Littelfuse 025504.6M Equivalent & Substitute Parts

Part Overview

The Littelfuse 025504.6M is a 4.6 A board mount axial fuse rated for 125 V AC/DC operation, designed for through-hole PCB assembly applications. This component is classified as obsolete, making identification of compatible substitute parts essential for ongoing production support, maintenance, and design updates. The PICO® 255 series fuse provides fast-blow response characteristics suitable for circuit protection in industrial and commercial electronics.

Substiute Parts

025503.5M

Littelfuse Inc.In Stock: 864025503.5M Datasheet

Current PartRFQ

025103.5MXL

Littelfuse Inc.In Stock: 1171025103.5MXL Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 025504.6M is determined by strict equivalence across the following electrical and mechanical parameters:

• Current Rating: 4.6 A (exact match required)
• Voltage Rating: 125 V AC and 125 V DC (exact match required)
• Response Time: Fast Blow (exact match required)
• Fuse Type: Board Mount, Through Hole, Axial configuration (exact match required)
• Breaking Capacity: 50 A AC, 300 A DC (exact match required)

The Littelfuse 025104.6MXL qualifies as a direct substitute because it maintains identical electrical ratings and functional characteristics. Although the 025104.6MXL belongs to the PICO® II 251 series (versus the original PICO® 255 series) and exhibits a slightly larger physical diameter (0.110" versus 0.095"), these differences do not affect electrical performance or standard PCB footprint compatibility for through-hole axial fuse applications.

Parameter Comparison

Engineering Selection Recommendations

The 025104.6MXL is the recommended substitute for the obsolete 025504.6M based on the following engineering criteria:

Product Status & Availability: The 025104.6MXL maintains active product status with confirmed inventory availability (1136 pcs), whereas the 025504.6M is obsolete. This ensures long-term supply chain continuity and reduces procurement risk.

Electrical Equivalence: Both fuses maintain identical current ratings (4.6 A), voltage ratings (125 V AC/DC), response characteristics (Fast Blow), and breaking capacity (50 A AC, 300 A DC). These parameters are the primary determinants of circuit protection performance and are fully compatible.

Regulatory Compliance: The 025104.6MXL carries expanded approval certifications (CSA, cURus, PSE, TUV) compared to the original part (CSA, UL) and achieves ROHS3 compliance, meeting modern environmental and safety standards.

Physical Compatibility: The axial through-hole mounting configuration and package dimensions remain compatible with standard PCB designs. The marginal increase in fuse diameter (0.110" versus 0.095") does not impact typical PCB hole spacing or component placement for through-hole applications.

Frequently Asked Questions (FAQ)

Q: Can the 025104.6MXL be used as a direct replacement for the 025504.6M in existing designs?

A: Yes. The 025104.6MXL provides electrical and functional equivalence across all critical parameters: current rating, voltage rating, response time, breaking capacity, and mounting configuration. The fuse will perform identically in circuit protection applications.

Q: What is the significance of the series change from PICO® 255 to PICO® II 251?

A: The series designation reflects product line evolution within Littelfuse's portfolio. The PICO® II 251 series represents an updated design that maintains backward compatibility with the original PICO® 255 electrical specifications while offering improved compliance certifications and active production status.

Q: Does the physical size difference (0.095" to 0.110" diameter) affect PCB compatibility?

A: No. Both fuses use standard axial through-hole packaging with identical lead spacing (0.280" length). The diameter increase does not impact hole placement or component mounting on PCBs designed for through-hole axial fuses.

Q: Why is the 025104.6MXL recommended over other potential substitutes?

A: The 025104.6MXL is the manufacturer-recommended substitute, maintaining exact electrical equivalence while offering active product status, expanded regulatory certifications, and ROHS3 compliance. These factors ensure both technical compatibility and long-term supply reliability.

Q: Are there any operating temperature differences between the original and substitute?

A: The 025504.6M does not specify an operating temperature range in the provided data. The 025104.6MXL operates across -55°C to 125°C, which covers standard industrial and commercial temperature ranges and represents an enhancement in environmental performance specification.

Q: What certifications should I verify for my specific application?

A: The 025104.6MXL carries CSA, cURus, PSE, and TUV approvals. Verify that these certifications align with your regional regulatory requirements and end-application standards before final component selection.