A hybrid micro-accelerometer system with CMOS readout circuit and self-test function

摘要

A hybrid two-chip micro-accelerometer system consisting of a novel lateral capacitive silicon micro-acceleration sensor and a CMOS readout circuit is presented. The micro-acceleration sensor has a proof mass with the size of 0.6?.4?.1mm3, the mass of 380 μg and the capacitive gap of 6μm, fabricated by deep reactive ion etching (DRIE) and anodic bonding, using three masks. The CMOS readout circuit with a dynamic range of 75dB, a measured capacitive sensitivity of 10.7V/pF, can offer a self-test voltage of 7V by utilizing a charge pump circuit. The hybrid-integrated system with power supply of DC5V has a measured sensitivity of 18mV/g, 1KHz frequency bandwidth and nonlinearity of 0.18% within the measured range of 50g.