31‐2: An Asynchronous Single‐Ended Touch Sensing Method for Y‐OCTA Using Adaptive TX Duty Control method

Abstract

In this paper, it is introduced a new touch sensing method for the flexible OLED (Y‐OCTA) eliminating the chronic constraints on selecting touch sensing frequencies. In the prior art, the touch sensing frequencies have been limited to the display scan frequency(H‐sync) or its harmonics to avoid the interference effects between Touch and Display operations, which results in some weaknesses in external noise immunity for the Touch sensor. This paper proposes a method to overcome the constraints such that any sensing frequencies would be available, while preserving Display Noise immunity for Touch IC and display flicker‐free for Display as well. As a result, the proposed IC showed SNR enhancement of 17 dB without display flicker in the asynchronous sensing mode for the worst test image patterns having the strongest Display Noise. The proposed IC was fabricated on a 90‐nm CMOS process and its silicon area is 21.2mm 2.