Littelfuse 0251.125MAT1 125 mA 125V AC/DC Board Mount Axial Fuse – Equivalent & Substitute Parts

Part Overview

The Littelfuse 0251.125MAT1 is a 125 mA, 125V AC/DC board mount axial fuse from the PICO® II 251 series. This component is classified as obsolete, making equivalent substitute parts necessary for ongoing design support and procurement. The part features fast-blow response characteristics, CSA and cURus approvals, and is designed for through-hole mounting applications requiring reliable overcurrent protection in the 125 mA range at 125V operating levels.

Substiute Parts

0251.125MAT1

Littelfuse Inc.In Stock: 10130251.125MAT1 Datasheet

Current PartRFQ

0251.125MAT1L

Littelfuse Inc.In Stock: 20300251.125MAT1L Datasheet

DirectRFQ

0251.125HAT1L

Littelfuse Inc.In Stock: 12640251.125HAT1L Datasheet

Parametric EquivalentRFQ

0251.125NAT1L

Littelfuse Inc.In Stock: 89300251.125NAT1L Datasheet

Parametric EquivalentRFQ

0251.125NAT6L

Littelfuse Inc.In Stock: 10630251.125NAT6L Datasheet

Parametric EquivalentRFQ

0251.125NF026L

Littelfuse Inc.In Stock: 7960251.125NF026L Datasheet

Parametric EquivalentRFQ

0251.125PAT1L

Littelfuse Inc.In Stock: 9180251.125PAT1L Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 0251.125MAT1 are qualified based on strict electrical and mechanical parameter equivalence within the PICO® II 251 series. All substitute parts maintain identical specifications across the following critical parameters:

• Current Rating: 125 mA
• Voltage Rating: 125 V AC / 125 V DC
• Response Time: Fast Blow
• Mounting Type: Through Hole
• Fuse Type: Board Mount (Cartridge Style Excluded)
• Package / Case: Axial
• Breaking Capacity: 50 A AC / 300 A DC
• Melting I²t: 0.00174
• DC Cold Resistance: 1.7 Ohms
• Operating Temperature Range: -55°C to 125°C
• Size / Dimension: 0.110" Dia × 0.280" L (2.80 mm × 7.11 mm)
• Approval Agencies: CSA, cURus

Substitution differences are limited to packaging format (Cut Tape, Tape & Box) and product status (Active vs. Obsolete). All substitute parts are manufactured by Littelfuse Inc. and belong to the same PICO® II 251 series.

Parameter Comparison

Engineering Selection Recommendations

All substitute parts listed are electrically and mechanically equivalent to the 0251.125MAT1 and maintain full compatibility with existing circuit designs. Selection among substitute options should be based on the following factors:

Product Status: The original 0251.125MAT1 is obsolete. All listed substitutes (0251.125MAT1L, 0251.125HAT1L, 0251.125NAT1L, 0251.125NAT6L, 0251.125NF026L, 0251.125PAT1L) are active products with ongoing manufacturer support and availability.

RoHS Compliance: The original part is RoHS non-compliant. All substitute parts are RoHS3 compliant, meeting current environmental and regulatory requirements for electronic component manufacturing and distribution.

Packaging Format: Substitute parts are available in two packaging formats—Cut Tape (CT) and Tape & Box (TB). Selection depends on procurement volume and assembly line requirements. Cut Tape format is suitable for automated pick-and-place operations, while Tape & Box format accommodates both manual and automated assembly processes.

Inventory Availability: Substitute parts maintain varying stock levels. 0251.125NAT1L offers the highest inventory (8,919 pcs), providing supply chain stability for high-volume applications.

REACH Compliance: 0251.125HAT1L is REACH Unaffected, while 0251.125MAT1L is REACH Affected. For applications subject to REACH regulations, 0251.125HAT1L may be preferred.

Frequently Asked Questions (FAQ)

Q: Can I directly replace 0251.125MAT1 with any of the listed substitute parts?

A: Yes. All substitute parts maintain identical electrical and mechanical specifications, including current rating, voltage rating, response time, breaking capacity, and physical dimensions. Direct substitution is supported without circuit modification.

Q: What is the difference between Cut Tape (CT) and Tape & Box (TB) packaging?

A: Cut Tape packaging is supplied on continuous tape suitable for automated assembly equipment. Tape & Box packaging includes the same tape format but is boxed for easier handling and storage. Both formats contain the same component and are electrically identical.

Q: Why is the original 0251.125MAT1 marked as obsolete?

A: Obsolescence indicates the manufacturer has discontinued production of this specific part number. Active substitute parts from the same PICO® II 251 series provide equivalent functionality with current manufacturing support and compliance certifications.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. All listed substitute parts are RoHS3 compliant, whereas the original 0251.125MAT1 is RoHS non-compliant. This ensures compliance with current environmental regulations for new designs and procurement.

Q: Which substitute part should I select for high-volume production?

A: 0251.125NAT1L in Cut Tape (CT) format is recommended for high-volume automated assembly due to its highest inventory level (8,919 pcs) and tape format compatibility with pick-and-place equipment.

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

A: Yes. All substitute parts carry CSA and cURus approvals, matching the original part's certification status. Breaking capacity ratings (50 A AC / 300 A DC) and operating temperature range (-55°C to 125°C) are identical across all parts.

Q: What is the significance of the melting I²t value?

A: The melting I²t value (0.00174) defines the thermal energy required to melt the fuse element. This parameter is identical across all parts, ensuring consistent overcurrent protection characteristics and response behavior in circuit applications.