Abstract: A mixer of a touch panel system includes a first switch configured to switch a sensing signal in accordance with a reference signal; a second switch configured to switch the sensing signal in accordance with a phase-inverted reference signal from the reference signal. Further, the mixer of the touch panel system includes a first low pass filter configured to perform low-pass filtering on a first output signal produced from the first switch; and a second low pass filter configured to perform low-pass filtering on a second output signal produced from the second switch. Furthermore, the mixer of the touch panel system includes a differentiator configured to differentiate signals produced from the first low pass filter and the second low pass filter, to thereby produce a signal of constant level as the sensing signal.

Abstract: A touch panel system includes a signal generator configured to generate a reference signal and one or more channels. Each of the channels comprises a sensing unit configured to sense a touch thereon to output a sensing signal indicative of the touch; and a delay unit configured to adjust the reference signal based on a delay compensation value to compensate delay of the reference signal caused by the difference of distance between the signal generator and the channel. Further, each of the channels comprises an operation unit configured to perform an operation on the sensing signal and the reference signal from the delay unit to produce an operation result representing difference between the sensing signal and the adjusted reference signal; and a controller configured to determine the delay compensation value of the delay unit in each channel based on the voltage signal from the operation unit.

Abstract: A mixer of a touch panel system includes a first switch configured to switch a sensing signal in accordance with a reference signal; a second switch configured to switch the sensing signal in accordance with a phase-inverted reference signal from the reference signal. Further, the mixer of the touch panel system includes a first low pass filter configured to perform low-pass filtering on a first output signal produced from the first switch; and a second low pass filter configured to perform low-pass filtering on a second output signal produced from the second switch. Furthermore, the mixer of the touch panel system includes a differentiator configured to differentiate signals produced from the first low pass filter and the second low pass filter, to thereby produce a signal of constant level as the sensing signal.

Abstract: A touch panel system includes a signal generator configured to generate a reference signal and one or more channels. Each of the channels comprises a sensing unit configured to sense a touch thereon to output a sensing signal indicative of the touch; and a delay unit configured to adjust the reference signal based on a delay compensation value to compensate delay of the reference signal caused by the difference of distance between the signal generator and the channel. Further, each of the channels comprises an operation unit configured to perform an operation on the sensing signal and the reference signal from the delay unit to produce an operation result representing difference between the sensing signal and the adjusted reference signal; and a controller configured to determine the delay compensation value of the delay unit in each channel based on the voltage signal from the operation unit.

Abstract: A method of modulating and demodulating a signal includes modulating data information included in an input data signal provided from an external source and clock information included in an input clock signal provided from the external source into a transmission signal, using (n+1) delay clock signals generated based on the input clock signal, where n is a natural number. The transmission signal is demodulated into an output clock signal including restored clock information and an output data signal including restored data information, using (m+1) delay clock signals generated based on the clock information, where m is a natural number less than n.

Abstract: An adjustable capacitor is provided including a capacitor unit including a plurality of capacitor groups aligned in a matrix format and a switch unit to adjust capacitance by connecting the plurality of capacitor groups in parallel according to a selection signal of a column and row of the matrix. Accordingly, the adjustable capacitor may be realized of a small size but with a high capacitance change rate.

Abstract: A time-to-digital converter (TDC) includes a converter which receives a first signal and a second signal, delays the second signal in phases using a plurality of delay elements which are coupled in series, compares the delayed second signal with the first signal, and outputs a phase error of the second signal with respect to the first signal, a phase frequency detector which receives the first signal, and a third signal from one of the nodes in the plurality of delay elements, and outputs a phase difference between the first signal and the third signal, and a frequency detector which outputs a frequency error of the second signal with respect to the first signal as a digital code using an output signal of the phase frequency detector and the second signal.

Abstract: A method of modulating and demodulating a signal includes modulating data information included in an input data signal provided from an external source and clock information included in an input clock signal provided from the external source into a transmission signal, using (n+1) delay clock signals generated based on the input clock signal, where n is a natural number. The transmission signal is demodulated into an output clock signal including restored clock information and an output data signal including restored data information, using (m+1) delay clock signals generated based on the clock information, where m is a natural number less than n.

Abstract: An adjustable capacitor is provided including a capacitor unit including a plurality of capacitor groups aligned in a matrix format and a switch unit to adjust capacitance by connecting the plurality of capacitor groups in parallel according to a selection signal of a column and row of the matrix. Accordingly, the adjustable capacitor may be realized of a small size but with a high capacitance change rate.

Abstract: A time-to-digital converter (TDC) includes a converter which receives a first signal and a second signal, delays the second signal in phases using a plurality of delay elements which are coupled in series, compares the delayed second signal with the first signal, and outputs a phase error of the second signal with respect to the first signal, a phase frequency detector which receives the first signal, and a third signal from one of the nodes in the plurality of delay elements, and outputs a phase difference between the first signal and the third signal, and a frequency detector which outputs a frequency error of the second signal with respect to the first signal as a digital code using an output signal of the phase frequency detector and the second signal.