SPD73-394M Equivalent & Substitute Parts Reference

Part Overview

The SPD73-394M is a 390 µH shielded drum core wirewound inductor manufactured by API Delevan Inc., rated for 280 mA with a maximum DC resistance of 2.94 Ohm. This surface mount component features ferrite core construction with nonstandard packaging and operates across the temperature range of -55°C to 125°C. The part is classified as obsolete, necessitating identification of equivalent substitute components that maintain electrical and mechanical compatibility for ongoing production and repair applications.

Substiute Parts

SPD73-394M

API Delevan Inc.In Stock: 805SPD73-394M Datasheet

Current PartRFQ

CDRH73NP-391MC-B

Sumida America Components Inc.In Stock: 725CDRH73NP-391MC-B Datasheet

SimilarRFQ

CDRH74NP-391MC-B

Sumida America Components Inc.In Stock: 879CDRH74NP-391MC-B Datasheet

SimilarRFQ

SRR0745A-391M

Bourns Inc.In Stock: 3776SRR0745A-391M Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the SPD73-394M are qualified based on the following electrical and mechanical parameters:

Primary Matching Criteria:

• Inductance value: 390 µH (±20% tolerance)
• Core material: Ferrite
• Shielding: Shielded construction
• Mounting type: Surface Mount
• Package footprint: 7.30mm x 7.30mm
• Inductance test frequency: 1 kHz

Secondary Compatibility Parameters:

• Current rating: Minimum 280 mA (substitute parts rated at or above this value are acceptable)
• DC resistance: Maximum 2.94 Ohm (lower values are acceptable; higher values require circuit validation)
• Operating temperature range: Minimum coverage of -55°C to 125°C (or subset thereof with application verification)

All three substitute parts meet the primary matching criteria. Variations in current rating, DC resistance, and operating temperature range are documented to enable selection based on specific application requirements.

Parameter Comparison

Engineering Selection Recommendations

CDRH73NP-391MC-B (Sumida America Components Inc.)

This substitute provides electrical equivalence with identical inductance and DC resistance specifications. The current rating of 260 mA is below the original 280 mA specification. Selection of this part requires circuit analysis to confirm that peak current demands do not exceed 260 mA. The operating temperature range (-40°C to 100°C) is narrower than the original part, excluding low-temperature operation below -40°C. The part is ROHS3 compliant and carries MSL 1 rating. Height is reduced to 3.40mm, providing potential PCB layout advantages.

CDRH74NP-391MC-B (Sumida America Components Inc.)

This substitute exceeds the original current rating at 290 mA and maintains identical DC resistance at 2.94 Ohm maximum. The operating temperature range (-40°C to 100°C) is narrower than the original specification. The part is ROHS3 compliant with MSL 1 rating. Height is increased to 4.50mm. This option is suitable for applications where the lower temperature limit of -40°C is acceptable and PCB height constraints permit the increased profile.

SRR0745A-391M (Bourns Inc.)

This substitute provides superior electrical performance with the highest current rating at 320 mA and the lowest DC resistance at 1.85 Ohm maximum. The operating temperature range (-40°C to 125°C) matches the upper limit of the original part but excludes operation below -40°C. The part carries AEC-Q200 automotive qualification and is ROHS3 compliant with MSL 1 rating. Height is 4.70mm. This option is recommended for applications requiring enhanced current capacity and lower resistive losses, provided the -40°C minimum temperature is acceptable.

Frequently Asked Questions (FAQ)

Q: Can CDRH73NP-391MC-B be used as a direct replacement for SPD73-394M?

A: CDRH73NP-391MC-B matches the inductance, tolerance, DC resistance, and package footprint of the original part. However, the current rating is 260 mA versus the original 280 mA. Direct substitution is permissible only if circuit analysis confirms that the maximum current demand does not exceed 260 mA. Additionally, the operating temperature range is limited to -40°C to 100°C, excluding the original -55°C lower limit.

Q: What are the height differences among substitute parts?

A: The original SPD73-394M has a seated height of 3.90mm. CDRH73NP-391MC-B measures 3.40mm (0.50mm lower), CDRH74NP-391MC-B measures 4.50mm (0.60mm higher), and SRR0745A-391M measures 4.70mm (0.80mm higher). PCB layout and component clearance requirements determine whether these variations are acceptable.

Q: Which substitute part has the lowest DC resistance?

A: SRR0745A-391M has the lowest maximum DC resistance at 1.85 Ohm, compared to 2.94 Ohm for the original part and the CDRH73NP-391MC-B. Lower DC resistance reduces power dissipation and heat generation in the inductor.

Q: Are all substitute parts RoHS compliant?

A: Yes. All three substitute parts are ROHS3 compliant. The original SPD73-394M is RoHS non-compliant. Compliance with RoHS regulations may be a requirement for new production or repair applications.

Q: What is the significance of the AEC-Q200 rating on SRR0745A-391M?

A: AEC-Q200 is an automotive qualification standard. This certification indicates that SRR0745A-391M has undergone automotive-grade reliability testing. Selection of this part is appropriate for automotive applications or systems requiring automotive-grade component qualification.

Q: Can I use SRR0745A-391M in applications requiring operation below -40°C?

A: No. SRR0745A-391M is rated for -40°C to 125°C operation. Applications requiring operation at -55°C (the original part's lower limit) cannot use this substitute. Only the original SPD73-394M supports the full -55°C to 125°C range among all parts listed.

Q: How do I determine which substitute is best for my application?

A: Selection depends on three factors: (1) maximum circuit current demand relative to the part's current rating, (2) required operating temperature range, and (3) PCB height constraints. CDRH74NP-391MC-B and SRR0745A-391M both exceed the original 280 mA current rating. SRR0745A-391M provides the lowest DC resistance. All three are limited to -40°C minimum temperature operation.