SC105B-390 Equivalent & Substitute Parts

Part Overview

The SC105B-390 is a 39 µH unshielded wirewound inductor rated for 1.8 A with a maximum DC resistance of 175mOhm, manufactured by Signal Transformer. This component is classified as obsolete, making substitute parts necessary for new designs and ongoing production requirements. The part operates across the temperature range of -40°C to 125°C and is RoHS3 compliant.

Substiute Parts

SC105B-390

Signal TransformerIn Stock: 1237SC105B-390 Datasheet

Current PartRFQ

SRR1050A-390Y

Bourns Inc.In Stock: 1406SRR1050A-390Y Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

The SRR1050A-390Y qualifies as a substitute for the SC105B-390 based on the following critical parameters:

Matching Parameters:

• Inductance: 39 µH (identical)
• Mounting Type: Surface Mount (identical)
• Operating Temperature Range: -40°C ~ 125°C (identical)
• RoHS3 Compliance: Both parts meet this requirement
• Moisture Sensitivity Level: 1 (Unlimited) for both parts

Allowable Variations:

• Current Rating: SRR1050A-390Y is rated for 2.25 A, exceeding the SC105B-390 requirement of 1.8 A
• DC Resistance: SRR1050A-390Y has 106 mOhm Max, lower than the SC105B-390 at 175 mOhm Max
• Shielding: SRR1050A-390Y is shielded versus unshielded for SC105B-390
• Inductance Tolerance: SRR1050A-390Y has ±30% versus ±20% for SC105B-390

The substitute part provides superior electrical performance with higher current capacity and lower DC resistance, making it suitable for applications requiring the SC105B-390 specification.

Parameter Comparison

Engineering Selection Recommendations

The SRR1050A-390Y is the designated substitute for the obsolete SC105B-390. Selection of this part is supported by:

• Active product status ensuring long-term availability and supply chain continuity
• Identical inductance value and operating temperature range
• Superior current handling capability (2.25 A versus 1.8 A)
• Lower DC resistance (106 mOhm Max versus 175 mOhm Max), reducing power dissipation
• Full RoHS3 compliance and unlimited moisture sensitivity rating
• AEC-Q200 automotive qualification rating on the substitute part

The SRR1050A-390Y meets or exceeds all critical electrical parameters of the SC105B-390, making it suitable for direct substitution in applications requiring the original part specification.

Frequently Asked Questions (FAQ)

Q: Can the SRR1050A-390Y directly replace the SC105B-390 in existing designs?

A: Yes. Both parts share identical inductance (39 µH), operating temperature range (-40°C ~ 125°C), and mounting type (Surface Mount). The SRR1050A-390Y provides higher current rating and lower DC resistance, making it electrically compatible for applications designed around the SC105B-390 specification.

Q: What is the impact of the shielding difference between these parts?

A: The SC105B-390 is unshielded while the SRR1050A-390Y is shielded. Shielding reduces electromagnetic interference emission and susceptibility. In applications where the original unshielded design was acceptable, the shielded substitute will not create compatibility issues and may improve EMI performance.

Q: How do the inductance tolerance specifications affect substitution?

A: The SC105B-390 has ±20% tolerance while the SRR1050A-390Y has ±30% tolerance. Both parts meet the 39 µH nominal specification. Circuit designs must accommodate the tolerance range of the substitute part. If the original design required tighter tolerance control, circuit validation is necessary.

Q: Are there packaging differences between these parts?

A: The SC105B-390 uses nonstandard packaging while the SRR1050A-390Y is supplied in Tape & Reel (TR) format. Both are surface mount components with similar physical dimensions (SC105B-390: 10.90mm L x 9.80mm W x 6.00mm H; SRR1050A-390Y: 10.20mm L x 10.00mm W x 5.10mm H). PCB layout compatibility should be verified for the specific application.

Q: What compliance certifications apply to the substitute part?

A: The SRR1050A-390Y is RoHS3 compliant, REACH unaffected, and carries AEC-Q200 automotive qualification. These certifications match or exceed the compliance profile of the obsolete SC105B-390.