Design and implementation of a preload electronics architecture for a MEMS accelerometer

Abstract

This thesis describes the design and implementation of an electronics system to provide rebalancing and readout for a force-rebalanced microelectromechanical accelerometer. A feedback control loop is devised using a novel preload architecture, compensating the proof mass of the sensor and providing an accurate acceleration measurement. This architecture is compared to alternative methods of linearizing the control loop. The electronics system is divided into analog and digital subsystems. The design is analyzed at several abstraction levels. The system is implemented for prototype testing with discrete components on a printed circuit board with a MEMS sensor attached. A computer program is implemented to receive and process the readout data using the serial port. The design methodology consists of a top-down design flow based on simulation. At each iteration in the design process, the lower level abstraction is verified with the previous model. Eventually, the design reaches the level of synthesizable digital logic and discrete analog components. This thesis describes the design process and implementation details for creating an accelerometer system prototype ready for lab testing. Detailed simulations indicate that the implemented design is likely to meet the design goals for a personal navigation system suitable for a human or land vehicle. Conclusions on design methodology and verification techniques are also presented.