A Monolithic Three-Axis Accelerometer with Low Cross-Axis Sensitivity

A 50,000g three-axis accelerometer using a single proof mass is presented. The sensitive structure is made of a single proof mass and eight cantilever beams. Twelve piezoresistors are placed on the cantilevers symmetrically, which can be used to detect 3-dimensional acceleration. The symmetric placement of the piezoresistors brings the reasonable sensitivity and simultaneously decreases the cross-axis sensitivity significantly. Simulation results show that the sensitivity in X-, Y- and Z-axis are 0.806uV/g, 0.806uV/g and 3.71uV/g respectively with 5V supply and the cross-axis sensitivities are all less than 2.4%, which ensures the high performance of the three-axis accelerometer.