Analog Chip Self-Test via Internal Signal Loop
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Solution Overview
Problem
Existing integrated circuit electronic chips face challenges in efficiently testing and diagnosing analog circuits without external devices, which complicates the process and reduces accuracy due to signal path length and exposure to disturbances.
Innovation Solution
Incorporating a switch-based connection between analog input and output pads on the chip, allowing for self-diagnosis through digital-analog interface circuits, enabling simultaneous testing of digital-analog converter (DAC) and analog-digital converter (ADC) circuits without external signal generation or measurement, and allowing for flexible configuration of analog signal paths during both diagnosis and use phases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If external devices are used for testing analog circuits, then measurement capability is provided, but device complexity and external dependencies increase
Solution Approach 1:
The electronic chip performs self-diagnosis of its own analog circuits by generating test signals internally through a digital-analog converter and measuring them using an analog-digital converter. The microcontroller analyzes the measured values to detect defects without requiring external testing equipment, thereby eliminating external dependencies while maintaining diagnosis capability
Solution Approach 2:
The existing analog input and output pads are made multi-functional by enabling them to serve both as operational interfaces for external analog signals and as test signal paths for self-diagnosis. During diagnosis mode, the output pad generates test signals that are routed back to the input pad, allowing the same physical interfaces to fulfill multiple purposes without adding dedicated test hardware
2Reliability
If analog signals are transmitted through external paths, then signal measurement is possible, but signal path length increases and exposure to disturbances occurs
Solution Approach 1:
The test signal path is extracted from the external operational path by creating a separate internal loop. The digital-analog converter generates test signals that are directed through a dedicated test path back to the analog input, bypassing external connections. This separation ensures that diagnosis signals remain isolated from external electromagnetic interference and other environmental disturbances
Solution Approach 2:
The switch matrix acts as an intermediary that dynamically routes signals between different paths. During self-diagnosis, the switch matrix directs internally generated test signals through a controlled internal path rather than external paths, mediating between the test signal source and the measurement point while preventing exposure to external disturbances
3Extent of automation
If dedicated test circuits are added for self-diagnosis, then testing capability is provided, but chip area and circuit complexity increase
Solution Approach 1:
The self-diagnosis functionality is merged with the existing operational circuits. The digital-analog converter and analog-digital converter that are already present for normal operation are also utilized for generating and measuring test signals. The switch matrix, which is already part of the signal routing infrastructure, is repurposed to create test signal paths, eliminating the need for separate dedicated test hardware and minimizing additional chip area requirements
4Adaptability or versatility
If analog input and output pads are used for both operation and testing, then versatility is improved, but signal path interference may occur
Solution Approach 1:
The switch matrix provides dynamic routing capability that changes signal paths based on operational mode. During normal operation, the pads are connected to external circuits through specific switch configurations. During self-diagnosis, the switch matrix dynamically reconfigures to route internally generated test signals through the pads in a controlled manner, ensuring that test signals do not interfere with operational signals and that the same physical infrastructure supports both functions without cross-interference
Data Source
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AI summary
The present description relates to an electronic chip comprising at least two analog input (140) and output (142) connection pads respectively, and at least one temporarily activatable electrical link (150) between the input and output pads.