In:
Key Engineering Materials, Trans Tech Publications, Ltd., Vol. 562-565 ( 2013-7), p. 344-349
Abstract:
Previous research on MWNTs/SiO2 humidity sensing film by our work group has proved that MWNTs sensor has a different response mechanism to humidity at AC testing signals and shows greater testing stability and higher sensitivity, compared with traditional DC signal measurement. An interface circuit for conductive MWNTs/SiO2 humidity sensor is designed in this paper for humidity detection and prospection in miniaturization and integration. It aims at detecting the sensor’s humidity sensitive conductance signal at AC testing signals, and inhibiting the interference of capacitance signals. The ASIC demodulates the two signals by their phase difference and outputs a direct voltage proportional to conductance. The layout for ASIC is drawn by standard 0.5um P2M2 CMOS process and has a total area of 4*2mm2. In circuit level simulation by HSPICE which introduces practical data of the sensor’s humidity sensing characteristics, the relation of circuit output to conductance turns out to have great linearity at no more than 300 kHz and zero offset can be neglected at less than 100 kHz frequency. It is feasible to select proper testing frequency for high sensitivity and stability and make further investigations on the sensor’s frequency property.
Type of Medium:
Online Resource
ISSN:
1662-9795
DOI:
10.4028/www.scientific.net/KEM.562-565
DOI:
10.4028/www.scientific.net/KEM.562-565.344
Language:
Unknown
Publisher:
Trans Tech Publications, Ltd.
Publication Date:
2013
detail.hit.zdb_id:
2073306-9
