ADC Multiplexer Self-Test Circuit for Channel Fault Checking
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Solution Overview
Problem
Current methods for checking multiplexers in analog-to-digital converter arrangements are inefficient, requiring extensive software commands and causing long waiting times for the microcontroller during testing, which is not suitable for safety-relevant applications.
Innovation Solution
An advanced logic circuit within the analog-to-digital converter arrangement that allows for automatic testing of multiplexers, enabling comprehensive checks of input channels for short circuits and couplings through a sequence control activated by a software command, allowing the microcontroller to process other tasks during testing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If current methods for checking multiplexers are used, then testing can be performed, but software complexity increases and waiting times become long
Solution Approach 1:
An intermediary logic circuit is introduced between the microcontroller and the multiplexer testing functions. This logic circuit receives control signals from the microcontroller, automatically executes the testing sequence for the multiplexer, and returns test results to the microcontroller. This intermediary handles the complex testing operations internally, freeing the microcontroller from direct involvement in the complex test sequencing while maintaining reliable testing capability.
2Reliability
If current methods for checking multiplexers are used, then testing can be performed, but waiting times for the microcontroller increase
Solution Approach 1:
The logic circuit is pre-configured with the complete testing sequence and control logic for multiplexer testing. When the microcontroller initiates a test, the logic circuit automatically executes the pre-programmed sequence without requiring the microcontroller to wait for each individual test step. This preliminary preparation of the test sequence in the logic circuit eliminates the need for the microcontroller to be idle during testing operations.
Solution Approach 2:
The logic circuit performs self-service by automatically executing the multiplexer testing sequence without continuous microcontroller intervention. The logic circuit manages its own operation, controlling the testing process, switching between test channels, and generating results autonomously after receiving the initial start command from the microcontroller. This self-service capability allows the microcontroller to proceed with other tasks simultaneously.
3Reliability
If comprehensive testing is implemented, then reliability improves, but device complexity increases
Solution Approach 1:
The logic circuit merges multiple testing functions and control operations into a single integrated unit. Instead of having separate circuits or microcontroller routines for each test function, the logic circuit combines channel switching, test signal generation, result analysis, and status reporting into one consolidated component. This merging reduces overall system complexity while maintaining comprehensive testing capability across all multiplexer channels.
Data Source
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AI summary
The invention relates to an analogue-to-digital converter arrangement (1) with a multiplexer (20) comprising a plurality of channels (K1 to Kn) comprising at least one switch, and an analogue-to-digital converter (30), the analogue input (Sana) of which is connected to the output portal (AP) of the multiplexer (20). The invention also relates to a method for checking a multiplexer (20) for an analogue-to-digital converter (30). According to the invention, at least one additional switch for testing the multiplexer (20) is provided in at least one channel (K1 to Kn), said switch connecting the input portal (EP1 to EPn) and/or the output portal (AP) of the corresponding channel (K1 to Kn) and/or the corresponding channel (K1 to Kn) to a predetermined voltage potential (Uint, UP, earth, UT).