Title
Touch Screen Sensing Circuit with Rotating Auto-Zeroing Offset Cancellation.
Abstract
In this paper, we present a rotating auto-zeroing offset cancellation technique, which can improve the performance of touch screen sensing circuits. Our target touch screen detection method employs multiple continuous sine waves to achieve a high speed for large touch screens. While conventional auto-zeroing schemes cannot handle such continuous signals properly, the proposed scheme does not suffer from switching noise and provides effective offset cancellation for continuous signals. Experimental results show that the proposed technique improves the signal-to-noise ratio by 14 dB compared to a conventional offset cancellation scheme. For the realistic simulation results, we used Cadence SPECTRE with an accurate TSP model and noise source. We also applied an asymmetric device size (10% MOS size mismatch) to the OP Amp design in order to measure the effectiveness of offset cancellation. We implemented the proposed circuit as part of a touch screen controller system-on-chip by using a Magnachip/SK Hynix 0.18-μm complementary metal-oxide semiconductor (CMOS) process.
Year
Venue
Field
2015
J. Inform. and Commun. Convergence Engineering
Cadence,Control theory,Offset cancellation,Computer science,CMOS,Electronic circuit,Electrical engineering,Operational amplifier,Sine wave,Amplifier
DocType
Volume
Issue
Journal
13
3
Citations 
PageRank 
References 
1
0.40
1
Authors
2
Name
Order
Citations
PageRank
Dong-Min Won110.73
Hyungwon Kim23014.13