SPD125-153M Equivalent & Substitute Parts

Part Overview

The SPD125-153M is a 15 µH shielded inductor manufactured by API Delevan Inc., rated for 3.3 A continuous current with a maximum DC resistance of 65 mOhm. This surface mount component features a ferrite core and operates across the temperature range of -55°C to 125°C. The part is classified as obsolete, making identification of equivalent and substitute components necessary for ongoing design support and procurement continuity.

Substiute Parts

SPD125-153M

API Delevan Inc.In Stock: 931SPD125-153M Datasheet

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SRR1206-150ML

Bourns Inc.In Stock: 1350SRR1206-150ML Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the SPD125-153M is determined by strict alignment of the following electrical and mechanical parameters:

Critical Electrical Parameters:

• Inductance value: 15 µH at 1 kHz test frequency
• Inductance tolerance: ±20%
• Continuous current rating: minimum 3.3 A
• DC resistance: must not exceed 65 mOhm
• Shielding: shielded construction required
• Core material: ferrite

Critical Mechanical Parameters:

• Mounting type: surface mount
• Package footprint: 12.00 mm x 12.00 mm (or compatible nonstandard footprint)
• Height constraint: maximum 6.00 mm seated height
• Operating temperature range: must support -55°C to 125°C minimum

The substitute part SRR1206-150ML from Bourns Inc. meets the core electrical specifications of inductance, tolerance, and shielding. However, specific application requirements regarding current rating, DC resistance, and thermal performance must be evaluated against the design constraints of the target application.

Parameter Comparison

Engineering Selection Recommendations

Product Status Consideration: The SPD125-153M is classified as obsolete. The SRR1206-150ML is an active product with ongoing manufacturer support, making it the preferred choice for new designs and long-term procurement stability.

Compliance and Certification: The SRR1206-150ML is ROHS3 compliant, meeting current environmental and regulatory requirements. The SPD125-153M is RoHS non-compliant, which may restrict its use in applications subject to RoHS directives. Both parts are REACH unaffected and carry EAR99 ECCN classification.

Electrical Performance: The SRR1206-150ML provides superior DC resistance performance (42 mOhm versus 65 mOhm), resulting in lower power dissipation and improved thermal characteristics. The continuous current rating of the substitute (2.8 A) is lower than the original part (3.3 A). Applications requiring the full 3.3 A continuous rating must evaluate whether the 2.8 A rating of the substitute is acceptable for the intended duty cycle and thermal environment.

Mechanical Compatibility: The SRR1206-150ML has a slightly larger footprint (12.70 mm x 12.70 mm versus 12.00 mm x 12.00 mm) and greater seated height (6.50 mm versus 6.00 mm). PCB layout and mechanical clearance must be verified before substitution.

Temperature Range: The SRR1206-150ML operates from -40°C to 125°C, compared to the original part's -55°C to 125°C range. Applications requiring operation below -40°C cannot use this substitute without additional thermal analysis.

Frequently Asked Questions (FAQ)

Q: Can the SRR1206-150ML directly replace the SPD125-153M in all applications?

A: Direct replacement requires verification of three factors: (1) continuous current requirement does not exceed 2.8 A, (2) PCB layout accommodates the larger 12.70 mm x 12.70 mm footprint and 6.50 mm height, and (3) minimum operating temperature requirement does not fall below -40°C. If all three conditions are met, substitution is electrically and mechanically compatible.

Q: What is the impact of the lower DC resistance in the SRR1206-150ML?

A: Lower DC resistance (42 mOhm versus 65 mOhm) reduces resistive power loss and heat generation. This is a performance improvement that benefits thermal management and efficiency. No negative impact results from this parameter difference.

Q: Why is the continuous current rating lower for the substitute part?

A: The SRR1206-150ML is rated for 2.8 A continuous current, while the SPD125-153M is rated for 3.3 A. This difference reflects the thermal and design characteristics of each inductor. Applications operating at or near 3.3 A continuous current must confirm that 2.8 A is sufficient for the intended duty cycle.

Q: Are there packaging implications for using the SRR1206-150ML?

A: The SRR1206-150ML is supplied in standard Tape & Reel (TR) packaging, whereas the SPD125-153M uses nonstandard packaging. Standard reel packaging improves supply chain efficiency and reduces procurement complexity. Verify that reel specifications are compatible with assembly equipment.

Q: Does the RoHS compliance difference affect substitution decisions?

A: The SRR1206-150ML is ROHS3 compliant, while the SPD125-153M is RoHS non-compliant. For applications subject to RoHS directives or customer requirements, the substitute part is the only compliant option. For applications without RoHS restrictions, compliance status does not affect electrical or mechanical compatibility.

Q: What is the significance of the saturation current (Isat) difference?

A: The SRR1206-150ML has a saturation current of 5.1 A compared to 3.3 A for the SPD125-153M. Higher saturation current provides greater margin before inductance degradation occurs under transient overcurrent conditions. This is a performance advantage of the substitute part.