PF2205-20RF1 Equivalent & Substitute Parts

Part Overview

The PF2205-20RF1 is a 20 Ohm ±1% 50W through-hole resistor in TO-220-2 package manufactured by Riedon. This thin film current sense resistor is designed for high-power applications requiring precision and pulse withstanding capability. The part is marked as Not For New Designs, making identification of suitable alternatives essential for ongoing production and new design initiatives.

Substiute Parts

PF2205-20RF1

RiedonIn Stock: 759PF2205-20RF1 Datasheet

Current PartRFQ

PWR221T-50-20R0F

Bourns Inc.In Stock: 1100PWR221T-50-20R0F Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the PF2205-20RF1 is determined by the following critical parameters:

• Resistance Value & Tolerance: 20 Ohms ±1% (exact match required)
• Power Rating: 50W (minimum requirement)
• Package Configuration: TO-220-2 (mechanical and thermal compatibility)
• Electrical Performance: Current sense capability with pulse withstanding characteristics
• Compliance: ROHS3 compliance and EAR99 classification

The PWR221T-50-20R0F from Bourns Inc. meets all substitution criteria. While it uses thick film composition instead of thin film, it maintains the same resistance, tolerance, power rating, and package type. The substitute part is Active status and includes automotive AEC-Q200 qualification, providing enhanced reliability for new designs.

Parameter Comparison

Engineering Selection Recommendations

The PWR221T-50-20R0F is the direct substitute for the PF2205-20RF1. Selection should be based on the following factors:

For Existing Designs: The PWR221T-50-20R0F maintains electrical equivalence with identical resistance, tolerance, and power rating. The thicker film composition and higher temperature coefficient (±100ppm/°C vs ±50ppm/°C) are acceptable for most current sense applications where the original thin film specification was not critical to circuit performance.

For New Designs: The PWR221T-50-20R0F is the recommended choice due to its Active product status and automotive AEC-Q200 qualification, ensuring long-term availability and enhanced reliability standards.

Compliance Considerations: Both parts are ROHS3 compliant and classified as EAR99, meeting regulatory requirements for industrial and commercial applications.

Temperature Operating Range: The PWR221T-50-20R0F operates to 150°C maximum versus 155°C for the original part. Verify that circuit thermal design does not require operation above 150°C.

Frequently Asked Questions (FAQ)

Q: Can the PWR221T-50-20R0F be used as a direct replacement in existing circuits?

A: Yes. The substitute part maintains the same 20 Ohm resistance, ±1% tolerance, 50W power rating, and TO-220-2 package configuration. No circuit modifications are required for mechanical or electrical compatibility.

Q: What is the difference between thin film and thick film composition?

A: The original PF2205-20RF1 uses thin film technology, while the PWR221T-50-20R0F uses thick film technology. For current sense applications, both compositions provide adequate performance. The thick film substitute has a higher temperature coefficient (±100ppm/°C vs ±50ppm/°C), which may introduce slightly greater resistance variation across temperature extremes but remains within acceptable tolerances for most applications.

Q: Are there thermal or mounting differences between these parts?

A: Both parts use the TO-220-2 package. The PWR221T-50-20R0F is specified as TO-220-2 Full Pack, indicating enhanced packaging. Physical dimensions differ slightly (height: 15.00mm vs 19.30mm), but both mount identically on standard TO-220 footprints. Verify heatsink clearance if space is constrained.

Q: Why is the PF2205-20RF1 marked as Not For New Designs?

A: This designation indicates the part is in mature or end-of-life status. The PWR221T-50-20R0F, with Active status and AEC-Q200 qualification, is the recommended alternative for new product development to ensure long-term supply chain stability.

Q: Are both parts RoHS compliant?

A: Yes. Both the PF2205-20RF1 and PWR221T-50-20R0F are ROHS3 compliant and suitable for applications requiring RoHS certification.