TRF250-145 Equivalent & Substitute Parts

Part Overview

The TRF250-145 is a polymeric PTC resettable fuse manufactured by Littelfuse Inc. in the PolySwitch® TRF250 series. This through-hole radial disc component provides overcurrent protection at 60V with a 145 mA hold current rating. The part is active in production with full RoHS3 compliance and international certifications (CSA, TUV, UL). Substitute parts are identified when electrical parameters, mechanical form factor, and regulatory compliance align with the original specification.

Substiute Parts

TRF250-145

Littelfuse Inc.In Stock: 940TRF250-145 Datasheet

Current PartRFQ

250R145ZR

Littelfuse Inc.In Stock: 3552250R145ZR Datasheet

MFR RecommendedRFQ

MF-RX014/250-0

Bourns Inc.In Stock: 37589MF-RX014/250-0 Datasheet

DirectRFQ

MF-RX014/250-2

Bourns Inc.In Stock: 14641MF-RX014/250-2 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the TRF250-145 are qualified based on the following criteria:

Electrical Parameters (Critical):

• Voltage rating: 60V (250V Int)
• Current hold (Ih): 145 mA maximum
• Current trip (It): 290 mA
• Maximum current: 3 A
• Initial resistance (Ri): 3 Ohms minimum
• Post-trip resistance (R1): 14 Ohms maximum
• Operating temperature range: -40°C to 85°C

Mechanical Parameters (Critical):

• Mounting type: Through hole
• Package form: Radial, disc
• Physical dimensions: 0.256" L x 0.181" W (6.50mm x 4.60mm)
• Height seated: 0.433" (11.00mm) maximum
• Lead spacing: 0.197" to 0.201" (5.00mm to 5.10mm)

Regulatory & Compliance:

• RoHS3 compliance required
• International certifications: cURus, TUV, or equivalent

All identified substitutes meet these criteria and are active production parts with confirmed inventory availability.

Parameter Comparison

Engineering Selection Recommendations

All identified substitute parts maintain electrical and mechanical compatibility with the TRF250-145 specification. Selection among alternatives is based on the following factors:

Littelfuse 250R145ZR: This part is the manufacturer-recommended substitute from Littelfuse Inc. It shares identical electrical parameters and physical dimensions with the TRF250-145. The primary difference is packaging format (Cut Tape vs. Bag) and a faster trip time (2.5 s vs. 5 s). Both parts carry RoHS3 compliance and international certifications (cURus, TUV). This option is suitable for direct replacement when Littelfuse parts are preferred.

Bourns MF-RX014/250-0 and MF-RX014/250-2: Both Bourns Multifuse® parts meet all critical electrical and mechanical parameters. They are functionally equivalent to the TRF250-145 with identical voltage, current hold, resistance, and temperature ratings. The MF-RX014/250-0 is supplied in bulk packaging, while the MF-RX014/250-2 is supplied in cut tape. Both carry RoHS3 compliance and cURus/TUV certifications. These options provide cross-manufacturer compatibility with significantly higher inventory availability.

All substitute parts are active production components with confirmed stock levels and full regulatory compliance.

Frequently Asked Questions (FAQ)

Q: Can the 250R145ZR replace the TRF250-145 directly?

A: Yes. The 250R145ZR is electrically and mechanically equivalent. Both are 60V, 145 mA hold current polymeric PTC resettable fuses with identical physical dimensions and lead spacing. The primary difference is packaging format (Cut Tape vs. Bag) and trip time specification (2.5 s vs. 5 s). Both are RoHS3 compliant and carry international certifications.

Q: Are the Bourns MF-RX014/250 parts compatible with the TRF250-145?

A: Yes. Both MF-RX014/250-0 and MF-RX014/250-2 meet the electrical and mechanical requirements of the TRF250-145. They share the same voltage rating (60V), current hold (145 mA), resistance values, and physical form factor (radial disc, through hole). Lead spacing is 0.201" (5.10mm) versus 0.197" (5.00mm) on the original, which is within acceptable tolerance for standard PCB hole spacing. Both are RoHS3 compliant with cURus and TUV certifications.

Q: What is the difference between the packaging options?

A: The TRF250-145 is supplied in Bag packaging. The 250R145ZR is available in Cut Tape (CT). The Bourns MF-RX014/250-0 is supplied in Bulk, while the MF-RX014/250-2 is in Cut Tape. Packaging format affects handling, storage, and automated assembly compatibility but does not impact electrical or mechanical performance.

Q: Does the faster trip time of the 250R145ZR affect compatibility?

A: The 250R145ZR has a trip time of 2.5 seconds compared to 5 seconds for the TRF250-145. Both meet the 290 mA trip current specification. The faster response time of the 250R145ZR provides more aggressive overcurrent protection. Circuit design must accommodate this characteristic difference.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. The TRF250-145, 250R145ZR, MF-RX014/250-0, and MF-RX014/250-2 are all RoHS3 compliant. All parts carry REACH Unaffected status and EAR99 export classification.

Q: What certifications do the substitute parts carry?

A: The TRF250-145 carries CSA, TUV, and UL certifications. The 250R145ZR, MF-RX014/250-0, and MF-RX014/250-2 carry cURus and TUV certifications. All parts meet international safety and performance standards for polymeric PTC resettable fuses.