RNF14FTC249K Equivalent & Substitute Parts

Part Overview

The RNF14FTC249K is a 249 kOhms ±1% metal film axial through-hole resistor rated at 0.25W (1/4W) manufactured by Stackpole Electronics Inc. This component features flame retardant coating and safety construction, with an operating temperature range of -55°C to 155°C. The part is active and ROHS3 compliant. Substitute parts are identified when equivalent resistance values, tolerance specifications, and mechanical compatibility requirements are met within the allowed parameter ranges for this resistor category.

Substiute Parts

RNF14FTC249K

Stackpole Electronics IncIn Stock: 723RNF14FTC249K Datasheet

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CMF55249K00BEEB

Vishay DaleIn Stock: 4614CMF55249K00BEEB Datasheet

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CMF55249K00FHEB

Vishay DaleIn Stock: 4512CMF55249K00FHEB Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the RNF14FTC249K are qualified based on the following criteria:

Mandatory Matching Parameters:

• Resistance value: 249 kOhms (exact match required)
• Composition: Metal Film
• Package type: Axial through-hole
• RoHS compliance: ROHS3 Compliant

Allowable Parameter Variations:

• Tolerance: ±1% or tighter (±0.1% acceptable)
• Power rating: Equal to or greater than 0.25W (0.5W acceptable)
• Temperature coefficient: ±50ppm/°C or better (±25ppm/°C acceptable)
• Operating temperature range: Must encompass or exceed -55°C ~ 155°C
• Features: Flame retardant coating and safety construction required; additional features such as moisture resistance are acceptable

The two substitute parts listed (CMF55249K00BEEB and CMF55249K00FHEB) meet these criteria with improved or equivalent specifications in power rating, tolerance, and temperature performance.

Parameter Comparison

Engineering Selection Recommendations

Both substitute parts are active products with ROHS3 compliance and REACH unaffected status, matching the regulatory requirements of the main part.

CMF55249K00BEEB provides improved tolerance specification (±0.1% versus ±1%) and higher power rating (0.5W versus 0.25W), with an extended operating temperature range to 175°C. The temperature coefficient is improved to ±25ppm/°C. This part is suitable for applications requiring tighter tolerance control and enhanced thermal performance.

CMF55249K00FHEB maintains the ±1% tolerance specification of the main part while providing the same power rating upgrade (0.5W) and extended operating temperature range (to 175°C). The temperature coefficient remains at ±50ppm/°C. This part provides direct functional compatibility with minimal specification changes.

Both substitute parts feature moisture-resistant construction in addition to flame retardant coating, and both are mechanically compatible with standard axial through-hole PCB layouts. The slight dimensional reduction (0.090" diameter versus 0.093") does not affect board-level compatibility.

Frequently Asked Questions (FAQ)

Q: Can CMF55249K00BEEB and CMF55249K00FHEB be used interchangeably with RNF14FTC249K?

A: Both parts meet the core substitution criteria: identical 249 kOhms resistance value, metal film composition, axial package type, and ROHS3 compliance. The primary differences are improved specifications (higher power rating, extended temperature range, and in the case of CMF55249K00BEEB, tighter tolerance). Interchangeability depends on circuit requirements; if the original design operates within the specifications of either substitute, direct replacement is valid.

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

A: Tolerance defines the maximum deviation from the nominal resistance value. The RNF14FTC249K and CMF55249K00FHEB both specify ±1%, meaning the actual resistance will fall within 246.51 kOhms to 251.49 kOhms. The CMF55249K00BEEB specifies ±0.1%, resulting in a tighter range of 248.75 kOhms to 249.25 kOhms. Tighter tolerance is beneficial in precision circuits but is not required for general applications.

Q: Are the physical dimensions compatible with existing PCB layouts?

A: The substitute parts (CMF55249K00BEEB and CMF55249K00FHEB) have slightly smaller dimensions (0.090" diameter and 0.240" length) compared to the main part (0.093" diameter and 0.250" length). Both remain within standard axial through-hole component spacing and will fit existing PCB footprints designed for 1/4W or 1/2W axial resistors.

Q: Why is the power rating higher on the substitute parts?

A: The substitute parts are rated at 0.5W (1/2W) compared to the 0.25W (1/4W) rating of the main part. A higher power rating provides additional thermal margin and allows the component to dissipate more heat without exceeding maximum junction temperature. This does not affect functionality in circuits designed for 0.25W components; the higher rating simply provides additional safety margin.

Q: What does the extended operating temperature range mean?

A: The substitute parts operate from -55°C to 175°C, compared to -55°C to 155°C for the main part. This extended upper temperature limit (20°C additional margin) allows the components to function reliably in higher-temperature environments or applications with elevated ambient conditions.

Q: Are moisture-resistant features required for substitution?

A: Moisture resistance is an additional feature provided by the substitute parts but is not a mandatory substitution criterion. The main part specifies flame retardant coating and safety construction, which are present in all three parts. Moisture resistance in the substitutes provides enhanced environmental protection but does not affect basic electrical compatibility.