Mstar Semiconductor, Inc.

Yi Cheng Hsieh

Guo-Kiang Hung

Tsung-Fu Lin

Tso Min Chen

A touch sensing method and associated circuit are provided. In one aspect, a touch control circuit includes a first current source, a second current source, a plurality of switches, a hysteresis comparator, a frequency divider and a flip-flop. The switches are couple to a plurality of external contact points. The hysteresis comparator is coupled to a first reference comparison voltage and a second reference comparison voltage. Each of the external contact points is selectively coupled to an input terminal of the hysteresis comparator through the switches. The first current source and the second current source are coupled to the input terminal of the hysteresis comparator to generate a sensing voltage. The hysteresis comparator compares the sensing voltage with the first reference comparison voltage and the second reference comparison voltage to generate a hysteresis comparison output to control the first current source or the second current source.

Touch sensing method and associated circuit

A digital apparatus includes a timing control circuit, a period counter, a phase digitizer and a calculation circuit. The timing control circuit generates a first control signal according to a square wave signal and a predetermined value. The period counter generates a first digital value according to a reference clock signal and the first control signal. The phase digitizer generates a second digital value according to a phase difference between the square wave signal and the reference clock signal. The calculation circuit generates an output digital value according to the first digital value and the second digital value. An object of obtaining a high-resolution digitization with a reasonable sampling clock is realized by effectively combining the period counter with the phase digitizer.

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Hsinchu Hsien, Taiwan

Yi Cheng Hsieh