MICROSMD500LR-2 Equivalent & Substitute Parts

Part Overview

The MICROSMD500LR-2 is a Polymeric PTC Resettable Fuse manufactured by Littelfuse Inc., rated for 6V at 5A hold current in a 1210 (3225 Metric) surface mount package. This component is classified as Obsolete, making equivalent substitute parts necessary for new designs and ongoing production requirements. The part operates across a temperature range of -40°C to 80°C and complies with ROHS3 standards.

Substiute Parts

MICROSMD500LR-2

Littelfuse Inc.In Stock: 1496MICROSMD500LR-2 Datasheet

Current PartRFQ

1210L500SLWR

Littelfuse Inc.In Stock: 22261210L500SLWR Datasheet

DirectRFQ

PTSLR12106V500

Eaton - Electronics DivisionIn Stock: 2004PTSLR12106V500 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the MICROSMD500LR-2 is determined by the following critical parameters:

• Voltage rating of 6V maximum
• Current hold (Ih) rating of 5A maximum
• Current trip (It) rating of 10A
• Maximum current capacity of 50A
• Trip time of 2 seconds
• Surface mount 1210 (3225 Metric) package configuration
• ROHS3 compliance

The substitute parts listed below maintain these core electrical and mechanical specifications, ensuring functional equivalence in circuit protection applications. Variations in initial resistance (Ri) and post-trip resistance (R1) are within acceptable tolerances for this component category.

Parameter Comparison

Engineering Selection Recommendations

For applications currently using the MICROSMD500LR-2, the following substitutes are available:

1210L500SLWR (Littelfuse Inc., Active) — This part maintains all critical electrical parameters and is actively manufactured. The higher initial resistance (100 mOhms vs. 2 mOhms) represents a design variation within the LoRho series. This part offers improved moisture sensitivity rating (MSL 1, Unlimited vs. MSL 2A, 4 Weeks), reducing handling and storage constraints.

PTSLR12106V500 (Eaton - Electronics Division, Active) — This part is manufacturer-recommended and maintains electrical specifications identical to the original. It carries expanded temperature operating range (-40°C to 85°C vs. -40°C to 80°C) and includes additional approval certifications (cURus, TUV). Post-trip resistance is 12 mOhms, consistent with alternative Littelfuse offerings.

Both substitute parts are ROHS3 compliant and available in active production status, ensuring long-term supply chain viability.

Frequently Asked Questions (FAQ)

Q: Can the 1210L500SLWR be used as a direct replacement for the MICROSMD500LR-2?

A: Yes. Both parts share identical voltage (6V), hold current (5A), trip current (10A), and package specifications (1210 Concave). The difference in initial resistance (100 mOhms vs. 2 mOhms) does not affect functional equivalence for circuit protection applications.

Q: What is the difference between the PTSLR12106V500 and the Littelfuse alternatives?

A: The PTSLR12106V500 is manufactured by Eaton and offers a wider operating temperature range (-40°C to 85°C). All three parts maintain the same electrical protection characteristics (6V, 5A hold, 10A trip, 2-second trip time). Selection depends on supply chain availability and certification requirements.

Q: Are all three parts pin-compatible?

A: Yes. All three parts use the 1210 (3225 Metric) surface mount package with concave configuration, ensuring mechanical and electrical compatibility on PCB layouts designed for the MICROSMD500LR-2.

Q: Does the higher initial resistance of the 1210L500SLWR affect circuit performance?

A: The initial resistance difference (100 mOhms vs. 2 mOhms) is within acceptable tolerance for PTC resettable fuse applications. Circuit design should account for the specified resistance range, but this variation does not compromise protection functionality.

Q: Which substitute part should be selected for new designs?

A: Both 1210L500SLWR and PTSLR12106V500 are suitable for new designs. Selection should be based on supply chain availability, required certifications (cURus/TUV for Eaton part), and moisture sensitivity requirements (MSL 1 for Littelfuse LoRho series vs. MSL 2A for Eaton part).