Littelfuse 0251.250M Fuse - Equivalent & Substitute Parts

Part Overview

The Littelfuse 0251.250M is a 250 mA, 125 V AC/DC board mount axial fuse from the PICO® II 251 series. This component is classified as obsolete, which necessitates identification of active equivalent parts for ongoing design support and procurement. The fuse is designed for through-hole mounting applications requiring fast-blow response characteristics and operates across a temperature range of -55°C to 125°C.

Substiute Parts

0251.250M

Littelfuse Inc.In Stock: 11590251.250M Datasheet

Current PartRFQ

0251.250MXL

LittelfuseIn Stock: 10320251.250MXL Datasheet

Parametric EquivalentRFQ

0251.250VXL

Littelfuse Inc.In Stock: 11980251.250VXL Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the 0251.250M is determined by strict equivalence across all critical electrical and mechanical parameters. The substitute parts must maintain identical specifications for current rating (250 mA), voltage ratings (125 V AC/DC), response time (Fast Blow), breaking capacity (50A AC, 300A DC), melting I²t (0.0116), physical dimensions (0.110" Dia x 0.280" L), DC cold resistance (0.665 Ohms), and approval certifications (CSA, cURus).

The two identified substitutes—0251.250MXL and 0251.250VXL—meet all these criteria. Both parts are active products from the same PICO® II 251 series, differ only in packaging configuration (bulk versus the original packaging), and maintain full electrical and mechanical compatibility with the obsolete 0251.250M.

Parameter Comparison

Engineering Selection Recommendations

Both 0251.250MXL and 0251.250VXL are direct functional equivalents to the obsolete 0251.250M. Selection between these two active substitutes should be based on procurement and packaging requirements rather than electrical performance, as all three parts maintain identical electrical and mechanical specifications.

The 0251.250MXL and 0251.250VXL offer the additional advantage of ROHS3 compliance and REACH Unaffected status, providing improved regulatory alignment for new designs and long-term supply chain sustainability compared to the non-compliant 0251.250M.

Frequently Asked Questions (FAQ)

Q: Can the 0251.250MXL or 0251.250VXL be used as direct replacements for the 0251.250M in existing designs?

A: Yes. Both substitute parts maintain identical electrical ratings (250 mA, 125 V AC/DC), response time (Fast Blow), breaking capacity (50A AC, 300A DC), physical dimensions (0.110" Dia x 0.280" L), and approval certifications (CSA, cURus). No circuit modifications are required.

Q: What is the difference between the 0251.250MXL and 0251.250VXL?

A: Both parts are electrically and mechanically identical. The difference is packaging configuration (bulk). Selection should be based on procurement quantity and packaging requirements for your application.

Q: Why is the 0251.250M classified as obsolete?

A: The 0251.250M is no longer in active production. The 0251.250MXL and 0251.250VXL are the current active equivalents from Littelfuse for this specification.

Q: Are there any compliance differences between the obsolete 0251.250M and the substitute parts?

A: Yes. The 0251.250M is RoHS non-compliant, while both 0251.250MXL and 0251.250VXL are ROHS3 compliant and REACH Unaffected. This provides improved regulatory compliance for new designs.

Q: Will the substitute parts fit the same PCB footprint as the 0251.250M?

A: Yes. All three parts share identical physical dimensions (0.110" Dia x 0.280" L) and axial through-hole mounting configuration, ensuring direct PCB compatibility.