Integrated circuit interface for metal oxide chemical sensor arrays

The design of a mixed-signal integrated circuit interface for the control of the heating resistance and reading of the chemically sensitive resistance of metal oxide chemical sensor arrays is reported. It contains in a single integrated circuit all the analog front-end to operate four MOX sensors while the control logic will be implemented on a microcontroller. Each heater is controlled from a dedicated digital to analog converter. Provision has been taken for both polysilicon and Pt heater control. The design has been realized in a standard 0.7 μm CMOS process.