Programmable CMOS Integrated Pressure Sensor 1999-01-1041

An integrated pressure sensor is presented which uses a custom digital signal processor and non-volatile memory to calibrate and temperature compensate a family of pressure sensor elements for a wide range of automotive applications. Unlike previously introduced analog solutions, this programmable signal conditioning engine operates in the digital domain utilizing a calibration algorithm that accounts for higher order effects beyond the realm of most analog signal conditioning approaches, and provides enhanced features that typically were implemented off-chip (or not at all) with traditional analog signal conditioning solutions that use laser or electronic trimming. A specially developed digital communication interface permits calibration of the individual sensor module via connector pins after the module has been fully assembled and encapsulated. Post-trim processing is eliminated, and calibration and module customization can be performed as an integral part of end-of-line testing at the completion of the manufacturing flow. The integrated circuit contains a pressure sensor element that is co-processed in a sub-micron mixed signal CMOS wafer fabrication process, and which can be scaled to a variety of automotive pressure sensing applications. Both digital and analog sensor outputs are available.