Littelfuse 41921000000 Equivalent & Substitute Parts

Part Overview

The Littelfuse 41921000000 is a 10A 125VAC/VDC board mount surface mount fuse in the 2410 (6125 Metric) package format. This component is classified as obsolete, making identification of functionally equivalent substitute parts essential for ongoing design support and procurement continuity. The part operates across a temperature range of -65°C to 125°C with fast blow response characteristics and is approved by cULus standards.

Substiute Parts

41921000000

Littelfuse Inc.In Stock: 83741921000000 Datasheet

Current PartRFQ

0451010.MRL

Littelfuse Inc.In Stock: 1002220451010.MRL Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 41921000000 is determined by strict alignment of the following critical parameters:

• Current Rating: 10 A (exact match required)
• Voltage Rating AC: 125 V (exact match required)
• Voltage Rating DC: 125 V (exact match required)
• Response Time: Fast Blow (exact match required)
• Fuse Type: Board Mount (Cartridge Style Excluded)
• Mounting Type: Surface Mount

The substitute part 0451010.MRL meets all mandatory electrical and functional criteria. Both parts share identical current and voltage ratings, fast blow response characteristics, and surface mount board mount configuration. Physical dimensions are identical (0.240" L x 0.106" W x 0.106" H / 6.10mm x 2.69mm x 2.69mm), ensuring mechanical compatibility in existing PCB layouts.

Parameter Comparison

Engineering Selection Recommendations

The 0451010.MRL (NANO²® 451 series) is the active production equivalent for the obsolete 41921000000. Both parts are manufactured by Littelfuse Inc. and maintain electrical equivalence across all critical parameters: 10A current rating, 125VAC/VDC voltage ratings, fast blow response, and identical physical dimensions.

The substitute part offers enhanced compliance status. The 0451010.MRL is ROHS3 compliant and carries broader regulatory approvals (CSA, PSE, UL) compared to the cULus approval of the original part. For new designs or redesigns, the 0451010.MRL is the appropriate selection due to its active product status and superior compliance profile.

The operating temperature range of the substitute extends to -55°C minimum (versus -65°C for the original), which is suitable for most industrial and commercial applications. The DC breaking capacity of the substitute (50A DC) is lower than the original (100A DC), though both exceed typical circuit protection requirements at the 10A rating.

Frequently Asked Questions (FAQ)

Q: Can the 0451010.MRL be used as a direct replacement for the 41921000000 in existing designs?

A: Yes. Both parts share identical electrical ratings (10A, 125VAC/VDC), response time (fast blow), and physical dimensions (0.240" x 0.106" x 0.106"). The substitute will function identically in existing PCB layouts without modification.

Q: What is the difference between the package designations "2410 (6125 Metric)" and "2-SMD, Square End Block"?

A: Both designations describe the same physical form factor and footprint. The 2410 and 2-SMD packages are equivalent in size and mounting configuration. The "Square End Block" descriptor for the substitute indicates the terminal style, which is compatible with the original part's PCB pads.

Q: Why does the substitute part have a lower DC breaking capacity (50A DC vs. 100A DC)?

A: The DC breaking capacity difference does not affect functional equivalence at the 10A rated current. Both parts meet the breaking capacity requirements for 10A circuits. The higher DC breaking capacity of the original part provides additional margin for fault conditions, but the substitute's 50A DC capacity remains adequate for the specified 10A application.

Q: Is the substitute part RoHS compliant?

A: Yes. The 0451010.MRL is ROHS3 compliant, whereas the original 41921000000 is RoHS non-compliant. This makes the substitute suitable for applications requiring RoHS compliance.

Q: What is the minimum operating temperature difference between the two parts?

A: The original part operates from -65°C to 125°C, while the substitute operates from -55°C to 125°C. The 10°C difference at the lower temperature limit does not affect equivalence for standard industrial and commercial temperature environments.