MF-R135 Polymeric PTC Resettable Fuse Equivalent & Substitute Parts

Part Overview

The MF-R135 is an active polymeric PTC resettable fuse manufactured by Bourns Inc. in the Multifuse® MF-R series. This component provides overcurrent protection at 30V with a 1.35A hold current rating in a through-hole radial disc package. The MF-R135 is ROHS3 compliant and carries cURus and TUV approvals. Equivalent and substitute parts are necessary when the primary part is unavailable, when alternative packaging formats are required for manufacturing processes, or when design flexibility across approved component sources is needed.

Substiute Parts

MF-R135

Bourns Inc.In Stock: 2443MF-R135 Datasheet

Current PartRFQ

30R135UPR

Littelfuse Inc.In Stock: 396830R135UPR Datasheet

DirectRFQ

30R135UU

Littelfuse Inc.In Stock: 122330R135UU Datasheet

DirectRFQ

PTR030V0135-TR

Eaton - Electronics DivisionIn Stock: 3893PTR030V0135-TR Datasheet

DirectRFQ

RUEF135

Littelfuse Inc.In Stock: 17372RUEF135 Datasheet

SimilarRFQ

PFRA.135

SCHURTER Inc.In Stock: 1919PFRA.135 Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the MF-R135 is determined by strict equivalence across the following critical parameters: maximum voltage rating (30V), hold current (1.35A), trip current (2.7A), time to trip (7.3s), operating temperature range (-40°C to 85°C), mounting type (through hole), and package form (radial disc). Lead spacing tolerance of ±0.01" is acceptable for PCB compatibility. All substitute parts must maintain ROHS3 compliance and carry equivalent regulatory approvals (cURus, TUV, or equivalent). Packaging format differences (bulk, cut tape, bag) do not affect electrical substitutability but may impact procurement and assembly workflows.

Parameter Comparison

Engineering Selection Recommendations

All listed substitute parts meet the electrical and mechanical requirements for direct substitution with the MF-R135. Selection should be based on the following factors:

Direct Electrical Equivalents: The 30R135UPR, 30R135UU, PTR030V0135-TR, and RUEF135 are electrically equivalent with identical voltage, hold current, trip current, and time-to-trip specifications. These parts feature lower initial resistance (40 mOhms vs. 65 mOhms) and lower post-trip resistance (130 mOhms vs. 170 mOhms), which may provide marginal performance benefits in low-impedance circuit applications.

Parametric Match: The PFRA.135 from SCHURTER Inc. provides an exact parametric match to the MF-R135, including identical initial and post-trip resistance values (65 mOhms and 170 mOhms respectively). This part is suitable for applications where resistance characteristics are critical design parameters.

Packaging Considerations: The MF-R135 and 30R135UU are supplied in bulk packaging. The 30R135UPR and PTR030V0135-TR are available in cut tape format, suitable for automated assembly. The RUEF135 is supplied in bag format. Selection should align with manufacturing process requirements.

Regulatory Compliance: All substitute parts maintain ROHS3 compliance. The MF-R135, PFRA.135, and PTR030V0135-TR carry cURus and TUV approvals. The 30R135UPR and 30R135UU carry cURus and TUV approvals. The RUEF135 carries CQC, CSA, TUV, and UL approvals, providing the broadest regulatory acceptance.

Lead Spacing: The PTR030V0135-TR has a lead spacing of 0.197" (5.00mm), which is 0.004" tighter than the MF-R135 standard of 0.201" (5.10mm). This minor difference is within typical PCB tolerance and does not preclude substitution. The RUEF135 has a lead spacing of 0.199" (5.05mm), also within acceptable tolerance.

Frequently Asked Questions (FAQ)

Q: Can the 30R135UPR be used as a direct replacement for the MF-R135?

A: Yes. The 30R135UPR meets all critical electrical parameters: 30V maximum voltage, 1.35A hold current, 2.7A trip current, and 7.3s time to trip. The primary difference is packaging format (cut tape vs. bulk) and slightly lower resistance values. Lead spacing is identical at 0.201".

Q: What is the difference between the PFRA.135 and the 30R135UPR?

A: Both are electrically equivalent in voltage, current, and trip characteristics. The PFRA.135 matches the MF-R135 in initial and post-trip resistance values (65 mOhms and 170 mOhms). The 30R135UPR has lower resistance values (40 mOhms and 130 mOhms). Selection depends on whether circuit design requires specific resistance characteristics.

Q: Is the PTR030V0135-TR compatible with the MF-R135 PCB footprint?

A: The PTR030V0135-TR has a lead spacing of 0.197" (5.00mm) compared to the MF-R135 standard of 0.201" (5.10mm). This 0.004" difference is within typical PCB manufacturing tolerance and does not prevent substitution. Verify PCB hole spacing before assembly.

Q: Which substitute part has the highest inventory availability?

A: The RUEF135 from Littelfuse Inc. has the highest inventory at 17,300 pieces. This part is supplied in bag format and carries the broadest regulatory approvals (CQC, CSA, TUV, UL).

Q: Are all substitute parts ROHS3 compliant?

A: Yes. All listed substitute parts are ROHS3 compliant. Regulatory approvals vary by manufacturer: the MF-R135 and PFRA.135 carry cURus and TUV approvals; the 30R135UPR and 30R135UU carry cURus and TUV approvals; the PTR030V0135-TR carries cURus and TUV approvals; the RUEF135 carries CQC, CSA, TUV, and UL approvals.

Q: Can packaging format affect the substitution decision?

A: Packaging format does not affect electrical substitutability but impacts procurement and assembly workflows. Bulk packaging (MF-R135, 30R135UU, PFRA.135) is suitable for manual assembly or small-volume production. Cut tape format (30R135UPR, PTR030V0135-TR) is optimized for automated pick-and-place assembly. Bag format (RUEF135) is suitable for manual assembly with moderate volume requirements.