A 27μW MEMS silicon oscillating accelerometer with bias instability and 10-μg/√Hz noise floor

This paper describes an in-plane ultra-low power Micro Electro-Mechanical System (MEMS) silicon oscillating accelerometer (SOA) based on pierce oscillators with CMOS readout circuit and automatic amplitude control (AAC). A noise model is proposed to analyze various noise sources in the system. The noises from the readout circuit are minimized so that the SOA performance is dominated by the Brownian noise from MEMS transducer. The fabricated MEMS SOA achieves a bias instability of 4 μg and a noise floor of 10 μg/√Hz, while consuming only 27 μW under a 1.8-V supply.