This paper is an overview of current gyroscopes and their roles based on their applications. The considered gyroscopes include mechanical gyroscopes and optical gyroscopes at macro- and micro-scale. Particularly, gyroscope technologies commercially available, such as Mechanical Gyroscopes, silicon MEMS Gyroscopes, Ring Laser Gyroscopes (RLGs) and Fiber-Optic Gyroscopes (FOGs), are discussed. The main features of these gyroscopes and their technologies are linked to their performance.

Gyroscope Technology and Applications: A Review in the Industrial Perspective

A load-dependant peak-current control single-inductor multiple-output (SIMO) DC-DC converter with hysteresis mode is proposed. It includes multiple buck and boost output voltages. Owing to the adaptive adjustment of the load-dependant peak-current control technique and the hysteresis mode, the cross-regulation can be minimized. Furthermore, a new delta-voltage generator can automatically switch the operating mode from pulse width modulation (PWM) mode to hysteresis mode, thereby avoiding inductor current accumulation when the total power of the buck output terminals is larger than that of the boost output terminals. The proposed SIMO DC-DC converter was fabricated in TSMC 0.25 mum 2P5M technology. The experimental results show high conversion efficiency at light loads and small cross-regulation within 0.35%. The power conversion efficiency varies from 80% at light loads to 93% at heavy loads.

https://ir.nctu.edu.tw:443/bitstream/11536/27787/1/000265092300008.pdf

Single-Inductor Multi-Output (SIMO) DC-DC Converters With High Light-Load Efficiency and Minimized Cross-Regulation for Portable Devices

Photonics for angular rate sensing is a well-established research field having very
 important industrial applications, especially in the field of strapdown inertial
 navigation. Recent advances in this research field are reviewed. Results obtained in
 the past years in the development of the ring laser gyroscope and the fiber optic
 gyroscope are presented. The role of integrated optics and photonic integrated
 circuit technology in the enhancement of gyroscope performance and compactness is
 broadly discussed. Architectures of new slow-light integrated angular rate sensors
 are described. Finally, photonic gyroscopes are compared with other solid-state
 gyros, showing their strengths and weaknesses.

Photonic technologies for angular velocity sensing

This review reports an overview and development of micro-gyroscope. The review first presents different types of micro-gyroscopes. Micro-gyroscopes in this review are categorized into Coriolis gyroscope, levitated rotor gyroscope, Sagnac gyroscope, nuclear magnetic resonance (NMR) gyroscope according to the working principle. Different principles, structures, materials, fabrications and control technologies of micro-gyroscopes are analyzed. This review compares different classes of gyroscopes in the aspects such as fabrication method, detection axis, materials, size and so on. Finally, the review evaluates the key technologies on how to improve the precision and anti-jamming ability and to extend the available applications of the gyroscopes in the market and patents as well.

https://iopscience.iop.org/article/10.1088/0960-1317/19/11/113001/pdf

The development of micro-gyroscope technology

This review surveys micromachined gyroscope structure and circuitry technology The principle of micromachined gyroscopes is first introduced Then, different kinds of MEMS gyroscope structures, materials and fabrication technologies are illustrated Micromachined gyroscopes are mainly categorized into micromachined vibrating gyroscopes (MVGs), piezoelectric vibrating gyroscopes (PVGs), surface acoustic wave (SAW) gyroscopes, bulk acoustic wave (BAW) gyroscopes, micromachined electrostatically suspended gyroscopes (MESGs), magnetically suspended gyroscopes (MSGs), micro fiber optic gyroscopes (MFOGs), micro fluid gyroscopes (MFGs), micro atom gyroscopes (MAGs), and special micromachined gyroscopes Next, the control electronics of micromachined gyroscopes are analyzed The control circuits are categorized into typical circuitry and special circuitry technologies The typical circuitry technologies include typical analog circuitry and digital circuitry, while the special circuitry consists of sigma delta, mode matching, temperature/quadrature compensation and novel special technologies Finally, the characteristics of various typical gyroscopes and their development tendency are discussed and investigated in detail

The Development of Micromachined Gyroscope Structure and Circuitry Technology

In this paper, we report on the design, fabrication, and characterization of an in-plane mode-matched tuning-fork gyroscope (M2-TFG). The M2-TFG uses two high-quality-factor (Q) resonant flexural modes of a single crystalline silicon mi- crostructure to detect angular rate about the normal axis. Operating the device under mode-matched condition, i.e., zero-hertz frequency split between drive and sense modes, enables a Q -factor mechanical amplification in the rate sensitivity and also improves the overall noise floor and bias stability of the device. The M2 -TFG is fabricated on a silicon-on-insulator substrate using a combination of device and handle-layer silicon etching that precludes the need for any release openings on the proof-mass, thereby maximizing the mass per unit area. Experimental data indicate subdegree-per-hour Brownian noise floor with a measured Allan deviation bias instability of 0.15deg /hr for a 60-mum-thick 1.5 mm X 1.7 mm footprint M2-TFG prototype. The gyroscope exhibits an open-loop rate sensitivity of approximately 83 mV/deg/s in vacuum. [2007-0100].

