Mechanical noise-limited CMOS-MEMS accelerometers

Abstract

The latest generation of CMOS-MEMS accelerometer has measured mechanical Brownian noise-limited resolution of 45 /spl mu/g//spl radic/(Hz) at 1 atm. A modified pre-amplifier design with sub-threshold transistor dc biasing is robust against leakage paths to positive and negative supplies and has an input referred noise of 14.6 nV//spl radic/(Hz) at the 2 MHz modulation frequency. The accelerometer proof mass is purposely sized to have equivalent mechanical Brownian noise. An array approach to improve the noise floor further is proposed and fabricated.