Freescale Semiconductor,inc.

Deyou Fang

Dejan Mijuskovic

Mark Edward Schlarmann

Keith L Kraver

Mike A Margules

Heinz Loreck

Hiroto Sahara

Systems and methods are provided for monitoring operation of MEMS accelerometers (). In these embodiments a control loop () having a forward path () is coupled a MEMS transducer (), and a test signal generator () and test signal detector () is provided. The test signal generator () is configured to generate a test signal and apply the test signal to the forward path () of the control loop () during operation of the MEMS accelerometer transducer (). The test signal detector () is configured to receive an output signal from the control loop and detect the effects of the test signal in the output signal. Finally, the test signal detector () is further configured to generate a monitor output indicative of the operation of the sensing device to provide for the continuous monitoring of the operation of the MEMS accelerometer ().

System and method for monitoring an accelerometer

A multi-mass resonator and a common-mode detection circuit are provided. The common-mode detection circuit, for example, may include a plurality of sensing electrodes, an interface circuit configured to interface with the plurality of sensing electrodes, and a common-mode capacitance extractor circuit electrically coupled in parallel to the interface circuit and configured to detect common-mode capacitance between the plurality of sensing electrodes and output a voltage representative the detected common-mode capacitance, and a differential-mode capacitance extractor circuit electrically coupled in parallel to the interface circuit and configured to detect differential-mode capacitance between the plurality of sensing electrodes and output a voltage representative the detected differential-mode capacitance.

Electro-mechanical oscillator and common-mode detection circuit

A MEMS resonator system comprises a MEMS resonator, kick start circuitry, feedback circuitry, an oscillator, and a switch. The MEMS resonator system is configured to provide a pulsed kick-start signal having a frequency and period such that energy delivered to the MEMS resonator is optimized in a short period of time, resulting is reduced oscillator startup time. The MEMS resonator system is configured to switch out the kick-start signal when the MEMS resonator oscillation has been achieved, and switch in feedback circuitry to maintain the MEMS resonator in a state of oscillation.

System and method for improved MEMS oscillator startup

Systems and methods are provided for monitoring operation of MEMS gyroscopes (). A test signal generator () is configured to generate and apply a test signal to the rate feedback loop () of a MEMS gyroscope (). A test signal detector () is coupled to the quadrature feedback loop () of the MEMS gyroscope () and is configured to receive a quadrature output signal from the quadrature feedback loop (). The test signal detector () demodulates the quadrature output signal to detect effects of the test signal. Finally, the test signal detector () is configured to generate a monitor output indicative of the operation of the sensing device based at least in part on the detected effects of the test signal in the quadrature output signal. Thus, the system is able to provide for the continuous monitoring of the operation of the MEMS gyroscope ().

System and method for monitoring a gyroscope

Systems and methods are provided for improved multifunction sensing. In these embodiments a multifunction sensing device () includes a microelectromechanical (MEMS) gyroscope () and at least a second sensor (). The MEMS gyroscope () is configured to generate a first clock signal, and the second sensor includes a second clock signal. The multifunction sensing device further includes a reset mechanism (), the reset mechanism () configured to generate a reset signal to set the relative periodic phase alignment of the second clock signal to the first clock signal. Consistently setting the relative periodic phase alignment of the clocks for the other sensor devices () to the clock of the MEMS gyroscope () can improve the performance of the devices by reducing the probability that varying output offsets will occur in the multiple sensing devices.

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Chandler, AZ, United States of America

Deyou Fang