Calibration in a MEMS based measurement system or how to make a sensor-ASIC loop of high resolution work

Abstract:
Micro-Electro-Mechanical Systems (MEMS) as inertial sensors, like accelerometers and gyroscopes, are finally becoming attractive for many industrial applications, and their potential range of use is about to explode in the coming years. The application trend towards high resolution, reliability, and miniaturization, pushes system integrators to combine both the inertial sensor and its application-specific integrated circuit (ASIC) in a force-balanced feedback arrangement, implemented as a single System-in-Package (SiP). The real challenge then consists in guaranteeing both performance and yield for the overall SiP. The system integrator must acknowledge that design flow and fabrication techniques are different for the mechanics and the electronics: MEMS sensor design relies on finite-element simulation to model electrostatic effects, whereas electronics must take into account worst-case corners of process steps and of operating conditions, voltage and temperature, with SPICElike simulations. Managing the design of mixed electronic-mechanical systems thus requires a common simulation environment, with specific models the fidelity of which to sub part of specifications must be assessed.