Title :
A capacitive-sensor interface circuit based on a first-order charge-balanced SC-oscillator
Author :
Li, Xiujun ; Meijer, Gerard C M
Author_Institution :
Fac. of Inf. Technol. & Syst., Delft Univ. of Technol., Netherlands
Abstract :
A new smart interface for capacitive sensors, which are shunted by a parasitic conductance is presented In the novel interface circuit, the effect of shunting conductance is reduced by using the charge/discharge method in a first-order charge-balanced SC-oscillator. The effect of the stray capacitances is eliminated by using the two-port measurement. Moreover, all multiplicative and additive errors of the interface are also eliminated by using auto-calibration and chopping
Keywords :
calibration; capacitive sensors; relaxation oscillators; switched capacitor networks; autocalibration; capacitive-sensor interface circuit; charge/discharge method; chopping; first-order charge-balanced SC-oscillator; parasitic conductance; relaxation oscillator; smart interface; stray capacitances; two-port measurement; Capacitance measurement; Capacitive sensors; Capacitors; Circuits; Electrical resistance measurement; Oscillators; Parasitic capacitance; Pollution measurement; Switches; Voltage;
Conference_Titel :
Instrumentation and Measurement Technology Conference, 2001. IMTC 2001. Proceedings of the 18th IEEE
Conference_Location :
Budapest
Print_ISBN :
0-7803-6646-8
DOI :
10.1109/IMTC.2001.928827
