MF-RX300-AP Equivalent & Substitute Parts

Part Overview

The MF-RX300-AP is a Polymeric PTC Resettable Fuse manufactured by Bourns Inc. as part of the Multifuse® MF-RX series. This component is rated for 60V maximum voltage with a 3A hold current and is designed for through-hole radial mounting in disc configuration. The product is currently listed as Obsolete, making identification of compatible substitute parts essential for ongoing system support and component procurement.

Substiute Parts

MF-RX300-AP

Bourns Inc.In Stock: 860MF-RX300-AP Datasheet

Current PartRFQ

MF-RX300/72-AP

Bourns Inc.In Stock: 836MF-RX300/72-AP Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the MF-RX300-AP is determined by the following critical parameters:

Mechanical Compatibility: Mounting type (Through Hole), package configuration (Radial, Disc), physical dimensions (0.980" L x 0.122" W, 1.181" max height), and lead spacing (0.402") must remain identical to ensure PCB fit without redesign.

Electrical Compatibility: Current hold rating (Ih) of 3A and trip current (It) of 6A are primary selection criteria. Time to trip (19.8s), initial resistance (40 mOhms min), and post-trip resistance (100 mOhms max) define the protective response characteristics.

Voltage Rating: The maximum voltage rating may be increased without functional impact, provided the substitute part maintains all other electrical and mechanical parameters.

Regulatory Compliance: RoHS3 compliance and cURus/TUV approvals must be maintained.

Parameter Comparison

Engineering Selection Recommendations

The MF-RX300/72-AP is a direct substitute for the MF-RX300-AP. Both components share identical electrical performance characteristics (3A hold current, 6A trip current, 19.8s trip time, 40 mOhms initial resistance, 100 mOhms post-trip resistance) and mechanical specifications (through-hole radial disc package, identical dimensions and lead spacing).

The primary distinction is the increased maximum voltage rating of 72V on the substitute part compared to 60V on the main part. This higher voltage rating does not compromise compatibility in applications operating at or below 60V.

The MF-RX300/72-AP carries Active product status, ensuring ongoing availability and supply chain continuity. Both parts maintain identical regulatory compliance: ROHS3 certification, cURus and TUV approvals, and MSL Level 1 (Unlimited) moisture sensitivity rating.

Frequently Asked Questions (FAQ)

Q: Can MF-RX300/72-AP replace MF-RX300-AP in all applications?

A: Yes, for applications operating at 60V or below. The substitute part maintains identical hold current (3A), trip current (6A), trip time (19.8s), and resistance characteristics. The increased voltage rating (72V vs 60V) provides additional margin without affecting performance in lower-voltage circuits.

Q: Are the physical dimensions identical between these parts?

A: Yes. Both components feature identical through-hole radial disc packaging with dimensions of 0.980" L x 0.122" W (24.90mm x 3.10mm), maximum seated height of 1.181" (30.00mm), and lead spacing of 0.402" (10.20mm). No PCB layout modifications are required.

Q: What is the difference in product status, and why does it matter?

A: The MF-RX300-AP is listed as Obsolete, while the MF-RX300/72-AP is Active. Active status ensures continued manufacturing, availability, and supply chain support. For new designs or ongoing procurement, the Active substitute part is the recommended choice.

Q: Are regulatory certifications maintained in the substitute part?

A: Yes. The MF-RX300/72-AP maintains identical regulatory compliance: ROHS3 certification, cURus and TUV approvals, and MSL Level 1 (Unlimited) rating. No compliance gaps exist between the main part and substitute.

Q: What packaging options are available for the MF-RX300/72-AP?

A: The substitute part is supplied in Tape & Box (TB) packaging, which is standard for component procurement and automated assembly processes.