A Mode-Matched Silicon-Yaw Tuning-Fork Gyroscope With Subdegree-Per-Hour Allan Deviation Bias Instability

This paper describes a system architecture and CMOS implementation that leverages the inherently high mechanical quality factor (Q) of a MEMS gyroscope to improve performance. The proposed time domain scheme utilizes the often-ignored residual quadrature error in a gyroscope to achieve, and maintain, perfect mode-matching (i.e., ~ 0 Hz split between the high-Q drive and sense mode frequencies), as well as electronically control the sensor bandwidth. A CMOS IC and control algorithm have been interfaced with a 60 mum thick silicon mode-matched tuning fork gyroscope (M2-mathchar TFG) to implement an angular rate sensing microsystem with a bias drift of 0.16deg/hr. The proposed technique allows microsystem reconfigurability-the sensor can be operated in a conventional low-pass mode for larger bandwidth, or in matched mode for low-noise. The maximum achieved sensor Q is 36,000 and the bandwidth of the microsensor can be varied between 1 to 10 Hz by electronic control of the mechanical frequencies. The maximum scale factor of the gyroscope is 88 mV/deg/s . The 3 V IC is fabricated in a standard 0.6 mum CMOS process and consumes 6 mW of power with a die area of 2.25 mm2.

A Sub-0.2 $^{\circ}/$ hr Bias Drift Micromechanical Silicon Gyroscope With Automatic CMOS Mode-Matching

This paper presents the perfect matched-mode operation of a type I non-degenerate z-axis tuning-fork gyroscope (i.e., 0 Hz frequency split between high-Q drive and sense modes). The matched-mode tuning fork gyroscope (M2-TFG) is fabricated on 50-µ m thick SOI substrate and displays an overall rate sensitivity of 24.2 mV/o/s. Allan Variance analysis of the mode-matched device demonstrates an angle random walk (ARW) of 0.045 o/√ hr and a measured bias instability of 0.96 o/hr. Temperature characterization of the M2-TFG verifies that mode matching is maintained over a temperature range of 20-100 ° C.

High Performance Matched-Mode Tuning Fork Gyroscope

In this paper, the design, implementation and characterization of a continuous time transimpedance-based ASIC for the actuation and sensing of a high-Q MEMS tuning fork gyroscope (TFG) is presented. A T-network transimpedance amplifier (TIA) is used as the front-end for low-noise, sub-atto-Farad capacitive detection. The T-network TIA provides on-chip transimpedance gains of up to 25 MOmega, has a measured capacitive resolution of 0.02 aF/radicHz at 15 kHz, a wide dynamic range of 104 dB in a bandwidth of 10 Hz and consumes 400 muW of power. The CMOS interface ASIC uses this TIA as the front-end to sustain electromechanical oscillations in a MEMS TFG with motional impedance greater than 10 MOmega. The TFG interfaced with the ASIC yields a two-chip angular rate sensor with measured rate noise floor of 2.7deg/hr/radicHz, bias instability of 1deg/hr and rate sensitivity of 2 mV/deg/s. The IC is fabricated in a 0.6-mum standard CMOS process with an area of 2.25 mm2 and consumes 15 mW.

A 104-dB Dynamic Range Transimpedance-Based CMOS ASIC for Tuning Fork Microgyroscopes

·In this paper, the design, implementation and characterization of a continuous time transimpedance-based ASIC for the actuation and sensing of a high-Q MEMS tuning fork gyroscope (TFG) is presented. A T-network transimpedance amplifier (TIA) is used as the front-end for low-noise, sub-atto-Farad capacitive detection. The T-network TIA provides on-chip transimpedance gains of up to 25 MΩ, has a measured capacitive resolution of 0.02 aF/√ Hz at 15 kHz, a wide dynamic range of 104 dB in a bandwidth of 10 Hz and consumes 400 μW of power. The CMOS interface ASIC uses this TIA as the front-end to sustain electromechanical oscillations in a MEMS TFG with motional impedance greater than 10 MΩ. The TFG interfaced with the ASIC yields a two-chip angular rate sensor with measured rate noise floor of2.7°/hr/√Hz, bias instability of 1°/hr and rate sensitivity of 2 mV/°/s. The IC is fabricated in a 0.6-μm standard CMOS process with an area of 2.25 mm 2 and consumes 15 mW.

Ajit Sharma

Papers

A Mode-Matched Silicon-Yaw Tuning-Fork Gyroscope With Subdegree-Per-Hour Allan Deviation Bias Instability

A Sub-0.2 $^{\circ}/$ hr Bias Drift Micromechanical Silicon Gyroscope With Automatic CMOS Mode-Matching

High Performance Matched-Mode Tuning Fork Gyroscope

A 104-dB Dynamic Range Transimpedance-Based CMOS ASIC for Tuning Fork Microgyroscopes

A 104-dB dynamic range transimpedance-based CMOS ASIC for tuning fork microgyroscopes