Littelfuse 0446003.ZR Surface Mount Fuse - Equivalent & Substitute Parts

Part Overview

The Littelfuse 0446003.ZR is a 3A 350VAC/125VDC surface mount board fuse with fast-blow response characteristics, designed for circuit protection in compact SMD applications. This part operates across a temperature range of -40°C to 125°C and features a breaking capacity of 100A AC and 50A DC.

The 0446003.ZR carries an obsolete product status. Identifying equivalent substitute parts is necessary to ensure design continuity, maintain supply chain reliability, and support ongoing production or repair requirements for legacy systems utilizing this component.

Substiute Parts

0446003.ZR

Littelfuse Inc.In Stock: 7450446003.ZR Datasheet

Current PartRFQ

0446003.ZRP

Littelfuse Inc.In Stock: 24170446003.ZRP Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 0446003.ZR is determined by strict equivalence across the following critical parameters:

• Current Rating: 3 A (exact match required)
• Voltage Rating: 350 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, Gull Wing (exact match required)
• Breaking Capacity: 100A AC, 50A DC (exact match required)
• Melting I²t: 9.4 (exact match required)
• Operating Temperature Range: -40°C to 125°C (exact match required)
• DC Cold Resistance: 0.034 Ohms (exact match required)

The substitute part 0446003.ZRP meets all these criteria and is manufactured by the same supplier (Littelfuse Inc.), ensuring electrical and mechanical compatibility with the original design.

Parameter Comparison

Engineering Selection Recommendations

The 0446003.ZRP is the direct parametric equivalent to the obsolete 0446003.ZR. Both parts are manufactured by Littelfuse Inc. within the 446 series and share identical electrical and mechanical specifications.

The 0446003.ZRP carries an active product status, ensuring ongoing availability and supply chain support. This part is ROHS3 compliant, meeting current environmental and regulatory requirements, whereas the original 0446003.ZR is RoHS non-compliant.

For new designs or production transitions, the 0446003.ZRP is the appropriate selection. The substitute part is available in Tape & Reel packaging, which is standard for high-volume manufacturing operations. Both parts maintain identical performance characteristics, including current rating, voltage ratings, response time, breaking capacity, and thermal operating range.

Frequently Asked Questions (FAQ)

Q: Can the 0446003.ZRP be used as a direct replacement for the 0446003.ZR?

A: Yes. The 0446003.ZRP is a parametric equivalent with identical electrical and mechanical specifications. All critical parameters—current rating, voltage ratings, response time, package type, breaking capacity, and operating temperature range—are identical between the two parts.

Q: What is the difference between the 0446003.ZR and 0446003.ZRP?

A: The primary differences are product status, packaging format, and regulatory compliance. The 0446003.ZR is obsolete and supplied in bulk packaging with RoHS non-compliant status. The 0446003.ZRP is an active product supplied in Tape & Reel packaging and is ROHS3 compliant.

Q: Are there any compatibility concerns when substituting the 0446003.ZRP for the 0446003.ZR?

A: No compatibility concerns exist. Both parts feature identical 2-SMD Gull Wing package geometry (0.430" L x 0.345" W x 0.150" H), identical DC cold resistance (0.034 Ohms), and identical melting I²t characteristics (9.4). PCB footprints and solder reflow profiles remain unchanged.

Q: What certifications and approvals apply to the substitute part?

A: The 0446003.ZRP carries CSA and UL approvals. The original 0446003.ZR included METI approval in addition to CSA and UL. Verify that your application requirements align with the available certifications for the substitute part.

Q: Is the 0446003.ZRP suitable for high-volume production?

A: Yes. The 0446003.ZRP is supplied in Tape & Reel packaging, which is the standard format for automated assembly and high-volume manufacturing operations.