Fuses
Fuses are core components used for overcurrent or short-circuit protection in electronic circuits. They cut off abnormal currents by fusing themselves to prevent equipment damage or fire risks and play the role of “safety guards” in electronic systems.
1. Fuses Overview
1) Core Composition
Fuse: The core part, made of materials such as lead-antimony alloy, cuts off the current when it melts.
Electrode: Connects the circuit, and requires low contact resistance and high conductivity.
Bracket: Fixes the fuse, and requires high-temperature resistance, flame retardancy, and insulation.
2) Working principle
When the current exceeds the rated value or a short circuit occurs, the fuse is heated and melted, quickly cutting off the circuit.
2. What are the Types of Fuses?
1) By Protection Form
Overcurrent Protection: Traditional fuse (such as tubular, SMD).
Overheat Protection: Temperature fuse, used in specific temperature control scenarios.
2) By Appearance and Structure
Tubular/Sheet: Such as glass tube, ceramic tube fuse.
SMD/Spiral Type: Suitable for high-density circuit boards or industrial equipment.
Fast-break (F) and Slow-break (T): Designed for instantaneous pulses and continuous overloads, respectively.
3) Special Type
eFuse (Electronic Fuse): Programmable one-time fuse for chip-level secure startup and data protection.
3. What are the Key Parameters of Fuses?
1) Core Parameters
Rated Current: Needs to be derated by 25% according to the circuit load.
Rated Voltage: Need to match the circuit operating voltage.
Fusing Characteristics: Including fusing time and withstand energy.
2) Selection Basis
Ambient temperature, pulse current, installation size, and certification standards (such as UL and IEC).
4. Where are Fuses Used?
Consumer Electronics: Overcurrent protection for mobile phones, computers, and other equipment.
Industrial and Power Systems: Short-circuit protection for distribution cabinets, motor control, and other scenarios.
Automotive Electronics: On-board circuit protection, such as battery management systems.
Chip-level Protection: eFuse is used for secure startup, key storage, etc..
5. Development Trends of Fuses
Intelligence: Programmable devices such as eFuse support dynamic adjustment of protection thresholds.
Miniaturization: SMD fuses meet the needs of highly integrated circuits.
High-performance Materials: Optimizing fuse materials to improve response speed and voltage resistance.