標題: Self-Sustaining Soil Electrical Conductance Measurement Using a DC-DC Power Converter
作者: Ou, I-Che
Tsai, Kun-Ju
Chu, Yuan-Hua
Liao, Yu-Te
電機工程學系
Department of Electrical and Computer Engineering
關鍵字: Self-powered;DC-DC converter;maximal power point tracking;soil electrical conductivity measurement
公開日期: 15-Nov-2019
摘要: This paper presents a self-sustained soil electrical conductivity (soil-EC) sensing IC. The sensing system harvests energy and measures the conductivity of the soil simultaneously using the proposed wide-range DC-DC converter. The power management circuits must accommodate the wide variations of the soil conductivity at varying power levels. The time-domain current sensing mechanism, which is embedded in the DC-DC converter, is employed to measure conductivity. Also, the digital codes are recorded and control the converter for achieving maximal power extraction and maintaining high conversion efficiency. The self-sustained soil-EC monitoring IC was fabricated using 0.18-mu m CMOS technology. The range of the input voltage from a soil cell is from 0.8 to 1 V when carbon and zinc electrodes are used. The design achieves a tracking efficiency of 98% over an input range of 416-5000 mu W, a throughput power range from 150 mu W to 4.32 mW, and a peak system conversion efficiency of 88%, while the regulated voltage is about 1.7-1.8 V. The design can also measure the soil EC from 0.114 to 0.744 mS/cm in a resolution of 0.00568 mS/cm per bit.
URI: http://dx.doi.org/10.1109/JSEN.2019.2931180
http://hdl.handle.net/11536/153613
ISSN: 1530-437X
DOI: 10.1109/JSEN.2019.2931180
期刊: IEEE SENSORS JOURNAL
Volume: 19
Issue: 22
起始頁: 10560
結束頁: 10567
Appears in Collections:Articles