A 0.4 V driving multi-touch capacitive sensor with the driving signal frequency set to (n+0.5) times the inverse of the LCD VCOM noise period

The time-periodic property of the LCD VCOM noise is utilized to reduce the effect of the VCOM noise on the mutual-capacitance measuring touch sensor placed on a LCD panel. The amplitude of the touch sensor driving signal (VSTM) can be reduced reliably down to 0.4 V with the reporting rate of 189 Hz,...

Full description

Saved in:
Bibliographic Details
Main Authors: Jae-seung Lee, Dong-Hee Yeo, Sang-Soo Lee, Hye-Jung Kwon, Jae-Yoon Sim, Byung-Sub Kim, Hong June Park
Format: Conference Proceeding
Language:English
Subjects:
Electrodes
Logic gates
mutual-capacitance
Noise
Noise measurement
Semiconductor device measurement
Tactile sensors
touch sensor
VCOM noise
Voltage measurement
Online Access:Request full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The time-periodic property of the LCD VCOM noise is utilized to reduce the effect of the VCOM noise on the mutual-capacitance measuring touch sensor placed on a LCD panel. The amplitude of the touch sensor driving signal (VSTM) can be reduced reliably down to 0.4 V with the reporting rate of 189 Hz, by using the following two methods. (1) The frequency of VSTM is set to (n+0.5)·f N , by synchronizing VSTM to a LCD gate driver signal with a referenceless CDR. fN is the inverse of the LCD VCOM noise period (TN) and n is a positive integer. (2) The reset period of the RX integrator is set to 2·TN.
ISSN:0271-4302
2158-1525
DOI:10.1109/ISCAS.2014.6865227