A MEMS ACCELEROMETER WITH A SINGLE AXIS TWO PROOF MASSES FOR A WIDE DETECTION RANGE

This paper describes a single axis MEMS accelerometer with the wide detection range of acceleration from micro-G level to 20 G
$(\mathrm{G}=9.8\ \mathrm{m}/\mathrm{s}^{2})$
. We propose the MEMS accelerometer with two proof masses on a single chip of
$4 \times 4\ \text{mm}^{2}$
in area. One proof mass is for over micro-G level sensing and the other is for below 20 G sensing. The experimental results of the fabricated device show that the Brownian noise
$B_{\mathrm{N}}$
and the sensitivity
$S$
of the proof mass for over micro-G level are
$0.18 \mu \mathrm{G}/\sqrt{\text{Hz}}$
and 5.0 pF/G, respectively and these of it for below 20 G are
$0.81 \mu \mathrm{G}/\sqrt{\text{Hz}}$
and
$3.7 \times 10^{-2}\ \text{pF}/\mathrm{G}$
, respectively. It is confirmed that the proposed device could realize the wide detection range of acceleration from micro-G level to 20 G. (130)