MF-USML650-2 PTC Resettable Fuse Equivalent & Substitute Parts

Part Overview

The MF-USML650-2 is a polymeric PTC resettable fuse manufactured by Bourns Inc., designed for overcurrent protection in surface mount applications. This component operates at 6V with a 6.5A hold current and provides automatic reset functionality after fault conditions are cleared. The MF-USML650-2 is currently listed as obsolete, making identification of compatible substitute parts essential for ongoing design support and component procurement.

Substiute Parts

MF-USML650-2

Bourns Inc.In Stock: 901MF-USML650-2 Datasheet

Current PartRFQ

MF-USML650/6-2

Bourns Inc.In Stock: 3126MF-USML650/6-2 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the MF-USML650-2 is determined by strict equivalence across the following critical parameters:

• Voltage rating: 6V maximum
• Current hold specification: 6.5A
• Current trip specification: 13A
• Package form factor: 1210 (3225 Metric), Concave
• Polymeric PTC type classification
• Regulatory compliance: cURus and TUV approval
• RoHS3 compliance status

The substitute part MF-USML650/6-2 meets all these criteria. Differences in post-trip resistance (R1) and thickness do not preclude substitution, as these parameters remain within acceptable operational ranges for the specified electrical characteristics.

Parameter Comparison

Engineering Selection Recommendations

The MF-USML650/6-2 is the direct substitute for the obsolete MF-USML650-2. Both components share identical electrical specifications across voltage, current hold, current trip, and time-to-trip parameters. The substitute maintains full regulatory compliance with cURus and TUV certifications and RoHS3 status.

The MF-USML650/6-2 is currently in active production with substantial inventory availability, making it the appropriate choice for new designs and ongoing component replacement. The reduced post-trip resistance (9 mOhms versus 14 mOhms) and decreased thickness (1.00mm versus 1.20mm) represent design improvements that do not compromise functional equivalence.

Frequently Asked Questions (FAQ)

Q: Can MF-USML650/6-2 be used as a direct replacement for MF-USML650-2?

A: Yes. Both components are polymeric PTC resettable fuses with identical voltage (6V), hold current (6.5A), trip current (13A), and operating temperature ranges. The package form factor, mounting type, and regulatory approvals are equivalent.

Q: What is the difference in thickness between these parts?

A: The MF-USML650-2 has a maximum thickness of 0.047" (1.20mm), while the MF-USML650/6-2 measures 0.039" (1.00mm) maximum. Both fit the 1210 (3225 Metric) package specification. Verify PCB layout clearances if space constraints are critical.

Q: Are there compliance differences between the two parts?

A: No. Both components carry cURus and TUV approvals and are ROHS3 compliant. REACH status is unaffected for both parts.

Q: Why is MF-USML650-2 listed as obsolete?

A: The MF-USML650/6-2 represents the current production equivalent. Bourns Inc. has transitioned to the newer part number while maintaining electrical and functional equivalence.

Q: What is the difference in post-trip resistance?

A: The MF-USML650-2 specifies a maximum post-trip resistance of 14 mOhms, while the MF-USML650/6-2 specifies 9 mOhms maximum. This represents an improvement in the substitute part and does not affect substitution compatibility.