MF-RX300

Overview

The Bourns MF-RX300 is a high-density polymeric positive temperature coefficient (PPTC) resettable fuse designed for PCB mounting. It belongs to the Multifuse MF-RX/72 series, featuring radial termination with a 10.2 mm lead spacing. The component operates at a maximum voltage of 72 VDC and maintains a hold current of 3 A, tripping at 6 A. It supports a maximum fault current rating of 40 A and exhibits a typical resistance of 60 mOhms. Rated for operation between -40°C and +85°C, it dissipates up to 2.8 W of power. Physical dimensions include a length of 26.7 mm, width and diameter of 20.67 mm, and a height of 3.1 mm.

Feature Summary

• Provides automatic circuit protection through reversible trip characteristics upon overcurrent events
• Engineered for high-density applications with compact physical footprint relative to current capacity
• Utilizes PTC polymer technology to limit fault currents without requiring manual replacement

Applications

• Overcurrent protection in portable electronic devices
• Protection circuits within telecommunications equipment
• Industrial control system board-level safeguarding
• Automotive electronics harness protection

Procurement Notes

Verify that the specific order matches the exact part number MF-RX300 to ensure correct electrical ratings. Confirm that the required hold current of 3 A and maximum voltage of 72 VDC align with the target circuit design parameters. Check for any specific packaging requirements or RoHS compliance documentation if mandated by project specifications before finalizing procurement.

Selection Notes

Select this component when a 3 A hold current and 72 VDC rating are required for space-constrained designs. The radial lead configuration with 10.2 mm spacing facilitates through-hole PCB integration. Ensure the application environment remains within the specified -40°C to +85°C operating range. Consider the 60 mOhms resistance impact on circuit efficiency during normal operation.

Part Context

This device is part of the Bourns Multifuse MF-RX/72 series, which specializes in high-current resettable fuses. The series offers various hold current options ranging from low amperage to high-density configurations like this 3 A model. These components serve as reusable alternatives to traditional one-time fuses in modern electronic assemblies.

Replacement Considerations

Direct substitutes within the same series include MF-RX030/72-0 for lower current needs or MF-RX300/72-0 for identical specifications. Verify lead spacing and physical dimensions match the existing PCB layout when considering alternative part numbers.