الفهرس 
An Overview of MEMS SensorsOnly 14 pages are availabe for public view
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Abstract
Delta-Sigma (∆Σ) technique represents an optimum way for realizing force-feedback electromechanical systems, especially for capacitive sen- sors.
Operating the sensor in feedback mode provides many benefits, such as increased signal bandwidth, improved linearity and better temperature stability compared to open-loop mode.
However, with operating the sensor in feedback, the stability of the sys- tem becomes a concern, particularly in ∆Σ based systems and the higher the order of the system the harder it becomes to achieve stability. Hence, following a systematic design flow for these systems is essential.
While the design of stable electrical ∆Σ loops is well established, the design of electromechanical ∆Σ loops present challenge due to the nature of the capacitive sensor resonator.
In this work, a way to stabilize fifth-order ∆Σ based interface system for inertial capacitive sensors is introduced and a systematic design ap- proach is proposed.
The design approach is based on noise transfer function (NTF) match- ing which translates the system design problem to an NTF design problem as in electrical ∆Σ loops.
The design approach is applied to the design of a fifth-order ∆Σ based interface for a capacitive accelerometer.
The sensor has a 0.12 µg proof-mass, a resonance frequency of 8 kHz, a displacement-to-capacitance factor of 3.22 pF/µm and a feedback factor of 0.7 µN/V2.
The designed system achieves a signal-to-quantization noise ratio (SQNR) and signal-to-noise and distortion ratio (SNDR) of 181 dB and 131 dB re- spectively.