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 0.6x2.4x0.1mm~3, 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.