Schurter USL 0603 Fuse Brings ATEX Compliance to Compact, High-Reliability Designs

As demand grows for miniaturised, high-reliability circuit protection, Schurter has released the USL 0603, a quick-acting chip fuse that brings ATEX-level safety to a 0603 footprint. Designed for space-constrained applications in medical, industrial, and hazardous environments, it offers a blend of safety, speed, and thermal resilience in one of the smallest available packages.

Designed for ATEX-Certified Systems

A key feature is the 1.1 mm creepage distance, measured pad-to-pad. This exceeds the IEC 60079-11 requirement of 1 mm for 60 VDC systems used in explosive environments. As a result, the USL 0603 is well suited to ATEX-certified equipment such as:

• Gas and chemical monitoring systems
• Mining electronics
• Portable instruments for hazardous areas

By meeting creepage requirements in a 0603 format, the fuse allows designers to maintain compact board layouts without compromising compliance.

Fast, Predictable Tripping with Low Power Loss

The USL 0603 delivers a quick-acting response, tripping in less than five seconds at 2.5 times the rated current. This provides reliable protection against brief overcurrent spikes without causing unnecessary interruptions.

Its low voltage drop during normal operation minimises power loss and thermal build-up, especially valuable in battery-powered devices and energy-sensitive designs.

Built for Demanding Thermal Environments

Rated for operation up to 150°C, the fuse performs reliably in thermally stressed environments where airflow is limited or where other components generate nearby heat. This includes:

• Embedded medical tools
• Industrial sensor nodes
• Consumer and IoT products with sealed enclosures

Its thermal tolerance gives engineers flexibility when designing for tight enclosures or high-ambient temperature zones.

Applications Beyond Safety-Critical Systems

While the fuse is designed with safety in mind, it’s also a strong fit for more mainstream use cases that require:

• High accuracy
• Tight board space
• Low standby loss

That includes portable medical devices, consumer wearables, and rugged electronics where durability and energy efficiency are essential.

Conclusion

The USL 0603 offers a rare combination of ATEX compliance, fast-acting performance, and thermal durability, all in a 0603 package. For engineers building compact systems with strict safety or efficiency demands, it provides a practical solution with no trade-offs in protection.

To learn more or read the original announcement, click here.