MICROSMD150-2

Overview

The Littelfuse MICROSMD150-2 is a polymer PTC resettable fuse from the PolySwitch microSMD series, designed for surface-mount circuit protection. It features a 1210 (3225 metric) recessed package with a maximum holding current of 1.5 A and a trip current of 3 A. The device operates at a maximum voltage of 6 V and can withstand a maximum fault current of 40 A. Initial resistance is typically 40 mOhms minimum, rising to a maximum of 110 mOhms after tripping. It functions within a temperature range of -40°C to 85°C and holds CSA, TUV, and UL certifications.

Feature Summary

• Provides automatic overcurrent protection by increasing resistance when heated during fault conditions
• Offers reliable recovery without manual replacement after the fault condition is removed
• Utilizes a compact surface-mount footprint suitable for dense PCB layouts

Applications

• Protection of portable electronic devices and handheld equipment
• Overcurrent safeguarding in battery-powered circuits
• Circuit protection for telecommunications and networking interfaces

Procurement Notes

Verify component status as this specific part number is discontinued and no longer manufactured. Confirm availability of direct replacements such as the MICROSMD150F-2 or cross-manufacturer equivalents like the MF-USMF150-2. Ensure that the selected substitute maintains identical electrical ratings, package dimensions, and agency approvals required for your design. Check RoHS compliance status as the original part may not meet current environmental standards.

Selection Notes

Select this component for applications requiring low-voltage, high-current protection in space-constrained environments. The 1.5 A holding current and 6 V rating suit low-power digital logic and interface lines. Consider the recessed package profile for compatibility with automated assembly processes. Evaluate thermal management requirements given the operating temperature limits and self-heating characteristics during normal operation.

Part Context

This device belongs to the PolySwitch microSMD family, which provides resettable overcurrent protection in small surface-mount packages. The series is engineered for consumer electronics and industrial applications where traditional fuses are impractical due to size or maintenance constraints. The microSMD line emphasizes low resistance and fast response times while maintaining robust fault handling capabilities.

Replacement Considerations

Direct substitutes include the MICROSMD150F-2 from Littelfuse and the MF-USMF150-2 from Bourns Inc. Verify that alternative parts match the 1210 package outline and electrical specifications exactly.

FAQ

Is the MICROSMD150-2 still in production?

No, the MICROSMD150-2 is discontinued and no longer manufactured by Littelfuse.

What is the maximum fault current rating for this device?

The MICROSMD150-2 has a maximum fault current rating of 40 A.