MF-S350S

Overview

The Bourns MF-S350S is a surface-mount polymeric positive temperature coefficient (PPTC) resettable fuse designed for overcurrent protection in electronic circuits. It belongs to the MF-USHT series, engineered for high-temperature environments. The device operates by increasing resistance significantly when excessive current causes self-heating, thereby limiting current flow. Upon fault removal and cooling, it returns to its low-resistance state, restoring circuit functionality without manual replacement.

Feature Summary

• Surface-mount construction suitable for automated assembly processes
• Self-resetting mechanism eliminates need for manual component replacement after fault clearance
• High-temperature capability ensures reliability in demanding thermal conditions

Applications

• Consumer electronics port protection
• Industrial control circuit safeguarding
• Telecommunications equipment input filtering

Procurement Notes

Verify the specific suffix codes against the official Bourns datasheet to confirm exact electrical ratings and package dimensions. Ensure the selected variant meets the required operating temperature range and holds necessary regulatory compliance certifications for the target market. Cross-reference the part number with authorized distributors to confirm availability and authenticity.

Selection Notes

Select this component based on the circuit's maximum operating voltage and the desired trip current threshold. Consider the ambient temperature environment, as higher temperatures may require derating the hold current. Evaluate the physical footprint constraints of the PCB layout to ensure the surface-mount package fits within the designated area without interfering with adjacent components.

Part Context

This part is a member of the MF-USHT series, representing Bourns' high-temperature PPTC resettable fuses. These devices are specifically developed to provide robust overcurrent protection where standard polymer fuses might fail due to thermal stress. The series supports various surface-mount packages to accommodate different current handling requirements and space limitations in modern electronic assemblies.

Replacement Considerations

Direct replacements must match the original part's voltage rating, hold current, and trip current specifications. Verify that any substitute component offers equivalent or superior high-temperature performance characteristics. Ensure the replacement maintains the same surface-mount package type to fit existing PCB footprints and soldering profiles.