Sensor Configuration With Differential Readout For Fault Detection
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Solution Overview
Problem
In safety-critical environments like automotive applications, existing sensor devices face challenges in achieving redundancy and fault detection while maintaining accuracy and minimizing the number of connections between the sensor and interface circuit, which affects reliability and cost.
Innovation Solution
A sensor device comprising at least three sensing elements with different sensitivities, where the first nodes are connected together and the second nodes are accessible for measuring differential signals, allowing for fault detection through sensitivity differences, and a readout circuit that applies driving signals and calibrates differential signals to determine correct functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If more sensing elements are added to achieve redundancy and fault detection, then safety and reliability are improved, but the number of connections increases
Solution Approach 1:
Multiple sensing elements share a common first node connection, merging multiple signal paths into a single common reference point. This reduces the total number of connections required while maintaining multiple measurement paths for redundancy and fault detection capability.
Solution Approach 2:
The common first node serves multiple sensing elements simultaneously, providing a universal reference point for all measurements. This multi-functional connection point enables redundancy without requiring separate dedicated connections for each sensing element.
2Reliability
If more connections are used to connect additional sensing elements, then fault detection capability is improved, but packaging complexity and cost increase
Solution Approach 1:
The patent merges multiple sensing elements into a shared configuration where the first nodes are connected together, reducing the number of external connections required for packaging while maintaining the capability to detect faults through differential measurement between second nodes.
3Device complexity
If single-ended signal measurement is used to reduce connections, then number of connections is reduced, but measurement accuracy and robustness deteriorate
Solution Approach 1:
The common first node acts as an intermediary reference point that enables differential measurement between second nodes. This intermediary connection allows accurate differential signaling while minimizing the number of external connections required, as the common node serves as a shared reference for all sensing elements.
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 configuration enhances the safety and accuracy of sensor devices by enabling fault detection with a minimal number of connections, improving functional safety integrity while integrating multiple sensors on a single die.
Implementation Method 1
The sensing elements are sensing resistors. The resistance of at least one of the sensing resistors is increasing with increasing physical parameter and the resistance of at least one of the sensing resistors is decreasing with increasing physical parameter
Data Source
AI summary
A sensor device for measuring a physical parameter. The sensor device comprises at least three sensing elements. Each sensing element comprises a first node and a second node. The first nodes of all sensing elements are connected together, and the second nodes are accessible to a readout circuit for measuring differential signals between the second nodes. At least three of the sensing elements have a different sensitivity to the physical parameter.