AHRF650 Polymeric PTC Resettable Fuse Equivalent & Substitute Parts

Part Overview

The AHRF650 is a polymeric PTC resettable fuse manufactured by Littelfuse in the PolySwitch® series. This through-hole radial disc component provides overcurrent protection with a maximum voltage rating of 16V and a hold current of 6.5A. The part is active in production status and carries AEC-Q200 automotive qualification, making it suitable for applications requiring reliable circuit protection in automotive and industrial environments. Equivalent and substitute parts may be required due to inventory availability, lead time considerations, or specific application requirements within the allowed electrical and mechanical parameter ranges.

Substiute Parts

AHRF650

LittelfuseIn Stock: 1181AHRF650 Datasheet

Current PartRFQ

MF-RHT450-0

Bourns Inc.In Stock: 8307MF-RHT450-0 Datasheet

DirectRFQ

MF-RHT650-0

Bourns Inc.In Stock: 3900MF-RHT650-0 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the AHRF650 are evaluated based on the following critical parameters that determine functional compatibility:

Voltage Rating: All substitutes must maintain the 16V maximum voltage specification to ensure safe operation within the circuit design envelope.

Current - Hold (Ih): The hold current defines the maximum continuous current the fuse allows without tripping. Substitutes with matching or higher Ih ratings (6.5A or greater) maintain equivalent circuit protection characteristics.

Mounting Type & Package: All substitutes must be through-hole radial disc components to ensure mechanical and electrical compatibility with existing PCB layouts and assembly processes.

Type & Compliance: All substitutes must be polymeric PTC resettable fuses with AEC-Q200 rating and ROHS3 compliance to maintain automotive qualification and environmental standards.

Based on these criteria, the following parts qualify as substitutes:

• MF-RHT650-0 (Bourns Inc.): Direct parameter match with identical voltage, hold current, and package specifications
• MF-RHT450-0 (Bourns Inc.): Lower hold current rating (4.5A) suitable for applications with reduced current requirements while maintaining voltage and package compatibility

Parameter Comparison

Engineering Selection Recommendations

MF-RHT650-0 (Bourns Inc.) is the primary equivalent substitute for AHRF650. This part maintains identical electrical specifications including 16V voltage rating, 6.5A hold current, and 100A maximum current. Both components carry AEC-Q200 automotive qualification and ROHS3 compliance. The MF-RHT650-0 is suitable for direct replacement in applications where the AHRF650 is specified, with the understanding that trip current characteristics differ (12A vs. 7A).

MF-RHT450-0 (Bourns Inc.) is a functional substitute for applications with reduced current protection requirements. This part maintains the 16V voltage rating and through-hole radial disc package but provides a lower hold current of 4.5A. Selection of this part is appropriate only when circuit design specifications permit a lower hold current threshold. The MF-RHT450-0 carries equivalent AEC-Q200 and ROHS3 certifications.

Both substitute parts are active production components with established inventory availability and meet all compliance and qualification standards required for automotive and industrial applications.

Frequently Asked Questions (FAQ)

Q: Can MF-RHT650-0 be used as a direct replacement for AHRF650?

A: Yes. The MF-RHT650-0 maintains identical voltage rating (16V), hold current (6.5A), maximum current (100A), operating temperature range (-40°C to 125°C), and package configuration (through-hole radial disc). Both parts are AEC-Q200 qualified and ROHS3 compliant. The trip current specification differs (12A vs. 7A), which may affect circuit protection timing characteristics.

Q: When is MF-RHT450-0 appropriate as a substitute?

A: MF-RHT450-0 is suitable only when the application circuit design permits a lower hold current rating of 4.5A instead of 6.5A. This part maintains voltage compatibility (16V) and package specifications (through-hole radial disc) but provides reduced current protection capacity. Verify circuit requirements before selection.

Q: Are all substitute parts automotive qualified?

A: Yes. Both MF-RHT650-0 and MF-RHT450-0 carry AEC-Q200 automotive qualification ratings, matching the AHRF650 specification.

Q: Do the substitute parts meet environmental compliance standards?

A: Yes. All substitute parts are ROHS3 compliant and REACH unaffected, matching the AHRF650 environmental compliance status.

Q: What are the physical package differences between these parts?

A: All three parts use through-hole radial disc packaging. The AHRF650 and MF-RHT650-0 share identical dimensions (0.500" L x 0.118" W, 12.70mm x 3.00mm length, 0.874" seated height). The MF-RHT450-0 has a smaller footprint (0.409" L x 0.118" W, 10.40mm x 3.00mm length, 0.614" seated height) and different lead spacing (0.114" vs. 0.199"), which may affect PCB layout compatibility.

Q: How do resistance characteristics compare between these parts?

A: Initial resistance (Ri) ranges from 9 mOhms (AHRF650) to 22 mOhms (MF-RHT450-0). Post-trip resistance (R1) is 26 mOhms for both AHRF650 and MF-RHT650-0, and 54 mOhms for MF-RHT450-0. These differences reflect the lower current rating of the MF-RHT450-0.