Small-size MEMS Accelerometer Encapsulated in Vacuum Using Sigma-Delta Modulation

Abstract

A vacuum encapsulated MEMS accelerometer using Sigma-Delta modulation is here presented. Three different modulation orders (second, third, and fourth) were implemented in a field-programable gate array (FPGA), enabling flexibility for tuning the loop parameters in real-time. Three devices were measured, and the results are in good agreement with simulations performed in Simulink. A noise figure of 123 μg/√Hz for a bandwidth of 400 Hz and a range of at least ±1 g was experimentally measured. A figure of merit considering device size and bandwidth is proposed, highlighting the relevance of the results for the current state of the art.

Silicon MEMS inertial sensors evolution over a quarter century

“…© 2020 IEEE. Reprinted, with permission, from [39]. (f) Back view of an in-plane sensor with additional gold bars to reduce thermomechanical noise floor.…”

Combined Temperature Compensation Method for Closed-Loop Microelectromechanical System Capacitive Accelerometer

“…Multiple ways have been proposed to improve the thermal behavior of MEMS accelerometers. Some studies propose the structure in [ 3 , 4 , 5 , 6 , 7 ], other studies reduce the thermal drift via compensating circuits and algorithm [ 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ]. In 2015, Sergei A. Zotov et al introduced a high-quality-factor resonant MEMS accelerometer [ 3 ].…”

“…The experimental data show that the acceleration random walk changes from 1712.66 g/h/Hz 0.5 to 79.15 g/h/Hz 0.5 and the zero-deviation stability changes from 49,275 g/h to 774.7 g/h. In 2020, Vasco L et al introduced a small-size, vacuum-packaged capacitive MEMS accelerometer through Sigma-Delta modulation [ 11 ], using an FPGA (field-programmable gate array) to achieve three different modulation levels, allowing for the flexible real-time adjustment of loop parameters. In 2021, Javier Martínez et al introduced a lightweight thermal compensation technique for a MEMS capacitive accelerometer [ 12 , 13 ].…”

“…Multiple ways have been proposed to improve the thermal behavior of MEMS accelerometers. Some studies propose the structure in [3][4][5][6][7], other studies reduce the thermal drift via compensating circuits and algorithm [8][9][10][11][12][13][14][15][16][17][18][19]. In 2015, Sergei A.…”