Design of Conductive MWNTs/SiO2 Humidity Sensor Interface ASIC Based on AC Signals
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.
multiwall carbon nanotubes (MWNTs) humidity sensor interface AC signal
Li Tuo Liu Xiaowei Yin Liang Dong Changchun
Department of Microelectronics, Harbin Institute of Technology, Harbin, Heilongjiang, China Key Laboratory of Micro-Systems and Micro-Structures Manufacturing, Ministry of Education,China
国际会议
中国微米纳米技术学会第14届学术年会、第3届国际年会暨第6届微米纳米技术“创新与产业化国际研讨与展览会(CSMNT2012 & ICMAN2012)
杭州
英文
1-6
2012-11-04（万方平台首次上网日期，不代表论文的发表时间）