MF-SMDF100-2 Equivalent & Substitute Parts

Part Overview

The MF-SMDF100-2 is a polymeric PTC resettable fuse manufactured by Bourns Inc., rated for 15V maximum voltage with 1.1A hold current. This component is designed for surface mount applications in the 2018 (5045 Metric) package format with concave configuration. The product is currently obsolete, making identification of suitable substitute components essential for ongoing system support and new design implementations.

Substiute Parts

MF-SMDF100-2

Bourns Inc.In Stock: 830MF-SMDF100-2 Datasheet

Current PartRFQ

SMD100F-2018-2

Littelfuse Inc.In Stock: 4524SMD100F-2018-2 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the MF-SMDF100-2 is determined by strict equivalence across the following critical parameters:

• Voltage rating: 15V maximum
• Hold current (Ih): 1.1A maximum
• Trip current (It): 2.2A
• Time to trip: 500 ms
• Initial resistance (Ri): 100 mOhms minimum
• Post-trip resistance (R1): 390 mOhms maximum
• Operating temperature range: -40°C to 85°C
• Mounting configuration: Surface mount
• Physical dimensions: 0.200" L x 0.180" W (5.08mm x 4.58mm)
• Component type: Polymeric PTC resettable fuse

The SMD100F-2018-2 from Littelfuse Inc. meets all critical electrical parameters and physical dimensions required for direct substitution. Minor variations in post-trip resistance (400 mOhms vs. 390 mOhms) and thickness (1.52mm vs. 1.25mm) remain within acceptable tolerance for equivalent functionality.

Parameter Comparison

Engineering Selection Recommendations

The SMD100F-2018-2 (Littelfuse PolySwitch®) is a direct functional equivalent to the obsolete MF-SMDF100-2. Both components are ROHS3 compliant and carry TUV approval. The Littelfuse part maintains active product status with higher inventory availability (4500 pcs vs. 785 pcs) and includes additional certifications (CSA, UL) beyond the original Bourns specification.

The 10 mOhms increase in post-trip resistance (400 mOhms vs. 390 mOhms) falls within normal manufacturing tolerance for polymeric PTC devices and does not affect functional equivalence. The thickness differential (1.52mm vs. 1.25mm) requires board layout verification for clearance in confined spaces, though both components maintain the same 2018 (5045 Metric) footprint.

Frequently Asked Questions (FAQ)

Q: Can SMD100F-2018-2 be used as a direct replacement for MF-SMDF100-2?

A: Yes. Both components share identical electrical ratings (15V, 1.1A hold current, 2.2A trip current, 500 ms trip time) and physical footprint (0.200" x 0.180"). The post-trip resistance variance (10 mOhms) is within acceptable tolerance for polymeric PTC resettable fuses.

Q: What is the impact of the thickness difference between these parts?

A: The SMD100F-2018-2 is 0.011" (0.27mm) thicker than the MF-SMDF100-2. This difference requires verification of available clearance above the component on the PCB. If space is constrained, the original Bourns part specifications should be consulted for alternative solutions.

Q: Are there compliance differences between these substitutes?

A: Both parts are ROHS3 compliant and carry TUV approval. The SMD100F-2018-2 includes additional CSA and UL certifications. Both are rated for MSL 1 or 2A moisture sensitivity, suitable for standard manufacturing and storage conditions.

Q: What determines whether a polymeric PTC resettable fuse can substitute for another?

A: Substitution requires matching voltage rating, hold current, trip current, trip time, initial and post-trip resistance specifications, operating temperature range, and physical footprint. Approval certifications and compliance status should also align with system requirements.

Q: Is the SMD100F-2018-2 available in the same packaging format?

A: The SMD100F-2018-2 is supplied in Tape & Reel (TR) format, while the original MF-SMDF100-2 packaging format is not specified in the provided data. Both components use the 2-SMD surface mount configuration compatible with standard pick-and-place assembly equipment.