کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
239689 | 466199 | 2009 | 4 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: A novel power-controlling approach for integrated, conductometric gas sensors A novel power-controlling approach for integrated, conductometric gas sensors](/preview/png/239689.png)
An original power controlling driving/reading circuit for Porous Silicon JFET (PSJFET) gas sensors is presented. The PSJFET is an integrated p-channel JFET with two independent gates: a meso-structured PS layer, acting as a sensing, floating gate, which modulates the JFET current upon adsorption/desorption of specific analytes, and a high-impedance electric gate, which allows the JFET current tuning independently from analytes in the environment. The circuit exploits the independence of the sensing and electrical gate terminals to set/control the sensor power-dissipation, which is kept almost constant independently from adsorption/desorption-induced effects, while simultaneously carrying out a current-voltage conversion. For such a purpose, a negative feedback loop is used to modulate the PSJFET electric gate voltage, which becomes the output signal, while keeping constant the source-drain sensor current and, hence, the power dissipation. The proposed approach is validated by performing time-resolved measurements on PSJFET sensors under different NO2 concentrations (100ppb, 300ppb, 500ppb), at room temperature.
Journal: Procedia Chemistry - Volume 1, Issue 1, September 2009, Pages 188-191