%0 Journal Article
%T Reconfigurable Closed-Loop Digital ¦¤¦˛ CapacitiveMEMS Accelerometer for Wide Dynamic Range, HighLinearity Applications
%A Chao Wang
%A Kevin T. C. Chai
%A Vladimir Suplin
%A David Nuttman
%J International Journal of Information and Electronics Engineering
%D 2013
%I IACSIT Press
%R 10.7763/ijiee.2013.v3.262
%X Closed-loop capacitive MEMS accelerometer issimilar to a ¦¤¦˛ ADC where the MEMS sensor introducessecond-order dynamics in the loop. The sensor has limitedsignal gain, hence provides very limited noise shaping capabilityto other noise contributions within the loop. Furthermore,fabrication non-idealities can cause unwanted stability issues inhigher order closed-loop operation. We present a 4th order ¦¤¦˛closed-loop system with a digital 2nd order ¦¤¦˛ modulator. Thedigital ¦¤¦˛ modulator allows fine accuracy in choosing thecoefficients for the ¦¤¦˛ modulators. It also provides flexibility inthe placement of poles and zeros for compensating theunforeseen phase delays caused by fabrication non-idealities.Our system is able to achieve an SNR > 120dB in simulationand > 90dB from experiment with an evaluation board. Thedigital implementation of ¦¤¦˛ modulator allows us to buildreconfigurable closed-loop system with the potential for evenhigher order system which can be optimized to suit differentMEMS sensor characteristics and performance.
%K Noise transfer function
%K electronic filter
%K feedback
%K MEMS sensor
%U http://www.ijiee.org/papers/262-L0056.pdf