scholarly journals A High-Performance Digital Interface Circuit for a High-Q Micro-Electromechanical System Accelerometer

Micromachines ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 675 ◽  
Author(s):  
Xiangyu Li ◽  
Jianping Hu ◽  
Xiaowei Liu
Keyword(s):  
High Performance ◽  
Low Noise ◽  
Electromechanical System ◽  
Digital Interface ◽  
Interface Circuit ◽  
Mems Accelerometer ◽  
High Q ◽  
Front End ◽  
Micro Electromechanical System ◽  
Micro Accelerometer

Micro-electromechanical system (MEMS) accelerometers are widely used in the inertial navigation and nanosatellites field. A high-performance digital interface circuit for a high-Q MEMS micro-accelerometer is presented in this work. The mechanical noise of the MEMS accelerometer is decreased by the application of a vacuum-packaged sensitive element. The quantization noise in the baseband of the interface circuit is greatly suppressed by a 4th-order loop shaping. The digital output is attained by the interface circuit based on a low-noise front-end charge-amplifier and a 4th-order Sigma-Delta (ΣΔ) modulator. The stability of high-order ΣΔ was studied by the root locus method. The gain of the integrators was reduced by using the proportional scaling technique. The low-noise front-end detection circuit was proposed with the correlated double sampling (CDS) technique to eliminate the 1/f noise and offset. The digital interface circuit was implemented by 0.35 μm complementary metal-oxide-semiconductor (CMOS) technology. The high-performance digital accelerometer system was implemented by double chip integration and the active interface circuit area was about 3.3 mm × 3.5 mm. The high-Q MEMS accelerometer system consumed 10 mW from a single 5 V supply at a sampling frequency of 250 kHz. The micro-accelerometer system could achieve a third harmonic distortion of −98 dB and an average noise floor in low-frequency range of less than −140 dBV; a resolution of 0.48 μg/Hz1/2 (@300 Hz); a bias stability of 18 μg by the Allen variance program in MATLAB.

scholarly journals Harmonic Distortion Optimization for Sigma-Delta Modulators Interface Circuit of TMR Sensors

Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 1041
Author(s):  
Xiangyu Li ◽  
Jianping Hu ◽  
Xiaowei Liu
Keyword(s):  
High Performance ◽  
Supply Voltage ◽  
Harmonic Distortion ◽  
Low Noise ◽  
Oxide Semiconductor ◽  
Signal Spectrum ◽  
Magnetic Multilayer ◽  
Sigma Delta ◽  
Interface Circuit ◽  
Front End

The tunneling magnetoresistance micro-sensors (TMR) developed by magnetic multilayer material has many advantages, such as high sensitivity, high frequency response, and good reliability. It is widely used in military and civil fields. This work presents a high-performance interface circuit for TMR sensors. Because of the nonlinearity of signal conversion between sensitive structure and interface circuit in feedback loop and forward path, large harmonic distortion occurs in output signal spectrum, which greatly leads to the reduction of SNDR (signal noise distortion rate). In this paper, we analyzed the main source of harmonic distortion in closed-loop detection circuit and establish an accurate harmonic distortion model in TMR micro-sensors system. Some factors are considered, including non-linear gain of operational amplifier unit, effective gain bandwidth, conversion speed, nonlinearity of analog transmission gate, and nonlinearity of polycrystalline capacitance in high-order sigma-delta system. We optimized the CMOS switch and first-stage integrator in the switched-capacitor circuit. The harmonic distortion parameter is optimally designed in the TMR sensors system, aiming at the mismatch of misalignment of front-end system, non-linearity of quantizer, non-linearity of capacitor, and non-linearity of analog switch. The digital output is attained by the interface circuit based on a low-noise front-end interface circuit and a third-order sigma-delta modulator. The digital interface circuit is implemented by 0.35μm CMOS (complementary metal oxide semiconductor) technology. The high-performance digital TMR sensors system is implemented by double chip integration and the active interface circuit area is about 3.2 × 2 mm. The TMR sensors system consumes 20 mW at a single 5 V supply voltage. The TMR sensors system can achieve a linearity of 0.3% at full scale range (±105 nT) and a resolution of 0.25 nT/Hz1/2(@1Hz).

scholarly journals A High Q-Factor Outer-Frame-Anchor Gyroscope Operating at First Resonant Mode

