A MONOLITHICALLY INTEGRATED SENSOR SYSTEM USING SENSOR-SPECIFIC CMOS CELLS

A 1 bar pressure sensor and an analog signal-conditioning circuit have been integrated on a single silicon chip by means of a standard CMOS process followed by micromechanical structuring of the device. The dev elopment and design of the sensor system are based on the commercial c ell library of the semiconductor manufacturer European Silicon Structu res (ES2). Suitable analog cells of the library have been modified reg arding the requirements of the sensor system. The electrical elements of the sensor module and the modified circuits have been defined as ne w library elements and adapted for use in conventional CAD tools. A me chanical simulation model of the piezoresistive sensor has been implem ented in an electrical analog simulator. Thus the complete system can be optimized and checked before the fabrication. After balancing of th e sensor, the experimental results of the demonstrator device show a t otal system error of less than 0.7% FSO for a pressure variation from 0 to 1000 mbar and in the temperature range -20 to 80 degrees C.