Low-Power CMOS Wireless MEMS Motion Sensor for Physiological Activity Monitoring

TitleLow-Power CMOS Wireless MEMS Motion Sensor for Physiological Activity Monitoring
Publication TypeJournal Article
Year of Publication2005
AuthorsSadat, A., H. Qu, C. Yu, J. Yuan, and H. Xie
JournalIEEE Transactions on Circuits and Systems I: Regular Papers
Pagination2539 - 2551
Date Published12/2005
KeywordsCMOS interface circuits, Gyroscope, microelectromechanical systems (MEMS), physiological activity monitoring, three-axis accelerometer, wireless motion sensor.

In this paper, a short distance wireless sensor node "AccuMicroMotion" for physiological activity monitoring is proposed for detecting motions in six degrees of freedom. System architecture, relevant microstructures, and electronic circuits to implement the sensor node are presented. A three-axis microelectromechanical systems (MEMS) accelerometer and a z-axis gyroscope are designed and fabricated using a new deep-reactive ion-etch CMOS-MEMS process. The interface circuits, an analog-to-digital converter, and a wireless transmitter are designed using Taiwan Semiconductor Manufacturing Company 0.35-μm CMOS process, wherein the interface circuits adopt chopper stabilization technique and can resolve a signal (dc to 1 kHz) as low as 200 nV from the microsensors; digitized outputs from the microsensors are transmitted by a 900-MHz amplitude-shift-keying radio-frequency transmitter that delivers a 2.2-mW power to a 50-Ω antenna. The system draws an average current of 4.8 mA from a 3-V supply when six sensors are in operation simultaneously and provides an overall 60-dB dynamic range.

Short TitleIEEE Trans. Circuits Syst. I