Differential Sensor Stress Compensation via Self-Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Differential sensors face inaccuracies due to mechanical stresses from components with different coefficients of thermal expansion, leading to inefficiencies and high costs in conventional stress compensation methods.
Innovation Solution
A differential sensor system with compensation circuitry that determines a compensation factor based on the difference in mechanical stress between sensor elements, adjusting their output signals to account for stress-related mismatches, eliminating the need for additional stress-sensing elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional stress compensation methods using special low-stress packages, low-stress die attach, mold compound, or ceramic packaging are used, then stress accuracy is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The sensor elements themselves are used to sense the mechanical stress affecting them, eliminating the need for separate stress-sensing elements or special low-stress packages. The sensor elements provide both the primary measurement signal and the stress indication signal, allowing the system to self-diagnose and compensate for stress effects without additional components.
Solution Approach 2:
The sensor elements perform multiple functions: they sense the primary physical quantity (magnetic field, pressure, temperature, etc.) and simultaneously sense the mechanical stress affecting them. This multi-functionality eliminates the need for separate stress-sensing elements or special packaging structures, reducing device complexity while maintaining stress compensation capability.
2Measurement precision
If conventional stress compensation methods using additional stress-sensing elements are used, then stress accuracy is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The sensor elements themselves are used to sense the mechanical stress affecting them, eliminating the need for separate stress-sensing elements or special low-stress packages. The sensor elements provide both the primary measurement signal and the stress indication signal, allowing the system to self-diagnose and compensate for stress effects without additional components.
Solution Approach 2:
The sensor elements perform multiple functions: they sense the primary physical quantity (magnetic field, pressure, temperature, etc.) and simultaneously sense the mechanical stress affecting them. This multi-functionality eliminates the need for separate stress-sensing elements or special packaging structures, reducing device complexity while maintaining stress compensation capability.
3Measurement precision
If individual stress compensation for each sensor element is attempted, then stress accuracy is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent combines the stress sensing function with the primary sensing function into a single integrated approach. By using the sensor elements themselves to sense stress and combining the compensation calculation in a unified circuit, the system avoids the complexity of individual compensation circuits for each sensor element while achieving accurate stress compensation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach simplifies and reduces the cost of stress compensation in differential sensors by using the sensor elements themselves to detect and correct for mechanical stress, providing accurate output signals without additional stress-sensing components.
Implementation Method 1
mechanical stresses that act on the sensor elements... These stresses often relate to sensor package assembly, where various components with different coefficients of thermal expansion are joined together
Data Source
AI summary
Embodiments relate to stress compensation in differential sensors. In an embodiment, instead of compensating for stress on each sensor element independently, stress compensation circuitry aims to remove stress-related mismatch between two sensor elements using the sensor elements themselves to detect the mismatch. A circuit can be implemented in embodiments to detect mechanical stress-related mismatch between sensor elements using the sensor elements, and tune the output signal by a compensation factor to eliminate the mismatch. Embodiments are therefore less complicated and less expensive than conventional approaches. While embodiments have applicability to virtually any differential sensor, including magnetic field, pressure, temperature, current and speed, an example embodiment discussed herein relates to magnetic field.