Electromechanical Sigma–Delta Modulators (&lt;inline-formula&gt; &lt;tex-math notation="LaTeX"&gt;$\Sigma \Delta {\mathrm{ M}}$ &lt;/tex-math&gt; &lt;/inline-formula&gt;) Force Feedback Interfaces for Capacitive MEMS Inertial Sensors: A Review

Chen, Fang; Li, Xinxin; Kraft, Michaël

doi:10.1109/jsen.2016.2582198

Cited by 77 publications

(27 citation statements)

References 90 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The electrical Σ∆ loop filter realizes the digitalization of the analog signal and provides main part of quantization noise modulation. The selection of Σ∆ modulating order is a compromise between the sensing element and circuit performance, which stems from the following aspects [6,11,15]:…”

Section: The Electrical σ∆ Loop Filtermentioning

confidence: 99%

“…However, this approach will introduce a pole located at the origin as well, which will severely impair the low frequency loop gain [8,12]. Thus, there is an inevitable trade-off between the effectiveness of the phase compensator and loop performance.The second aspect is synthesizing the desired noise transfer function (NTF) derived from traditional methodology [15]. However due to the unchangeable nature of the MEMS transfer function, there is one degree-of-freedom(DOF) lost in the synthesizing procedure; thus, not all NTFs can be successfully synthesized [12,16].…”

mentioning

confidence: 99%

“…The second aspect is synthesizing the desired noise transfer function (NTF) derived from traditional methodology [15]. However due to the unchangeable nature of the MEMS transfer function, there is one degree-of-freedom(DOF) lost in the synthesizing procedure; thus, not all NTFs can be successfully synthesized [12,16].…”

mentioning

confidence: 99%

See 2 more Smart Citations

A Straightforward Approach for Synthesizing Electromechanical Sigma-Delta MEMS Accelerometers

Chen

Yin

et al. 2019

Sensors

View full text Add to dashboard Cite

The EM-Σ∆ (electromechanical sigma-delta) approach is a concise and efficient way to realize the digital interface for micro-electromechanical systems (MEMS) accelerometers. However, including a fixed MEMS element makes the synthesizing of the EM-Σ∆ loop an intricate problem. The loop parameters of EM-Σ∆ can not be directly mapped from existing electrical Σ∆ modulator, and the synthesizing problem relies an experience-dependent trail-and-error procedure. In this paper, we provide a new point of view to consider the EM-Σ∆ loop. The EM-Σ∆ loop is analyzed in detail from aspects of the signal loop, displacement modulation path and digital quantization loop. By taking a separate consideration of the signal loop and quantization noise loop, the design strategy is made clear and straightforward. On this basis, a discrete-time PID (proportional integral differential) loop compensator is introduced which enhances the in-band loop gain and suppresses the displacement modulation path, and hence, achieves better performance in system linearity and stability. A fifth-order EM-Σ∆ accelerometer system was designed and fabricated using 0.35 µm CMOS-BCD technology. Based on proposed architecture and synthesizing procedure, the design effort was saved, and the in-band performance, linearity and stability were improved. A noise floor of 1 µg/ √ Hz, with a bandwidth 1 kHz and a dynamic range of 140 dB was achieved.Sensors 2020, 20, 91 2 of 17 processing. Moreover, the use of one-bit feedback linearizes the inherent second-order relationship between voltage and electrostatic force effectively [6-10]. Despite the advantages mentioned above, there are still obstacles for a simple implementation. The obstacles mainly come from the MEMS sensing element. Since the limited in-band gain is provided by the MEMS sensing element [11], the total in-band characteristic is degenerated compared to a purely electrical Σ∆ modulator [8]; thus, high-order modulation is inevitable. Meanwhile, in order to suppress the Brownian noise, the sensing element is typically packaged in a vacuum cavity [9,11], resulting a highly under-damped subsystem. Moreover, this second order section is fixed and the inside first-order node (which is velocity) is inaccessible for an electrical circuit [12]. These negative factors mixed together seriously aggravate the synthesizing of loop parameters, which is already a complicated problem for a purely electrical Σ∆ modulator.This problem can be divided into two aspects. First is the stabilization of the EM-Σ∆ loop. For an electrical Σ∆ loop, the proof of stability has not been rigorously established; approximate models and empirical observations are used for stability check [8,13]. The situation is worse for EM-Σ∆, since there is an unchangeable highly under-damped MEMS structure. For most researchers [7-9,14] the first thing is to degenerate this second order section into a first-order one by introducing an adjustable zero. Then, the traditional design strategy for electrical Σ∆ can be used. However, this approach will int...

