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 circuit concept is optimized for a large temperature range (¿40...+125°C) and a minimum number of connections (three terminal device). The chip is fabricated in a 2 ¿m 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 × 1.5 mm².