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A Monolithic Implementation of Interface Circuitry for CMOS Compatible Gas-Sensor System



Muhammad Afridi, John S. Suehle, Mona E. Zaghloul, David W. Berning, Allen R. Hefner Jr., Stephen Semancik, Richard E. Cavicchi


A monolithic CMOS micro-gas-sensor system, designed and fabricated in a standard CMOS process, is described. The gas-sensor system incorporates an array of four microhotplate-based gas-sensing structures. The system utilizes a thin film of tin-oxide (SnO2) as a sensing material. The interface circuitry on the chip has digital decoders to select each element of the sensing array, and an operational amplifier to monitor the change in conductance of the film. The chip is post-processed to create microhotplates using bulk micro-machining techniques. Measurements are presented for various portions of the interface circuitry used for the gas sensor system.
Proceedings Title
Proc., ISCAS
Conference Dates
May 26-29, 2002
Conference Location
Scottsdale, AZ, USA
Conference Title
IEEE International Symposium on Circuits and Systems


Array, Gas Sensor, Interface Circuit, MEMS, Microhotplate, Micromachining, Monolithic, Post Processing


Afridi, M. , Suehle, J. , Zaghloul, M. , Berning, D. , Hefner Jr., A. , Semancik, S. and Cavicchi, R. (2002), A Monolithic Implementation of Interface Circuitry for CMOS Compatible Gas-Sensor System, Proc., ISCAS, Scottsdale, AZ, USA, [online], (Accessed April 25, 2024)
Created June 30, 2002, Updated October 12, 2021