Built-in Self Test Circuit for Analog Verification
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Solution Overview
Problem
Existing methods for testing analog circuit components in integrated circuits are inefficient, complex, and costly, often failing to provide adequate test coverage due to limitations in accessing internal nodes and clock rates.
Innovation Solution
The implementation of a built-in self test (BIST) circuit design that includes an analog circuit block, a current sensor, and a sequencer to capture digital measurements of current flow across various operating modes, enabling efficient verification of analog circuit components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If automated test equipment is used without BIST circuitry to test analog circuits, then the testing process is limited to external terminals, but the test coverage is inadequate and many defects are not detected
Solution Approach 1:
The patent introduces BIST circuitry as an intermediary component within the device under test that enables internal node access. This BIST circuitry acts as a mediator between the external tester and internal circuit nodes, allowing comprehensive testing of analog circuits without requiring direct physical access to internal nodes during normal operation.
2Reliability
If BIST circuitry is implemented to access internal nodes, then test coverage improves, but the areal requirements and complexity increase relative to the circuitry being tested
Solution Approach 1:
The patent implements a universal BIST architecture that can test multiple types of analog circuits (amplifiers, filters, oscillators, data converters) using a single set of test circuits. The BIST circuitry is designed to be multi-functional, handling various test modes and circuit configurations without requiring separate dedicated test circuits for each analog component type.
Solution Approach 2:
The patent utilizes parameter changes in current consumption as the basis for detecting analog circuit defects. By monitoring and comparing current parameters under different operating conditions and test modes, the BIST system can identify faults without requiring complex measurement circuits, thereby reducing overall test circuit complexity while maintaining high test coverage.
3Reliability
If traditional analog testing methods are used, then testing can be performed, but the process is infeasibly slow relative to the circuitry being tested
Solution Approach 1:
The patent replaces traditional slow analog measurement methods with digital current sensing and processing. By converting analog current measurements into digital signals and using digital signal processing techniques, the system achieves both high measurement accuracy and fast test speeds, overcoming the fundamental speed-accuracy tradeoff in traditional analog testing.
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 approach allows for rapid and comprehensive testing of integrated circuit devices, achieving high test coverage and detecting manufacturing faults with minimal surface area requirements, while being significantly faster than comparable methods.
Implementation Method 1
a current sensor configured to provide digital measurements of the current flow
Data Source
AI summary
Illustrative integrated circuit devices are provided with built-in self test circuit designs and verification methods. One disclosed integrated circuit device includes: an analog circuit block configured to be powered by a current flow from a first power rail and an intermediate node; a current sensor configured to provide digital measurements of the current flow; a built-in self test circuit configured to set the analog circuit block in a sequence of operating modes and coupled to the current sensor to capture for each operating mode a corresponding one of the digital measurements.