Design and implement the readout circuit of an in-cell high-resolution capacitive touch panel

Abstract

This paper proposes a high resolution capacitive touch panel readout circuit to sense the Variation by self-capacitance method. This AM display of in-cell structure includes an active architecture for improved resolution, that controlling the TFT (Thin-film transistor) to make the accuracy better. In addition, the panel has 60 sensing point per 0.88 inches and the proposed readout circuit used switched capacitor charge amplifier(SCCA) to sensing the charge change and enhances the SNR (Signal-to-noise) by eliminating the baseline. The experimental results show that the proposed readout circuit SNR achieves 38dB and the frame rate is 200Hz.