MF-RX135-2-99 Equivalent & Substitute Parts

Part Overview

The Bourns MF-RX135-2-99 is a polymeric PTC resettable fuse rated for 60V at 1.35A hold current, designed for through-hole radial mounting in disc configuration. This component is classified as obsolete, making identification of suitable substitutes essential for ongoing design support and production continuity. Substitute parts must maintain electrical compatibility across voltage, current, and thermal characteristics while accommodating available packaging options.

Substiute Parts

MF-RX135-2-99

Bourns Inc.In Stock: 1179MF-RX135-2-99 Datasheet

Current PartRFQ

MF-RX135/72-0

Bourns Inc.In Stock: 21990MF-RX135/72-0 Datasheet

DirectRFQ

MF-RX135/72-2

Bourns Inc.In Stock: 70269MF-RX135/72-2 Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the MF-RX135-2-99 are identified based on the following electrical and mechanical compatibility criteria:

Critical Parameters for Substitution:

• Current - Hold (Ih): Must equal 1.35 A
• Current - Trip (It): Must equal 2.7 A
• Time to Trip: Must equal 9.6 s
• Resistance - Initial (Ri) and Post Trip (R1): Must remain within specified ranges
• Mounting Type: Must be Through Hole
• Package / Case: Must be Radial, Disc
• Physical Dimensions and Lead Spacing: Must match or be mechanically compatible
• Operating Temperature Range: Must support -40°C ~ 85°C
• Approval Agencies: Must maintain cURus and TUV certifications

Voltage Consideration: The substitute parts operate at 72V maximum voltage, which exceeds the original 60V rating. This represents an uprated voltage specification. Substitutes are valid for applications where the circuit voltage does not exceed 60V, as the higher voltage rating provides additional safety margin without affecting lower-voltage operation.

Parameter Comparison

Engineering Selection Recommendations

Both MF-RX135/72-0 and MF-RX135/72-2 are direct electrical and mechanical substitutes for the obsolete MF-RX135-2-99. Selection between these two substitute parts is determined by procurement and assembly requirements rather than electrical performance.

MF-RX135/72-0 (Bulk Packaging): Suitable for high-volume production environments where components are processed through automated pick-and-place systems with bulk reel handling.

MF-RX135/72-2 (Cut Tape Packaging): Suitable for lower-volume production, prototype builds, or applications requiring individual component handling and manual assembly processes.

Both substitutes maintain active product status with Bourns Inc., ensuring long-term availability and supply chain stability. All three parts carry identical regulatory certifications (cURus, TUV) and comply with ROHS3 and REACH requirements. The 72V maximum voltage rating of the substitute parts provides enhanced voltage margin for applications operating at or below 60V.

Frequently Asked Questions (FAQ)

Q: Can MF-RX135/72-0 or MF-RX135/72-2 be used as direct replacements for MF-RX135-2-99?

A: Yes. Both substitute parts are electrically and mechanically compatible. They maintain identical hold current (1.35 A), trip current (2.7 A), time to trip (9.6 s), initial resistance (120 mOhms minimum), and post-trip resistance (300 mOhms maximum). Physical dimensions, lead spacing, and mounting configuration are identical. The higher voltage rating (72V vs. 60V) does not affect operation in circuits designed for 60V or lower.

Q: What is the difference between MF-RX135/72-0 and MF-RX135/72-2?

A: The electrical and mechanical specifications are identical. The difference is packaging format: MF-RX135/72-0 is supplied in bulk, while MF-RX135/72-2 is supplied in cut tape. Selection depends on assembly process requirements and order quantity.

Q: Are there any compliance or certification differences between the main part and substitutes?

A: No. All three parts carry identical regulatory approvals (cURus, TUV), maintain ROHS3 compliance, and are REACH unaffected. Moisture sensitivity level (MSL 1) is identical across all variants.

Q: Why does the substitute have a higher voltage rating?

A: The MF-RX135/72 series represents an updated product line within the Multifuse® family. The 72V rating provides additional design margin while maintaining all other electrical characteristics. For applications operating at 60V or below, this higher rating presents no compatibility issues.

Q: Can these parts be used interchangeably in PCB assembly?

A: Yes, provided the PCB footprint and lead spacing accommodate the 0.201" (5.10mm) radial configuration. All three parts share identical physical dimensions and mounting requirements for through-hole radial disc packages.