Phase-tagged capacitance sensing circuit and electronic device using the same
An electronic device includes a touch panel, a driving circuit, and a sensing circuit. The driving circuit generates a driving signal, and superposes phase information on the driving signal. The touch panel includes multiple crossing conductors, for providing a sensing signal in response to a contact of an object on one of the sensing conductors and to a driving signal applied on the sensing element. The sensing circuit includes a signal extractor and a tag detector. The signal extractor generates a demodulation signal based on the period of the driving signal, width of the phase information, and for demodulating the sensing signal by using the demodulation signal to determine a sensing value. The tag detector enables the signal extractor as soon as a magnitude of the sensing signal is over a predetermined threshold. The signal demodulates the sensing signal by using a demodulation signal whose period is the same as the driving signal to determine the sensing value. The present electronic device can determine a touch position by processing of analog signal using the demodulation signal without phase compensation.
u-Pixel Technologies, Inc.
G G
G06F G06F
inventional inventional
Hung Wei Chih-Yu Ying-Jyh
Wu Chang Yeh