Littelfuse 0451003.MRL Surface Mount Board Mount Fuse Equivalent & Substitute Parts

Part Overview

The Littelfuse 0451003.MRL is a 3 A, 125 V AC/DC surface mount board mount fuse in the NANO²® 451 series. This fast-blow fuse is designed for circuit protection in applications requiring compact, high-reliability fusing solutions. The part is active in production with full inventory availability. Equivalent and substitute parts may be required due to packaging format preferences, supply chain considerations, or specific approval agency requirements for end applications.

Substiute Parts

0451003.MRL

Littelfuse Inc.In Stock: 302130451003.MRL Datasheet

Current PartRFQ

0448003.MR

Littelfuse Inc.In Stock: 171320448003.MR Datasheet

Parametric EquivalentRFQ

0451003.NRL

Littelfuse Inc.In Stock: 103060451003.NRL Datasheet

Parametric EquivalentRFQ

0453003.MR

Littelfuse Inc.In Stock: 566290453003.MR Datasheet

Parametric EquivalentRFQ

CB61F3A-TR1

Eaton - Electronics DivisionIn Stock: 3418CB61F3A-TR1 Datasheet

DirectRFQ

SF-2410FP300T-2

Bourns Inc.In Stock: 2653SF-2410FP300T-2 Datasheet

DirectRFQ

SF-2410HI300T-2

Bourns Inc.In Stock: 3429SF-2410HI300T-2 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 0451003.MRL is determined by the following critical parameters:

• Current Rating: 3 A (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)
• Size / Dimension: 0.240" L x 0.106" W x 0.106" H or mechanically compatible alternatives (exact match required)
• Operating Temperature Range: -55°C ~ 125°C (exact match or wider range acceptable)
• RoHS Status: ROHS3 Compliant (exact match required)

Substitute parts are grouped into two categories:

Littelfuse NANO²® Series (Parametric Equivalents): Parts 0448003.MR, 0451003.NRL, and 0453003.MR share identical electrical and mechanical specifications with the main part. These differ only in packaging format (Cut Tape vs. Tape & Reel) or internal series designation. All maintain the same breaking capacity, melting I²t characteristics, and approval agencies.

Cross-Manufacturer Alternatives (Direct Substitutes): Parts CB61F3A-TR1 (Eaton), SF-2410FP300T-2 (Bourns), and SF-2410HI300T-2 (Bourns) meet all critical electrical parameters and mechanical dimensions. These parts are from different manufacturers and may have variations in breaking capacity, melting I²t, or approval agency certifications.

Parameter Comparison

Engineering Selection Recommendations

Littelfuse NANO²® Series Substitutes (0448003.MR, 0451003.NRL, 0453003.MR): These parts are direct parametric equivalents with identical electrical performance and approval certifications (CSA, PSE, UL). Selection between these and the main part 0451003.MRL should be based on packaging format requirements. The 0451003.NRL and 0453003.MR are supplied in Tape & Reel format, while 0451003.MRL is supplied in Cut Tape & Digi-Reel format. The 0448003.MR differs slightly in melting I²t (1.72 vs. 1.65) and DC cold resistance (0.02445 vs. 0.0227 Ohms) but remains functionally equivalent for standard circuit protection applications.

Eaton CB61F3A-TR1: This part meets all critical electrical and mechanical parameters with identical current, voltage, and response time ratings. The CB61F3A-TR1 features a higher breaking capacity (100A AC, 300A DC vs. 50A) and slightly higher melting I²t (2.08 vs. 1.65). Approval agencies differ (CQC, cULus, PSE vs. CSA, PSE, UL). This part is suitable for applications where higher breaking capacity is beneficial or where cULus certification is required.

Bourns SinglFuse™ SF-2410FP300T-2: This part meets all critical electrical parameters with identical current, voltage, and response time ratings. The SF-2410FP300T-2 has a lower melting I²t (1.548 vs. 1.65) and higher DC cold resistance (0.036 vs. 0.0227 Ohms). Approval agencies are cUL and UL. This part is suitable for applications where lower melting I²t is acceptable and cUL certification is required.

Bourns SinglFuse™ SF-2410HI300T-2: This part meets all critical electrical parameters with identical current, voltage, and response time ratings. The SF-2410HI300T-2 has significantly higher melting I²t (24.99 vs. 1.65) and DC cold resistance of 0.0228 Ohms. REACH Status is listed as Affected (vs. Unaffected for other parts). Approval agencies are cUL and UL. This part is suitable for applications where higher melting I²t is required and cUL certification is acceptable.

Frequently Asked Questions (FAQ)

Q: Can I substitute 0451003.MRL with 0451003.NRL? A: Yes. Both parts are from the Littelfuse NANO²® 451 series with identical electrical specifications, current rating (3 A), voltage rating (125 V AC/DC), response time (Fast Blow), and physical dimensions. The primary difference is packaging format: 0451003.MRL is supplied in Cut Tape & Digi-Reel format, while 0451003.NRL is supplied in Tape & Reel format. Selection depends on your assembly process requirements.

Q: What is the difference between the Littelfuse NANO²® series substitutes? A: The 0448003.MR, 0451003.NRL, and 0453003.MR are all parametric equivalents with the same electrical performance. The 0448003.MR (NANO²® 448 series) has a slightly higher melting I²t (1.72 vs. 1.65) and DC cold resistance (0.02445 vs. 0.0227 Ohms). The 0451003.NRL and 0453003.MR maintain identical specifications to the main part. Differences are primarily in internal series designation and packaging format.

Q: Can I use the Eaton CB61F3A-TR1 as a direct replacement? A: Yes, for most applications. The CB61F3A-TR1 meets all critical electrical parameters and mechanical dimensions. However, it features higher breaking capacity (100A AC, 300A DC vs. 50A) and different approval agencies (CQC, cULus, PSE vs. CSA, PSE, UL). Verify that cULus certification is acceptable for your application before substitution.

Q: What are the key differences between the Bourns SinglFuse™ options? A: Both SF-2410FP300T-2 and SF-2410HI300T-2 meet the critical electrical parameters. The SF-2410FP300T-2 has lower melting I²t (1.548) and higher DC cold resistance (0.036 Ohms). The SF-2410HI300T-2 has significantly higher melting I²t (24.99) and lower DC cold resistance (0.0228 Ohms). The SF-2410HI300T-2 also has REACH Status listed as Affected. Select based on your specific thermal and electrical requirements.

Q: Are all substitute parts RoHS3 compliant? A: Yes. All listed substitute parts are ROHS3 Compliant with Moisture Sensitivity Level 1 (Unlimited), matching the main part 0451003.MRL.

Q: What packaging formats are available? A: The 0451003.MRL is supplied in Cut Tape (CT) & Digi-Reel® format. The 0448003.MR is also available in Cut Tape & Digi-Reel format. The 0451003.NRL, 0453003.MR, CB61F3A-TR1, SF-2410FP300T-2, and SF-2410HI300T-2 are all supplied in Tape & Reel (TR) format. Select based on your assembly equipment compatibility.

Q: Which substitute has the best inventory availability? A: The 0453003.MR has the highest inventory with 56,556 pieces in stock, followed by the main part 0451003.MRL with 30,200 pieces. The 0448003.MR has 17,025 pieces, 0451003.NRL has 10,263 pieces, CB61F3A-TR1 has 3,400 pieces, SF-2410HI300T-2 has 3,392 pieces, and SF-2410FP300T-2 has 2,631 pieces.