RNF12FTC221R Equivalent & Substitute Parts

Part Overview

The RNF12FTC221R is a 221 Ohm ±1% metal film through-hole resistor rated at 0.5W (1/2W) in axial package configuration, manufactured by Stackpole Electronics Inc. This component is classified as Active product status and is designed for applications requiring precision resistive elements with flame retardant coating and safety features. Substitute parts are identified to provide alternative sourcing options while maintaining electrical and mechanical compatibility within specified parameter tolerances.

Substiute Parts

RNF12FTC221R

Stackpole Electronics IncIn Stock: 968RNF12FTC221R Datasheet

Current PartRFQ

CMF55221R00FHEB

Vishay DaleIn Stock: 7137CMF55221R00FHEB Datasheet

MFR RecommendedRFQ

CMF55221R00FHEK

Vishay DaleIn Stock: 1252CMF55221R00FHEK Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the RNF12FTC221R are qualified based on the following electrical and mechanical parameters:

• Resistance value: 221 Ohms (exact match required)
• Tolerance: ±1% (exact match required)
• Power rating: 0.5W / 1/2W (exact match required)
• Composition: Metal Film (exact match required)
• Package: Axial through-hole (exact match required)
• Temperature coefficient: ±50ppm/°C (exact match required)
• Flame retardant coating and safety features (required)
• RoHS3 compliance (required)

The identified substitutes are CMF55221R00FHEB and CMF55221R00FHEK, both manufactured by Vishay Dale under the CMF series. These parts satisfy all critical electrical parameters and compliance requirements. Differences in packaging format (Cut Tape vs. Bulk) and operating temperature range extension do not affect functional equivalence for component selection purposes.

Parameter Comparison

Engineering Selection Recommendations

Both CMF55221R00FHEB and CMF55221R00FHEK meet the electrical and compliance requirements for substitution with RNF12FTC221R. Selection between these alternatives should be based on:

• Packaging format availability: CMF55221R00FHEB is supplied in Cut Tape (CT) format; CMF55221R00FHEK is supplied in Bulk format
• REACH compliance status: CMF55221R00FHEB maintains REACH Unaffected status, while CMF55221R00FHEK is REACH Affected
• Physical dimensions: Substitute parts are smaller (0.090" Dia x 0.240" L) compared to the main part (0.108" Dia x 0.344" L), which may affect PCB layout considerations
• Operating temperature range: Substitute parts extend the upper operating limit to 175°C, providing additional thermal margin

Frequently Asked Questions (FAQ)

Q: Can CMF55221R00FHEB and CMF55221R00FHEK be used interchangeably with RNF12FTC221R?

A: Yes, both parts are electrically equivalent. They share identical resistance (221 Ohms), tolerance (±1%), power rating (0.5W), composition (metal film), and temperature coefficient (±50ppm/°C). The primary differences are packaging format and physical dimensions.

Q: What is the impact of the smaller physical dimensions of the substitute parts?

A: The Vishay Dale substitutes are physically smaller (0.090" Dia x 0.240" L vs. 0.108" Dia x 0.344" L). This may require PCB layout verification to ensure component placement compatibility, particularly in space-constrained applications or existing designs with fixed mounting patterns.

Q: Does the extended operating temperature range of the substitutes affect compatibility?

A: No. The substitute parts operate from -55°C to 175°C, which encompasses the original part's range of -55°C to 155°C. This extension provides additional thermal margin and does not create compatibility issues.

Q: What is the difference between CMF55221R00FHEB and CMF55221R00FHEK?

A: Both parts are electrically identical. The primary differences are packaging (Cut Tape vs. Bulk) and REACH compliance status (Unaffected vs. Affected). Selection depends on supply chain requirements and regulatory obligations.

Q: Are moisture-resistant features of the substitutes required?

A: The substitute parts include moisture-resistant features in addition to flame retardant coating. These additional features do not create incompatibility and may provide enhanced performance in humid environments.