RXEF030-AP Polymeric PTC Resettable Fuse - Equivalent & Substitute Parts

Part Overview

The RXEF030-AP is a polymeric PTC resettable fuse manufactured by Littelfuse, part of the PolySwitch® RXEF series. This component is designed for overcurrent protection in electronic circuits operating at 72V with a 300 mA hold current. The device automatically resets after a fault condition is cleared, eliminating the need for manual fuse replacement. The part is currently in active production status with 43,300 units in stock.

Substitute parts are identified when electrical characteristics, mechanical dimensions, and regulatory compliance align with the original specification, enabling direct replacement in circuit designs without functional degradation.

Substiute Parts

RXEF030-AP

LittelfuseIn Stock: 43406RXEF030-AP Datasheet

Current PartRFQ

72R030XPR

Littelfuse Inc.In Stock: 246172R030XPR Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the RXEF030-AP is determined by strict equivalence across the following critical parameters:

Electrical Parameters: Voltage rating (72V), hold current (300 mA), trip current (600 mA), maximum current (40 A), and trip time (3 s) must be identical. Resistance characteristics—initial resistance (880 mOhms minimum) and post-trip resistance (2.1 Ohms maximum)—must fall within specified tolerances.

Mechanical Parameters: Mounting type (Through Hole), package style (Radial, Disc), and lead spacing must be compatible with the original PCB layout.

Regulatory Compliance: Parts must maintain ROHS3 compliance and possess appropriate approval agency certifications (CQC, CSA, TUV, UL, or equivalent).

The 72R030XPR meets all substitution criteria and is classified as a direct equivalent.

Parameter Comparison

Engineering Selection Recommendations

Both RXEF030-AP and 72R030XPR are active production components from Littelfuse with full ROHS3 compliance. The 72R030XPR carries additional REACH Unaffected status documentation. Both parts hold equivalent regulatory approvals (TUV certification is common to both; RXEF030-AP includes CQC and CSA; 72R030XPR includes cURus).

Dimensional variance is minimal: lead spacing differs by 0.002" (0.05mm) and thickness by 0.004" (0.10mm), both within standard PCB tolerance ranges for radial through-hole components. These minor differences do not impact functional performance or circuit board compatibility.

Selection between these parts may be based on inventory availability, supply chain logistics, or existing design documentation preferences. Both are suitable for direct substitution in 72V, 300 mA polymeric PTC resettable fuse applications.

Frequently Asked Questions (FAQ)

Q: Can the 72R030XPR replace the RXEF030-AP in an existing design?

A: Yes. Both parts are polymeric PTC resettable fuses with identical electrical specifications (72V, 300 mA hold current, 600 mA trip current, 3 s trip time). Mechanical compatibility is confirmed through equivalent mounting type, package style, and lead spacing within standard PCB tolerances.

Q: What is the difference between the RXEF and 72R series designations?

A: RXEF030-AP belongs to the PolySwitch® RXEF series, while 72R030XPR belongs to the POLY-FUSE® 72R series. Both are Littelfuse product lines for polymeric PTC resettable fuses. Series designation reflects internal product categorization but does not affect electrical or mechanical equivalence.

Q: Are there dimensional concerns with the lead spacing difference?

A: The lead spacing difference of 0.002" (0.05mm) is negligible for standard PCB through-hole designs. Both parts use 0.199" to 0.201" spacing, which falls within typical PCB hole tolerance specifications. No design modification is required.

Q: Do both parts have the same regulatory certifications?

A: Both parts are ROHS3 compliant and hold TUV certification. RXEF030-AP includes CQC and CSA approvals; 72R030XPR includes cURus approval. All certifications are appropriate for industrial and consumer electronics applications.

Q: What is the moisture sensitivity level for these components?

A: Both parts have MSL 1 (Unlimited), indicating no moisture sensitivity concerns. Standard storage and handling practices are sufficient; no special desiccant packaging or baking procedures are required.

Q: Can these parts be used interchangeably in high-temperature applications?

A: Yes. Both parts operate across the identical temperature range of -40°C to 85°C. Selection between them is not affected by temperature considerations within this range.