A highly area-efficient controller for capacitive touch screen panel systems

Author

Hwang, Tong-Hun ; Cui, Wen-Hai ; Yang, Ik-Seok ; Kwon, Oh-Kyong

Author_Institution

Dept. of Electron. Eng., Hanyang Univ. in Seoul, Seoul, South Korea

Volume

56

Issue

2

fYear

2010

fDate

5/1/2010 12:00:00 AM

Firstpage

1115

Lastpage

1122

Abstract

In this paper, a highly area-efficient controller for capacitive touch screen panels (TSPs) is proposed. The proposed controller uses a 10-bit successive approximation register analog-to-digital converter (SAR ADC) with an adder to compensate for the capacitance variation in the TSP and for the offset voltage variation in the charge amplifier of the sensing circuit. By using the proposed compensation method, the area of the controller can be reduced by 90.3% of the area of the conventional controllers. The measurement results showed that the signal-to-noise ratio (SNR) of the controller increases from 12.5 to 21.3 dB after compensation. Also, its spatial jitter decreases from ±1.5 to ±0.46 mm, which is 7% of the sensor pitch of 8 mm

Keywords

Adders; Analog-digital conversion; Capacitance; Circuits; Commercialization; Control systems; Displays; Mobile handsets; Optical amplifiers; Tactile sensors; Projected capacitive touch screen panel, compensation technique, mutual capacitance, successive approximation register analog-to-digital converter;

fLanguage

English

Journal_Title

Consumer Electronics, IEEE Transactions on

Publisher

ieee

ISSN

0098-3063

Type

jour

DOI

10.1109/TCE.2010.5506047

Filename

5506047