RUSBF155-2

Ptc Resettable Fuses Overview

The Littelfuse RUSBF155-2 is a polymeric PTC resettable fuse rated for a maximum voltage of 6V and a hold current (Ih) of 1.55A. It features a trip current (It) of 2.65A with a maximum trip time of 2.2 seconds. The device exhibits an initial resistance (Ri) minimum of 40 mOhms and a post-trip resistance (R1) maximum of 100 mOhms. Designed for through-hole radial disc mounting, it has a lead spacing of 0.201 inches (5.10mm). The component operates within a temperature range of -40°C to 85°C and supports a maximum fault current of 40A.

Ptc Resettable Fuses Feature Summary

• Polymer-based self-resetting overcurrent protection mechanism
• Low initial resistance for minimal power loss in normal operation
• Fast response time to overcurrent conditions
• Through-hole radial disc package for standard PCB integration

Ptc Resettable Fuses Applications

• Portable electronic devices requiring low-voltage circuit protection
• Battery-powered equipment safeguarding against short circuits
• Consumer electronics interfaces and peripheral connections
• Automotive low-voltage signal line protection

Ptc Resettable Fuses Procurement Notes

Verify the specific suffix designation when ordering, as packaging quantities and reel specifications may vary between standard and tape-and-reel variants. Confirm that the selected variant meets the required thermal derating curves for the intended operating environment. Ensure compatibility with automated insertion equipment if high-volume production is planned. Cross-reference certification marks such as UL, CSA, and TUV against regional regulatory requirements for the final product assembly.

Ptc Resettable Fuses Selection Notes

Select this component based on the system's nominal voltage not exceeding 6V and the continuous load current remaining below 1.55A. Evaluate the ambient temperature conditions to ensure the hold current rating remains sufficient after applying necessary thermal derating factors. Consider the physical dimensions and lead spacing constraints of the target printed circuit board layout. Assess the expected fault current levels to confirm the device can withstand the 40A maximum fault current without damage during tripping events.

Ptc Resettable Fuses Part Context

This part belongs to the Littelfuse PolySwitch RUSBF series, which offers a wide range of form factors and termination methods. The series is designed for high-volume electronics manufacturing and provides reliable overcurrent protection. The RUSBF155-2 specifically utilizes a radial leaded configuration suitable for through-hole applications, distinguishing it from surface mount alternatives within the broader family.

Ptc Resettable Fuses Replacement Considerations

Direct substitutes include other 1.55A hold current PTC fuses from the same manufacturer series with compatible voltage ratings. Verify that any replacement maintains the same radial disc package dimensions and lead spacing to fit existing footprints. Ensure the alternative device meets identical safety certifications and operates within the same temperature range.