Abstract: According to an embodiment, a phased-locked loop (PLL) circuit, within a gyroscope system, generates demodulation signals. It includes a phase frequency detector receiving gyroscope output, which compares a reference signal with a feedback signal to produce an error signal. A charge pump then converts this error into a first analog control signal. A programmable clamp circuit refines this into a second analog control signal. A voltage-controlled oscillator uses the second signal to produce an output signal at a controlled frequency determined by the clamp circuit. A frequency divider sends a comparison frequency signal back to the detector, completing the loop.

Abstract: According to an embodiment, a circuit is proposed for generating rate and quadrature demodulation signals, incorporating unidirectional hysteresis for negative edges. The circuit features a preliminary stage that amplifies the differential sinusoidal signal from gyroscopic proof mass oscillations; a gain stage for boosting this signal with adjustable hysteresis levels; an output stage delivering a full-swing square wave output; and a customizable offset component to deepen the drop in the non-inverting compared to the inverting signal for the third signal's falling edge.

Abstract: According to an embodiment, a circuit for quadrate error correction is proposed. The circuit includes a set of first resistors receiving a demodulated low-voltage differential signal from gyroscope sense electrodes; an ICMFB circuit with adjustable current sinks maintaining a low-voltage input level by controlling current; an HV driver circuit creating a high-voltage differential output from the low-voltage input, supplied to gyroscope correction electrodes; a set of second resistors where the input-to-output differential gain is defined by their relative resistances; and an output common-mode feedback circuit adapting the high-voltage output to a low-voltage for the HV driver.

Abstract: According to an embodiment, a circuit is proposed for generating rate and quadrature demodulation signals, incorporating unidirectional hysteresis for negative edges. The circuit features a preliminary stage that amplifies the differential sinusoidal signal from gyroscopic proof mass oscillations; a gain stage for boosting this signal with adjustable hysteresis levels; an output stage delivering a full-swing square wave output; and a customizable offset component to deepen the drop in the non-inverting compared to the inverting signal for the third signal's falling edge.

Abstract: According to an embodiment, a phased-locked loop (PLL) circuit, within a gyroscope system, generates demodulation signals. It includes a phase frequency detector receiving gyroscope output, which compares a reference signal with a feedback signal to produce an error signal. A charge pump then converts this error into a first analog control signal. A programmable clamp circuit refines this into a second analog control signal. A voltage-controlled oscillator uses the second signal to produce an output signal at a controlled frequency determined by the clamp circuit. A frequency divider sends a comparison frequency signal back to the detector, completing the loop.

Abstract: At start-up of a microelectromechanical system (MEMS) gyroscope, the drive signal is inhibited, and the phase, frequency and amplitude of any residual mechanical oscillation is sensed and processed to determine a process path for start-up. In the event that the sensed frequency of the residual mechanical oscillation is a spurious mode frequency and a quality factor of the residual mechanical oscillation is sufficient, an anti-phase signal is applied as the MEMS gyroscope drive signal in order to implement an active dampening of the residual mechanical oscillation. A kicking phase can then be performed to initiate oscillation. Also, in the event that the sensed frequency of the residual mechanical oscillation is a resonant mode frequency with sufficient drive energy, a quadrature phase signal with phase lock loop frequency control and amplitude controlled by the drive energy is applied as the MEMS gyroscope drive signal in order to induce controlled oscillation.

Abstract: According to an embodiment, a method includes adjusting a reference generator into a first configuration based on a temporary trim value resulting, in a first reference voltage and a first reference current being generated for a first memory. The method further includes performing an integrity check on an initial set of data downloaded from the first memory based on the first reference voltage and the first reference current. The initial set of data includes a first trim value. The method further includes downloading contents from the first memory into a second memory in response to a successful integrity check after adjusting the reference generator into a second configuration. In the second configuration, the reference generator generates a second reference voltage and a second reference current for the first memory. The reference generator is adjusted by the first trim value in response to a successful integrity check.

Abstract: According to an embodiment, a method includes adjusting a reference generator into a first configuration based on a temporary trim value resulting, in a first reference voltage and a first reference current being generated for a first memory. The method further includes performing an integrity check on an initial set of data downloaded from the first memory based on the first reference voltage and the first reference current. The initial set of data includes a first trim value. The method further includes downloading contents from the first memory into a second memory in response to a successful integrity check after adjusting the reference generator into a second configuration. In the second configuration, the reference generator generates a second reference voltage and a second reference current for the first memory. The reference generator is adjusted by the first trim value in response to a successful integrity check.

Abstract: At start-up of a microelectromechanical system (MEMS) gyroscope, the drive signal is inhibited, and the phase, frequency and amplitude of any residual mechanical oscillation is sensed and processed to determine a process path for start-up. In the event that the sensed frequency of the residual mechanical oscillation is a spurious mode frequency and a quality factor of the residual mechanical oscillation is sufficient, an anti-phase signal is applied as the MEMS gyroscope drive signal in order to implement an active dampening of the residual mechanical oscillation. A kicking phase can then be performed to initiate oscillation. Also, in the event that the sensed frequency of the residual mechanical oscillation is a resonant mode frequency with sufficient drive energy, a quadrature phase signal with phase lock loop frequency control and amplitude controlled by the drive energy is applied as the MEMS gyroscope drive signal in order to induce controlled oscillation.

Abstract: A microelectromechanical system (MEMS) gyroscope includes a driving mass and a driving circuit that operates to drive the driving mass in a mechanical oscillation at a resonant drive frequency. An oscillator generates a system clock that is independent of and asynchronous to the resonant drive frequency. A clock generator circuit outputs a first clock and a second clock that are derived from the system clock. The drive loop of the driving circuit including an analog-to-digital converter (ADC) circuit that is clocked by the first clock and a digital signal processing (DSP) circuit that is clocked by the second clock.

