ABSTRACT
This chapter describes the designs of the front-end amplifiers for MEMS silicon oscillating accelerometers (SOA). It first introduces the capacitive sensing principle for MEMS resonators, followed by a review of the front-end topologies adopted in MEMS oscillators since they are similar to the readout circuit in MEMS SOAs. The review covers single-stage and two-stage resistive transimpedance amplifier (TIA), T-network TIA, charge-sensing amplifier, capacitive feedback TIA, and focuses on their design trade-offs and techniques to relax these trade-offs. In practice, most MEMS processes, such as bulk micromachining, are not compatible with CMOS integrated circuit process. Two-chip solution is usually adopted, where MEMS device and CMOS ASIC or readout circuits are fabricated separately and integrated via wire bonding on a carrier, such as a PCB. The chapter concludes with a performance comparison of some typical front-end amplifiers employed in MEMS oscillators and SOAs.
