NANOSMD500LR-2 Equivalent & Substitute Parts

Part Overview

The NANOSMD500LR-2 is a Polymeric PTC Resettable Fuse manufactured by Littelfuse, rated for 6V maximum voltage with 5A hold current. This component is classified as Obsolete, making identification of compatible substitute parts essential for ongoing design support and procurement.

PTC resettable fuses provide automatic overcurrent protection by increasing resistance when current exceeds the trip threshold, then resetting when the fault condition is removed. The obsolete status of the NANOSMD500LR-2 necessitates evaluation of active alternative components that maintain electrical and mechanical compatibility.

Substiute Parts

NANOSMD500LR-2

LittelfuseIn Stock: 105368NANOSMD500LR-2 Datasheet

Current PartRFQ

1206L500SL-VWR

Littelfuse Inc.In Stock: 12631206L500SL-VWR Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the NANOSMD500LR-2 is determined by the following critical parameters:

• Voltage Rating: Maximum voltage must be 6V or greater
• Current - Hold (Ih): Must be rated for 5A or greater
• Current - Trip (It): Must be 10A or greater
• Package / Case: Must be 1206 (3216 Metric) for PCB compatibility
• Mounting Type: Must be Surface Mount
• RoHS Compliance: Must maintain ROHS3 Compliant status

The substitute part 1206L500SL-VWR meets all critical electrical parameters and maintains the same 1206 surface mount package footprint, enabling direct substitution in existing designs.

Parameter Comparison

Engineering Selection Recommendations

The 1206L500SL-VWR is the qualified substitute for the obsolete NANOSMD500LR-2. Selection is based on the following factors:

Electrical Compatibility: All critical electrical parameters match or exceed the original specification. The 1206L500SL-VWR maintains identical voltage, hold current, trip current, and trip time characteristics.

Mechanical Compatibility: Both components use the 1206 (3216 Metric) surface mount package, ensuring PCB footprint compatibility. The concave profile of the substitute does not affect mounting or assembly.

Compliance Status: The 1206L500SL-VWR maintains ROHS3 compliance and holds active product status, ensuring long-term availability and supply chain continuity.

Thermal Performance: The extended operating temperature range (-40°C ~ 85°C) of the substitute provides improved thermal margin compared to the original part.

Frequently Asked Questions (FAQ)

Q: Can the 1206L500SL-VWR be used as a direct replacement for the NANOSMD500LR-2?

A: Yes. The 1206L500SL-VWR meets all critical electrical specifications and uses the same 1206 surface mount package, enabling direct substitution without circuit redesign.

Q: What is the difference between the "microSMD" and "LoRho" series designations?

A: These are Littelfuse product line designations. Both are Polymeric PTC Resettable Fuses with identical electrical performance for this application. The LoRho series (1206L500SL-VWR) is the active product line.

Q: Are there dimensional differences between these parts?

A: Minor dimensional variations exist. The NANOSMD500LR-2 has a maximum thickness of 0.032" (0.80mm), while the 1206L500SL-VWR has a maximum thickness of 0.039" (1.00mm). Both fit the 1206 package specification and are compatible with standard PCB assembly processes.

Q: Does the higher post-trip resistance of the substitute part affect circuit performance?

A: The post-trip resistance difference (8 mOhms maximum vs. 12 mOhms maximum) is within acceptable tolerance for PTC resettable fuse applications and does not impact functional performance in standard overcurrent protection circuits.

Q: What is the packaging difference between these parts?

A: The NANOSMD500LR-2 is supplied in standard packaging, while the 1206L500SL-VWR is supplied in Tape & Reel (TR) format. Both are suitable for automated assembly processes.