A High-accuracy Multi-element Silicon Barometric Pressure Sensor

This paper reports the development of a high-accuracy multi-element barometric pressure sensor for use in environmental monitoring and automated process control. The capacitive device consists of one diaphragm that spans the entire measurement range and a series of higher-resolution diaphragms that span segments of the range. An embedded microcontroller determines the applied pressure at low resolution and then reads out the appropriate segment device to determine the pressure with higher accuracy. The overall pressure sensor is digitally-compensated in EPROM and resolves 25mTorr over a dynamic range from 600 to 80OTorr. The pressure sensitivity is over 4000ppm/Torr for the segment devices while the uncompensated temperature coefficient of offset is about +2600ppm//spl deg/C. The device is self-testing and reads out in less than 10pec using a switched-capacitor charge integrator.