Littelfuse 045104.6NR Surface Mount Board Mount Fuse Equivalent & Substitute Parts

Part Overview

The Littelfuse 045104.6NR is a 4.6 A, 125 V AC/DC surface mount board mount fuse from the NANO²® 451 series. This component is classified as obsolete, necessitating identification of active equivalent alternatives for new designs and ongoing production requirements. Direct functional replacements and parametric equivalents are available from both Littelfuse and Bourns manufacturers, all meeting identical electrical and mechanical specifications for 4.6 A fast-blow fuse applications in 125 V AC/DC circuits.

Substiute Parts

045103.5NR

Littelfuse Inc.In Stock: 1035045103.5NR Datasheet

Current PartRFQ

045103.5NRL

Littelfuse Inc.In Stock: 1055045103.5NRL Datasheet

DirectRFQ

044803.5MR

Littelfuse Inc.In Stock: 1541044803.5MR Datasheet

Parametric EquivalentRFQ

045103.5MRL

Littelfuse Inc.In Stock: 9642045103.5MRL Datasheet

Parametric EquivalentRFQ

045303.5MR

Littelfuse Inc.In Stock: 5495045303.5MR Datasheet

Parametric EquivalentRFQ

045303.5NR

Littelfuse Inc.In Stock: 1085045303.5NR Datasheet

Parametric EquivalentRFQ

SF-2410FP350T-2

Bourns Inc.In Stock: 3027SF-2410FP350T-2 Datasheet

DirectRFQ

SF-2410HI350T-2

Bourns Inc.In Stock: 2842SF-2410HI350T-2 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 045104.6NR is determined by strict equivalence across the following critical 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)
• 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 ~ 125°C (exact match required)

All identified substitute parts meet these criteria. Variations in secondary parameters such as melting I²t, DC cold resistance, and packaging format (Tape & Reel vs. Cut Tape) do not affect functional interchangeability within the specified electrical and mechanical constraints.

Parameter Comparison

Engineering Selection Recommendations

For applications currently using the obsolete 045104.6NR, the following selection criteria apply:

Primary Recommendation: 045104.6NRL (Littelfuse NANO²® 451 series, Tape & Reel packaging). This part maintains identical electrical and mechanical specifications while offering active product status and ROHS3 compliance. It represents a direct form-fit-function replacement with no design modifications required.

Alternative Littelfuse Options: 045104.6MRL, 044804.6MR, 045304.6MR, and 045304.6NR all meet electrical and mechanical requirements. These alternatives differ only in series designation (NANO²® 448 or 453) and packaging format (Cut Tape & Digi-Reel® vs. Tape & Reel). All are active products with ROHS3 compliance.

Cross-Manufacturer Alternative: SF-2410FP350T-2 and SF-2410HI350T-2 (Bourns SinglFuse™ series) provide equivalent electrical and mechanical performance. Both are active products with ROHS3 compliance and UL/cUL certification. Selection between these Bourns options depends on application-specific requirements for melting I²t characteristics.

All substitute parts carry appropriate regulatory approvals (UL, CSA, PSE certifications) and operate within the specified -55°C to 125°C temperature range.

Frequently Asked Questions (FAQ)

Q: Can I use 045104.6NRL as a direct replacement for 045104.6NR?

A: Yes. Both parts share identical electrical ratings (4.6 A, 125 V AC/DC), response time (Fast Blow), mechanical package (2-SMD, Square End Block), and breaking capacity (50 A). The primary difference is product status (045104.6NRL is active) and RoHS compliance (ROHS3 vs. non-compliant). No circuit modifications are required.

Q: What is the difference between Littelfuse NANO²® series variants (451, 448, 453)?

A: All three series (NANO²® 451, 448, and 453) meet the electrical and mechanical specifications for this 4.6 A, 125 V application. Series designation reflects internal design iterations within Littelfuse's product line. Functional interchangeability is maintained across all three series for this current and voltage rating.

Q: Can I substitute a Bourns SinglFuse™ part for the Littelfuse 045104.6NR?

A: Yes. SF-2410FP350T-2 and SF-2410HI350T-2 meet all critical electrical and mechanical parameters: 4.6 A current rating, 125 V AC/DC voltage rating, Fast Blow response, 2-SMD Square End Block package, and 50 A breaking capacity. Both carry UL/cUL certification. Verify application-specific requirements for melting I²t if thermal response characteristics are critical.

Q: Does packaging format (Tape & Reel vs. Cut Tape) affect electrical performance?

A: No. Packaging format affects only component handling, storage, and assembly logistics. Electrical and mechanical performance is identical regardless of whether the part is supplied in Tape & Reel (TR) or Cut Tape & Digi-Reel® (CT) format. Selection should be based on manufacturing process requirements.

Q: Are all substitute parts RoHS compliant?

A: All active substitute parts (045104.6NRL, 044804.6MR, 045104.6MRL, 045304.6MR, 045304.6NR, SF-2410FP350T-2, SF-2410HI350T-2) are ROHS3 compliant. The original 045104.6NR is RoHS non-compliant, which is one reason substitution is necessary for new designs.

Q: What is the difference between SF-2410FP350T-2 and SF-2410HI350T-2?

A: Both parts meet the electrical and mechanical specifications for this application. The primary difference is melting I²t: SF-2410FP350T-2 has 2.695 and SF-2410HI350T-2 has 24.908. This affects thermal response characteristics. Select based on application requirements for fuse response time and thermal protection.