MEMS Sensor Equalization with Stored Resonance Parameters
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Solution Overview
Problem
Existing MEMS sensors face challenges in compensating for manufacturing and processing variations, leading to undesired peaking and resonance characteristics in their output signals, which affect signal quality and accuracy.
Innovation Solution
Storing measured sensor parameters, such as resonant frequency, quality factor, and gain, in a non-volatile memory (NVM) of a sensor signal processor, allowing a digital signal processor (DSP) to equalize sensor data using these parameters, thereby compensating for manufacturing variations and improving signal fidelity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If manufacturing variations are present in MEMS sensors, then production cost and ease of manufacture are improved, but signal accuracy and fidelity deteriorate due to peaking and resonance characteristics
Solution Approach 1:
The patent performs preliminary characterization of each MEMS sensor during manufacturing to measure actual resonant frequency, quality factor, and gain parameters. These measured values are stored in non-volatile memory before the sensor is deployed, enabling later use for equalization to compensate for manufacturing variations and maintain signal accuracy.
Solution Approach 2:
The patent changes the operational parameters of the sensor signal processor by adjusting filter coefficients based on measured sensor characteristics. The system modifies resonant frequency, quality factor, and gain parameters through software equalization, transforming the sensor output to compensate for manufacturing variations and eliminate peaking and resonance issues.
2Measurement precision
If per-part measurements and equalization are performed, then signal fidelity is improved, but processing time and device complexity increase
Solution Approach 1:
The patent performs all per-part measurements and characterizations during the manufacturing process, storing the results in non-volatile memory. This preliminary action eliminates the need for complex real-time measurements during deployment, reducing operational processing complexity while maintaining high signal fidelity through pre-computed equalization parameters.
Solution Approach 2:
The patent creates a digital copy of the sensor's characteristic parameters (resonant frequency, quality factor, gain) and stores it in non-volatile memory. This copied information can be retrieved and used for equalization without requiring repeated physical measurements or complex real-time analysis, simplifying the deployment process while maintaining signal fidelity.
3Productivity
If manufacturing variations are present, then production efficiency is improved, but signal quality deteriorates due to resonance peaking
Solution Approach 1:
The patent performs characterization measurements and stores equalization parameters during manufacturing, enabling efficient production without sacrificing signal quality. The pre-measured parameters allow for automated equalization that compensates for manufacturing variations, maintaining signal quality while preserving production efficiency.
Solution Approach 2:
The patent adjusts signal processing parameters based on measured sensor characteristics to compensate for manufacturing variations. By modifying filter coefficients and equalization parameters, the system maintains signal quality and eliminates resonance peaking while allowing for efficient manufacturing processes.
Data Source
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AI summary
Apparatus and methods for equalizing microelectromechanical systems (MEMS) sensors are disclosed. In certain embodiments, measured sensor parameters of a MEMS sensor are stored in a non-volatile memory (NVM) of a sensor signal processor used to process a sensor output signal of the MEMS sensor. The measured sensor parameters are retrieved by a digital signal processor (DSP) and used for equalizing sensor data provided to the DSP by the sensor signal processor during operation. The measured sensor parameters can be determined at test, per individual part, by measurements of the MEMS sensor's characteristics, and thus equalize the MEMS sensor while accounting for manufacturing and/or processing variations.