panel can be improved. | 04-26-2012 |
20120182255 | CONTROL DEVICE FOR A TOUCH PANEL - The present invention discloses a control device for a touch panel that comprises a plurality of X-directional sensing lines and Y-directional sensing lines. The X-directional sensing lines and Y-directional sensing lines are arranged in an interlaced manner. The control device comprises a clock generation circuit, a selection module, a driving signal generation circuit, a differential detection module, and a digital-to-analog conversion module. The selection module selects a first sensing line and a second sensing line from the X-directional sensing lines or Y-directional sensing lines. The driving signal generation circuit generates first and second driving signals to the first and second sensing lines, respectively. The digital to analog conversion module selectively outputs a first voltage to the first sensing line or outputs a second voltage to the second sensing line. The operation frequency of the touch panel can be increased using the control device of the present invention. | 07-19-2012 |
20120200358 | COMPARATOR - A comparator includes: a wide-swing operation transconductance amplifier (OTA), having first and second differential input pairs for receiving first and second differential input signals respectively, the wide-swing OTA generating first and second intermediate output voltages in comparing the first with the second differential input signals; a current switch group; a current mirror group, wherein when an input common mode voltage of the first and the second differential input signal tends to one of a first and a second reference voltage, one of the first and the second differential input pair is turned off, and the current switch group and the current mirror group compensate a current flowing through the other of the first and the second differential input pair; and a decision circuit coupled to the wide-swing OTA, for enlarging a voltage difference between the first and the second intermediate output voltage to output a voltage comparison output signal. | 08-09-2012 |
20130076376 | CAPACITANCE MEASUREMENT CIRCUIT AND METHOD THEREFOR - A capacitance measurement circuit includes an operation amplifier; a reference capacitor having a first terminal coupled to a first input terminal of the operation amplifier and a second terminal selectively coupled to a first or second reference voltage; a sensor capacitor having a first terminal coupled to a second input terminal of the operation amplifier and a second terminal selectively coupled to the first or second reference voltage; an approximation unit having an output terminal and an input terminal coupled to an output terminal of the operation amplifier; a conversion unit having an output terminal and an input terminal coupled to the output terminal of the approximation unit; and a coupling capacitor having a first terminal coupled to the first or second input terminal of the operation amplifier and a second terminal coupled to the output terminal of the conversion unit. | 03-28-2013 |
20130076377 | CAPACITANCE MEASUREMENT CIRCUIT AND METHOD THEREFOR - A capacitance measurement circuit includes an operation amplifier; a reference capacitor having a first terminal coupled to a first input terminal of the operation amplifier and a second terminal selectively coupled to a first or second reference voltage; a sensor capacitor having a first terminal coupled to a second input terminal of the operation amplifier and a second terminal selectively coupled to the first or second reference voltage; an approximation unit having an output terminal and an input terminal coupled to an output terminal of the operation amplifier; a conversion unit having an output terminal and an input terminal coupled to the output terminal of the approximation unit; and a coupling capacitor having a first terminal coupled to the first or second input terminal of the operation amplifier and a second terminal coupled to the output terminal of the conversion unit. | 03-28-2013 |
20140028622 | TOUCH INPUT ELECTRONIC DEVICE - An touch input electronic device includes: a touch input device; a clock generation circuit, generating a first clock and a second clock; a touch sensing circuit, coupled to the touch input device, the touch sensing circuit operated under the first clock; a logic circuit, receiving a sensing output signal from the touch sensing circuit, the logic circuit operated under the second clock; and a conversion circuit, outputting an output voltage under control of the logic circuit, the output voltage coupled to the touch sensing circuit, the conversion circuit operated under the second clock. In response to the sensing output signal from the touch sensing circuit, the logic circuit controls the conversion circuit to adjust the output voltage to detect a capacitance variance of the touch input device. | 01-30-2014 |