DR124-181-R Equivalent & Substitute Parts Reference

Part Overview

The DR124-181-R is a 180 µH shielded drum core wirewound inductor manufactured by Eaton - Electronics Division. This surface mount component is rated for 1.1 A continuous current with a maximum DC resistance of 602 mOhm and operates across the temperature range of -40°C to 125°C. The part is currently active in production and ROHS3 compliant, making it suitable for modern electronic applications requiring fixed inductance in compact form factors.

Substitute parts are identified when equivalent electrical performance can be achieved within the allowed parameter tolerances for this inductor category, particularly when the main part faces supply constraints or when design requirements permit operation within the substitute's electrical specifications.

Substiute Parts

DR124-181-R

Eaton - Electronics DivisionIn Stock: 1010DR124-181-R Datasheet

Current PartRFQ

SRR1240-181K

Bourns Inc.In Stock: 1490SRR1240-181K Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the DR124-181-R is determined by the following critical parameters:

Primary Matching Criteria:

• Inductance value: 180 µH (exact match required)
• Core type: Ferrite drum core, wirewound construction
• Shielding: Shielded configuration
• Mounting: Surface mount, nonstandard package
• Physical footprint: 12.50 mm × 12.50 mm × 4.50 mm maximum height
• Operating temperature range: -40°C to 125°C minimum

Secondary Compatibility Parameters:

• Current rating: Substitute must support minimum 980 mA continuous operation
• DC resistance: Substitute maximum 550 mOhm to 602 mOhm acceptable
• Saturation current: Substitute minimum 950 mA acceptable
• Tolerance: ±10% to ±20% acceptable
• Compliance: ROHS3 and MSL Level 1 required

The SRR1240-181K from Bourns Inc. meets all primary and secondary criteria, with identical inductance, core material, shielding, mounting type, and physical dimensions. The substitute exhibits lower current rating (980 mA vs. 1.1 A) and lower DC resistance (550 mOhm vs. 602 mOhm), making it suitable for applications where the design current does not exceed 980 mA.

Parameter Comparison

Engineering Selection Recommendations

DR124-181-R Selection Criteria: Select the DR124-181-R when the application requires continuous current operation at or above 980 mA up to the rated 1.1 A maximum. This part provides higher current capacity and saturation current margin (1.3 A). The part is ROHS3 compliant and maintains active production status with confirmed inventory availability.

SRR1240-181K Selection Criteria: Select the SRR1240-181K when the application design current does not exceed 980 mA continuous operation. This substitute offers lower DC resistance (550 mOhm vs. 602 mOhm), resulting in reduced power dissipation and heat generation. The tighter inductance tolerance (±10% vs. ±20%) provides improved circuit performance predictability. The part is ROHS3 compliant, REACH unaffected, and maintains active production status with higher inventory availability (1451 pcs vs. 904 pcs).

Compliance Verification: Both parts satisfy ROHS3 compliance requirements and MSL Level 1 moisture sensitivity ratings, permitting unrestricted storage and handling. Both parts carry EAR99 export classification and are suitable for standard commercial and industrial applications within the specified temperature range.

Frequently Asked Questions (FAQ)

Q: Can the SRR1240-181K replace the DR124-181-R in all applications?

A: The SRR1240-181K is a direct substitute only when the circuit design current requirement does not exceed 980 mA. If the application requires continuous operation above 980 mA, the DR124-181-R must be used to ensure the inductor operates within its rated current capacity and saturation limits.

Q: What is the impact of the different DC resistance values?

A: The SRR1240-181K exhibits 550 mOhm maximum DC resistance compared to 602 mOhm for the DR124-181-R. At equivalent current levels, the lower resistance results in reduced I²R power dissipation. For a 980 mA load, the SRR1240-181K dissipates approximately 0.53 W versus 0.60 W for the DR124-181-R, a reduction of approximately 12%.

Q: Are the physical packages identical?

A: Yes. Both the DR124-181-R and SRR1240-181K share identical surface mount package dimensions of 12.50 mm length × 12.50 mm width × 4.50 mm maximum seated height. Both are nonstandard package configurations suitable for tape and reel handling. PCB footprints and assembly processes are interchangeable.

Q: What is the difference in inductance tolerance?

A: The DR124-181-R specifies ±20% inductance tolerance, while the SRR1240-181K specifies ±10% tolerance. The tighter tolerance of the SRR1240-181K provides more predictable circuit performance and reduced variation in resonant frequency, impedance, and filtering characteristics across production batches.

Q: Are both parts suitable for high-temperature applications?

A: Yes. Both the DR124-181-R and SRR1240-181K operate across the identical temperature range of -40°C to 125°C. Both maintain ROHS3 compliance and MSL Level 1 ratings across this full range, permitting use in automotive, industrial, and commercial temperature environments without derating.

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

A: The DR124-181-R has a saturation current of 1.3 A, while the SRR1240-181K saturates at 950 mA. Saturation current represents the point at which the inductor's inductance value begins to degrade due to core flux density limits. Operating above saturation current causes inductance collapse and increased core losses. The DR124-181-R provides 350 mA additional saturation margin above its 1.1 A rating, while the SRR1240-181K provides only -30 mA margin below its 980 mA rating.

Q: Can these parts be used interchangeably in existing designs?

A: Interchangeability requires verification that the circuit design current does not exceed 980 mA. If the original design uses the DR124-181-R at currents between 980 mA and 1.1 A, substitution with the SRR1240-181K will cause saturation and inductor failure. If the design operates below 980 mA, the SRR1240-181K is a direct substitute with improved performance characteristics.