RN55C4990FRE6 Equivalent & Substitute Parts

Part Overview

The RN55C4990FRE6 is a 499 Ohms ±1% metal film axial resistor rated at 0.125W (1/8W) with flame retardant coating, designed for military applications per MIL-R-10509/7 specification. This component is currently active in production with 1049 units in stock. Substitute parts are identified when equivalent electrical performance and mechanical compatibility can be maintained within the allowed parameter tolerances for this resistor category.

Substiute Parts

RN55C4990FRE6

Vishay DaleIn Stock: 1136RN55C4990FRE6 Datasheet

Current PartRFQ

RN55E4990BRE6

Vishay DaleIn Stock: 1782RN55E4990BRE6 Datasheet

UpgradeRFQ

CMF50499R00FHEB

Vishay DaleIn Stock: 3215CMF50499R00FHEB Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the RN55C4990FRE6 is determined by the following criteria:

Primary Substitution Criteria:

• Resistance value: 499 Ohms (exact match required)
• Composition: Metal Film (required for performance equivalence)
• Package: Axial (mechanical compatibility)
• Tolerance: ±1% or tighter (±0.1% qualifies as upgrade)
• Power rating: Equal to or greater than 0.125W
• Operating temperature range: Must encompass or match -65°C ~ 175°C minimum
• Termination count: 2 (standard for axial resistors)

Identified Substitute Categories:

1. Upgrade Substitute (Tighter Tolerance): RN55E4990BRE6 — Same military series, same power rating, improved tolerance (±0.1% vs ±1%), lower temperature coefficient (±25ppm/°C vs ±50ppm/°C)

2. Manufacturer Recommended Substitute (Higher Power Rating): CMF50499R00FHEB — Same resistance and tolerance, higher power rating (0.25W vs 0.125W), different series (CMF vs RN55), different RoHS compliance status

Parameter Comparison

Engineering Selection Recommendations

RN55E4990BRE6 (Upgrade Substitute): Select this part when improved tolerance and temperature stability are required within the same military-grade RN55 series. Both parts maintain RoHS non-compliant and REACH Affected status. Inventory availability is higher (1716 units vs 1049 units). This substitution maintains full military specification compliance.

CMF50499R00FHEB (Manufacturer Recommended Substitute): Select this part when higher power dissipation capability is required or when ROHS3 compliance and REACH Unaffected status are mandatory for the application. The operating temperature minimum is -55°C (versus -65°C for RN55 series), which may limit use in extreme cold environments. This part exits the military specification series but maintains equivalent electrical performance at the specified resistance and tolerance.

Frequently Asked Questions (FAQ)

Q: Can RN55E4990BRE6 be used as a direct replacement for RN55C4990FRE6?

A: Yes. Both parts are 499 Ohms ±1% metal film axial resistors rated at 0.125W with identical package dimensions and operating temperature range. RN55E4990BRE6 offers tighter tolerance (±0.1%) and lower temperature coefficient (±25ppm/°C), making it functionally superior while maintaining military specification compliance.

Q: When should CMF50499R00FHEB be selected instead of RN55C4990FRE6?

A: CMF50499R00FHEB should be selected when the circuit requires higher power dissipation (0.25W vs 0.125W) or when ROHS3 compliance and REACH Unaffected status are regulatory requirements. The lower operating temperature minimum (-55°C vs -65°C) must be verified against application requirements.

Q: Are all three parts mechanically interchangeable?

A: All three parts use axial package configuration with 2 terminations. However, CMF50499R00FHEB has different physical dimensions (0.065" Dia x 0.150" L) compared to RN55 series parts (0.090" Dia x 0.240" L). Verify PCB layout and mechanical clearance before substitution.

Q: What is the significance of the tolerance difference between ±1% and ±0.1%?

A: Tolerance defines the maximum deviation from the nominal 499 Ohm value. ±1% allows ±4.99 Ohms deviation; ±0.1% allows ±0.499 Ohms deviation. Select ±0.1% (RN55E4990BRE6) for precision circuits requiring tighter resistance control.

Q: Does RoHS compliance affect electrical performance?

A: RoHS compliance status does not affect electrical performance. It indicates manufacturing process restrictions on hazardous substances. CMF50499R00FHEB (ROHS3 Compliant) and RN55 series parts (RoHS non-compliant) perform identically electrically; selection depends on regulatory and procurement requirements.