论文信息 - A Capacitive Sensor Interface Circuit Based on Phase Differential Method

A Capacitive Sensor Interface Circuit Based on Phase Differential Method

A new interface circuit for capacitive sensor is presented. This paper presents the design and simulation of soil moisture capacitive sensor interface circuit based on phase differential technique. The circuit has been designed and fabricated using MIMOS’ 0.35μm CMOS technology. Simulation and test results show linear characteristic from 36 – 52 degree phase difference, representing 0 – 100% in soil moisture level. Test result shows the circuit has sensitivity of 0.79mV/0.1 phase difference, translating into resolution of 10% soil moisture level. Keywords—Capacitive sensor, interface, phase differential.

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