Littelfuse 0453.315MR Surface Mount Fuse Equivalent & Substitute Parts

Part Overview

The Littelfuse 0453.315MR is a 315 mA, 125 V AC/DC surface mount board fuse in the NANO²® 453 series. This fast-blow fuse is designed for circuit protection in compact 2-SMD, square end block configurations. The part is active in production with full CSA and UL approval certifications. Equivalent and substitute parts are identified to support procurement flexibility, inventory management, and design continuity when the primary part becomes unavailable or when alternative sourcing is required.

Substiute Parts

0453.315MR

LittelfuseIn Stock: 73340453.315MR Datasheet

Current PartRFQ

0448.315MR

Littelfuse Inc.In Stock: 103970448.315MR Datasheet

Parametric EquivalentRFQ

0451.315MRL

Littelfuse Inc.In Stock: 72030451.315MRL Datasheet

Parametric EquivalentRFQ

SF-2410FP0315T-2

Bourns Inc.In Stock: 3131SF-2410FP0315T-2 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 0453.315MR is determined by strict equivalence across the following critical parameters:

• Current Rating: 315 mA (exact match required)
• Voltage Rating: 125 V AC and 125 V DC (exact match required)
• Mounting Type: Surface Mount (exact match required)
• Package / Case: 2-SMD, Square End Block (exact match required)
• Response Time: Fast Blow (exact match required)
• Breaking Capacity @ Rated Voltage: 50 A (exact match required)
• Approval Agencies: CSA and/or UL certification (required for regulatory compliance)
• Operating Temperature Range: -55°C ~ 125°C (exact match required)
• RoHS Status: ROHS3 Compliant (required for environmental compliance)

All identified substitute parts meet these criteria. Variations in secondary parameters such as melting I²t, DC cold resistance, and series designation do not disqualify substitution when primary electrical and mechanical parameters are identical.

Parameter Comparison

Engineering Selection Recommendations

All identified substitute parts are active products with current manufacturing status and full regulatory compliance. Selection among equivalent parts should be based on:

Littelfuse NANO²® 453 (0453.315MR) and NANO²® 451 (0451.315MRL) are functionally identical across all critical parameters and represent direct substitutes within the Littelfuse product family.

Littelfuse NANO²® 448 (0448.315MR) is electrically equivalent but exhibits different thermal characteristics (melting I²t of 0.0265 versus 0.0311) and higher DC cold resistance (0.79 Ohms versus 0.3918 Ohms). This part remains a valid substitute for applications where these secondary characteristics do not impose design constraints.

Bourns SinglFuse™ SF-2410FP0315T-2 is a cross-manufacturer equivalent with identical primary electrical and mechanical specifications. This part carries cUL and UL certifications and exhibits different thermal response (melting I²t of 0.1365) and slightly different physical dimensions (0.102" W x 0.102" H versus 0.106" W x 0.106" H). Physical dimension variance is within typical PCB layout tolerances for 2-SMD configurations.

All parts maintain ROHS3 compliance, unlimited moisture sensitivity level (MSL 1), and REACH unaffected status, ensuring compatibility with current environmental and regulatory requirements.

Frequently Asked Questions (FAQ)

Q: Can the 0448.315MR be used as a direct replacement for the 0453.315MR?

A: Yes. Both parts share identical current rating (315 mA), voltage ratings (125 V AC/DC), response time (fast blow), mounting type (surface mount), package configuration (2-SMD, square end block), breaking capacity (50 A), operating temperature range (-55°C ~ 125°C), and regulatory certifications (CSA, UL). Differences in melting I²t and DC cold resistance do not prevent substitution in standard circuit protection applications.

Q: What is the difference between the Littelfuse and Bourns equivalents?

A: The Littelfuse 0453.315MR, 0448.315MR, and 0451.315MRL are all Littelfuse products within the NANO²® series. The Bourns SF-2410FP0315T-2 is a cross-manufacturer equivalent from a different supplier. All four parts meet identical electrical and mechanical specifications. The Bourns part carries cUL certification in addition to UL, and exhibits a higher melting I²t value (0.1365 versus 0.0311 or 0.0265). Physical dimensions are nominally equivalent with minor tolerance variations.

Q: Are there any compatibility concerns with PCB layout when substituting the Bourns part?

A: The Bourns SF-2410FP0315T-2 has physical dimensions of 0.240" L x 0.102" W x 0.102" H, compared to the Littelfuse parts at 0.240" L x 0.106" W x 0.106" H. The 0.004" (0.10 mm) reduction in width and height is within standard PCB layout tolerances for 2-SMD footprints and does not require design modification.

Q: Do all substitute parts have the same regulatory certifications?

A: The Littelfuse parts (0453.315MR, 0448.315MR, 0451.315MRL) carry CSA and UL certifications. The Bourns SF-2410FP0315T-2 carries cUL and UL certifications. All parts meet the required safety standards for circuit protection applications. cUL indicates Canadian UL certification, which is an additional compliance credential.

Q: What is the inventory status of these substitute parts?

A: Current inventory levels are: 0453.315MR (7,238 pcs), 0448.315MR (10,300 pcs), 0451.315MRL (7,100 pcs), and SF-2410FP0315T-2 (3,033 pcs). All parts are listed as new original stock in active production.