A fully-differential capacitive touch controller with input common-mode feedback for symmetric display noise cancellation

Author

Ki-Duk Kim ; Sanghyub Kang ; Yoon-Kyung Choi ; Kyung-Hoon Lee ; Choong-Hoon Lee ; Jin-chul Lee ; Choi, Michael ; Kyungjun Ko ; Joonwoo Jung ; Namgu Park ; Hojin Park ; Gyoo-Cheol Hwang

Author_Institution

Syst. LSI Bus., Samsung Electron., Yongin, South Korea

fYear

2014

fDate

10-13 June 2014

Firstpage

1

Lastpage

2

Abstract

A fully-differential capacitive touch sensing method is proposed in which common-mode noise currents are symmetrically subtracted at the differential input of the first stage such that it doesn´t contribute to dynamic range reduction in the later stages. And, for better sensitivity, the proposed method could accumulate signal charges in continuous time domain, and does not suffer from aliasing issues observed in many discrete-time charge integrating methods. Measurement results showed 42 dB SNR for a 1-mm diameter stylus on a 5-inch full-HD on-cell touch display panel.

Keywords

capacitive sensors; touch sensitive screens; SNR; common-mode noise currents; continuous time domain; discrete-time charge integrating methods; dynamic range reduction; full-HD on-cell touch display panel; fully-differential capacitive touch controller; fully-differential capacitive touch sensing method; input common-mode feedback; size 1 mm; size 5 inch; symmetric display noise cancellation; Capacitance; Frequency-domain analysis; Noise; Noise measurement; Sensitivity; Sensors; Voltage control;

fLanguage

English

Publisher

ieee

Conference_Titel

VLSI Circuits Digest of Technical Papers, 2014 Symposium on

Conference_Location

Honolulu, HI

Print_ISBN

978-1-4799-3327-3

Type

conf

DOI

10.1109/VLSIC.2014.6858444

Filename

6858444