MF-RX250-2 Equivalent & Substitute Parts

Part Overview

The Bourns MF-RX250-2 is a polymeric PTC resettable fuse rated for 60V at 2.5A hold current, designed for through-hole radial mounting in disc configuration. This component is classified as obsolete, making identification of compatible substitutes essential for ongoing system support and procurement planning. The MF-RX series provides automatic overcurrent protection with self-resetting capability across the specified operating temperature range of -40°C to 85°C.

Substiute Parts

MF-RX250-2

Bourns Inc.In Stock: 850MF-RX250-2 Datasheet

Current PartRFQ

MF-RX250/72-0

Bourns Inc.In Stock: 4130MF-RX250/72-0 Datasheet

DirectRFQ

MF-RX250/72-2

Bourns Inc.In Stock: 4144MF-RX250/72-2 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the MF-RX250-2 is determined by the following electrical and mechanical parameters:

Electrical Compatibility Criteria:

• Current - Hold (Ih): Must remain at 2.5 A to maintain circuit protection characteristics
• Current - Trip (It): Must remain at 5 A for consistent overcurrent response
• Resistance - Initial (Ri) and Resistance - Post Trip (R1): Must match specified ranges
• Time to Trip: Must remain at 15.6 s for predictable fault response timing

Mechanical Compatibility Criteria:

• Mounting Type: Through Hole configuration required
• Package / Case: Radial, Disc format required
• Lead Spacing: Must be 0.402" (10.20mm) for PCB compatibility

Voltage Consideration: The substitute parts operate at 72V maximum voltage, which exceeds the original 60V rating. This represents an uprated voltage specification and is acceptable for applications where the circuit voltage does not exceed 60V, as the component will operate within its safe margin.

Thermal and Compliance:

• Operating Temperature range: -40°C ~ 85°C (identical)
• RoHS3 Compliance: Required
• Approval Agencies: cURus, TUV certification maintained

Parameter Comparison

Engineering Selection Recommendations

MF-RX250/72-0 (Bulk Packaging)

This substitute maintains identical electrical characteristics and physical dimensions to the original MF-RX250-2. The uprated 72V specification provides additional voltage margin for applications operating at or below 60V. Active product status ensures long-term availability and supply chain continuity. Bulk packaging is suitable for high-volume production environments. ROHS3 compliance and cURus/TUV certifications are maintained.

MF-RX250/72-2 (Cut Tape Packaging)

This substitute provides identical electrical performance with active product status. Physical dimensions are reduced (0.702" L vs. 0.839" L and 0.939" height vs. 1.039" height), which may require PCB layout verification for clearance compatibility. Cut tape packaging is appropriate for automated assembly processes. All compliance certifications and electrical specifications remain equivalent to the original component.

Selection Basis:

Both substitutes are qualified alternatives based on maintained electrical parameters (2.5A hold current, 5A trip current, 15.6s trip time, identical resistance specifications), identical lead spacing for PCB compatibility, and active product status from the same manufacturer. The choice between MF-RX250/72-0 and MF-RX250/72-2 depends on packaging requirements and physical space constraints within the application.

Frequently Asked Questions (FAQ)

Q: Can MF-RX250/72-0 and MF-RX250/72-2 be used interchangeably with MF-RX250-2?

A: Both substitutes are electrically equivalent for applications operating at 60V or below. The primary differences are packaging format (bulk vs. cut tape) and physical dimensions. MF-RX250/72-0 maintains identical size to the original. MF-RX250/72-2 has reduced length and height, requiring verification that PCB layout accommodates the smaller footprint.

Q: What does the 72V rating mean for a 60V application?

A: The 72V maximum voltage specification indicates the component is rated to safely operate at voltages up to 72V. In a 60V application, the component operates within its rated specification with additional voltage margin. This does not affect performance or protection characteristics.

Q: Are there packaging differences between the substitutes?

A: MF-RX250/72-0 is supplied in bulk packaging, while MF-RX250/72-2 is supplied in cut tape format. Both contain identical components. Packaging selection depends on assembly process requirements and inventory management practices.

Q: Do the substitutes maintain the same lead spacing?

A: Yes. Both MF-RX250/72-0 and MF-RX250/72-2 maintain 0.402" (10.20mm) lead spacing, ensuring direct PCB compatibility without layout modifications.

Q: Are compliance certifications maintained?

A: Both substitutes maintain cURus and TUV approvals, ROHS3 compliance, and MSL 1 (Unlimited) moisture sensitivity rating. Regulatory and environmental compliance is equivalent to the original component.

Q: What is the significance of active vs. obsolete product status?

A: The original MF-RX250-2 is obsolete, meaning Bourns has discontinued production. Both substitutes are active products with ongoing manufacturing and guaranteed long-term availability, ensuring supply chain reliability for future procurement and system support.