RXEF090-2 Polymeric PTC Resettable Fuse Equivalent & Substitute Parts

Part Overview

The RXEF090-2 is an active polymeric PTC resettable fuse manufactured by Littelfuse in the PolySwitch® RXEF series. This component provides overcurrent protection at 72V with a 900 mA hold current rating and 1.8 A trip current in a through-hole radial disc package. Substitute parts are identified based on matching electrical specifications, mechanical compatibility, and regulatory compliance to ensure direct interchangeability in circuit protection applications.

Substiute Parts

RXEF090-2

LittelfuseIn Stock: 2942RXEF090-2 Datasheet

Current PartRFQ

72R090XPR

Littelfuse Inc.In Stock: 356372R090XPR Datasheet

SimilarRFQ

RXEF090-2

LittelfuseIn Stock: 2942RXEF090-2 Datasheet

Parametric EquivalentRFQ

RXEF090-AP

LittelfuseIn Stock: 1042RXEF090-AP Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the RXEF090-2 is determined by the following critical parameters:

• Voltage Rating: Maximum voltage must equal or exceed 72V
• Current - Hold (Ih): Must match 900 mA specification
• Current - Trip (It): Must match 1.8 A specification
• Mounting Type: Must be Through Hole to ensure PCB compatibility
• Package / Case: Must be Radial, Disc configuration
• Lead Spacing: Mechanical tolerance within 0.199" ± acceptable variation
• Operating Temperature Range: Must encompass -40°C ~ 85°C
• Regulatory Compliance: Must maintain ROHS3 compliance and relevant agency approvals

The identified substitute parts meet all electrical and mechanical parameters required for direct replacement in the same circuit application.

Parameter Comparison

Engineering Selection Recommendations

All three parts—RXEF090-2, 72R090XPR, and RXEF090-AP—are active products from Littelfuse with identical electrical specifications and ROHS3 compliance. Selection between these parts is based on the following factors:

RXEF090-2 and RXEF090-AP: Both are PolySwitch® RXEF series components with identical dimensions (0.441" Dia x 0.118" T) and lead spacing (0.199"). RXEF090-2 carries broader regulatory approvals (CQC, CSA, TUV, UL) compared to RXEF090-AP (CQC, CSA, TUV, UL). RXEF090-2 has higher inventory availability (2854 pcs).

72R090XPR: POLY-FUSE® 72R series substitute with marginally different mechanical dimensions (0.441" Dia x 0.122" T, lead spacing 0.201"). This part carries cURus and TUV approvals. The 0.004" thickness difference and 0.002" lead spacing variation remain within typical PCB tolerance specifications for radial disc components. Inventory availability is 3533 pcs.

All parts maintain identical electrical performance across voltage, current, resistance, and thermal specifications. Selection should prioritize part availability and regulatory approval alignment with end-application requirements.

Frequently Asked Questions (FAQ)

Q: Can 72R090XPR replace RXEF090-2 directly on the PCB?

A: Yes. The 72R090XPR has a 0.004" thickness difference (3.10mm vs 3.00mm) and 0.002" lead spacing variation (5.10mm vs 5.05mm). These dimensional differences fall within standard PCB tolerance specifications for through-hole radial components and do not affect electrical performance or mechanical fit.

Q: Are all three parts electrically identical?

A: Yes. RXEF090-2, 72R090XPR, and RXEF090-AP share identical electrical specifications: 72V maximum voltage, 900 mA hold current, 1.8 A trip current, 7.2 s trip time, and 200 mOhms initial resistance. All operate across -40°C to 85°C.

Q: What regulatory approvals differ between these parts?

A: RXEF090-2 and RXEF090-AP carry CQC, CSA, TUV, and UL approvals. The 72R090XPR carries cURus and TUV approvals. Selection should align with application-specific regulatory requirements.

Q: Is the REACH status the same across all parts?

A: RXEF090-2 and 72R090XPR both have REACH Unaffected status. RXEF090-AP does not list REACH status in the provided specifications.

Q: Which part should I select for new designs?

A: All three parts are active products suitable for new designs. RXEF090-2 offers the broadest regulatory approval set and highest inventory. 72R090XPR provides an alternative with comparable availability. Selection should be based on supply chain requirements, regulatory compliance needs, and inventory availability at the time of procurement.