Readout electronics for wide temperature range with integrated surface micromachined capacitive pressure sensor

A monolithically integrated pressure sensor with on-chip readout electronics for a wide range of applications is presented. The cicuit concept is optmized for a large temperature range (-40...+125øC) and a minimum number of connections (three terminal device). The chip is fabricated in a 2 µm CMOS process with additional surface micromachining steps to implement the sensor. Using a pressure independent reference element the maximum overall temperature coefficient can be reduced to 500 ppm without any electronic compensation. the die size is 2.5 x 1.5 mm2.