Littelfuse 043402.5NRP Surface Mount Fuse 2.5A 32V 0603

Part Overview

The Littelfuse 043402.5NRP is a 2.5 A surface mount board fuse rated for 32 V AC/DC operation in 0603 (1608 Metric) package format. This component is classified as obsolete, making equivalent substitutes necessary for new designs and ongoing production requirements. The fuse provides fast-blow response characteristics suitable for circuit protection applications requiring rapid fault isolation.

Key Parameters

Parameter	Value
Manufacturer Part Number	043402.5NRP
Manufacturer	Littelfuse Inc.
Current Rating	2.5 A
Voltage Rating (AC/DC)	32 V AC / 32 V DC
Response Time	Fast Blow
Package / Case	0603 (1608 Metric)
Mounting Type	Surface Mount
Fuse Type	Board Mount (Cartridge Style Excluded)
Breaking Capacity @ Rated Voltage	35 A
Product Status	Obsolete
RoHS Status	RoHS non-compliant

Substitute Part Grouping Explanation

Substitution eligibility for the 043402.5NRP is determined by the following critical parameters:

Current Rating: 2.5 A (exact match required)
Voltage Rating: 32 V AC and 32 V DC (exact match required)
Response Time: Fast Blow (exact match required)
Package / Case: 0603 (1608 Metric) (exact match required)
Mounting Type: Surface Mount (exact match required)
Fuse Type: Board Mount (Cartridge Style Excluded) (exact match required)

All identified substitutes meet these core electrical and mechanical parameters. Differences in secondary characteristics such as melting I²t, DC cold resistance, breaking capacity, and RoHS compliance are noted but do not disqualify substitution eligibility when primary parameters align.

Parameter Comparison

Parameter	043402.5NRP (Main)	046702.5NR	046702.5NRHF	SF-0603F250-2
Manufacturer	Littelfuse Inc.	Littelfuse Inc.	Littelfuse Inc.	Bourns Inc.
Current Rating (Amps)	2.5 A	2.5 A	2.5 A	2.5 A
Voltage Rating - AC	32 V	32 V	32 V	—
Voltage Rating - DC	32 V	32 V	32 V	32 V
Response Time	Fast Blow	Fast Blow	Fast Blow	Fast Blow
Package / Case	0603 (1608 Metric)	0603 (1608 Metric)	0603 (1608 Metric)	0603 (1608 Metric)
Mounting Type	Surface Mount	Surface Mount	Surface Mount	Surface Mount
Fuse Type	Board Mount (Cartridge Style Excluded)	Board Mount (Cartridge Style Excluded)	Board Mount (Cartridge Style Excluded)	Board Mount (Cartridge Style Excluded)
Breaking Capacity @ Rated Voltage	35 A	35 A	35 A	50 A
DC Cold Resistance (Ohms)	0.028	0.021	0.021	0.024
Melting I²t	0.175	0.2066	0.2066	0.055
Approval Agency	CSA, UL	CSA, UL	CSA, UL	UL
Operating Temperature	-55°C ~ 90°C	-55°C ~ 90°C	-55°C ~ 90°C	-20°C ~ 105°C
Product Status	Obsolete	Active	Active	Active
RoHS Status	RoHS non-compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant

Engineering Selection Recommendations

046702.5NR and 046702.5NRHF are parametric equivalents manufactured by Littelfuse Inc. with active product status. Both parts maintain identical electrical specifications to the main part while offering ROHS3 compliance and improved availability. The primary distinction between these two Littelfuse options is packaging format: 046702.5NR is supplied in standard Tape & Reel, while 046702.5NRHF is supplied in Tape & Reel with halogen-free material composition.

SF-0603F250-2 is a manufacturer-recommended substitute from Bourns Inc. This part meets all critical electrical and mechanical parameters while offering enhanced breaking capacity (50 A versus 35 A) and extended operating temperature range (-20°C to 105°C). The Bourns part carries UL approval and ROHS3 compliance. The melting I²t value of 0.055 differs significantly from the main part; this characteristic should be evaluated against specific circuit protection requirements.

For new designs and production requiring RoHS compliance, either Littelfuse 046702.5NR/046702.5NRHF or Bourns SF-0603F250-2 are suitable selections based on active product status and regulatory compliance.

Frequently Asked Questions (FAQ)

Q: Can 046702.5NR and 046702.5NRHF be used interchangeably with 043402.5NRP?

A: Yes. Both parts are parametric equivalents meeting the critical specifications: 2.5 A current rating, 32 V AC/DC voltage rating, fast-blow response, 0603 package, and surface mount configuration. The primary difference is packaging format and material composition (halogen-free for NRHF variant).

Q: What is the significance of the melting I²t difference between 043402.5NRP (0.175) and its substitutes?

A: Melting I²t defines the thermal energy required to melt the fuse element. The 046702.5NR/046702.5NRHF variants (0.2066) and SF-0603F250-2 (0.055) exhibit different thermal characteristics. Circuit protection behavior may vary; application-specific thermal analysis is necessary to confirm suitability.

Q: Is the Bourns SF-0603F250-2 a direct replacement?

A: SF-0603F250-2 meets all critical electrical and mechanical parameters. However, it differs in breaking capacity (50 A versus 35 A), operating temperature range (-20°C to 105°C versus -55°C to 90°C), and melting I²t (0.055 versus 0.175). These differences require evaluation against specific circuit requirements.

Q: Why is 043402.5NRP marked as obsolete?

A: Obsolete status indicates the part is no longer manufactured or supported by Littelfuse Inc. Active substitutes ensure continued availability and access to current manufacturing processes and compliance standards.

Q: Are all substitutes RoHS compliant?

A: 046702.5NR, 046702.5NRHF, and SF-0603F250-2 are all ROHS3 compliant. The original 043402.5NRP is RoHS non-compliant. For applications requiring RoHS compliance, substitutes are necessary.

Q: What packaging options are available for substitutes?

A: 046702.5NR and 046702.5NRHF are supplied in Tape & Reel format. SF-0603F250-2 is supplied in Tape & Reel format. Packaging format should be confirmed against assembly equipment requirements.

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