Invensense, Inc.

Infineon Technologies Ag

Aurelio Pellegrini

Maurizio Galvano

Omid Oliaei

Marco Pamato

Daniele Ottini

Damiano Sartori

Enrico Tonazzo

Roberto Guerra

An inertial sensor such as a MEMS accelerometer or gyroscope has a proof mass that is driven by a self-test signal, with the response of the proof mass to the self-test signal being used to determine whether the sensor is within specification. The self-test signal is provided as a non-periodic self-test pattern that does not correlate with noise such as environmental vibrations that are also experienced by the proof mass during the self-test procedure. The sense output signal corresponding to the proof mass is correlated with the non-periodic self-test signal, such that an output correlation value corresponds only to the proof mass response to the applied self-test signal.

Robust inertial sensor self-test

A circuit for a feedback system incorporates a gating mechanism to reduce flicker noise (e.g., a source for bias instability within a MEMS device) at a digital output. The gating mechanism generates a gating pulse with a delay period (e.g., a common, or fixed, delay including symmetrical rising and falling edge delays) that overrides internal delays (e.g., asymmetrical rising and falling edge delays) of a phase generator to prevent propagation delay (e.g., delay affected by jitter) from reaching subsequent feedback components (e.g., a digital-to-analog converter (DAC)) and contributing to the generation of flicker noise within the system.

Clocking scheme for reduced noise in continuous-time sigma-delta adcs preliminary class

A modified version of a MEMS self-test procedure is presented that can be used to detect the amplitude and frequency of an external vibration from an ambient environment. The method implements processing circuitry that correlates an output sense signal, s(t), with a plurality of periodic signal portions and a plurality of shifted periodic signal portions to generate a plurality of correlation values. A frequency associated with the external vibration is determined based on the plurality of correlation values.

Inertial sensor sensing of vibration frequency

The disclosure is directed to a circuit that may detect a single short in a chain of loads, such as light emitting diodes (LEDs). The circuit may drive either multiple LED chains or a single LED chain to determine whether one, or more, of the LEDs in the LED chain is no longer working because of a short. The circuit determines whether the LED chain voltage satisfies a threshold based on a single LED voltage drop. Therefore, the same circuit may be used for applications regardless of the number of LEDs in an LED chain. Additionally, the circuit, according to the techniques of this disclosure may use may use no output pins, other than those used to deliver current to LED chains, regardless of the number of LED chains that the circuit drives.

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Sestola, Italy

Aurelio Pellegrini