A multi-touch interface circuit for a large-sized capacitive touch panel

Juan Yao Ruan, Paul C.-P. Chao, Wei Dar Chen*

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

19 Scopus citations


This study presents a multi-touch sensing circuit for large-sized (more than 12 inches) capacitive touch panel. A new AC sensing technique is developed to enable the touch sensing in a large-sized capacitive touch panel. This novel designs of multi-touch sensing circuit lies in the operation principles through a 4X4 ITO film sensor array, a low-disturbance array circuit, a capacitance to voltage converter circuit and the proposed design procedure of chip parameters by circuit simulation. Furthermore, the sequence control for the array is generated by an FPGA module to accomplish the operation of the whole circuit. Some of objectives are to reduce environmental disturbance of the panel and to distinguish multi-touching locations from the panel. The corresponding output voltages of multi-touch sensing circuit are output in proportional to location touched by a human finger. Finally, the whole circuit is implemented by using TSMC 0.35 μm 2P4M process. The circuit output voltages are used to distinguish touch locations by a proposed algorithm.

Original languageEnglish
Title of host publicationIEEE Sensors 2010 Conference, SENSORS 2010
Number of pages6
StatePublished - 1 Dec 2010
Event9th IEEE Sensors Conference 2010, SENSORS 2010 - Waikoloa, HI, United States
Duration: 1 Nov 20104 Nov 2010

Publication series

NameProceedings of IEEE Sensors


Conference9th IEEE Sensors Conference 2010, SENSORS 2010
CountryUnited States
CityWaikoloa, HI


  • AC sensing technique
  • Capacitive sensing circuit
  • Multi-touch
  • Projected capacitive touch panel
  • Readout circuit

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