Semiconductor Self-Diagnosis Circuit Current Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The self-diagnosis circuit in on-vehicle MCUs experiences unstable operation due to a large current change rate during power-on self-test, leading to voltage variations in power supply wires.
Innovation Solution
A semiconductor device is designed with a self-diagnosis control circuit that controls pattern generators to differ in stop timings, thereby managing the current flow and reducing rapid changes, ensuring stable operation by suppressing the current change rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple pattern generators operate simultaneously during self-diagnosis, then diagnosis coverage is improved, but current change rate increases causing voltage variation
Solution Approach 1:
The patent segments the simultaneous operation of multiple pattern generators into sequential phases. The self-diagnosis control circuit divides the diagnosis process so that pattern generators operate at different times rather than concurrently, thereby reducing peak current demand and preventing voltage variation while maintaining comprehensive diagnosis coverage.
Solution Approach 2:
The patent implements periodic action by controlling pattern generators to operate in alternating intervals. The self-diagnosis control circuit activates each pattern generator for specific time periods in a sequence, ensuring that current consumption is distributed over time rather than concentrated, thus avoiding harmful voltage fluctuations.
2Device complexity
If pattern generators stop at the same time, then control simplicity is maintained, but rapid current change occurs causing unstable operation
Solution Approach 1:
The patent applies dynamics by making the stop timings of pattern generators variable rather than fixed and uniform. The self-diagnosis control circuit dynamically adjusts the operation periods and stop times of each pattern generator based on their individual characteristics, allowing for smooth current transitions while maintaining reasonable control complexity.
Solution Approach 2:
The patent changes the timing parameters of pattern generator operations. The self-diagnosis control circuit modifies the operation duration and stop timing parameters of each pattern generator individually, creating a controlled sequence that prevents rapid current changes while preserving diagnostic effectiveness.
Data Source
AI summary
A semiconductor device includes a first circuit and a plurality of pattern generators connected to the first circuit and each supplying a test pattern to the first circuit. A pattern-generator control circuit controls each of the plurality of pattern generators such that the pattern generator starts to operate when a control signal is at a first level and the pattern generator stops operating when the control signal is not at the first level. A pattern compressor compresses a result output from the first circuit in response to supply of the test patterns from the plurality of pattern generators. A pattern-compressor control circuit controls the pattern compressor. A self-diagnosis control circuit is connected to the pattern-generator control circuit and the pattern-compressor control circuit and controls the pattern-generator control circuit such that stop timings of the test patterns differ from one another among the plurality of pattern generators due to changing the control signals to selectively stop the pattern generators in a predetermined manner.