Micromachines ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1071
Author(s):  
Bo Jiang ◽  
Yan Su ◽  
Guowen Liu ◽  
Lemin Zhang ◽  
Fumin Liu
Keyword(s):  
High Performance ◽  
Microelectromechanical Systems ◽  
Resonant Mode ◽  
Low Noise ◽  
Silicon On Insulator ◽  
Q Factor ◽  
Wafer Level ◽  
High Q ◽  
Ring Structures ◽  
Static Performance

Disc gyroscope manufactured through microelectromechanical systems (MEMS) fabrication processes becomes one of the most critical solutions for achieving high performance. Some reported novel disc constructions acquire good performance in bias instability, scale factor nonlinearity, etc. However, antivibration characteristics are also important for the devices, especially in engineering applications. For multi-ring structures with central anchors, the out-of-plane motions are in the first few modes, easily excited within the vibration environment. The paper presents a multi-ring gyro with good dynamic characteristics, operating at the first resonant mode. The design helps obtain better static performance and antivibration characteristics with anchor points outside of the multi-ring resonator. According to harmonic experiments, the nearest interference mode is located at 30,311 Hz, whose frequency difference is 72.8% far away from working modes. The structures were fabricated with silicon on insulator (SOI) processes and wafer-level vacuum packaging, where the asymmetry is 780 ppm as the frequency splits. The gyro also obtains a high Q-factor. The measured value at 0.15 Pa was 162 k, which makes the structure have sizeable mechanical sensitivity and low noise.

Study of a closed-loop high-precision front-end circuit for tunneling magneto-resistance sensors

2019 ◽  
Vol 33 (08) ◽  
pp. 1950085 ◽  
Author(s):  
Xiangyu Li ◽  
Jianping Hu ◽  
Xiaowei Liu
Keyword(s):  
High Precision ◽  
Closed Loop ◽  
Low Frequency ◽  
Cmos Technology ◽  
Low Noise ◽  
Corner Frequency ◽  
Cmos Process ◽  
Interface Circuit ◽  
Front End ◽  
Magneto Resistance

A closed-loop high-precision front-end interface circuit in a standard 0.35 [Formula: see text]m CMOS technology for a tunneling magneto-resistance (TMR) sensor is presented in this paper. In consideration of processing a low frequency and weak geomagnetic signal, a low-noise front-end detection circuit is proposed with chopper technique to eliminate the 1/f noise and offset of operational amplifier. A novel ripple suppression loop is proposed for eliminating the ripple in a tunneling magneto-resistance sensor interface circuit. Even harmonics is eliminated by fully differential structure. The interface is fabricated in a standard 0.35 [Formula: see text]m CMOS process and the active circuit area is about [Formula: see text]. The interface chip consumes 7 mW at a 5 V supply and the 1/f noise corner frequency is lower than 1 Hz. The interface circuit of TMR sensors can achieve a better noise level of [Formula: see text]. The ripple can be suppressed to less than 10 [Formula: see text]V by ripple suppression loop.

Design of High-SNR CMOS Interface Circuit for Micro-Machined Gyroscope

2011 ◽  
Vol 483 ◽  
pp. 508-512
Author(s):  
Hai Xi Lu ◽  
Yong Ping Xu ◽  
Shou Rong Wang
Keyword(s):  
High Gain ◽  
Low Noise ◽  
Sigma Delta Modulator ◽  
Sigma Delta ◽  
Interface Circuit ◽  
Fully Differential ◽  
Chopper Stabilization ◽  
Front End ◽  
Cascade Structure ◽  
Stabilization Technique

A CMOS integrated interface circuit for micro-machined gyroscope containing a novel front-end and 6th-order Sigma-delta modulator is presented in this paper. To reduce the noise coming from the sensor and circuit, the front-end is accomplished by a switched-capacitor architecture, which constructed by a high-gain fully-differential amplifier and improved by chopper-stabilization technique, and work under a designed charging and sampling logic scheme. A cascade 6th-order Sigma-Delta modulator is designed to get high resolution, reduce quantized error and suppress the instability brought by high-order modulator. With the cascade structure and 16-bit resolution 32 OSR, the modulator outputs 3-bits digital stream. The whole circuit is designed with AMS technique and 3.3V power consumption. The simulation result presents that the interface circuit performs a appointed under a low-noise design specification in signal band, and the SNR of the circuit achieves remarkable value of 106dB.

