MF-R400

Overview

The Bourns MF-R400 is a resettable polymeric positive temperature coefficient (PPTC) device designed for overcurrent protection in electronic circuits. It functions as a self-resetting fuse, providing reliable circuit safeguarding without the need for manual replacement after a fault event. The component utilizes polymer technology to increase resistance significantly when excessive current generates heat, thereby limiting current flow to safe levels until the fault is removed and the device cools down.

Feature Summary

• Self-resetting functionality eliminates the need for manual fuse replacement after overcurrent events
• Polymeric positive temperature coefficient construction provides stable thermal response
• Compact form factor suitable for space-constrained printed circuit board layouts

Applications

• Overcurrent protection for portable consumer electronics
• Circuit safeguarding in telecommunications equipment
• Protection of battery-powered devices against short circuits

Procurement Notes

Verify the specific holding current and trip time parameters against the official datasheet for the exact suffix variant, as performance characteristics vary by model designation. Confirm RoHS compliance status and packaging configuration directly with the manufacturer or authorized distributor documentation prior to ordering to ensure alignment with project requirements.

Selection Notes

Select this component based on the required hold current and trip current specifications for the target application circuit. Ensure the maximum voltage rating exceeds the system operating voltage and that the package size fits the available PCB footprint. Evaluate the thermal environment to guarantee proper operation within the specified temperature range.

Part Context

This part belongs to the Multifuse series of resettable fuses from Bourns Inc., a line of PPTC devices widely used for circuit protection. These components are engineered to replace traditional one-time fuses in applications where serviceability and automatic recovery are critical design factors.

Replacement Considerations

Consult official cross-reference guides for direct replacements. Verify that any substitute component matches the original hold current, trip current, and maximum voltage ratings to maintain circuit safety and performance integrity.