Littelfuse RXE020 PTC Resettable Fuse – Equivalent & Substitute Parts

Part Overview

The Littelfuse RXE020 is a polymeric PTC resettable fuse rated for 72V at 200 mA hold current, designed for through-hole radial mounting in disc configuration. This component is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement.

The RXE020 belongs to the PolySwitch® RXE series and provides automatic overcurrent protection with a trip current of 400 mA and a time-to-trip specification of 2.2 seconds. Its compact radial disc form factor (7.40mm diameter × 3.00mm thickness) makes it suitable for space-constrained applications requiring reliable resettable protection.

Substiute Parts

RXE020

LittelfuseIn Stock: 814RXE020 Datasheet

Current PartRFQ

RXEF020

Littelfuse Inc.In Stock: 10155RXEF020 Datasheet

DirectRFQ

60R020XU

Littelfuse Inc.In Stock: 309260R020XU Datasheet

MFR RecommendedRFQ

MF-R020

Bourns Inc.In Stock: 10481MF-R020 Datasheet

DirectRFQ

PFRA.020

SCHURTER Inc.In Stock: 870PFRA.020 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the RXE020 is determined by the following critical parameters:

• Voltage Rating: Substitute parts must meet or exceed 72V maximum voltage rating
• Current – Hold (Ih): Must be 200 mA
• Current – Trip (It): Must be 400 mA
• Time to Trip: Must be 2.2 seconds
• Mounting Type: Through hole radial disc configuration required
• Physical Compatibility: Lead spacing and overall dimensions must accommodate existing PCB layouts

Based on these criteria, the following parts are classified as substitutes:

Direct Equivalent (Full Parameter Match):

• RXEF020 (Littelfuse) – Active status, identical electrical specifications, improved compliance

Voltage-Reduced Substitutes (60V Rating):

• 60R020XU (Littelfuse POLY-FUSE® series)
• MF-R020 (Bourns Multifuse® series)
• PFRA.020 (SCHURTER series)

These 60V-rated alternatives are suitable for applications where the circuit voltage does not exceed 60V, providing equivalent protection characteristics with active product status and modern compliance certifications.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (72V Applications):

RXEF020 is the primary substitute for RXE020. Both components share identical electrical specifications and physical dimensions. RXEF020 offers the advantage of active product status, expanded approval certifications (CQC addition), and ROHS3 compliance. This part is recommended for new designs and ongoing production requiring the full 72V rating.

For Voltage-Reduced Applications (≤60V):

When circuit voltage does not exceed 60V, the following alternatives provide equivalent protection characteristics with active status and modern compliance:

• 60R020XU (Littelfuse POLY-FUSE® series): Maintains Littelfuse ecosystem compatibility with identical electrical performance and CSA/TUV certifications
• MF-R020 (Bourns Multifuse® series): Offers lower initial resistance (1.5 Ohms vs. 1.83 Ohms), suitable for applications where reduced voltage drop is beneficial
• PFRA.020 (SCHURTER series): Provides alternative sourcing with equivalent specifications and cURus/TUV approvals

All active substitutes include specified operating temperature ranges (-40°C to 85°C) and ROHS3 compliance, addressing modern regulatory requirements absent from the obsolete RXE020.

Frequently Asked Questions (FAQ)

Q: Can RXEF020 be used as a direct replacement for RXE020?

A: Yes. RXEF020 is electrically and mechanically identical to RXE020, with matching 72V rating, 200 mA hold current, 400 mA trip current, and 2.2-second time-to-trip specification. Both use the same radial disc form factor with 5.05mm lead spacing. RXEF020 is preferred due to active product status and enhanced compliance certifications.

Q: What is the difference between 72V-rated and 60V-rated substitutes?

A: The RXE020 and RXEF020 are rated for maximum 72V operation. The 60R020XU, MF-R020, and PFRA.020 are rated for maximum 60V. These 60V alternatives are suitable only for circuits where the applied voltage does not exceed 60V. All other electrical parameters (hold current, trip current, time-to-trip) remain identical across all substitutes.

Q: Are there physical compatibility concerns when substituting?

A: Minor dimensional variations exist. The RXE020 and RXEF020 have thickness of 0.118" (3.00mm) and lead spacing of 0.199" (5.05mm). The 60V alternatives (60R020XU, MF-R020, PFRA.020) have thickness of 0.122" (3.10mm) and lead spacing of 0.201" (5.10mm). These differences are within typical PCB tolerance ranges for radial through-hole components, but physical verification on the target PCB is recommended for space-constrained layouts.

Q: What compliance advantages do active substitutes offer?

A: RXEF020 and all 60V alternatives carry ROHS3 compliance certification, addressing modern regulatory requirements. The obsolete RXE020 is non-compliant. Active substitutes also include specified operating temperature ranges (-40°C to 85°C), providing defined performance boundaries absent from the RXE020 specification.

Q: Which substitute offers the lowest initial resistance?

A: MF-R020 and PFRA.020 both specify 1.5 Ohms minimum initial resistance, compared to 1.83 Ohms for RXE020, RXEF020, and 60R020XU. Lower initial resistance reduces voltage drop during normal operation, which may be advantageous in low-voltage or high-current applications.

Q: Are all substitutes available in active production?

A: Yes. RXEF020, 60R020XU, MF-R020, and PFRA.020 are all classified as active products with current inventory availability. The original RXE020 is obsolete and no longer manufactured.