Redundant Sensor Self-Testing Circuit for Multi-Channel ADC Fault Detection
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Solution Overview
Problem
Testing multiple input channels with redundant sensors in IC devices, such as transmission control units, is time-consuming and inefficient, as existing methods require manual testing of all sensors and components, which is not only labor-intensive but also does not effectively utilize the redundancy for self-diagnosis.
Innovation Solution
A self-testing circuit is implemented using analog-to-digital converters (ADCs), multiplexers, and checker circuits that synchronize outputs from primary and redundant sensors to compare digital samples, allowing for efficient detection of faults and component failures within the IC device, thereby reducing testing time and improving diagnostic capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If manual testing of all sensors and components is performed, then testing completeness is improved, but testing time increases
Solution Approach 1:
The circuit enables self-testing functionality where the redundant sensor and associated components automatically test themselves without external testing equipment. The checker circuit compares outputs from primary and redundant sensors, allowing the system to self-diagnose faults in sensors, ADCs, and multiplexers, eliminating the need for time-consuming manual testing while maintaining complete test coverage
Solution Approach 2:
Instead of using external equipment to test the system, the patent inverts the approach by using the system's own redundant components to test each other. The redundant sensor tests the primary sensor path, and the primary sensor tests the redundant sensor path, creating a mutual testing mechanism that reduces external testing requirements
2Reliability
If redundancy is implemented for safety, then reliability is improved, but device complexity increases
Solution Approach 1:
The patent merges the testing functionality into the existing redundant sensor structure. The same redundant sensor that provides safety backup also serves as a test instrument for the primary sensor path. The checker circuit combines the outputs of primary and redundant sensors into a single comparison mechanism, reducing overall system complexity while maintaining both safety and testing capabilities
Solution Approach 2:
The redundant sensor component serves multiple functions: it acts as a backup for safety purposes and simultaneously functions as a test instrument for diagnosing faults in the primary sensor path. This multi-functionality reduces the need for separate testing components, thereby reducing device complexity while maintaining reliability
3Difficulty of detecting and measuring
If all sensors in all input channels are tested, then fault detection capability is improved, but testing time increases
Solution Approach 1:
The checker circuit automatically compares outputs from primary and redundant sensors to detect faults. This self-testing mechanism continuously monitors all input channels without requiring external testing equipment or manual intervention, maintaining high fault detection capability while minimizing testing time
Solution Approach 2:
The self-testing mechanism operates continuously or periodically without interrupting normal system operation. The checker circuit continuously compares sensor outputs, enabling ongoing fault detection across all input channels without requiring separate testing sessions, thereby maintaining detection capability while reducing overall testing time
Data Source
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AI summary
A circuit includes: first analog-to-digital converters, ADCs (105) configured to be coupled to respective ones of first sensors(101); a first multiplexer, MUX (111) coupled to output terminals of the first ADCs; a second MUX (109) configured to be coupled to second sensors (103) which are redundant sensors for the first sensors; a second ADC (107) coupled to an output terminal of the second MUX, the first MUX and the second MUX being controlled by a selection signal (108); a first checker circuit (133) configured to compare a first data at an output terminal of the first MUX with a second data at an output terminal of the second ADC; and a plurality of switches (155) coupled between respective ones of the input terminals of the second MUX and a reference voltage node(154).