SPD74-122M Equivalent & Substitute Parts

Part Overview

The SPD74-122M is a 1.2 µH shielded drum core wirewound inductor manufactured by API Delevan Inc., rated for 4.4 A continuous current with a maximum DC resistance of 25 mOhm. This component is designed for surface mount applications in nonstandard package configurations and operates across the temperature range of -55°C to 125°C.

The SPD74-122M is classified as obsolete. Identification of equivalent and substitute parts is necessary to support ongoing maintenance, repair, and redesign activities for systems currently utilizing this inductor. Substitute parts must maintain electrical compatibility while meeting current availability and compliance requirements.

Substiute Parts

SPD74-122M

API Delevan Inc.In Stock: 740SPD74-122M Datasheet

Current PartRFQ

HRSPD74-122M

API Delevan Inc.In Stock: 1111HRSPD74-122M Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the SPD74-122M are identified based on strict electrical and mechanical parameter matching within the constraints of this inductor category. The substitution logic is as follows:

Electrical Compatibility Criteria:

• Inductance value must equal 1.2 µH at the specified test frequency of 100 kHz
• Inductance tolerance must be ±20% or tighter
• Core material must be ferrite to maintain magnetic characteristics
• Shielding must be present to preserve electromagnetic containment
• Operating temperature range must encompass or exceed -55°C to 125°C

Mechanical Compatibility Criteria:

• Mounting type must be surface mount
• Package classification must be nonstandard
• Physical dimensions (length, width, height) must be compatible with existing PCB layouts
• Footprint must not exceed 7.30mm x 7.30mm with height not exceeding 4.70mm

Current and Resistance Considerations:

• Continuous current rating of substitute must be sufficient for the application; a lower rating indicates reduced capability
• DC resistance affects thermal performance; lower DCR values indicate improved efficiency

The HRSPD74-122M meets the core electrical requirements but presents trade-offs in current rating and DC resistance that must be evaluated against specific application demands.

Parameter Comparison

Engineering Selection Recommendations

Primary Consideration: Product Status

The SPD74-122M is obsolete and no longer manufactured. The HRSPD74-122M is the active equivalent from the same manufacturer and series family, making it the primary substitute candidate for new procurement and long-term supply chain planning.

Current Rating Assessment

The HRSPD74-122M is rated for 3.9 A continuous current compared to the SPD74-122M's 4.4 A rating. This 0.5 A reduction represents an 11% decrease in current capacity. Selection of the substitute requires confirmation that the application's maximum current demand does not exceed 3.9 A. If the circuit operates at or near the 4.4 A specification of the original part, the substitute may not be suitable.

DC Resistance Advantage

The HRSPD74-122M features a maximum DC resistance of 10 mOhm compared to 25 mOhm for the SPD74-122M. This 60% reduction in resistance results in lower power dissipation and improved thermal performance, which is advantageous for applications sensitive to heat generation.

Mechanical Fit Verification

The HRSPD74-122M has slightly larger footprint dimensions (7.37mm x 7.37mm versus 7.30mm x 7.30mm) and greater height (5.03mm versus 4.70mm). These differences must be verified against PCB layout constraints and assembly clearances before substitution. The 0.33mm height increase may impact designs with limited vertical clearance.

Temperature Range Extension

The HRSPD74-122M extends the upper operating temperature limit to 130°C, providing an additional 5°C margin. This is beneficial for applications operating in elevated temperature environments.

Compliance and Packaging

Both parts maintain identical RoHS non-compliance status. The HRSPD74-122M is supplied in standard Tape & Reel packaging, which improves handling and automated assembly compatibility compared to the nonstandard packaging of the original part.

Frequently Asked Questions (FAQ)

Q: Can the HRSPD74-122M be used as a direct replacement for the SPD74-122M?

A: The HRSPD74-122M is electrically compatible for the core inductance specification (1.2 µH) and maintains ferrite shielded construction. However, substitution requires verification of two factors: (1) the application's maximum current demand must not exceed 3.9 A, and (2) the physical dimensions (7.37mm x 7.37mm footprint and 5.03mm height) must fit within the available PCB space. If both conditions are met, substitution is permissible.

Q: What is the significance of the lower DC resistance in the HRSPD74-122M?

A: The HRSPD74-122M's 10 mOhm maximum DC resistance compared to the SPD74-122M's 25 mOhm represents improved efficiency. Lower resistance reduces I²R power losses and heat generation during operation. For applications where thermal management is critical, this is an advantage. The lower resistance does not affect the inductance value or frequency response.

Q: Why is the current rating lower on the substitute part?

A: The HRSPD74-122M is rated for 3.9 A continuous current versus 4.4 A for the SPD74-122M. This difference reflects the design characteristics of the HRSPD74 series. Applications operating below 3.9 A are unaffected. Applications requiring the full 4.4 A capacity must retain the original SPD74-122M or identify alternative suppliers.

Q: Are there dimensional compatibility issues with the HRSPD74-122M?

A: The HRSPD74-122M has a footprint of 7.37mm x 7.37mm and height of 5.03mm compared to the SPD74-122M's 7.30mm x 7.30mm footprint and 4.70mm height. The differences are 0.07mm in lateral dimensions and 0.33mm in height. These are minor but must be verified against PCB layout tolerances and assembly clearances, particularly in space-constrained designs.

Q: What is the advantage of the extended temperature range in the HRSPD74-122M?

A: The HRSPD74-122M operates to 130°C maximum compared to 125°C for the SPD74-122M. This 5°C extension provides additional margin for applications operating in elevated ambient temperatures or with high internal heat generation. For applications within the -55°C to 125°C range, this difference is not significant.

Q: Does the packaging difference affect compatibility?

A: The SPD74-122M uses nonstandard packaging while the HRSPD74-122M is supplied in Tape & Reel format. For manual assembly or repair applications, packaging type may not be critical. For automated manufacturing, Tape & Reel packaging is standard and preferred. Verify packaging requirements with your assembly process.

Q: Are there any compliance or regulatory differences between these parts?

A: Both the SPD74-122M and HRSPD74-122M are RoHS non-compliant and REACH unaffected. They share identical regulatory classification. No compliance advantage exists with substitution.

Q: What should be the primary decision criterion for substitution?

A: The primary decision criterion is current rating. If the application's maximum current demand is 3.9 A or below, the HRSPD74-122M is suitable. If the application requires the full 4.4 A capacity, the substitute is not appropriate. Secondary criteria include verification of physical fit and confirmation that the extended temperature range (if applicable) does not introduce design complications.