Microcontroller-Controlled eFuse for Fast Overcurrent Protection
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Solution Overview
Problem
Conventional fuses are slow to respond to overcurrent faults, lack adjustable thresholds, and are prone to false triggers, requiring maintenance and failing to provide fast and precise protection in electrified vehicle powertrains.
Innovation Solution
A microcontroller-based system that monitors electric circuits, detects high current events using time-based thresholds, and controls an electronically resettable fuse to rapidly open the circuit, preventing damage and avoiding false triggers through fast response times and adjustable thresholds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional fuses are used for overcurrent protection, then the circuit is protected against high current, but the response time is slow and false triggers occur
Solution Approach 1:
The patent replaces the mechanical fuse system with an electronically resettable fuse (eFuse) controlled by a microcontroller. The microcontroller monitors current in real-time and can rapidly open the circuit by controlling the eFuse switch, achieving microsecond-scale response times compared to the slow thermal response of conventional fuses. This substitution of mechanical/thermal systems with electronic control systems resolves the contradiction between reliability and speed.
Solution Approach 2:
The patent implements a feedback mechanism where the microcontroller continuously monitors the current flowing through the circuit and compares it against predefined thresholds. When an overcurrent condition is detected, the microcontroller activates the eFuse to open the circuit. This closed-loop feedback system enables fast response and prevents false triggers by using intelligent threshold comparison, resolving the contradiction between protection reliability and response speed.
2Adaptability or versatility
If conventional fuses are used, then simple protection is provided, but adjustable thresholds and fast response are not achieved
Solution Approach 1:
The patent implements a multi-functional system where the microcontroller performs multiple tasks: monitoring current, comparing against multiple thresholds, detecting overcurrent conditions, and controlling the eFuse. This universal controller handles both simple and complex protection requirements, providing adjustable thresholds for different operating conditions while managing system complexity through integration. The eFuse itself serves multiple functions as a protective device that can be electronically controlled.
Solution Approach 2:
The patent introduces dynamic threshold adjustment capabilities where the microcontroller can adapt protection thresholds based on operating conditions. The system can switch between different current thresholds and respond dynamically to varying load conditions, providing adaptability without requiring multiple fixed-threshold devices. This dynamic behavior resolves the contradiction between versatility and complexity by using software-based adaptability rather than hardware multiplication.
3Reliability
If conventional fuses respond to overcurrent, then protection is provided, but maintenance is required and false triggers occur
Solution Approach 1:
The patent implements a self-service system where the microcontroller continuously monitors circuit conditions and autonomously detects overcurrent events. The eFuse can be electronically reset without physical replacement, and the system provides its own protection accuracy through intelligent current monitoring and threshold comparison. This eliminates the need for manual inspection and replacement of fuses, resolving the contradiction between protection accuracy and maintenance requirements.
Solution Approach 2:
The patent replaces the mechanical fuse that requires physical replacement after blowing with an electronically resettable fuse controlled by a microcontroller. The electronic system can detect overcurrent conditions accurately and reset the circuit without maintenance intervention, eliminating the maintenance burden while maintaining high protection accuracy through continuous electronic monitoring rather than passive mechanical elements.
Data Source
AI summary
Examples described herein provide a computer-implemented method that includes monitoring, using a microcontroller, an electric circuit of a vehicle, the electric comprising a battery source and a load. The battery source supplies electric power to the load. The method further includes detecting, using the microcontroller, a high current event in the electric circuit by comparing a current level of a current flowing through the electric circuit to a time-based current threshold. The method further includes responsive to detecting the high current event, controlling a gate driver to cause a switch of an electronically resettable fuse to open the electric circuit to stop the flow of the current through the electric circuit.