High-Performance Closed-Loop Interface Circuit for High-Q Capacitive Microaccelerometers

2013 ◽  
Vol 13 (5) ◽  
pp. 1425-1433 ◽  
Author(s):  
Zhenhua Ye ◽  
Haigang Yang ◽  
Tao Yin ◽  
Guocheng Huang ◽  
Fei Liu
Keyword(s):  
High Performance ◽  
Closed Loop ◽  
Interface Circuit ◽  
High Q

scholarly journals Chopper Stabilized, Low-Power, Low-Noise, Front End Interface Circuit for Capacitive CMOS MEMS Sensor Applications

2013 ◽  
Vol 7 (12) ◽  
Author(s):  
Nebyu Yonas Sutri ◽  
John Ojur Dennis ◽  
Mohd Haris Md Khir ◽  
Muhammad Umer Mian ◽  
Tong Boon Tang
Keyword(s):  
Low Power ◽  
Low Noise ◽  
Interface Circuit ◽  
Sensor Applications ◽  
Mems Sensor ◽  
Front End ◽  
Cmos Mems

scholarly journals Ultra-Low-Loss Silicon Waveguides for Heterogeneously Integrated Silicon/III-V Photonics

2018 ◽  
Author(s):  
Minh Tran ◽  
Duanni Huang ◽  
Tin Komljenovic ◽  
Jonathan Peters ◽  
Aditya Malik ◽  
...  
Keyword(s):  
High Performance ◽  
Photonic Devices ◽  
Low Noise ◽  
Integrated Photonics ◽  
Delay Lines ◽  
Low Loss ◽  
Silicon Waveguides ◽  
High Q ◽  
Silicon Waveguide ◽  
Ultra Low Noise

Integrated ultra-low-loss waveguides are highly desired for integrated photonics to enable applications that require long delay lines, high-Q resonators, narrow filters, etc. Here we present an ultra-low-loss silicon waveguide on 500 nm thick SOI platform. Meter-scale delay lines, million-Q resonators and tens of picometer bandwidth grating filters are experimentally demonstrated. We design a low-loss low-reflection taper to seamlessly integrate the ultra-low-loss waveguide with standard heterogeneous Si/III-V integrated photonics platform to allow realization of high-performance photonic devices such as ultra-low-noise lasers and optical gyroscopes.

Exquisite Design of a CCD Analog Front End Module

2013 ◽  
Vol 300-301 ◽  
pp. 414-418 ◽  
Author(s):  
Wen Tzeng Huang ◽  
Chao Nan Hung ◽  
Yao Ming Yu ◽  
Qing Han Wu ◽  
Chiu Ching Tuan
Keyword(s):  
High Performance ◽  
Image Sensor ◽  
Low Noise ◽  
Color Filter ◽  
Front End ◽  
Analog Front End ◽  
Filter Array ◽  
Ccd Image Sensor ◽  
Front End Module ◽  
Ccd Image

One of the key technologies for high-resolution camera is the analog front end (AFE) design, which is between the lens and image system process (ISP). The 2 major evaluations of AFE are to evaluate the noise and the ratio between the RGB pixels. Hence, based on the charge coupled device (CCD) image sensor, we present our proposed AFE design to evaluate the CCD noise of the output image with a lower dark current. Our proposed AFE board design is to employee the 1080p (1920×1080) CCD image sensor and its corresponding timing controller with the digital-analog converter (ADC). Our results indicate that our design has the high performance among 6 different digital brands in the low noise applications. Moreover, the CCD sensors with the different resolutions can be installed within the same socket of our AFE board, which can also simultaneously support 3 types, Bayer, Truesense, and Black/White, color filter array.

scholarly journals Ultra-Low-Loss Silicon Waveguides for Heterogeneously Integrated Silicon/III-V Photonics

2018 ◽  
Author(s):  
Minh Tran ◽  
Duanni Huang ◽  
Tin Komljenovic ◽  
Jonathan Peters ◽  
Aditya Malik ◽  
...  
Keyword(s):  
High Performance ◽  
Photonic Devices ◽  
Low Noise ◽  
Integrated Photonics ◽  
Delay Lines ◽  
Low Loss ◽  
Silicon Waveguides ◽  
High Q ◽  
Silicon Waveguide ◽  
Ultra Low Noise

Integrated ultra-low-loss waveguides are highly desired for integrated photonics to enable applications that require long delay lines, high-Q resonators, narrow filters, etc. Here we present an ultra-low-loss silicon waveguide on 500 nm thick SOI platform. Meter-scale delay lines, million-Q resonators and tens of picometer bandwidth grating filters are experimentally demonstrated. We design a low-loss low-reflection taper to seamlessly integrate the ultra-low-loss waveguide with standard heterogeneous Si/III-V integrated photonics platform to allow realization of high-performance photonic devices such as ultra-low-noise lasers and optical gyroscopes.

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