차량용 고 분해능 디지털 MEMS 가속도센서 시스템 IC 개발

This paper presents design, fabrication and measurement of a high resolution digital microelectromechanical systems (MEMS) accelerometer system IC. This system IC consists of a MEMS sensing element and a high resolution digital readout circuit. The MEMS sensing element is fabricated using the sacrificial/bulk micromachining (SBM) process. In order to protect the sensing element from environmental changes, wafer level hermetic packaging(WLHP) process is performed. The developed readout circuit offers 32-bit resolution using an 1-bit, 4th-order ΣΔ modulator and a digital decimator/demodulator. The proposed system IC provides a 128-㎐, 32-bit digital output with ±5g dynamic range, 0.52% nonlinearity, and 1.6*10? count/g scale factor.