A Noise-Immune High-Speed Readout Circuit for In-Cell Touch Screen Panels

作者：Yang Jun Hyeok^*; Jung Seung Chul; Son Young Suk; Ryu Seung Tak; Cho Gyu Hyeong

来源：IEEE Transactions on Circuits and Systems I-Regular Papers, 2013, 60(7): 1800-1809.

DOI：10.1109/TCSI.2012.2230494

• Charge amplifier
• delta-integration
• in-cell
• noise
• touch screen panel

Delta-Integration, a novel readout method, is introduced in an effort to solve the noise and speed issues impeding the performance of in-cell touch screen panels. In the proposed method, a differential sensing scheme effectively cancels common noise components and locally occurring noise is spatially low-pass filtered. Due to the consequently enhanced Signal-to-Noise Ratio, the proposed scheme is simply implemented by a comparator and a counter only in place of a complex ADC. The comparator is designed to have a 'dead-zone' for noise-immune characteristics. In addition, a new global charge amplifier that has much wider bandwidth and higher current-driving capability than the conventional one is proposed for high speed operation. The prototype chip consumes a static power of 1.15 mW and the total chip area without panel loads is 2.5 mm(2).

• 出版日期2013-7