A Feedforward Noise Reduction Technique in Capacitive MEMS Accelerometer Analog Front-End for Ultra-Low-Power IoT Applications

An ultra-low-power (ULP) capacitive micro-electromechanical systems (MEMS) accelerometer analog front-end (AFE) chip with 290-<inline-formula> <tex-math notation="LaTeX">$\mu \text{g}/\surd $ </tex-math></inline-formula>Hz noise floor and 252-nW power consumption is presented. To achieve such low-noise characteristics under ULP operation, the proposed AFE utilizes a novel circuitry scheme, namely, feedforward noise reduction technique (FNRT), which cancels some of the correlated noise. The FNRT is a simple modification of the conventional self-balancing bridge (SBB) architecture without using any extra power and it can relax the noise requirement on amplifiers in AFE, thereby reducing its power consumption. The designed system uses an SAR ADC employing a simple signal-to-noise ratio (SNR) enhancement technique and includes a finite state machine (FSM) to enable dynamic configuration and duty-cycling operation. The AFE chip is implemented in a 0.18-<inline-formula> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> complementary metal–oxide–semiconductor (CMOS) process and achieves a dynamic range of 65 dB and the bias instability of 62.8 <inline-formula> <tex-math notation="LaTeX">$\mu \text{g}$ </tex-math></inline-formula>.

[1]  Kari Halonen,et al.  A 1.5μW 1V 2nd-Order ΔΣ Sensor Front-End with Signal Boosting and Offset Compensation for a Capacitive 3-Axis Micro-Accelerometer , 2008, 2008 IEEE International Solid-State Circuits Conference - Digest of Technical Papers.

[2]  C. Van Hoof,et al.  A 3-axis accelerometer and strain sensor system for building integrity monitoring , 2011, 2011 16th International Solid-State Sensors, Actuators and Microsystems Conference.

[3]  Soon-Jyh Chang,et al.  A 10-bit 50-MS/s SAR ADC With a Monotonic Capacitor Switching Procedure , 2010, IEEE Journal of Solid-State Circuits.

[4]  Kari Halonen,et al.  A High-Resolution Accelerometer With Electrostatic Damping and Improved Supply Sensitivity , 2012, IEEE Journal of Solid-State Circuits.

[5]  Erkka Laulainen,et al.  A Micropower �-Based Interface ASIC for a Capacitive 3-Axis Micro-Accelerometer , 2009 .

[6]  H. Leuthold,et al.  An ASIC for high-resolution capacitive microaccelerometers , 1990 .

[7]  Behraad Bahreyni,et al.  A Wideband, Low-Noise Accelerometer for Sonar Wave Detection , 2018, IEEE Sensors Journal.

[8]  Boris Murmann,et al.  A ΔΣ interface for MEMS accelerometers using electrostatic spring-constant modulation for cancellation of bondwire capacitance drift , 2012, 2012 IEEE International Solid-State Circuits Conference.

[9]  Vladimir P. Petkov,et al.  A Fully Differential Charge-Balanced Accelerometer for Electronic Stability Control , 2013, IEEE Journal of Solid-State Circuits.

[10]  Mikko Saukoski,et al.  A Micropower Interface ASIC for a Capacitive 3-Axis Micro-Accelerometer , 2007, IEEE Journal of Solid-State Circuits.

[11]  Lei Shu,et al.  Survey of Fog Computing: Fundamental, Network Applications, and Research Challenges , 2018, IEEE Communications Surveys & Tutorials.

[12]  Kari Halonen,et al.  Continuous-time interface for a micromachined capacitive accelerometer with NEA of 4 μg and bandwidth of 300 Hz , 2009 .

[13]  H. Oguey,et al.  CMOS Current Reference without Resistance , 1996, ESSCIRC '96: Proceedings of the 22nd European Solid-State Circuits Conference.

[14]  Michael Kraft,et al.  A High-Precision and High-Bandwidth MEMS-Based Capacitive Accelerometer , 2018, IEEE Sensors Journal.

[15]  Yan Su,et al.  A 0.23- $\mu \text{g}$ Bias Instability and 1- $\mu \text{g}/\surd $ Hz Acceleration Noise Density Silicon Oscillating Accelerometer With Embedded Frequency-to-Digital Converter in PLL , 2017, IEEE Journal of Solid-State Circuits.

[16]  Yan Su,et al.  A Sub-µg Bias-Instability MEMS Oscillating Accelerometer With an Ultra-Low-Noise Read-Out Circuit in CMOS , 2015, IEEE Journal of Solid-State Circuits.

[17]  Zengjun Liu,et al.  An Accelerometers-Size-Effect Self-Calibration Method for Triaxis Rotational Inertial Navigation System , 2018, IEEE Transactions on Industrial Electronics.

[18]  Ippei Akita,et al.  A chopper-stabilized instrumentation amplifier using area-efficient self-trimming technique , 2014 .

[19]  Sergey Edward Lyshevski,et al.  Signal Processing in Cyber-Physical MEMS Sensors: Inertial Measurement and Navigation Systems , 2017, IEEE Transactions on Industrial Electronics.

[20]  Huikai Xie,et al.  A Monolithic CMOS-MEMS 3-Axis Accelerometer With a Low-Noise, Low-Power Dual-Chopper Amplifier , 2008, IEEE Sensors Journal.

[21]  Yong Ping Xu,et al.  A 0.4 $\mu \text{g}$ Bias Instability and 1.2 $\mu \text{g}/\surd $ Hz Noise Floor MEMS Silicon Oscillating Accelerometer With CMOS Readout Circuit , 2017, IEEE Journal of Solid-State Circuits.

[22]  R. Jacob Baker.  Cmos: Mixed-Signal Circuit Design , 2002 .

[23]  Bernhard E. Boser,et al.  A three-axis micromachined accelerometer with a CMOS position-sense interface and digital offset-trim electronics , 1999, IEEE J. Solid State Circuits.

[24]  Boris Murmann,et al.  A $\Delta \Sigma$ Interface for MEMS Accelerometers Using Electrostatic Spring Constant Modulation for Cancellation of Bondwire Capacitance Drift , 2012, IEEE Journal of Solid-State Circuits.

[25]  Peng Peng,et al.  Structural Designing of a MEMS Capacitive Accelerometer for Low Temperature Coefficient and High Linearity , 2018, Sensors.

[26]  Huikai Xie,et al.  A Low-Power Low-Noise Dual-Chopper Amplifier for Capacitive CMOS-MEMS Accelerometers , 2011, IEEE Sensors Journal.

[27]  Ye Li,et al.  Accelerometer-Based Speed-Adaptive Gait Authentication Method for Wearable IoT Devices , 2019, IEEE Internet of Things Journal.

[28]  Ippei Akita,et al.  A 181NW 970µG✓HZ Accelerometer Analog Front-End Employing Feedforward Noise Reduction Technique , 2018, 2018 IEEE Symposium on VLSI Circuits.

[29]  Gabor C. Temes,et al.  Circuit techniques for reducing the effects of op-amp imperfections: autozeroing, correlated double sampling, and chopper stabilization , 1996, Proc. IEEE.

[30]  Hao Kang,et al.  A Closed-Loop Accelerometer Based on Three Degree-of-Freedom Weakly Coupled Resonator With Self-Elimination of Feedthrough Signal , 2018, IEEE Sensors Journal.

[31]  PRADIP KUMAR SHARMA,et al.  A Software Defined Fog Node Based Distributed Blockchain Cloud Architecture for IoT , 2018, IEEE Access.