Integration technology for MEMS automotive sensors

MEMS (microelectromechanical systems) is an enabling technology that has been used in high volume automotive applications such as pressure sensors and accelerometers for a variety of applications such as that control the engine performance as well as the safety of the occupants. MEMS sensors require an interface circuit to convert the input mechanical signal to the equivalent electrical signal that is used to generate the required control function. The integration of the MEMS sensor with the interface circuit can be achieved either in the same piece of silicon or in the package. The challenges in this integration are discussed in the paper with specific examples for piezoresistive pressure sensors, capacitive accelerometers and capacitive pressure sensors. The effects of the application environment on the performance of these sensors are also discussed in the paper. Examples of system partitioning and integration are described using a satellite accelerometer system and a tire pressure monitoring system.