RKEF065 Polymeric PTC Resettable Fuse - Equivalent & Substitute Parts

Part Overview

The RKEF065 is a polymeric PTC resettable fuse manufactured by Littelfuse Inc. in the PolySwitch® series. This component provides overcurrent protection at 60V with a 650 mA hold current rating and is designed for through-hole radial mounting applications. The part is currently active in production with full compliance to ROHS3 and international approval certifications (CSA, TUV, UL).

Substitute parts are identified when equivalent electrical performance and mechanical compatibility can be maintained across the critical operating parameters: maximum voltage, hold current, trip current, operating temperature range, and physical form factor.

Substiute Parts

RKEF065

Littelfuse Inc.In Stock: 10196RKEF065 Datasheet

Current PartRFQ

RKEF065

Littelfuse Inc.In Stock: 10196RKEF065 Datasheet

Parametric EquivalentRFQ

MF-R065

Bourns Inc.In Stock: 31295MF-R065 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the RKEF065 is determined by strict equivalence across the following critical parameters:

• Voltage rating: 60V maximum
• Hold current (Ih): 650 mA maximum
• Trip current (It): 1.3 A
• Operating temperature range: -40°C to 85°C
• Mounting configuration: Through-hole radial
• Lead spacing: 0.199" to 0.201" (5.05 to 5.10 mm)
• Polymeric PTC type construction

The MF-R065 from Bourns Inc. meets all electrical equivalence criteria and maintains compatible mechanical form factor for direct substitution in circuit applications.

Parameter Comparison

Engineering Selection Recommendations

Both the RKEF065 and MF-R065 are active production components with ROHS3 compliance and international regulatory approvals. Selection between these parts should be based on:

• Circuit board layout compatibility: Lead spacing differs by 0.002" (0.05 mm), which is within standard PCB tolerance for radial component mounting.
• Approval requirements: The RKEF065 carries CSA, TUV, and UL certifications. The MF-R065 carries cURus and TUV certifications. Verify that the target application's regulatory requirements are met by the selected part's approval agency list.
• Trip time characteristics: The RKEF065 trips at 1 second while the MF-R065 trips at 5.3 seconds. Applications requiring faster fault response should specify the RKEF065.
• Inventory availability: The MF-R065 has higher stock availability (31,243 pcs vs. 10,100 pcs).

Frequently Asked Questions (FAQ)

Q: Can the MF-R065 be used as a direct replacement for the RKEF065?

A: The MF-R065 is electrically equivalent in voltage, hold current, trip current, and operating temperature range. Lead spacing is compatible within standard PCB tolerances (0.199" vs. 0.201"). However, the trip time differs (1 s vs. 5.3 s), which may affect circuit protection response time. Verify that the application's protection timing requirements are met by the MF-R065's 5.3-second trip characteristic.

Q: What are the key differences between these two parts?

A: The primary differences are: manufacturer (Littelfuse vs. Bourns), series designation (PolySwitch® vs. Multifuse®), trip time (1 s vs. 5.3 s), initial resistance (250 mOhms vs. 270 mOhms), and regulatory approvals (CSA/TUV/UL vs. cURus/TUV). All other electrical and mechanical parameters are equivalent.

Q: Are both parts suitable for the same operating temperature range?

A: Yes. Both the RKEF065 and MF-R065 operate across the identical temperature range of -40°C to 85°C.

Q: Do both parts meet RoHS compliance?

A: Yes. Both the RKEF065 and MF-R065 are ROHS3 compliant.

Q: Which part should I select if trip time is critical to my application?

A: If fast fault response is required, the RKEF065 with its 1-second trip time is the appropriate choice. If slower trip time is acceptable or preferred to reduce nuisance trips, the MF-R065 with its 5.3-second trip time may be suitable.

Q: Are the lead spacings identical?

A: Lead spacing is 0.199" (5.05 mm) for the RKEF065 and 0.201" (5.10 mm) for the MF-R065. This 0.002" difference is within standard PCB mounting tolerances for radial components and does not prevent direct board-level substitution.