MEMS Gyroscope Circuit for Direct Phase Offset Measurement
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Solution Overview
Problem
Existing methods for compensating phase offset in MEMS gyroscopes are limited by indirect measurements, leading to significant errors due to stringent precision requirements, and often require costly temperature measurements in production.
Innovation Solution
A circuit and method for MEMS gyroscopes that includes a signal generator to apply a sinusoidal test signal directly to the driver and readout circuits, allowing direct measurement and accurate determination of phase offset without external support, enabling built-in automatic calibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Difficulty of detecting and measuring
If indirect measurement methods are used to determine phase offset, then the measurement process is simpler, but the measurement precision deteriorates significantly
Solution Approach 1:
The gyroscope system performs self-diagnosis by using its own operational signals (drive signal and readout signal) to measure the phase offset. The system generates a test signal, processes it through its own circuits, and measures the phase difference between input and output signals, eliminating the need for external measurement equipment and achieving high precision through self-characterization.
2Manufacturing precision
If temperature measurements are performed in production to adjust offset coefficients, then the compensation accuracy is improved, but the manufacturing cost increases
Solution Approach 1:
The gyroscope performs automatic calibration using its own operational signals without requiring external temperature measurement equipment or manual adjustment. The system measures the phase offset using its drive and readout signals, calculates the optimal compensation coefficient automatically, and applies the correction, eliminating costly production testing while maintaining high compensation accuracy.
3Measurement precision
If external devices are used to measure phase offset, then the measurement capability is provided, but the device complexity and cost increase
Solution Approach 1:
The gyroscope system measures its own phase offset by utilizing its internal drive signal and readout signal paths. The system generates a test signal, passes it through the driver and readout circuits, and measures the phase difference between the applied signal and the resulting response signal, completely eliminating the need for external measurement devices and reducing overall system complexity.
Data Source
AI summary
A circuit for a MEMS gyroscope having at least one mass excitable to an oscillatory motion. The circuit includes: a signal generator circuit for generating a periodic test signal, the test signal being applicable to a first MEMS-side signal input of a driver circuit and/or to a second MEMS-side signal input of a readout circuit and causing a response measurement signal, so that the phase offset between a demodulation signal and the response measurement signal can be determined on the basis of the response measurement signal. A corresponding method for operating a MEMS gyroscope is also described.