ESD Self-Test Circuit Using System Monitor Leakage Detection
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Solution Overview
Problem
Integrated circuits are susceptible to damage from Electro-Static Discharge (ESD) events, which can occur during manufacturing or after testing, leading to functional issues and reduced lifespan, as existing detection methods are inadequate for identifying minor ESD damage that may not render devices non-functional immediately.
Innovation Solution
An integrated circuit with a system monitor that includes a driving/measurement node, an ESD protection circuit, and a controller, capable of driving and measuring voltages to detect leakage currents, determining voltage differences indicative of ESD damage, and storing results in memory for quality control purposes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional testing methods are used, then functional failures are detected, but minor ESD damage that does not immediately render devices non-functional cannot be identified
Solution Approach 1:
The system performs preliminary self-testing operations to detect ESD damage before the device is shipped or deployed. The test circuit applies test voltages and measures leakage currents proactively, identifying potential damage early in the manufacturing process or before deployment, preventing future failures without affecting normal device operation.
Solution Approach 2:
A dedicated test circuit acts as an intermediary between the power supply and the ESD protection circuit. This test circuit includes voltage sources, current measurement circuits, and control logic that mediate the testing process, allowing precise measurement of leakage currents through the ESD protection circuit without disrupting the normal function of the protected circuit.
2Measurement precision
If a system monitor is added to detect ESD damage, then detection capability is improved, but device complexity increases
Solution Approach 1:
The test circuit is merged with the existing power supply and control structures of the integrated circuit. The voltage sources are integrated with the power supply network, and the measurement circuits share control logic with other system monitoring functions, reducing the need for entirely separate testing infrastructure and minimizing added complexity.
Solution Approach 2:
The system monitor is designed to perform multiple functions: it monitors power consumption, detects ESD damage through leakage current measurement, and can potentially detect other anomalies. This multi-functionality reduces the need for dedicated separate circuits for each monitoring task, thereby limiting the increase in device complexity while improving detection capabilities.
3Measurement precision
If leakage current measurement is performed continuously, then detection accuracy is improved, but energy consumption increases
Solution Approach 1:
The system performs leakage current measurements periodically rather than continuously. The control circuit schedules test operations at intervals or under specific conditions (e.g., during power-up, before critical operations, or based on usage patterns), maintaining detection accuracy for ESD damage while significantly reducing average power consumption compared to continuous monitoring.
Solution Approach 2:
The system applies test voltages only when necessary to detect ESD damage, rather than maintaining constant high-level monitoring. The test circuit activates voltage sources and measurement circuits partially or excessively only during scheduled test windows, achieving sufficient detection accuracy while minimizing energy consumption during normal operation.
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
Enables self-testing to detect ESD damage in integrated circuits, allowing for early identification and potential rework or scrapping of damaged devices, thereby enhancing quality control and extending the lifespan of functional products.
Implementation Method 1
the system monitor is configured to drive and measure a voltage of the driving/measurement node. The system monitor is further configured to determine, based on driving and measuring the voltage of the driving/measurement node, whether a damaged device is present
Data Source
AI summary
Examples described herein provide a circuit and methods for self-testing to detect damage to a device, which damage may be caused by an Electro-Static Discharge (ESD) event. In an example, an integrated circuit includes an input/output circuit, an ESD protection circuit, and a system monitor. The input/output circuit has an input/output node. The ESD protection circuit is connected to the input/output node. The system monitor has a driving/measurement node selectively connectable to the input/output node. The system monitor is configured to drive and measure a voltage of the driving/measurement node. The system monitor is further configured to determine, based on driving and measuring the voltage of the driving/measurement node, whether a damaged device is present. The damaged device is in the input/output circuit or the ESD protection circuit.