DR124-390-R Equivalent & Substitute Parts Reference

Part Overview

The DR124-390-R is a 39 µH shielded drum core wirewound inductor manufactured by Eaton - Electronics Division. This surface mount component is designed for applications requiring fixed inductance with moderate current handling capability. The part is actively produced and widely available, with 958 units in current inventory stock.

Substitute parts are identified when equivalent electrical performance and mechanical compatibility can be maintained across critical parameters including inductance value, current rating, DC resistance, package dimensions, and operating temperature range. The DR124-390-R has one qualified substitute in the Bourns Inc. SRR1240 series.

Substiute Parts

DR124-390-R

Eaton - Electronics DivisionIn Stock: 1013DR124-390-R Datasheet

Current PartRFQ

SRR1240-390M

Bourns Inc.In Stock: 4163SRR1240-390M Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the DR124-390-R is determined by strict equivalence across the following parameters:

Electrical Parameters (Non-Negotiable):

• Inductance value must equal 39 µH within the ±20% tolerance band
• Current rating must meet or exceed 2.3 A continuous operation
• DC resistance must not exceed 132 mOhm maximum
• Saturation current must support the intended application margin
• Shielding type must be shielded to maintain EMI performance
• Core material must be ferrite for magnetic compatibility

Mechanical Parameters (Non-Negotiable):

• Package dimensions must be 12.50 mm L × 12.50 mm W × 4.50 mm H maximum
• Mounting type must be surface mount
• Packaging format must be Tape & Reel (TR)

Environmental & Compliance Parameters (Required):

• Operating temperature range must span -40°C to 125°C minimum
• RoHS3 compliance status must be maintained
• Moisture sensitivity level must be MSL 1 or equivalent

The SRR1240-390M from Bourns Inc. meets all substitution criteria and is classified as a direct equivalent.

Parameter Comparison

Engineering Selection Recommendations

DR124-390-R (Primary Selection): The DR124-390-R remains the preferred component when available. It provides the highest current rating (2.3 A) and saturation current margin (2.85 A) within the 39 µH, 39 µH shielded drum core inductor category. The part is actively manufactured, ROHS3 compliant, and maintains full environmental certification across the -40°C to 125°C operating range. Current inventory of 958 units supports immediate procurement.

SRR1240-390M (Substitute Selection): The SRR1240-390M from Bourns Inc. is a qualified substitute when DR124-390-R availability is constrained. This part maintains electrical equivalence in inductance, tolerance, and DC resistance specifications. The substitute exhibits superior DC resistance performance (120 mOhm vs. 132 mOhm maximum), reducing power dissipation in the inductor element.

Critical Substitution Limitation: The SRR1240-390M carries a reduced current rating of 2.15 A and saturation current of 2.0 A compared to the primary part specifications of 2.3 A and 2.85 A respectively. Applications operating at or near the 2.3 A current specification require detailed circuit analysis to confirm the 2.15 A rating provides adequate margin. The 0.15 A reduction in continuous current capacity and 0.85 A reduction in saturation margin must be evaluated against specific application requirements.

Both parts maintain identical package dimensions (12.50 × 12.50 × 4.50 mm), surface mount compatibility, and environmental compliance ratings, ensuring direct PCB layout compatibility and assembly process compatibility.

Frequently Asked Questions (FAQ)

Q: Can the SRR1240-390M directly replace the DR124-390-R in all applications?

A: Direct replacement is possible only when the application current requirement does not exceed 2.15 A continuous operation. The SRR1240-390M is rated 0.15 A lower than the primary part. Applications operating at 2.3 A require circuit analysis to confirm adequate operating margin with the substitute part's 2.15 A rating.

Q: Are the package dimensions identical between these parts?

A: Yes. Both the DR124-390-R and SRR1240-390M share identical package dimensions of 12.50 mm length × 12.50 mm width × 4.50 mm height maximum seated height. PCB footprints and assembly processes are directly compatible.

Q: What is the difference in DC resistance between these inductors?

A: The DR124-390-R specifies 132 mOhm maximum DC resistance, while the SRR1240-390M specifies 120 mOhm maximum. The substitute part exhibits lower DC resistance, resulting in reduced resistive power dissipation. This represents a performance advantage in the substitute part.

Q: Do both parts meet the same environmental and compliance standards?

A: Yes. Both the DR124-390-R and SRR1240-390M are ROHS3 compliant, rated for -40°C to 125°C operating temperature range, and carry MSL 1 (Unlimited) moisture sensitivity classification. Environmental and regulatory compliance are equivalent.

Q: What is the saturation current difference, and why does it matter?

A: The DR124-390-R saturates at 2.85 A, while the SRR1240-390M saturates at 2.0 A. Saturation current defines the maximum current before magnetic core saturation occurs, causing inductance degradation. The 0.85 A difference in saturation margin affects circuit headroom during transient conditions or fault scenarios. Applications with transient current spikes require evaluation of this reduced margin.

Q: Are both parts available in Tape & Reel packaging?

A: Yes. Both the DR124-390-R and SRR1240-390M are supplied in Tape & Reel (TR) format, supporting automated assembly processes and high-volume production environments.

Q: What inductance tolerance applies to both parts?

A: Both parts carry ±20% inductance tolerance at the 100 kHz test frequency. This tolerance band defines the acceptable inductance range for circuit design calculations and component selection.