RN55C3921FRE6 Equivalent & Substitute Parts

Part Overview

The RN55C3921FRE6 is a 3.92 kOhms ±1% metal film axial through-hole resistor rated at 0.125W (1/8W) manufactured by Vishay Dale. This component is part of the Military MIL-R-10509/7 RN55 series and features flame retardant coating, moisture resistance, and safety-grade construction. The part is currently active in production with 627 units in stock. Substitute parts are identified when equivalent electrical specifications and mechanical compatibility are maintained while offering alternative packaging, power ratings, or compliance certifications.

Substiute Parts

RN55C3921FRE6

Vishay DaleIn Stock: 687RN55C3921FRE6 Datasheet

Current PartRFQ

CMF553K9200FHEB

Vishay DaleIn Stock: 6867CMF553K9200FHEB Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the RN55C3921FRE6 is determined by the following critical parameters:

• Resistance Value: Must be 3.92 kOhms
• Tolerance: Must be ±1%
• Composition: Must be Metal Film
• Temperature Coefficient: Must be ±50ppm/°C
• Package Type: Must be Axial with 2 terminations
• Physical Dimensions: Must be 0.090" Dia x 0.240" L (2.29mm x 6.10mm)

The substitute part CMF553K9200FHEB meets all these core electrical and mechanical requirements. The primary difference is the power rating (0.5W vs. 0.125W) and packaging format (Cut Tape vs. Tape & Reel), which represent functional enhancements and alternative supply configurations rather than incompatibilities.

Parameter Comparison

Engineering Selection Recommendations

The CMF553K9200FHEB is a direct electrical substitute for the RN55C3921FRE6 based on matching resistance, tolerance, temperature coefficient, and physical dimensions. Selection between these parts should be based on the following factors:

RN55C3921FRE6 is appropriate when:

• Military-grade MIL-R-10509/7 series specification is required
• Operating temperature minimum of -65°C is necessary
• Tape & Reel packaging format is specified for automated assembly

CMF553K9200FHEB is appropriate when:

• ROHS3 compliance is required
• REACH compliance is required
• Higher power dissipation capability (0.5W vs. 0.125W) provides design margin
• Cut Tape packaging format is acceptable
• Operating temperature minimum of -55°C is acceptable
• Higher inventory availability is beneficial

Both parts are manufactured by Vishay Dale and maintain identical electrical performance within the specified tolerance and temperature coefficient parameters.

Frequently Asked Questions (FAQ)

Q: Can CMF553K9200FHEB replace RN55C3921FRE6 in all applications?

A: CMF553K9200FHEB is electrically equivalent for circuits designed for the RN55C3921FRE6 specifications. The higher power rating (0.5W vs. 0.125W) is compatible with applications requiring 0.125W. Physical dimensions are identical, enabling direct board-level substitution. Verify that compliance requirements (RoHS, REACH) and operating temperature range (-55°C minimum vs. -65°C minimum) are acceptable for your application.

Q: What are the key differences between these parts?

A: The primary differences are power rating (0.5W vs. 0.125W), packaging format (Cut Tape vs. Tape & Reel), compliance certifications (ROHS3/REACH vs. non-compliant), and minimum operating temperature (-55°C vs. -65°C). All electrical parameters including resistance, tolerance, and temperature coefficient are identical.

Q: Are the physical dimensions identical?

A: Yes. Both parts are 0.090" diameter by 0.240" length (2.29mm x 6.10mm) axial components with 2 terminations, enabling direct mechanical substitution on printed circuit boards.

Q: Which part should be selected for new designs?

A: CMF553K9200FHEB is recommended for new designs due to ROHS3 and REACH compliance, higher power rating providing design margin, and greater inventory availability. RN55C3921FRE6 should be retained only when military-grade MIL-R-10509/7 specification or -65°C minimum operating temperature is explicitly required.

Q: Is packaging format interchangeable?

A: Tape & Reel (TR) and Cut Tape (CT) formats are both suitable for automated assembly but differ in supply configuration. Tape & Reel is optimized for high-volume production runs, while Cut Tape is suitable for lower-volume or mixed-component assembly. Board-level performance is identical.