SC105B-331 Equivalent & Substitute Parts

Part Overview

The SC105B-331 is a 330 µH unshielded wirewound inductor rated for 660 mA continuous current with a maximum DC resistance of 1.26Ohm. Manufactured by Signal Transformer, this component is classified as obsolete product status. Due to its obsolete designation, identifying qualified substitute parts is essential for ongoing design support, production continuity, and component sourcing in applications requiring equivalent inductance and current handling characteristics.

Substiute Parts

SC105B-331

Signal TransformerIn Stock: 846SC105B-331 Datasheet

Current PartRFQ

SRR1050A-331Y

Bourns Inc.In Stock: 869SRR1050A-331Y Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SC105B-331 is based on the following critical parameters that must remain compatible:

• Inductance Value: 330 µH (primary functional requirement)
• Current Rating: Minimum 660 mA to maintain equivalent current handling
• DC Resistance: Lower DCR values improve efficiency and reduce power dissipation
• Operating Temperature Range: Must support -40°C ~ 125°C minimum
• Mounting Type: Surface mount configuration required
• Environmental Compliance: ROHS3 compliance and MSL rating for manufacturing compatibility

The SRR1050A-331Y qualifies as a substitute based on matching inductance value, exceeding current rating specifications, and maintaining full environmental compliance. Differences in shielding type and core material represent design trade-offs that do not prevent functional substitution in applications where the original unshielded design was not a critical requirement.

Parameter Comparison

Engineering Selection Recommendations

The SRR1050A-331Y is an active product from Bourns Inc. and represents the qualified substitute for the obsolete SC105B-331. Selection of this substitute is supported by:

• Active Product Status: Ensures ongoing availability and manufacturing support
• Equivalent Inductance: Both parts specify 330 µH at the same test frequency
• Superior Current Handling: The SRR1050A-331Y provides 730 mA rating versus 660 mA, offering design margin
• Improved DC Resistance: Lower DCR (815 mOhm vs. 1.26 Ohm) reduces power dissipation
• Full Compliance Alignment: Both parts maintain ROHS3 compliance and MSL 1 rating
• Temperature Range Compatibility: Identical operating temperature specifications
• AEC-Q200 Qualification: The substitute carries automotive-grade reliability certification

The transition from unshielded to shielded construction in the substitute part provides electromagnetic interference mitigation benefits in most applications.

Frequently Asked Questions (FAQ)

Q: Can the SRR1050A-331Y directly replace the SC105B-331 in existing designs?

A: Yes, the SRR1050A-331Y meets or exceeds all critical electrical parameters. The primary design consideration is the transition from unshielded to shielded construction. In applications where the original unshielded design was not a specific requirement, the shielded substitute provides equivalent or improved performance.

Q: What is the impact of the different DC resistance values?

A: The SRR1050A-331Y has lower DC resistance (815 mOhm vs. 1.26 Ohm), resulting in reduced power dissipation and improved efficiency. This represents a performance improvement over the original part.

Q: Are there packaging differences between these parts?

A: The SC105B-331 packaging is listed as nonstandard. The SRR1050A-331Y is supplied in Tape & Reel (TR) format, which is standard for high-volume manufacturing and automated assembly processes.

Q: Does the tolerance difference affect substitution?

A: The SC105B-331 specifies ±20% tolerance while the SRR1050A-331Y specifies ±30%. Both tolerances are within acceptable ranges for inductor applications. Circuit designs should account for the wider tolerance of the substitute if inductance precision is critical.

Q: What is the significance of the shielded versus unshielded design?

A: The substitute part features shielded drum core construction, which reduces electromagnetic radiation and susceptibility to external interference. This is beneficial in most applications and does not prevent substitution unless the original unshielded design was specifically required for circuit operation.

Q: Are both parts compliant with current environmental regulations?

A: Yes, both the SC105B-331 and SRR1050A-331Y are ROHS3 compliant and REACH unaffected, meeting current environmental and regulatory requirements for electronic component manufacturing and use.