A novel Universal Resonator Controller (URC) architecture and ASIC design is presented for precision, wideband resonator velocity control and the digitally demodulated readout of resonator velocity and frequency with the designed resolution «100ppb/rt-Hz), linearity (lppm) and sensor bandwidth (>100Hz) required for navigation grade vibratory inertial sensors. In this paper, our two-channel URC ASIC design is described for control and readout of the two inertially-coupled modes of a vibratory gyroscope or the two uncoupled modes of a dual beam vibratory accelerometer. Like the evolution of the high yield, high performance operational amplifier, single, dual, or quad channel URC ASIC configurations are anticipated to implement single-axis, two-axis, or three-axis IMU or INS. Our first URC ASIC has been submitted for fabrication in a 4.1mmx4.1mm, 180nm CMOS die. Each URC additionally provides digitally selectable analog gains and two DACs per channel with up to 30V range for tuning of residual machining errors, on-line precision quadrature or amplitude control. A low power digital demodulator is being developed with FPGA for subsequent CMOS integration. With this universal ASIC architecture and exemplary wafer-level-packaged, high Q MEMS in-plane resonators, a compact 2D and 3D Navigation System on Chip (NSoC™) architecture is enabled to increase the production scale and radically reduce the cost, size, weight, and power of electronics and systems for numerous existing and future highly compact MEMS inertial navigation applications. The ASIC design and its application to CVG and DRBA control, will be discussed including the electronics trades, and analog breadboard developments supporting its design.

The 300°C Microelectromechanical system (MEMS) gyroscope project aims to contribute to DOE’s goal of increased geothermal drilling efficiency by 2025 through the development of a 300°C MEMS gyroscope for Measurement While Drilling (MWD). At the conclusion of the 2-year project, the team will develop a 300°C capable MEMS gyroscope containing GE’s patented Multi-Ring Gyroscope Transducer (MRGT) design, custom Silicon-On-Insulator (SOI) based frontend and feedback control electronics, and with demonstrated functionality and lifetime beyond 1000 hours. The project is divided into two budget periods with Go/No-Go decision at the end of the first budget period. The goal for the first budget period is to establish the feasibility of the MRGT and electronics design for meeting the 300°C performance requirements. The goal for the second budget period is to integrate the MRGT with the SOI-based application specific integrated circuit (ASIC) and demonstrate capability to operate at 300°C for 1000 hours. In Budget Period 1 we met the phase 1 goal. We successfully validated the combined MRG, electronics and packaging capability entitlement to achieving 0.5 degrees azimuth uncertainty while enabling operation at significantly higher temperatures than the state-of-the-art. In Budget Period 2, we successfully completed the integration of the MRGT and ASIC with associated high temperature, high reliability packaging to demonstrate the performance and functionality of the integrated gyroscope across the temperature range from room temperature to at 300°C. Furthermore, the team demonstrated operating life of >1,000 hours at 300°C, thus providing a validation of application-relevant lifetime capability.

A universal ASIC, iWCA1001, for navigation grade inertial sensors and a Navigation System on Chip (NSoC™) integration architecture is presented to greatly increase the production scale and radically reduce the cost, size, weight and power of integrated inertial navigation systems for any terrestrial application, with efficient extensions for space radiation (1Mrad) environments. Given the laboratory demonstration of navigation- or near-navigation grade inertial MEMS and compact sensors with performance suitable for high volume commercial and military applications, the emergence of high-yield precision MEMS fabrication platforms with thick device layers, wafer level vacuum packaging [3] and flexible substrates, such a universal compact electronics approach for low C-SWaP navigation grade sensors, IMUs and INSs is feasible and timely.

This paper presents a new Inertial Measurement Unit aimed at near term, low cost, compact terrestrial navigation and space pointing applications. It is enabled by InertialWave's Navigation Grade CVG ASIC for precise, collocated digital control of a symmetric, piezoelectrically-transduced Coriolis Vibratory Gyro (CVG). This ASIC also provides digital readout of a co-axial accelerometer enabling a compact IMU architecture comprising three single-axis digital sensor assemblies integrated into a rigid IMU block along with a central processor for host interface. This paper reviews the need for such an IMU and current state of the art. The CVG analog electronics background and earlier breadboard concept demonstration of a lower noise digitally controlled symmetric PZT CVG achieving 0.00033 deg/rt-h ARW [1] are summarized leading to discussion of this new development of an ASIC enabled compact, low cost IMU based on this CVG and a selected accelerometer. The mechanical, electronic and digital control approaches are outlined and the planned progression of development models leading to a final IMU product are discussed including early environmental test assessment. Finally recent development test results using an enclosed CVG with front-end electronics mounted on an IMU test block with improved digital control and compensation demonstrating repeatable drift performance over an 8-hour period with 0.015 deg/h in-run stability are reported.

We present a novel electronics method of operation of a Coriolis Vibratory Rate Integrating Gyroscope (RIG) that corrects or compensates all sources of asymmetry with sufficient precision and low front-end electronic noise to yield milli-arc-second/rt-Hz angle noise and minimum rate error only limited by mechanical thermal noise. This method enables complete RIG self-calibration with zero rate input and yields zero rate bias for low fixed rate measurement e.g., earth rate and supports wideband analog control or highly precise digital control. The method provides ideal RIG performance, excellent scale factor, wide bandwidth, electronics suitable for ASIC implementation, and is anticipated to be suitable for emerging navigation grade MEMS gyroscopes and may surpass current state-of-the-art Rate Gyro (RG) operation.