Littelfuse 72R250XF Polymeric PTC Resettable Fuse - Equivalent & Substitute Parts

Part Overview

The Littelfuse 72R250XF is a polymeric PTC resettable fuse rated for 72V maximum voltage with a 2.5A hold current. This component functions as an automatic circuit protection device that trips at 5A and resets after the fault condition is cleared. The part is active in production and widely used in power distribution and circuit protection applications requiring automatic recovery capability. Substitute parts are necessary when the original manufacturer part is unavailable, when alternative packaging formats are required, or when supply chain optimization demands component standardization across multiple qualified sources.

Substiute Parts

72R250XF

LittelfuseIn Stock: 127772R250XF Datasheet

Current PartRFQ

RXEF250

Littelfuse Inc.In Stock: 1839RXEF250 Datasheet

DirectRFQ

MF-RX250/72-0

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

DirectRFQ

PFRY.250

SCHURTER Inc.In Stock: 2614PFRY.250 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 72R250XF is determined by strict electrical and mechanical parameter matching. All qualified substitute parts must meet the following criteria:

Electrical Parameters (Non-Negotiable):

• Voltage - Max: 72V
• Current - Hold (Ih) (Max): 2.5 A
• Current - Trip (It): 5 A
• Current - Max: 40 A
• Time to Trip: 15.6 s
• Resistance - Initial (Ri) (Min): 50 mOhms
• Resistance - Post Trip (R1) (Max): 130 mOhms
• Operating Temperature: -40°C ~ 85°C

Mechanical Parameters (Flexible Within Tolerance):

• Mounting Type: Through Hole
• Package / Case: Radial, Disc
• Lead Spacing: 0.400" to 0.402" (10.15mm to 10.20mm)
• Physical dimensions: Minor variations acceptable within standard PCB layout tolerances

Compliance Requirements:

• Product Status: Active
• RoHS Status: ROHS3 Compliant
• REACH Status: REACH Unaffected

All three substitute parts listed below satisfy these criteria and are direct functional equivalents.

Parameter Comparison

Engineering Selection Recommendations

All three substitute parts are functionally equivalent to the 72R250XF and meet identical electrical specifications. Selection between alternatives should be based on the following factors:

Littelfuse RXEF250: This part carries expanded regulatory approvals including CQC, CSA, TUV, and UL certifications, providing broader geographic compliance coverage. The PolySwitch® series designation indicates compatibility with Littelfuse's established product ecosystem. Lead spacing of 0.400" (10.15mm) is within standard PCB tolerance ranges.

Bourns MF-RX250/72-0: The Multifuse® series from Bourns offers the highest inventory availability (4076 pcs) among substitute options. Bulk packaging format aligns with the original part's packaging specification. Lead spacing and physical dimensions match the original specification exactly.

SCHURTER PFRY.250: This option provides the most compact physical footprint with the smallest diameter (0.702" L) and height (0.937"), making it suitable for space-constrained applications. Moisture Sensitivity Level is listed as Not Applicable, indicating enhanced environmental robustness. Lead spacing matches the original specification.

All parts are active products with ROHS3 compliance and REACH unaffected status, ensuring long-term availability and regulatory compliance.

Frequently Asked Questions (FAQ)

Q: Can I substitute the 72R250XF with any of these parts without PCB modification?

A: Lead spacing for all substitute parts falls within 0.400" to 0.402" (10.15mm to 10.20mm), which is within standard PCB tolerance ranges. However, verify your specific PCB layout accommodates the minor dimensional variations listed in the parameter comparison table. The RXEF250 has the tightest lead spacing tolerance at 0.400".

Q: What is the difference between the POLY-FUSE® and PolySwitch® series designations?

A: Both are polymeric PTC resettable fuse product lines from Littelfuse. The POLY-FUSE® series (72R) and PolySwitch® series (RXEF) share identical electrical characteristics for this 72V/2.5A rating. Series designation reflects product line organization and does not affect functional equivalence.

Q: Are there packaging format differences I should consider?

A: The 72R250XF and MF-RX250/72-0 are supplied in Bulk packaging. The RXEF250 is supplied in Bag packaging. Both formats contain the same component; packaging format affects only handling and storage procedures, not electrical or mechanical performance.

Q: Which substitute part has the best regulatory approval coverage?

A: The Littelfuse RXEF250 carries the broadest approval agency certifications: CQC, CSA, TUV, and UL. The original 72R250XF and Bourns MF-RX250/72-0 are certified by cURus and TUV. SCHURTER PFRY.250 is certified by cURus and TUV. Selection should align with your specific regional regulatory requirements.

Q: Can I use these parts interchangeably in existing designs?

A: Yes. All electrical parameters, operating temperature range, and mechanical mounting specifications are identical. The parts are direct functional equivalents and require no circuit design changes. Verify PCB layout accommodates the dimensional variations noted in the parameter comparison table.

Q: What is the significance of the 15.6 second time-to-trip specification?

A: This parameter defines the thermal response time of the polymeric PTC element. All qualified substitutes share this identical specification, ensuring consistent circuit protection behavior and fault response timing across all equivalent parts.