Abstract: At start-up of a microelectromechanical system (MEMS) gyroscope, the drive signal is inhibited, and the phase, frequency and amplitude of any residual mechanical oscillation is sensed and processed to determine a process path for start-up. In the event that the sensed frequency of the residual mechanical oscillation is a spurious mode frequency and a quality factor of the residual mechanical oscillation is sufficient, an anti-phase signal is applied as the MEMS gyroscope drive signal in order to implement an active dampening of the residual mechanical oscillation. A kicking phase can then be performed to initiate oscillation. Also, in the event that the sensed frequency of the residual mechanical oscillation is a resonant mode frequency with sufficient drive energy, a quadrature phase signal with phase lock loop frequency control and amplitude controlled by the drive energy is applied as the MEMS gyroscope drive signal in order to induce controlled oscillation.

Abstract: A microelectromechanical system (MEMS) gyroscope includes a driving mass and a driving circuit that operates to drive the driving mass in a mechanical oscillation at a resonant drive frequency. An oscillator generates a system clock that is independent of and asynchronous to the resonant drive frequency. A clock generator circuit outputs a first clock and a second clock that are derived from the system clock. The drive loop of the driving circuit including an analog-to-digital converter (ADC) circuit that is clocked by the first clock and a digital signal processing (DSP) circuit that is clocked by the second clock.

Abstract: A microelectromechanical system (MEMS) gyroscope sensor has a sensing mass and a quadrature error compensation control loop for applying a force to the sensing mass to cancel quadrature error. To detect fault, the quadrature error compensation control loop is opened and an additional force is applied to produce a physical displacement of the sensing mass. A quadrature error resulting from the physical displacement of the sensing mass in response to the applied additional force is sensed. The sensed quadrature error is compared to an expected value corresponding to the applied additional force and a fault alert is generated if the comparison is not satisfied.

Abstract: A microelectromechanical system (MEMS) gyroscope includes a driving mass and a driving circuit that operates to drive the driving mass in a mechanical oscillation at a resonant drive frequency. An oscillator generates a system clock that is independent of and asynchronous to the resonant drive frequency. A clock generator circuit outputs a first clock and a second clock that are derived from the system clock. The drive loop of the driving circuit including an analog-to-digital converter (ADC) circuit that is clocked by the first clock and a digital signal processing (DSP) circuit that is clocked by the second clock.

Abstract: A microelectromechanical system (MEMS) accelerometer sensor has a mobile mass and a sensing capacitor. To self-test the sensor, a test signal is applied to the sensing capacitor during a reset phase of a sensing circuit coupled to the sensing capacitor. The test signal is configured to cause an electrostatic force which produces a physical displacement of the mobile mass corresponding to a desired acceleration value. Then, during a read phase of the sensing circuit, a variation in capacitance of sensing capacitor due to the physical displacement of the mobile mass is sensed. This sensed variation in capacitance is converted to a sensed acceleration value. A comparison of the sensed acceleration value to the desired acceleration value provides an indication of an error in operation of the MEMS accelerometer sensor if the sensed acceleration value and desired acceleration value are not substantially equal.

Abstract: A microelectromechanical system (MEMS) gyroscope sensor has a sensing mass and a quadrature error compensation control loop for applying a force to the sensing mass to cancel quadrature error. To detect fault, the quadrature error compensation control loop is opened and an additional force is applied to produce a physical displacement of the sensing mass. A quadrature error resulting from the physical displacement of the sensing mass in response to the applied additional force is sensed. The sensed quadrature error is compared to an expected value corresponding to the applied additional force and a fault alert is generated if the comparison is not satisfied.

Abstract: A microelectromechanical system (MEMS) gyroscope sensor has a sensing mass and a quadrature error compensation control loop for applying a force to the sensing mass to cancel quadrature error. To detect fault, the quadrature error compensation control loop is opened and an additional force is applied to produce a physical displacement of the sensing mass. A quadrature error resulting from the physical displacement of the sensing mass in response to the applied additional force is sensed. The sensed quadrature error is compared to an expected value corresponding to the applied additional force and a fault alert is generated if the comparison is not satisfied.

Abstract: A microelectromechanical system (MEMS) gyroscope includes a driving mass and a driving circuit that operates to drive the driving mass in a mechanical oscillation at a resonant drive frequency. An oscillator generates a system clock that is independent of and asynchronous to the resonant drive frequency. A clock generator circuit outputs a first clock and a second clock that are derived from the system clock. The drive loop of the driving circuit including an analog-to-digital converter (ADC) circuit that is clocked by the first clock and a digital signal processing (DSP) circuit that is clocked by the second clock.

Abstract: A microelectromechanical system (MEMS) gyroscope includes a driving mass and a driving circuit that operates to drive the driving mass in a mechanical oscillation at a resonant drive frequency. An oscillator generates a system clock that is independent of and asynchronous to the resonant drive frequency. A clock generator circuit outputs a first clock and a second clock that are derived from the system clock. The drive loop of the driving circuit including an analog-to-digital converter (ADC) circuit that is clocked by the first clock and a digital signal processing (DSP) circuit that is clocked by the second clock.

Abstract: A microelectromechanical system (MEMS) gyroscope includes a driving mass and a driving circuit that operates to drive the driving mass in a mechanical oscillation at a resonant drive frequency. An oscillator generates a system clock that is independent of and asynchronous to the resonant drive frequency. A clock generator circuit outputs a first clock and a second clock that are derived from the system clock. The drive loop of the driving circuit including an analog-to-digital converter (ADC) circuit that is clocked by the first clock and a digital signal processing (DSP) circuit that is clocked by the second clock.