Touch sensing apparatus and method capable of supporting hover sensing

A touch sensing method capable of supporting hover sensing of a touch sensing apparatus including a plurality of capacitance-voltage converters (C-V converters) outputting different voltage values depending on a change in capacitance of each of the sensing electrodes, a plurality of integrators integrating output voltages of each of the C-V converters, a first multiplexer multiplexing outputs of the plurality of integrators, a second multiplexer multiplexing the outputs of the plurality of integrators, a first differential amplification unit for touch sensing receiving an output of the first multiplexer and an output of the second multiplexer, a second differential amplification unit for hover sensing receiving the output of the first multiplexer and the output of the second multiplexer, a first analog-to-digital converter converting the output of the first differential amplification unit into a digital data, a second analog-to-digital converter converting the output of the second differential amplification unit into the digital data, and a digital signal processing unit receiving the outputs of the first analog-to-digital converter and the second analog-to-digital converter to sense a touch event and a hover event, the touch sensing method comprising:

• (A) determining whether the mode selected by a user is an analog mode or a digital mode by the digital signal processing unit;
• (B) in the step (A), when it is determined that the mode selected by the user is the analog mode, subtracting, amplifying, and outputting, by each of the first differential amplification unit and the second differential amplification unit, input signals depending on a control signal of the digital signal processing unit;
• (C) converting, by each of the first analog-to-digital converter and the second analog-to-digital converter, the outputs of the first differential amplification unit and the second differential amplification unit into the digital data;
• (D) sensing, by the digital signal processing unit, the touch event or the hover event based on the digital data;
• (E) in the step (A), when it is determined that the mode selected by the user is the digital mode, subtracting, amplifying, and outputting, by each of the first differential amplification unit and the second differential amplification unit, the input signals of the channels and a predetermined reference voltage, depending on a control signal of the digital signal processing unit;
• (F) converting, by each of the first analog-to-digital converter and the second analog-to-digital converter, the outputs of the first differential amplification unit and the second differential amplification unit into the digital data;
• and
• (G) when the digital signal processing unit receives the data of the two channels, subtracting the data of the two channels and sensing the touch event or the hover event based on the subtracted result.