Design and implementation of readout circuit on glass substrate with digital correction for touch‐panel applications |
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Authors: | Tzu‐Ming Wang Ming‐Dou Ker |
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Affiliation: | 1. Nanoelectronics and Gigascale Systems Laboratory, Institute of Electronics, National Chiao‐Tung University, 1001 Ta‐Hsueh Rd., Hsinchu, Taiwan 300, ROC.;2. Institute of Electronics, National Chiao‐Tung University, Hsinchu, Taiwan, ROC, and the Department of Electronic Engineering, I‐Shou University, Kaohsuing, Taiwan, ROC. |
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Abstract: | Abstract— A readout circuit on glass substrate with digital correction, which contains a transconductance amplifier, counter, and digital correction circuit, has been designed for touch‐panel applications for 3‐μm low‐temperature polysilicon (LTPS) technology. The voltage difference as a result of a change in capacitance due to a touch event is converted to current by a transconductance amplifier. By charging and discharging the capacitor in the counter, the counter displays different digital‐output codes according to touch or non‐touch events. Furthermore, not only can the touch or non‐touch event be distinguished, but also the influence of LTPS process variation can be compensated by a digital correction circuit in the proposed readout circuit. |
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Keywords: | Readout circuit low‐temperature polysilicon (LTPS) system‐on‐panel (SOP) touch panel digital correction |
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