Brick Fuses: High-current Circuit Protection For Automotive, Industrial, And Energy Applications
What is a Brick Fuse?
Brick Fuse is a surface mount (SMD) fuse with a shape similar to a brick and a relatively large volume. It is usually packaged in rectangular ceramic or composite materials, with metal fuse elements inside. It is mainly used in circuit protection scenarios that require high rated current, high Breaking Capacity, as well as high temperature and shock resistance.They are widely used in automotive electronics, electric vehicles, industrial control systems, and renewable energy equipment.
How Does a Brick Fuse Work?
A brick fuse operates by using a specially designed fusible element inside the housing. When the electrical current exceeds the fuse’s rated limit, the element heats up due to electrical resistance and melts, breaking the circuit to prevent damage to the protected components. Because brick fuses are built for higher current and voltage ratings, they can safely interrupt large fault currents without shattering or causing secondary damage, even in harsh environments.
Types of Brick Fuses
Brick fuses can be classified according to several criteria:
By Time-Current Characteristic
Fast-Acting: Responds quickly to overcurrent; suitable for sensitive electronics.
Slow-Blow (Time-Delay): Withstands short inrush currents before blowing; suitable for inductive loads like motors.
By Mounting Style
Surface-Mount (SMD): Compatible with automated SMT assembly.
Through-Hole: Provides mechanical stability for high-vibration environments.
By Voltage Rating
Low-voltage automotive types (e.g., 32V, 58V)
Medium to high-voltage industrial and EV types (e.g., 125V, 250V or higher)
Applications of Brick Fuses
Brick fuses are used in applications requiring high reliability and robust circuit protection, such as:
Automotive Electronics
- Electric power steering (EPS)
- Battery management systems (BMS)
- On-board chargers (OBC)
- Advanced driver-assistance systems (ADAS) modules
Renewable Energy and Energy Storage
- Solar inverters
- Energy storage systems (ESS)
- DC fast charging stations
Industrial and Power Equipment
- Industrial motor drives
- High-power power supplies
- Uninterruptible power supplies (UPS)
Brick Fuse Selection Guide
When choosing a brick fuse, consider the following parameters:
- Rated Current – Select a rating slightly above the normal operating current (typically 25%–30% margin).
- Rated Voltage – Must be equal to or higher than the system voltage.
- Breaking Capacity – Ensure it can safely interrupt the maximum short-circuit current in your system.
- Time-Current Characteristics – Choose fast-acting or slow-blow depending on load type.
- Package Size – Match common footprints such as 2410, 3425, or 4512 to your PCB design.
- Operating Temperature – Verify that the fuse meets the environmental requirements of your application.
- Certifications & Standards – Check for compliance with RoHS, REACH, and automotive AEC-Q200 standards if required.