show abstract

Section: The Electrical σ∆ Loop Filtermentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

A Straightforward Approach for Synthesizing Electromechanical Sigma-Delta MEMS Accelerometers

Chen

Yin

et al. 2019

Sensors

View full text Add to dashboard Cite

show abstract

“…Micro-electromechanical systems (MEMS) gyroscopes are widely used to measure the rotation rate and have many advantages, such as low cost, small size, low power consumption, good complementary metal-oxide semiconductor (CMOS) compatibility, and suitability for batch fabrication [1]. Furthermore, the demand for high-performance micro-machined gyroscopes is growing in platform stabilization, industrial measurement, and many other areas [2,3].…”

Section: Introductionmentioning

confidence: 99%

“…Furthermore, the demand for high-performance micro-machined gyroscopes is growing in platform stabilization, industrial measurement, and many other areas [2,3]. A typical capacitive MEMS gyroscope interface is composed of a capacitance-to-voltage converter (C/V) and an analog-to-digital converter (ADC) [1]. For high precision MEMS gyroscopes, an ADC should have features of high signal-to-noise and distortion ratio (SNDR), a low noise floor, and stable performances under different temperatures and process errors.…”

Section: Introductionmentioning

confidence: 99%

An Auto-Tuning Continuous-Time Bandpass Sigma-Delta Modulator with Signal Observation for MEMS Gyroscope Readout Systems

Zou

et al. 2020

Sensors

View full text Add to dashboard Cite

This paper presents the design and implementation of an auto-tuning continuous-time bandpass sigma-delta (ΣΔ) modulator for micro-electromechchanical systems (MEMS) gyroscope readout systems. Its notch frequency can well match the input signal frequency by adding a signal observation to the traditional ΣΔ modulator. The filter of the observation adopts the same architecture as that of the traditional ΣΔ modulator, allowing the two filters to have the same response to input signal change, which is converted into a control voltage on metal-oxide semiconductor (MOS) resistance in the filters. The automatic tuning not only works to solve the mismatch problem caused by process error and temperature variation, but can also be applied to the interface circuit of gyroscopes with different resonant frequencies. The circuit is implemented in a 0.18-μm complementary metal-oxide semiconductor (CMOS) process with a core area of 2.4 mm2. The improved modulator achieves a dynamic range of 106 dB, a noise floor below 120 dB and a maximum signal-to-noise and distortion ratio (SNDR) of 86.4 dB. The tuning capability of the chip is relatively stable under input signals from 6 to 15 kHz at temperatures ranging from −45 to 60 °C.

show abstract

Design of a Force Balance Geophone Utilizing Bandwidth Extension and Data Acquisition Interface

Zhang

Wang

et al. 2020

Advances in Intelligent Systems and Computing

View full text Add to dashboard Cite

Electromechanical Sigma–Delta Modulators (<inline-formula> <tex-math notation="LaTeX">$\Sigma \Delta {\mathrm{ M}}$ </tex-math> </inline-formula>) Force Feedback Interfaces for Capacitive MEMS Inertial Sensors: A Review

Cited by 77 publications

References 90 publications

A Straightforward Approach for Synthesizing Electromechanical Sigma-Delta MEMS Accelerometers

A Straightforward Approach for Synthesizing Electromechanical Sigma-Delta MEMS Accelerometers

An Auto-Tuning Continuous-Time Bandpass Sigma-Delta Modulator with Signal Observation for MEMS Gyroscope Readout Systems

Design of a Force Balance Geophone Utilizing Bandwidth Extension and Data Acquisition Interface

Contact Info

Product

Resources

About