MICROSMD010-2 Equivalent & Substitute Parts

Part Overview

The MICROSMD010-2 is a Polymeric PTC Resettable Fuse manufactured by Littelfuse, rated for 30V maximum voltage with 100 mA hold current. This component is classified as Obsolete, which necessitates identification of equivalent substitute parts for ongoing design support and procurement. The part is designed for surface mount applications in the 1210 (3225 Metric) package format with a concave profile.

Substiute Parts

MICROSMD010-2

LittelfuseIn Stock: 3229MICROSMD010-2 Datasheet

Current PartRFQ

MICROSMD010F-2

Littelfuse Inc.In Stock: 29520MICROSMD010F-2 Datasheet

DirectRFQ

MF-USMF010-2

Bourns Inc.In Stock: 5837MF-USMF010-2 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the MICROSMD010-2 are qualified based on the following electrical and mechanical parameters:

Critical Matching Parameters:

• Voltage rating: 30V maximum
• Current hold specification: 100 mA
• Package format: 1210 (3225 Metric), Concave
• Mounting type: Surface Mount
• Post-trip resistance: 15 Ohms maximum
• Component type: Polymeric PTC Resettable Fuse

Acceptable Variation Parameters:

• Current trip (It): Tolerance range 250 mA to 300 mA
• Time to trip: Tolerance range 600 ms to 1 s
• Resistance initial (Ri): Tolerance range 800 mOhms to 2.1 Ohms
• Operating temperature range: -40°C to 85°C

The two identified substitutes meet these criteria while offering improved product status and compliance characteristics.

Parameter Comparison

Engineering Selection Recommendations

MICROSMD010F-2 (Littelfuse Inc.) is the primary substitute for the obsolete MICROSMD010-2. This part maintains identical electrical specifications including voltage, hold current, trip current, and post-trip resistance. As an Active product from the same manufacturer, it provides direct functional equivalence with improved compliance status (ROHS3 Compliant) and maintains all required certifications (CSA, TUV, UL). The identical time-to-trip specification (1 s) and initial resistance (2.1 Ohms minimum) ensure circuit behavior consistency.

MF-USMF010-2 (Bourns Inc.) serves as an alternative substitute when supply constraints or design requirements necessitate a secondary source. This part meets all critical electrical parameters with acceptable variations: current trip of 300 mA (versus 250 mA) and faster response time of 600 ms (versus 1 s). The lower initial resistance of 800 mOhms provides improved power efficiency characteristics. This part carries AEC-Q200 automotive qualification and superior moisture sensitivity rating (MSL 1, Unlimited), making it suitable for demanding environmental applications. Certifications include cURus and TUV.

Both substitutes are electrically and mechanically compatible with the original MICROSMD010-2 footprint and function. Selection between them should be based on supply availability, compliance requirements, and specific circuit timing requirements.

Frequently Asked Questions (FAQ)

Q: Can MICROSMD010F-2 be used as a direct replacement for MICROSMD010-2?

A: Yes. The MICROSMD010F-2 is electrically and mechanically equivalent to the obsolete MICROSMD010-2. Both parts share identical voltage rating (30V), hold current (100 mA), trip current (250 mA), post-trip resistance (15 Ohms maximum), and package format (1210 Concave). The MICROSMD010F-2 is an Active product with improved RoHS3 compliance.

Q: What are the differences between MICROSMD010F-2 and MF-USMF010-2?

A: Both parts meet the core electrical requirements of the original MICROSMD010-2. Key differences include: (1) Current trip specification: MICROSMD010F-2 at 250 mA matches the original exactly, while MF-USMF010-2 is rated at 300 mA; (2) Response time: MICROSMD010F-2 trips in 1 s (matching original), MF-USMF010-2 trips in 600 ms; (3) Initial resistance: MICROSMD010F-2 at 2.1 Ohms minimum matches the original, MF-USMF010-2 is 800 mOhms; (4) Moisture sensitivity: MF-USMF010-2 offers superior MSL rating (1, Unlimited) versus 2A (4 Weeks); (5) Certifications: MICROSMD010F-2 includes UL, MF-USMF010-2 includes AEC-Q200 automotive qualification.

Q: Are the package dimensions identical across all three parts?

A: Yes. All three parts use the 1210 (3225 Metric) Concave package with identical footprint dimensions of 0.127" L x 0.102" W (3.22mm x 2.58mm). Thickness specifications differ slightly: MICROSMD010-2 at 0.019" (0.48mm) maximum, while both substitutes are rated at 0.033" (0.85mm) maximum. This thickness difference does not affect PCB layout compatibility for standard surface mount assembly.

Q: Which substitute should be selected for new designs?

A: For new designs requiring direct electrical equivalence to the original specification, MICROSMD010F-2 is the recommended choice due to identical electrical parameters and Active product status from the original manufacturer. For applications requiring enhanced environmental performance or automotive qualification, MF-USMF010-2 provides superior moisture sensitivity rating and AEC-Q200 certification, with acceptable variations in trip current and response time.

Q: Are both substitutes RoHS compliant?

A: Yes. Both MICROSMD010F-2 and MF-USMF010-2 are ROHS3 Compliant, whereas the original MICROSMD010-2 is RoHS non-compliant. This represents an improvement in environmental compliance for substitute applications.