A CMOS Gas Sensor Array Platform With Fourier Transform Based Impedance Spectroscopy

Murali, Pramod and Ranjit, K and Bhat, Navakanta and Banerjee, Gaurab and Amrutur, Bharadwaj and Bhat, KN and Ramamurthy, Praveen C (2012) A CMOS Gas Sensor Array Platform With Fourier Transform Based Impedance Spectroscopy. In: IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS, 59 (11). pp. 2507-2517.

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Abstract

A CMOS gas sensor array platform with digital read-out containing 27 sensor pixels and a reference pixel is presented. A signal conditioning circuit at each pixel includes digitally programmable gain stages for sensor signal amplification followed by a second order continuous time delta sigma modulator for digitization. Each sensor pixel can be functionalized with a distinct sensing material that facilitates transduction based on impedance change. Impedance spectrum (up to 10 KHz) of the sensor is obtained off-chip by computing the fast Fourier transform of sensor and reference pixel outputs. The reference pixel also compensates for the phase shift introduced by the signal processing circuits. The chip also contains a temperature sensor with digital readout for ambient temperature measurement. A sensor pixel is functionalized with polycarbazole conducting polymer for sensing volatile organic gases and measurement results are presented. The chip is fabricated in a 0.35 CMOS technology and requires a single step post processing for functionalization. It consumes 57 mW from a 3.3 V supply.

Item Type:	Journal Article
Publication:	IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS
Publisher:	IEEE, NEW YORK, USA
Additional Information:	Copyright for this article belongs to IEEE, NEW YORK, USA
Department/Centre:	Division of Biological Sciences > Centre for Neuroscience Division of Electrical Sciences > Electrical Communication Engineering Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	31 Dec 2012 05:29
Last Modified:	31 Dec 2012 05:29
URI:	http://eprints.iisc.ac.in/id/eprint/45473

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