Open AccessAn Efficient Pulse Width Measurement Method using Multiphase Clock Signals for Capacitive Touch Switches
Author(s) -
Kwang-Su Seong
Publication year - 2013
Publication title -
journal of electrical engineering and technology/journal of electrical engineering and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.226
H-Index - 27
eISSN - 2093-7423
pISSN - 1975-0102
DOI - 10.5370/jeet.2013.8.4.773
Subject(s) - capacitive sensing , pulse (music) , measure (data warehouse) , clock signal , pulse width modulation , electronic engineering , computer science , electrical engineering , engineering , voltage , jitter , database
We propose an efficient method to measure a pulse width using multiphase clock signals generated from a ring oscillator. These clocks, which have the same frequency and are evenly spaced, give multiple rising edges within a clock cycle. Thus, it is possible to measure a pulse width more accurately than with existing single clock-based methods. The proposed method is applied to a capacitive touch switch. Experimental results show that the capacitive touch switch with the proposed method gives a 118 fF resolution, which is 6.4 times higher than that of the touch switch with a single clock-based pulse width measurement method.