SPD73-473M Equivalent & Substitute Parts Reference

Part Overview

The SPD73-473M is a 47 µH shielded drum core wirewound inductor manufactured by API Delevan Inc., rated for 801 mA continuous current with a maximum DC resistance of 360 mOhm. This component operates across the temperature range of -55°C to 125°C and is designed for surface mount applications in nonstandard packaging.

The SPD73-473M carries an obsolete product status. Identifying equivalent substitute parts is necessary to maintain design continuity, ensure supply chain availability, and support ongoing production requirements for applications utilizing this inductor specification.

Substiute Parts

SPD73-473M

API Delevan Inc.In Stock: 892SPD73-473M Datasheet

Current PartRFQ

SRR0745A-470M

Bourns Inc.In Stock: 21224SRR0745A-470M Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SPD73-473M is determined by the following critical parameters:

Primary Matching Criteria:

• Inductance value: 47 µH (±20% tolerance band)
• Core material: Ferrite shielded construction
• Mounting type: Surface mount
• Physical footprint: 7.30 mm × 7.30 mm base dimensions
• Test frequency: 1 kHz

Secondary Compatibility Criteria:

• Current rating: Equal to or greater than 801 mA
• DC resistance: Equal to or less than 360 mOhm
• Operating temperature range: Must encompass or exceed -55°C to 125°C
• Saturation current: Equal to or greater than 801 mA

The SRR0745A-470M manufactured by Bourns Inc. satisfies all primary matching criteria and demonstrates superior performance in secondary parameters, including higher current rating (1.05 A), lower DC resistance (210 mOhm), and higher saturation current (1.2 A). Physical dimensions remain identical at 7.30 mm × 7.30 mm, with a marginal height increase from 3.90 mm to 4.70 mm.

Parameter Comparison

Engineering Selection Recommendations

Substitution Feasibility:

The SRR0745A-470M is a direct functional substitute for the SPD73-473M based on matched inductance, tolerance, core material, shielding, mounting type, and physical footprint. The substitute part demonstrates superior electrical performance across all secondary parameters: higher current rating, lower DC resistance, and higher saturation current provide additional design margin.

Compliance and Status Considerations:

The SPD73-473M is obsolete and non-RoHS compliant. The SRR0745A-470M is actively manufactured and ROHS3 compliant, meeting current regulatory requirements. The substitute carries AEC-Q200 automotive qualification, indicating enhanced reliability screening.

Temperature Range Limitation:

The SRR0745A-470M 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 must evaluate this 15°C lower limit against actual system requirements.

Physical Accommodation:

The substitute part is 0.80 mm taller (4.70 mm vs. 3.90 mm seated height). PCB layout and enclosure clearance must accommodate this dimensional increase.

Packaging Advantage:

The substitute is supplied in standard Tape & Reel packaging, improving supply chain efficiency compared to the nonstandard packaging of the original part.

Frequently Asked Questions (FAQ)

Q: Can the SRR0745A-470M directly replace the SPD73-473M in existing designs?

A: The SRR0745A-470M is electrically and mechanically compatible for applications operating within -40°C to 125°C. The 0.80 mm height increase must be verified against PCB layout and enclosure constraints. No circuit redesign is required.

Q: What is the significance of the lower DC resistance in the substitute part?

A: The SRR0745A-470M exhibits 210 mOhm maximum DC resistance compared to 360 mOhm in the original part. This 42% reduction decreases resistive losses and heat generation, improving efficiency in current-carrying applications.

Q: Does the substitute part meet automotive qualification standards?

A: Yes. The SRR0745A-470M carries AEC-Q200 qualification, indicating compliance with automotive reliability and environmental stress screening requirements. The original SPD73-473M does not specify automotive qualification.

Q: Why is the operating temperature range different?

A: The SRR0745A-470M is rated -40°C to 125°C, while the SPD73-473M is rated -55°C to 125°C. Applications requiring operation below -40°C must confirm that alternative substitutes or the original part remain available. For most commercial and industrial applications, the -40°C lower limit is sufficient.

Q: Is the substitute part RoHS compliant?

A: Yes. The SRR0745A-470M is ROHS3 compliant. The original SPD73-473M is non-compliant. For new designs or products subject to RoHS regulations, the substitute is required.

Q: What is the impact of the increased height on PCB design?

A: The substitute part is 4.70 mm tall versus 3.90 mm for the original. This 0.80 mm increase must be accommodated in PCB stackup and component placement. Verify clearance to adjacent components and enclosure walls before implementation.

Q: Are there inventory advantages to using the substitute part?

A: Yes. The SRR0745A-470M is actively manufactured with 21,200 pieces in stock, compared to 794 pieces of the obsolete SPD73-473M. The substitute offers superior supply chain availability and long-term sourcing security.

Q: How do the current ratings compare?

A: The SRR0745A-470M is rated for 1.05 A continuous current with 1.2 A saturation current, compared to 801 mA for both parameters in the SPD73-473M. The substitute provides 31% additional current capacity, offering design margin for transient conditions.