Abstract
This paper presents the analysis and experimental results on the noise performances of a capacitive-sensor interface. The interface is able to measure low capacitance values in the order of picofarads and is implemented with a simple relaxation oscillator, a fast counter, and a microcontroller. The goal is to find the criteria to implement a low-noise system, so that, even with a short measuring time, low noise can be obtained. Experimental results are performed in order to prove the validity of the theoretical analysis. The achieved resolution, with a measuring time of 20 ms, was better than 14.2 /spl times/ 10/sup -7/ for the measurement of a capacitance value of 2.2 pF.
Original language | Undefined/Unknown |
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Pages (from-to) | 1934-1940 |
Number of pages | 7 |
Journal | IEEE Instrumentation and Measurement Magazine |
Volume | 54 |
Issue number | 5 |
DOIs | |
Publication status | Published - 2005 |
Keywords
- academic journal papers
- ZX CWTS JFIS < 1.00