SPD125-123M

Part Overview

The SPD125-123M is a fixed shielded inductor manufactured by API Delevan Inc., rated for 12 µH inductance with a 3.5 A current rating and 60 mOhm maximum DC resistance. This product is classified as Obsolete, necessitating identification of suitable substitute components for continued circuit implementation. The SPD125-123M operates within a temperature range of -55°C to 125°C and is packaged as a nonstandard surface mount device measuring 12.00mm x 12.00mm x 6.00mm (height seated maximum).

Substiute Parts

SPD125-123M

API Delevan Inc.In Stock: 1084SPD125-123M Datasheet

Current PartRFQ

SRR1206-120ML

Bourns Inc.In Stock: 13511SRR1206-120ML Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SPD125-123M requires matching of the following critical electrical parameters: 12 µH inductance value, ±20% tolerance, minimum 3.5 A current rating capability, ferrite core construction, and shielded configuration. The mechanical footprint must accommodate surface mount assembly with maximum dimensions of 12.00mm length and width, and 6.00mm height seated. The operating temperature range must span the -55°C to 125°C specification. DCR performance should be evaluated based on circuit thermal and efficiency requirements, with lower DCR values providing improved power dissipation characteristics. The SRR1206-120ML from Bourns Inc. meets these critical substitution criteria within the defined electrical and mechanical parameter envelope.

Parameter Comparison

Engineering Selection Recommendations

The SRR1206-120ML serves as a direct substitute for the obsolete SPD125-123M in applications requiring 12 µH inductance at 3.5 A rated current. The substitute part maintains identical inductance value and tolerance, ferrite core material, shielded construction, and surface mount assembly compatibility. The SRR1206-120ML offers superior compliance status with ROHS3 certification compared to the non-compliant RoHS status of the main part, ensuring compatibility with modern procurement and environmental regulations.

Circuit implementation must account for the following parameter differences: the SRR1206-120ML has a continuous current rating of 3 A versus 3.5 A for the SPD125-123M; however, saturation current (Isat) of 5.5 A provides equivalent headroom for transient current conditions. The substitute exhibits lower DC resistance at 38 mOhm maximum compared to 60 mOhm, resulting in reduced power dissipation and improved thermal performance. The minimum operating temperature of -40°C for the SRR1206-120ML remains sufficient for most commercial and industrial applications, though designs requiring -55°C operation must evaluate alternative sources. Mechanical dimensions increase marginally (12.70mm x 12.70mm footprint and 6.50mm height) relative to the original 12.00mm x 12.00mm x 6.00mm profile; PCB layout verification is required to confirm accommodation within the available assembly space.

Frequently Asked Questions (FAQ)

What electrical parameters must match when substituting the SPD125-123M?

The inductance value (12 µH) and tolerance (±20%) define the core functionality. Current rating and saturation characteristics determine circuit operability under nominal and transient conditions. DC resistance affects thermal performance and power dissipation. All three parameters must be evaluated collectively against circuit requirements.

Does the SRR1206-120ML meet the current requirements of applications originally designed for the SPD125-123M?

The SRR1206-120ML is rated for 3 A continuous current compared to 3.5 A for the SPD125-123M. Circuit analysis is required to determine whether the 0.5 A reduction impacts performance. The saturation current of 5.5 A provides transient current handling capability. Applications operating at or above 3.5 A continuous current must evaluate alternative sources.

Are there mechanical compatibility concerns when substituting to the SRR1206-120ML?

The SRR1206-120ML footprint is 12.70mm x 12.70mm with 6.50mm seated height, compared to the SPD125-123M at 12.00mm x 12.00mm x 6.00mm. PCB layout must be verified to confirm adequate clearance and pad spacing within the assembly area. Thermal management design should account for the lower DCR (38 mOhm versus 60 mOhm), which reduces localized heat generation.

What are the compliance advantages of the SRR1206-120ML?

The SRR1206-120ML carries ROHS3 certification, ensuring compliance with modern environmental and procurement standards. The SPD125-123M is RoHS non-compliant. This certification difference becomes significant in applications subject to regulatory requirements or supply chain specifications mandating RoHS compliance.

Can the SPD125-123M be used in applications requiring -55°C minimum operating temperature?

The SRR1206-120ML operates to -40°C minimum, which does not meet the -55°C lower temperature specification of the original part. Applications requiring -55°C operation must identify alternative substitute sources with equivalent expanded temperature range specifications.