Touch sensing circuit and its method for sensing multi-frequency signals

A readout circuit comprising:

• a driving circuit configured to output, to a touch panel, driving signal having a first frequency;
• and
• a reception circuit configured to simultaneously receive a first sensing signal having the first frequency and a second sensing signal having a second frequency which is different from the first frequency and corresponding to a downlink signal transferred from a stylus pen,
• wherein a digital signal processing circuit in the reception circuit simultaneously performs a Fourier transform with respect to the first sensing signal and the second sensing signal so as to divide the first sensing signal and the second sensing signal.

A touch sensing method comprising:

• receiving a first touch signal having a first frequency and corresponding to a driving signal of a touch panel;
• receiving a second touch signal having a second frequency distinguished from the first frequency and corresponding to a downlink signal of a stylus pen;
• and
• separating the touch signals respectively having the first frequency and the second frequency by a discrete Fourier transform simultaneously performing with respect to the touch signals,
• wherein the first touch signal and the second touch signal are received in a same time period.