In summary, STMicroelectronics MEMS gyroscopes use a tuning fork configuration with a pair of masses that are driven to oscillate in opposite directions. When an angular velocity is applied, the Coriolis force on each mass also acts in opposite directions. The differential capacitance is then used to measure the rotation. Compared to a single mass approach, the differential nature of the tuning fork makes the system intrinsically insensitive to undesired linear acceleration or vibration. ST also uses a System-in-Package approach where the ASIC die is stacked on top of the MEMS structure to address applications where small size is a key constraint.