MF-USML450/6-2 Polymeric PTC Resettable Fuse Equivalent & Substitute Parts

Part Overview

The MF-USML450/6-2 is a polymeric PTC resettable fuse manufactured by Bourns Inc., rated for 6V at 4.5A hold current in a 1210 (3225 Metric) surface mount package. This component is classified as Active product status and is ROHS3 compliant. Substitute parts may be required due to inventory availability, supply chain considerations, or specific application voltage requirements while maintaining equivalent electrical and mechanical characteristics.

Substiute Parts

MF-USML450/6-2

Bourns Inc.In Stock: 1064MF-USML450/6-2 Datasheet

Current PartRFQ

MF-USML450/12-2

Bourns Inc.In Stock: 4312MF-USML450/12-2 Datasheet

UpgradeRFQ

PTSLR12106V450

Eaton - Electronics DivisionIn Stock: 8612PTSLR12106V450 Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the MF-USML450/6-2 are grouped based on the following criteria:

Parametric Equivalent (Same Voltage Rating): PTSLR12106V450 from Eaton - Electronics Division maintains identical electrical specifications including 6V maximum voltage, 4.5A hold current, 9A trip current, 2 mOhms initial resistance, and 14 mOhms post-trip resistance. This part shares the same 1210 (3225 Metric) concave package, surface mount configuration, and operating temperature range of -40°C to 85°C. Both parts carry cURus and TUV approvals and are ROHS3 compliant.

Upgrade Variant (Higher Voltage Rating): MF-USML450/12-2 from Bourns Inc. is a voltage-upgraded variant within the same Multifuse® MF-USML/X series. While rated for 12V maximum voltage instead of 6V, it maintains all other electrical parameters identical to the main part: 4.5A hold current, 9A trip current, 2 mOhms initial resistance, and 14 mOhms post-trip resistance. The package, dimensions, and operating temperature remain unchanged. This variant is suitable only for applications requiring higher voltage protection.

Parameter Comparison

Engineering Selection Recommendations

PTSLR12106V450 (Eaton - Electronics Division): This part is a direct parametric equivalent suitable for applications requiring identical 6V voltage protection. Both the main part and this substitute carry active product status with cURus and TUV approvals. Selection of this part is appropriate when Bourns inventory is unavailable and cross-manufacturer compatibility is acceptable within the same electrical and mechanical specifications.

MF-USML450/12-2 (Bourns Inc.): This part is a voltage-upgraded variant within the Bourns Multifuse® series. It is suitable only for applications where the circuit voltage requirement is 12V or lower, and where the higher voltage rating provides additional protection margin. Both parts maintain active product status and identical mechanical compatibility. This variant should be selected only when the application circuit voltage exceeds 6V but does not exceed 12V.

Frequently Asked Questions (FAQ)

Q: Can PTSLR12106V450 be used as a direct replacement for MF-USML450/6-2?

A: Yes. PTSLR12106V450 is a parametric equivalent with identical electrical specifications (6V, 4.5A hold current, 9A trip current, 2 mOhms initial resistance, 14 mOhms post-trip resistance) and mechanical package (1210 concave, surface mount). Both parts are ROHS3 compliant with cURus and TUV approvals. The primary difference is manufacturer (Eaton vs. Bourns).

Q: When should MF-USML450/12-2 be used instead of the main part?

A: MF-USML450/12-2 should be used only when the application circuit voltage is higher than 6V but does not exceed 12V. This part provides higher voltage protection while maintaining all other electrical and mechanical characteristics. If the circuit voltage is 6V or lower, the main part MF-USML450/6-2 or its parametric equivalent PTSLR12106V450 should be used.

Q: Are all three parts mechanically interchangeable?

A: Yes. All three parts share identical package specifications: 1210 (3225 Metric) concave, surface mount configuration, dimensions of 0.127" L x 0.101" W (3.22mm x 2.58mm), and maximum thickness of 0.047" (1.20mm). They are mechanically interchangeable on PCBs designed for this footprint.

Q: What are the compliance and certification differences between these parts?

A: MF-USML450/6-2 carries cURus and TUV approvals. MF-USML450/12-2 carries cUL, cURus, and TUV approvals. PTSLR12106V450 carries cURus and TUV approvals. All three parts are ROHS3 compliant, REACH unaffected, and classified as EAR99 for export control purposes.

Q: What is the moisture sensitivity level for these parts?

A: All three parts are rated MSL 2A (4 Weeks), indicating they can be exposed to moisture for up to 4 weeks at specified humidity levels before soldering without requiring baking.