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VOLUME 7 , ISSUE 5 (December 2014) > List of articles
Special issue ICST 2014
Citation Information : International Journal on Smart Sensing and Intelligent Systems. Volume 7, Issue 5, Pages 1-6, DOI: https://doi.org/10.21307/ijssis-2019-088
License : (CC BY-NC-ND 4.0)
Published Online: 15-February-2020
Capacitance-to-Digital Converter (CDC) ICs available in the market use square wave excitation signals but a sinusoidal excitation is preferred in various applications, such as ice detection, liquid level measurement, humidity measurement, proximity sensing, etc. A dual slope technique based CDC that employs a sinusoidal excitation has been reported recently, but it requires a large number of excitation cycles, to complete an accurate conversion. This paper presents an improved CDC that employs a specially designed method to achieve high accuracy even when a much smaller number of excitation cycles, than the reported scheme, are employed to complete the conversion. A prototype CDC has been developed and tested. In comparison with an existing CDC, the new CDC achieved a substantial reduction (by a factor of 4000) in the number of excitation cycles during integration period, resulting in an improved update rate. Worst case error observed from the prototype CDC was less than 0.24%.
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