Bhat, Navakanta and Jayaraman, Balaji and Pratap, Rudra and Bagga, Shobi and Mohan, S (2009) Integrated CMOS Gas Sensors. In: 2nd International Workshop on Electron Devices and Semiconductor Technology, JUN 01-02, 2009, Bombay, INDIA, pp. 31-35.
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We present a low power gas sensor system on CMOS platform consisting of micromachined polysilicon microheater, temperature controller circuit, resistance readout circuit and SnO2 transducer film. The design criteria for different building blocks of the system is elaborated The microheaters are optimized for temperature uniformity as well as static and dynamic response. The electrical equivalent model for the microheater is derived by extracting thermal and mechanical poles through extensive laser doppler vibrometer measurements. The temperature controller and readout circuit are realized on 130nm CMOS technology The temperature controller re-uses the heater as a temperature sensor and controls the duty cycle of the waveform driving the gate of the power MOSFET which supplies heater current. The readout circuit, with subthreshold operation of the MOSFETs, is based oil resistance to time period conversion followed by frequency to digital converter Subthreshold operatin of MOSFETs coupled with sub-ranging technique, achieves ultra low power consumption with more than five orders of magnitude dynamic range RF sputtered SnO2 film is optimized for its microstructure to achive high sensitivity to sense LPG gas.
|Item Type:||Conference Paper|
|Additional Information:||Copyright 2009 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.|
|Keywords:||CMOS Gas Sensors; Polysilicon microheater; Subthreshold read-out; Temperature controller; SnO2|
|Department/Centre:||Division of Electrical Sciences > Electrical Communication Engineering|
|Date Deposited:||02 Feb 2010 07:18|
|Last Modified:||19 Sep 2010 05:54|
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