Littelfuse 0448.800MR Surface Mount Fuse Equivalent & Substitute Parts

Part Overview

The Littelfuse 0448.800MR is an 800 mA, 125 V AC/DC surface mount board fuse in the NANO²® 448 series. This fast-blow fuse is designed for circuit protection in applications requiring SMD mounting with a 2-SMD square end block package. The part is currently active in production with full RoHS3 compliance and CSA/UL approval certifications. Equivalent substitute parts are available within the NANO²® product family to support design flexibility, inventory optimization, and supply chain continuity.

Substiute Parts

0448.800MR

Littelfuse Inc.In Stock: 10400448.800MR Datasheet

Current PartRFQ

0451.800MRL

LittelfuseIn Stock: 185670451.800MRL Datasheet

Parametric EquivalentRFQ

0453.800MR

Littelfuse Inc.In Stock: 28510453.800MR Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 0448.800MR are qualified based on the following critical parameters that must remain constant:

• Current Rating: 800 mA (exact match required)
• Voltage Rating: 125 V AC and 125 V DC (exact match required)
• Response Time: Fast Blow (exact match required)
• Mounting Type: Surface Mount (exact match required)
• Package / Case: 2-SMD, Square End Block (exact match required)
• Breaking Capacity @ Rated Voltage: 50 A (exact match required)
• Operating Temperature Range: -55°C to 125°C (exact match required)
• Physical Dimensions: 0.240" L x 0.106" W x 0.106" H (exact match required)
• Approval Agencies: CSA, UL (exact match required)
• RoHS Status: ROHS3 Compliant (exact match required)

The substitute parts 0451.800MRL and 0453.800MR are members of the NANO²® fuse family and meet all critical electrical, mechanical, and regulatory requirements for direct substitution with the 0448.800MR.

Parameter Comparison

Engineering Selection Recommendations

All three parts—0448.800MR, 0451.800MRL, and 0453.800MR—are active production items with identical electrical ratings, mechanical dimensions, and regulatory certifications. Selection among these equivalents may be based on:

• Inventory availability and lead time requirements
• DC cold resistance tolerance specifications for your application (0448.800MR: 0.1907 Ω; 0451.800MRL and 0453.800MR: 0.212 Ω)
• Melting I²t characteristics (0448.800MR: 0.272; 0451.800MRL and 0453.800MR: 0.271)
• Supply chain and procurement preferences

All parts maintain CSA and UL approval certifications and are ROHS3 compliant, ensuring regulatory compliance across all substitution scenarios.

Frequently Asked Questions (FAQ)

Q: Can the 0451.800MRL or 0453.800MR be used as direct replacements for the 0448.800MR?

A: Yes. Both parts are direct electrical and mechanical equivalents. They share identical current ratings (800 mA), voltage ratings (125 V AC/DC), response time (fast blow), package type (2-SMD square end block), physical dimensions, and regulatory certifications (CSA, UL, ROHS3).

Q: What is the difference between these three fuse models?

A: The primary differences are the series designation (NANO²® 448, 451, and 453) and minor variations in DC cold resistance and melting I²t values. The 0448.800MR has a DC cold resistance of 0.1907 Ω, while the 0451.800MRL and 0453.800MR both measure 0.212 Ω. Melting I²t values are 0.272 for the 0448.800MR and 0.271 for both substitute parts. These variations are within acceptable engineering tolerances for the 800 mA, 125 V fast-blow fuse category.

Q: Are there any packaging or mounting differences?

A: No. All three parts use identical 2-SMD square end block packaging with the same physical dimensions (0.240" L x 0.106" W x 0.106" H). Surface mount compatibility is identical across all three models.

Q: Do all three parts have the same regulatory approvals?

A: Yes. All three parts carry CSA and UL approvals and are ROHS3 compliant. Moisture sensitivity level (MSL) is 1 (Unlimited) for all three parts.

Q: Which part should I select if all three are available?

A: Selection should be based on inventory availability, lead time, and any specific DC cold resistance or melting I²t requirements for your circuit protection design. From an engineering standpoint, all three parts are functionally equivalent for standard 800 mA, 125 V AC/DC circuit protection applications.