RSMF3JB300R Equivalent & Substitute Parts

Part Overview

The RSMF3JB300R is a 300 Ohms ±5% 3W through hole resistor manufactured by Stackpole Electronics Inc. This axial metal oxide film resistor features flame proof and safety characteristics, designed for applications requiring reliable power dissipation in compact form factors. The part is currently active in production with 735 units in stock. Substitute parts may be required due to inventory constraints, application-specific performance needs, or design optimization for higher power ratings or alternative thermal characteristics.

Substiute Parts

RSMF3JB300R

Stackpole Electronics IncIn Stock: 828RSMF3JB300R Datasheet

Current PartRFQ

SQP500JB-300R

YAGEOIn Stock: 6578SQP500JB-300R Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

The SQP500JB-300R qualifies as a substitute for the RSMF3JB300R based on the following critical parameters:

• Resistance Value: Both parts are rated at 300 Ohms, ensuring electrical equivalence in circuit applications
• Tolerance: Both maintain ±5% tolerance, providing identical accuracy specifications
• Package Configuration: Both utilize axial through-hole packaging, enabling direct mechanical compatibility in PCB layouts
• Compliance Standards: Both are ROHS3 compliant and REACH unaffected, meeting regulatory requirements
• Termination Count: Both feature 2 terminations, maintaining identical connection architecture

The SQP500JB-300R provides a higher power rating (5W versus 3W), making it suitable for applications where the RSMF3JB300R may be thermally limited. The substitute uses cement composition instead of metal oxide film, with a reduced operating temperature maximum of 155°C compared to 235°C.

Parameter Comparison

Engineering Selection Recommendations

Both the RSMF3JB300R and SQP500JB-300R are active production parts with full ROHS3 compliance and REACH unaffected status, meeting current regulatory requirements for electronic component procurement.

Selection between these parts should be based on application thermal requirements. The RSMF3JB300R operates to 235°C maximum, suitable for high-temperature environments. The SQP500JB-300R, with its 5W power rating and 155°C maximum operating temperature, is appropriate for applications requiring higher power dissipation within standard industrial temperature ranges.

Both parts maintain identical electrical specifications (300 Ohms, ±5% tolerance) and axial through-hole packaging, ensuring direct substitution capability at the circuit level. The choice between metal oxide film and cement composition should be evaluated based on specific application requirements for pulse withstanding capability and thermal stability characteristics.

Frequently Asked Questions (FAQ)

Q: Can the SQP500JB-300R directly replace the RSMF3JB300R in existing designs?

A: Yes, at the electrical and mechanical level. Both parts share identical resistance values, tolerance specifications, and axial through-hole packaging. However, the reduced maximum operating temperature (155°C versus 235°C) must be verified against your application's thermal environment.

Q: What is the primary difference between these two resistors?

A: The SQP500JB-300R provides a higher power rating (5W versus 3W) and includes pulse withstanding capability. The RSMF3JB300R operates to a higher maximum temperature (235°C versus 155°C) and uses metal oxide film composition instead of cement.

Q: Are both parts compliant with current regulatory standards?

A: Yes. Both the RSMF3JB300R and SQP500JB-300R are ROHS3 compliant and REACH unaffected, meeting current electronic component procurement regulations.

Q: Does the difference in composition affect circuit performance?

A: Both compositions meet the specified electrical parameters (300 Ohms, ±5% tolerance). The composition difference affects thermal characteristics and pulse handling capability, not the fundamental resistance value or tolerance.

Q: Which part should I select for high-temperature applications?

A: The RSMF3JB300R is rated to 235°C maximum operating temperature, making it suitable for high-temperature environments. The SQP500JB-300R is limited to 155°C maximum.

Q: Can I use the SQP500JB-300R in applications requiring the full 235°C operating range?

A: No. The SQP500JB-300R maximum operating temperature is 155°C. Applications requiring operation above this temperature must use the RSMF3JB300R or identify alternative parts with higher temperature ratings.