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A new sample-and-hold (S&H) architecture is proposed for time-interleaved analog-to-digital converter (ADC). The use of this S&H circuit in front-end of a time-interleaved ADC system eliminates the need for sample-time calibration. Using the techniques of precharging and output capacitor coupling along with a new sampling technique called middle-plate-sampling can mitigate the stringent performance requirements for the opamp and sampling switches, resulting in low power consumption and allowing very high sampling rate. Simulated by HSPICE with a standard BSIM3v3 0.18 [micro]m technology, the S&H achieves 10-12 bits resolution for a 1.6-[V.sub.pp] output at 1-GHz sampling rate. The S&H dissipates 12 mW from a 1.8-V supply. Index Terms--Analog integrated circuits, analog-to-digital circuits (ADCs), CMOS analog integrated circuits, low power analog circuits, pipeline, sample-and-hold (S&H) circuits.

This paper presents a digital gyroscope interface system for high-frequency bulk-acoustic-wave (BAW) gyroscopes with in-run automatic mode-matching (AMM) capability. The presented work demonstrates the design and implementation of the dual-mode (DM) operation architecture on a flexible digital platform, which allows for low-cost rapid development and evaluation of new functions and architectures. Two prototype silicon BAW gyroscopes are tested on this platform using the proposed system to verify the advantages of the DM architecture. The AMM in DM showed below 4-ppb mode split accuracy and fast converge time without overshoot or oscillation. The DM operation with in-run AMM substantially reduced the bias drift of the gyros, leading to significantly lower rate random walk (RRW) compared to conventional single-mode (SM) operation. The performance repeatability and stability over the temperature of the DM gyro system are characterized, showing as high as $50\times $ improvement compared to the SM architecture. [ABSTRACT FROM AUTHOR]

This paper demonstrates a dual-mode actuation and sensing scheme for differential operation and self-calibration of axisymmetric Coriolis resonant gyroscopes. The proposed scheme actuates both modes of an axisymmetric gyroscope with two identical in-phase excitation signals, and senses both modes concurrently. This dual-mode actuation architecture utilizes the difference of the individual mode outputs to cancel out the common-mode bias terms, and provide rate-independent frequency split monitoring. The symmetry of the dual-mode architecture can be utilized to provide in-run scale factor calibration capability by mimicking the mechanical Coriolis force in the electrical domain, thereby providing a virtual electrical rotation to the gyroscope, to estimate the drift of the physical scale factor over time and temperature. The dual-mode architecture is demonstrated on a 2.625-MHz substrate-decoupled bulk acoustic wave gyroscope. The inherent bias cancellation provides sub-10°/hr bias instability, with $1.4\times $ improvement of angle random walk, as compared with the conventional single-mode actuation scheme. Benefiting from the in-run mode-matching capability, the dual-mode actuation scheme exhibits $45\times $ reduction of bias drift over a temperature range of [10–80] °C. In-run scale factor calibration achieves $150\times $ reduction of scale factor turn-on repeatability error down to 62 ppm, and over $100\times $ reduction of the temperature drift of scale factor over [10–50] °C. [ABSTRACT FROM PUBLISHER]

This paper introduces an active electrical technique for dynamic tuning of MEMS resonators. The proposed technique is based on using the resonator output current to generate displacement or acceleration signals by integration or differentiation operations, respectively. The resulting signal is then scaled to generate an appropriate tuning signal. When applied to the resonator through additional signal ports, the tuning signal electrically modifies the equivalent mechanical stiffness or mass of the resonator, thereby tuning the resonance frequency in a bidirectional fashion depending on the polarity of the scaling. This tuning scheme has been applied to a piezoelectric AlN-on-Si BAW square resonator to tune its 14.2 MHz resonance frequency by 22 kHz, equivalent to 1550 ppm. The proposed tuning technique can be applied to a wide range of MEMS resonators and resonant sensors, e.g., to compensate for temperature or process-induced variations in their resonance frequencies. [ABSTRACT FROM AUTHOR]