E-Fuse Protection Circuit

This project presents the design and implementation of an Electronic Fuse (E-Fuse) protection circuit developed for protecting low-voltage electronic systems from overcurrent and short-circuit conditions. Unlike conventional fuses that permanently break after a fault, this electronic fuse provides faster response, improved reliability, and reusable protection functionality. The circuit is designed using operational amplifiers, passive components, and an IRF9540 P-channel MOSFET to detect abnormal current conditions and disconnect the load instantly whenever the current exceeds the preset threshold value. A sensing network continuously monitors the current flowing through the load, and the op-amp comparator section compares the sensed voltage with a reference voltage generated using resistor dividers. When the fault current rises above the safe limit, the comparator output changes state and drives the MOSFET into cutoff mode, thereby isolating the output from the power source and protecting the connected device. The circuit also includes RC timing components for stability and filtering, along with diode-based feedback and LED indication for fault monitoring. The PCB for the project was custom designed to ensure compact layout, proper trace routing, and reliable operation under load conditions. This project demonstrates practical applications of analog electronics, op-amp comparator circuits, MOSFET switching, and electronic protection systems. The E-Fuse can be used in power supplies, embedded systems, battery-powered devices, IoT applications, laboratory circuits, and automotive low-voltage electronics where reliable and reusable protection is required. Future improvements for the project include adding automatic reset functionality, digital current monitoring, microcontroller integration, display modules for real-time status monitoring, and programmable protection thresholds. This project was developed as an educational and practical electronics design project to understand circuit protection techniques, PCB development, and hardware implementation of intelligent power management systems.