MF-USML550/6-2 Equivalent & Substitute Parts

Part Overview

The MF-USML550/6-2 is a Polymeric PTC Resettable Fuse manufactured by Bourns Inc., rated for 6V maximum voltage with 5.5A hold current. This component is part of the Multifuse® MF-USML/X series and maintains Active product status. The device is designed for surface mount applications in the 1210 (3225 Metric) package format with concave configuration. Substitute parts are identified to provide alternative sourcing options while maintaining electrical and mechanical compatibility within specified parameter tolerances.

Substiute Parts

MF-USML550/6-2

Bourns Inc.In Stock: 653MF-USML550/6-2 Datasheet

Current PartRFQ

MF-USML550/12-2

Bourns Inc.In Stock: 1344MF-USML550/12-2 Datasheet

UpgradeRFQ

PTSLR12106V550

Eaton - Electronics DivisionIn Stock: 4801PTSLR12106V550 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the MF-USML550/6-2 are identified based on the following critical parameters that determine functional compatibility:

Primary Compatibility Criteria:

• Current - Hold (Ih) (Max): 5.5 A
• Current - Trip (It): 11 A
• Current - Max: 50 A
• Resistance - Initial (Ri) (Min): 1 mOhms
• Resistance - Post Trip (R1) (Max): 10 mOhms
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 1210 (3225 Metric), Concave
• RoHS Status: ROHS3 Compliant
• Moisture Sensitivity Level (MSL): 2A (4 Weeks)

Voltage Consideration: The MF-USML550/6-2 operates at 6V maximum. The MF-USML550/12-2 operates at 12V maximum and is listed as an upgrade option. The PTSLR12106V550 operates at 6V maximum, matching the original specification.

Parameter Comparison

Engineering Selection Recommendations

MF-USML550/12-2 (Upgrade Option): This Bourns Inc. component maintains identical current ratings, resistance characteristics, and thermal operating range as the MF-USML550/6-2. The 12V maximum voltage rating provides higher voltage margin. Both components are ROHS3 compliant with cURus and TUV certifications. The MF-USML550/12-2 carries additional cUL approval. Physical dimensions and package specifications are identical. Selection of this upgrade is appropriate for applications requiring higher voltage tolerance while maintaining all other electrical specifications.

PTSLR12106V550 (Similar Option): This Eaton component matches the 6V voltage rating and current specifications of the MF-USML550/6-2. Current - Hold, Current - Trip, Current - Max, resistance parameters, and operating temperature range are identical. Both components are ROHS3 compliant with cURus and TUV certifications. Physical dimensions differ slightly (0.135" L x 0.110" W versus 0.127" L x 0.101" W), and thickness is reduced (0.039" versus 0.047"). Time to Trip specification differs (5 s versus 2 s). Selection of this component requires confirmation that the dimensional variance and trip time difference are acceptable for the target application.

Frequently Asked Questions (FAQ)

Q: Can MF-USML550/12-2 be used as a direct replacement for MF-USML550/6-2?

A: The MF-USML550/12-2 shares identical current ratings, resistance characteristics, operating temperature range, and package dimensions with the MF-USML550/6-2. The primary difference is the maximum voltage rating (12V versus 6V). In applications operating at 6V or below, the MF-USML550/12-2 functions as a direct substitute with enhanced voltage margin. Applications requiring the specific 6V maximum rating should confirm that 12V rating compatibility is acceptable for the circuit design.

Q: What are the dimensional differences between PTSLR12106V550 and MF-USML550/6-2?

A: The PTSLR12106V550 has length of 0.135" (3.43mm) and width of 0.110" (2.80mm), compared to 0.127" L x 0.101" W (3.22mm x 2.58mm) for the MF-USML550/6-2. Thickness is 0.039" (1.00mm) for the PTSLR12106V550 versus 0.047" (1.20mm) for the MF-USML550/6-2. These dimensional variations must be evaluated against PCB layout constraints and available mounting space.

Q: How does Time to Trip specification affect substitution?

A: The MF-USML550/6-2 has a Time to Trip of 2 seconds, while the PTSLR12106V550 has a Time to Trip of 5 seconds. This parameter defines the response speed to overcurrent conditions. Applications with specific overcurrent response requirements must confirm that the substitute part's trip time is compatible with circuit protection objectives.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. The MF-USML550/6-2, MF-USML550/12-2, and PTSLR12106V550 are all ROHS3 compliant with Moisture Sensitivity Level 2A (4 Weeks).

Q: What certifications apply to each part?

A: MF-USML550/6-2 carries cURus and TUV approvals. MF-USML550/12-2 carries cUL, cURus, and TUV approvals. PTSLR12106V550 carries cURus and TUV approvals. Applications requiring specific certification standards should confirm alignment with these agency approvals.