SC105B-221 Equivalent & Substitute Parts

Part Overview

The SC105B-221 is a 220 µH unshielded wirewound inductor manufactured by Signal Transformer, rated for 820 mA continuous current with a maximum DC resistance of 730 mOhm. This component is classified as obsolete, making equivalent substitutes necessary for ongoing production and maintenance applications. The part operates across the industrial temperature range of -40°C to 125°C and is packaged in a nonstandard surface mount configuration.

Substiute Parts

SC105B-221

Signal TransformerIn Stock: 1068SC105B-221 Datasheet

Current PartRFQ

7447714221

Würth ElektronikIn Stock: 34577447714221 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SC105B-221 is determined by the following critical parameters:

• Inductance value: 220 µH (fixed requirement)
• Inductance tolerance: ±20% (acceptable range)
• Current rating: minimum 820 mA continuous
• Operating temperature range: -40°C to 125°C (minimum requirement)
• Surface mount packaging configuration
• RoHS3 compliance and MSL Level 1 rating

The substitute part 7447714221 (Würth Elektronik WE-PD Performance series) meets these criteria with improved electrical performance characteristics, including higher current rating (1 A), lower DC resistance (439 mOhm), and shielded construction. The shielded design provides additional electromagnetic interference mitigation compared to the original unshielded configuration.

Parameter Comparison

Engineering Selection Recommendations

The 7447714221 (Würth Elektronik WE-PD Performance series) is the qualified substitute for the obsolete SC105B-221. Selection is based on the following factors:

• Active product status ensures long-term availability and supply chain continuity
• Identical inductance value and tolerance specification
• Current rating of 1 A exceeds the original 820 mA requirement, providing design margin
• Lower DC resistance (439 mOhm vs. 730 mOhm) reduces power dissipation and thermal load
• Shielded construction provides improved electromagnetic compatibility compared to the unshielded original
• Matching operating temperature range (-40°C to 125°C)
• ROHS3 compliance and MSL Level 1 rating maintained
• AEC-Q200 automotive qualification provides additional reliability assurance

Frequently Asked Questions (FAQ)

Q: Can the 7447714221 be used as a direct replacement for SC105B-221?

A: Yes. Both parts share identical inductance (220 µH) and tolerance (±20%), matching operating temperature range, and equivalent surface mount packaging. The substitute exceeds the original current rating and DC resistance specifications.

Q: What is the impact of the shielded design in the substitute part?

A: The shielded drum core construction in the 7447714221 provides electromagnetic interference containment. This is an improvement over the unshielded SC105B-221 and does not create compatibility issues in applications where the original unshielded part was used.

Q: Are there any thermal considerations when switching to the substitute?

A: The 7447714221 has lower DC resistance (439 mOhm vs. 730 mOhm), resulting in reduced power dissipation at equivalent current levels. This improves thermal performance and allows for higher current operation within the same temperature envelope.

Q: Does the substitute part meet the same compliance requirements?

A: Yes. Both parts are ROHS3 compliant with MSL Level 1 rating. The substitute additionally carries AEC-Q200 automotive qualification, providing enhanced reliability documentation.

Q: What is the difference in physical dimensions between the two parts?

A: SC105B-221 dimensions are 10.90mm L × 9.80mm W × 6.00mm H. The 7447714221 dimensions are 10.00mm L × 10.00mm W × 5.00mm H. Both are nonstandard surface mount packages; PCB layout verification is required for mechanical fit confirmation.