A Low-Power Low-Noise Dual-Chopper Amplifier for Capacitive CMOS-MEMS Accelerometers

Author

Sun, Hongzhi ; Fang, Deyou ; Jia, Kemiao ; Maarouf, Fares ; Qu, Hongwei ; Xie, Huikai

Author_Institution

Dept. of Electr. & Comput. Eng., Univ. of Florida, Gainesville, FL, USA

Volume

11

Issue

4

fYear

2011

fDate

4/1/2011 12:00:00 AM

Firstpage

925

Lastpage

933

Abstract

This paper reports a novel dual-chopper amplifier (DCA) and its application to monolithic complementary metal-oxide semiconductor-microelectromechanical systems accelerometers. The DCA design minimizes the power consumption and noise by chopping the sensing signals at two clocks. The first clock is a high frequency for removing the flicker noise while the second clock is a significantly lower frequency to keep the unit gain bandwidth low. A monolithic three-axis accelerometer integrated with the DCA on the same chip has been successfully fabricated using a post-CMOS micromachining process. The measured noise floors are 40 μ g/√Hz in the x - and y -axis and 130 μ g/√Hz in the z -axis, and the power consumption is about 1 mW per axis.

Keywords

CMOS analogue integrated circuits; accelerometers; capacitive sensors; choppers (circuits); electric noise measurement; flicker noise; low noise amplifiers; low-power electronics; micromachining; microsensors; DCA; DCA design; capacitive CMOS-MEMS accelerometer; clock; flicker noise; low-power low-noise dual-chopper amplifier; monolithic complementary metal-oxide semiconductor-microelectromechanical system; monolithic three-axis accelerometer; noise measurement; post-CMOS micromachining process; power consumption; Accelerometer; capacitive sensing; chopper stabilization; complementary metal–oxide semiconductor–microelectromechanical systems (CMOS-MEMS); dual-chopper amplifier (DCA); microelectromechanical systems (MEMS); monolithic integration;

fLanguage

English

Journal_Title

Sensors Journal, IEEE

Publisher

ieee

ISSN

1530-437X

Type

jour

DOI

10.1109/JSEN.2010.2064296

Filename

5582186