Interface circuit for metal-oxide gas sensor

Abstract

This paper describes a sensor interface for metal-oxide chemical gas sensor for pollution detection. The function of the ASIC is to control the sensor working temperature by applying a programmable voltage with 10 bit resolution, to measure the resistance of the sensitive elements ranging from 5 k/spl Omega/ to 100 M/spl Omega/, measure the ambient temperature with an external NTC thermistor and offer a fully digital user interface. It gives the possibility to make low power and low cost high performance gas sensing microsystems for consumer application.