A 0.64mm²Sensor Size, 32.5μg/√Hz Noise Floor, High Efficiency MEMS Capacitive Accelerometer Using High-Voltage Pulse Excitation Technique

Small-size MEMS accelerometer with low noise floor and high efficiency is required by the wearable applications such as the bone-conducted speech enhancement. The challenge for the small-size MEMS accelerometer is that the sensor sensitivity decreases with the sensor size scaling down, leading to deterioration of the equivalent input noise floor and the power efficiency [1]–[5]. To meet this challenge, this work proposes an interface IC using high-voltage pulse excitation technique. It achieves a low noise floor of 32.5μg/√Hz with high efficiency (37.2μW·μg·mm 2 /Hz) and small sensor size (0.64mm2/axis).